HLE1 COll ION LIBRARY ~ ~ PACIFIC BIOLOGI AL STAT -

• -

U52 no.59

Cetaceans of Canada

2

Cetaceans of Canada

Randall R. Reeves and Edward Mitchell Arctic Biological Station

Department of Fisheries and Oceans 555 St. Pierre Boulevard

Sainte-Anne-de-Bellevue, Quebec H9X 3R4

Cover photograph: A pod of narwhals in Milne Inlet, Northwest Territories, on 20 August 1985. It appears that most members of the pod have large tusks and thus are adult males. Only one of them, in the left foreground, is darkly pigmented with a relatively short tusk, suggesting it may not be fully mature. Photograph by Robert R. Campbell, Department of Fisheries and Oceans.

I

Figure 1. Water pours off the flukes of a right whale as it dives near the New Brunswick coast, lower Bay of Fundy. Photo­graph by Porter Turnbull.

Underwater WQrld

Introduction 2 What is a cetacean? 2 Dolphin, porpoise, or whale? 3 Evolutionary origins of cetaceans 3 Sensory systems 4 Diving 4 Temperature regulation 4 Food and feeding 4 Behavior at the surface 5

History of whaling in Canada 5 Early Commercial Whaling 5 Arctic Whaling 5 Modern Commercial Whaling on the

Atlantic Coast 6 Modern Commercial Whaling on the

Pacific Coast 7 Regulation of Whaling 7

Species accounts 7 Right Whale 7 Bowhead 8 Gray Whale 9 Blue Whale 10 Fin Whale II Sei Whale 12 Minke Whale 12 Humpback Whale 13 Sperm Whales 14 Beaked Whales 15 Killer Whale 16 Long-finned Pilot Whale 17 White Whale or Beluga 17 Narwhal 20 Dolphins 21 Porpoises 22

Further Reading 24

INTRODUCTION Canadian waters are defined here 011 a

purely topographic or bathymetric basis. The continental shelf is the area between shore and the 200 m depth contour. At the shelf edge, the continental slope begins; it extends at least as far as the 2,000 m contour. For this article, Canadian waters are considered to extend across the entire shelf and slope. Thus, on the east coast our area of interest reaches 600 km offshore in places, and on the west coast as much as 100 km offshore.

What is a Cetacean? There are at least 75 to 80 living species

in the mammalian order Cetacea. They inhabit all oceans as well as many estuaries and a few large river systems. The cetaceans have made the most complete and successful adaptation to an aquatic existence of any group of mammals. Some of the smaller kinds of porpoise are less than 2 m long and weigh only a few tens of kg; the great whales can be up to 30 m long and weigh well over 100 metric tons (t).

All cetaceans have a number of charac­teristics in common. The body is elongate and superficially shaped like that of a fish. However, unlike a fish's tail, the cetacean's bi-lobed flukes are horizontal rather than vertical (Figure I). Neither the flukes nor the dorsal fin (present in most species, lacking in a few) are supported by a bony skeleton. The two paddle-like front limbs, called flippers or pectoral fins, are supported by short armbones and many "extra" finger­bones. The external ear openings are pinholes on either side of the head. The nostrils are situated on top of the h~ad instead of near the front as in most mammals. The genitalia, as well as two nipples in females, are con­cealed within the ventral outline of the body. Cetacean skin is smooth and somewhat rubbery to the touch. It is hairless except for a few bristles on parts of the head.

There are two living cetacean suborders: the Mysticeti, whales with baleen (whale­bone), and the Odontoceti, whales with teeth. All mysticetes have paired external, fleshy blowholes, whereas all odontocetes have a single blowhole.

Mysticetes possess teeth during the fetal stage, but these are resorbed or lost before birth. They are replaced functionally by baleen, rooted in the palate, inside the "old" tooth row. The baleen consists of a series of blades or plates, formed from keratin, a material similar to human fingernails. The fringed inner edges of these transversely oriented plates form a sieve or mat against which prey organisms become trapped as sea­water is expelled from the mouth (Figure 2). Thus, baleen whales, like certain birds (e.g. flamingos and some ducks) and fishes (e.g.

Underwater World

Figure 2. The mouth of a young blue whale at the Coal Harbour, B.C., whaling station, showing the mat comprised of the frayed ends of the darkly pigmented baleen in the upper jaws. Gordon C. Pike, standing in front of the whale, was a Canadian government scientist who studied the whales caught off British Columbia during the 1950s and 1960s. Photograph from G.C. Pike collection.

basking sharks), are filter-feeders. Odontocetes, by contrast, do not have

baleen during any stage of their develop­ment. All odontocetes possess teeth throughout life, although in a number of species some or all the teeth remain embedded and do not erupt through the gums. In the narwhal, one tooth of males becomes a highly modified tusk protruding outside the mouth.

cetaceans in an inconsistent manner, and they cannot be rigorously defined. In North America, the terms dolphin and porpoise are used for most species whose maximum body length is less than about 5 m, and all the larger cetaceans (a few of the smaller ones as well) are called whales. Textbooks often indicate that members of the family Phocoenidae are porpoises; members of

3

the family Delphinidae, dolphins. By this view, porpoises have spade-shaped teeth and a greatly reduced beak, or a blunt snout (Figure 3). Dolphins have conical teeth and a beak which usually is set off from the melon (the bulbous part of the head in front of the nostrils, corresponding to the upper lip in other mammals) by a crease. How­ever, such definitions break down in many instances and are violated by common usage. Fishermen, whalers and many scientists use the words dolphin and porpoise arbitrarily or interchangeably.

In this article, we adhere to the termi­nology for species followed by the Scientific Committee of the International Whaling Commission. Many references to whales, dolphins, or porpoises in the introductory sections that follow can be understood to mean cetaceans in general, rather than any specific taxonomic group.

Evolutionary Origins of Cetaceans The earliest ancestors of cetaceans have yet

to be discovered. However, there is no doubt that they were terrestrial mammals. The fossil remains of a primitive cetacean, Pakicetus, were recently found in Pakistan. It lived during the early Eocene, more than 55 million years ago. Like other early cetaceans, Pakicetus had a full battery of teeth which made it a formidable predator in the warm, shallow waters near which it evolved.

We can only speculate about what made the archaeocetes, or ancient whales (a long­extinct suborder of Cetacea), venture into the sea. Was it to escape intense predation on land, to avoid competition for food and living space, or simply and more probably to exploit an abundance of food found along the margins of rivers and seas? These early whales were all long and slender of body, with a relatively small head. The nostrils opened well in front of the eyes, for the

With few exceptions, cetacean coloration consists of some combination of black, white, and shades of gray. Males and females of most species have a similar colour pattern, making it difficult for humans to tell the sexes apart. Pigmentation patterns have evolved to help meet the ecological and social needs of the animals. The complex pigmen­tation of many other odontocetes probably allows them to recognize one another and may also serve to confuse their prey. The black and white markings of Dall's porpoise could be a form of mimicry, making this small porpoise difficult to distinguish from its similarly pigmented predator, the killer whale.

Figure 3. An adult harbor porpoise taken from a gillnet off Grand Manan, N.B., in the lower Bay of Fundy. Photograph copyright L. Murison, courtesy D.E. Gaskin.

Dolphin, Porpoise, or Whale? These non-scientific terms are applied to

4

pronounced "telescoping" or over-riding of the bones of the skull, characteristic of living odontocetes and mysticetes, did not occur in archaeocetes. These early whales probably had external>hind limbs, although they may have been vestigial and greatly reduced in size and utility.

Whether the living suborders Odontoceti and Mysticeti both had evolutionary origins in the Archaeoceti is a question which has long been debated. In spite of major differ­ences in living species, earlier forms of the living suborders show substantial similarities to some archaeocetes and were probably derived from them. Thus, the origin and evo­lutionary flowering of whales appears to show a pattern of continued and radical adaptation to exploit food resources at all higher levels of the food chain in ever deeper and more offshore marine waters.

Sensory Systems Of the five familiar senses used by most

terrestrial mammals to communicate and assess their environment - sight, smell, taste, hearing, and touch - hearing is the most important to cetaceans. Olfaction, the ability to detect I airborne smells, is diminished or absent. 'Vision, although well developed in some species, is of use to a whale mainly in close-range activities. Whales are believed to have a well-developed tactile sense.

All cetaceans are acoustically active, and although direct evidence concerning the importance of sound to some species is lacking, it is clear that their keen sense of hearing and highly specialized systems of sound production are essential qualities per­mitting cetaceans to exploit a wide variety of habitats.

Diving The diving capabilities of cetaceans are

Underwater World

developed to an extraordinary degree. A trained porpoise in Hawaii proved capable of descending to nearly 600 meters; sperm whales can dive to even greater depths and sometimes remain submerged for an hour or more. But cetaceans do not suffer from the bends, a painful and sometimes fatal con­dition in human divers in which dissolved nitrogen forms tiny bubbles in the blood­stream and limb joints. A porpoise's mus­cle tissue becomes supersaturated with dis­solved nitrogen during a long dive, but the mechanism enabling cetaceans to tolerate high levels of dissolved nitrogen while avoid­ing the bends remains a mystery.

Cetaceans have up to two or three times more blood per unit of body weight than humans. In addition, some cetaceans have enough myoglobin in their muscles to carry more than half again as much oxygen as the haemoglobin in red blood cells alone can carry. This substantial capacity for acquiring and distributing oxygen within the body is enhanced by a powerful heart, large sinuses in the venous system, and large networks of capillaries, called retia mirabilia or "won­derful nets", that facilitate the "diving response". These retia are especially pronounced in odontocetes. While breathing at the surface, the cetacean's heart rate increases, thus adding to the rapid reloading of red blood cells with oxygen, then slows appreciably while diving.

Temperature Regulation Among the most serious challenges facing

a warm-blooded animal living an aquatic existence is heat retention. The core body temperature of cetaceans is about 37°C, a condition maintained even in the Arctic where ambient water temperatures can be as low as - 2°C. This is made possible by a layer of blubber between the skin and muscle which serves as an efficient insulator. The

Figure 4. A fin whale ends its feeding run by surfacing on its right side, mouth open and throat greatly expanded. The left flipper sticks up in the air, water streams from the left corner of the whale's mouth, and white water is pushed ahead of the rostrum in the foreground. Photograph in the St. Lawrence River, near Tadoussac, by Fred Bruemmer.

lipid-rich blubber also serves as a depot for storing large amounts of energy, which sustain the whale during periods when an adequate food supply is unavailable.

Efficient though it may be for conserving body heat, a cetacean's insulative blubber could cause overheating during bursts of physical activitiy or as sea temperatures rise. Whales have no sweat glands, which in humans permit evaporative cooling -instead, they have the capability of con­trolling their blood flow by means of a "counter current heat exchange" system in the flukes and flippers. They can either release excess heat by allowing a generous flow of blood to these appendages, or retain it by restricting the blood supply to the flukes and flippers.

Food and Feeding Cetaceans are at or near the top of the

marine food chain. The baleen whales can be regarded as marine counterparts of terrestrial grazers. Their social structure, foraging and feeding behavior, and long­distance migrations allow them to exploit relatively diffuse aggregations of small marine invertebrates and fishes. Certain broad parallels can be drawn between popu­lations of baleen whales and the large migratory herds of ungulates on land.

Zooplankton, a major food of baleen whales, are small swarming organisms which are carried some distance by currents; they are thus distinguished from swimming organ­isms, called nekton, which generally travel on their own power. The term krill is often loosely applied to all the planktonic crusta­ceans eaten by baleen ' whales, although it properly refers only to a group of relatively large shrimp-like forms called euphausiids.

The ventral pleats of rorquals (Balaenop­teridae) allow them to expand the throat and accommodate a large volume of seawater in the gullet (Figure 4). As the water is expelled, prey organisms are filtered by the baleen and retained for ingestion, and the whale's throat returns to its normal slim profile.

Toothed whales prey mainly on fish, squid, and crustaceans. Some also eat worms, molluscs, and other benthic (bot­tom-dwelling) creatures. Usually, toothed whales chase and grasp or suction individual organisms and swallow them whole. With a few exceptions, the teeth of whales, dolphins, and porpoises are not useful for chewing.

The toothed whales are thus hunters in the truest mammalian sense, searching, chasing, and capturing their prey on a one-to-one basis. Some, like killer whales, have been likened to wolves; hunting in packs (called "pods" in the case of whales), they manage to kill and consume the largest potential prey in their domain. Others, like sperm whales,

Underwater World

Figure 5. The sight of a humpback whale's long, flexible flipper waving in the air is common along parts of the Canadian east coast in summer. Photograph in the lowef Bay of Fundy by Porter Turnbull.

hunt alone in the darkness of abyssal depths, using strategies as yet u.nobserved by humans.

Behavior at the Surface

whales commercially in Canada. Recent archival and archaeological research has revealed that large ships began visiting the Strait of Belle Isle region to catch whales before 1567. The Spanish and French Basques called this strait the Grand Bay, and in it they pursued the "Grand Bay whale", which we take to mean the bowhead. Right whales were also caught there.

5

By the late 17th century, the Basque whaling initiative in the New World had declined. However, French colonists in the St. Lawrence region began a fishery for white whales (belugas) during the late 17th and early 18th centuries. Also, during the second half of the 18th century, pelagic whalers from New England began to visit the coasts of Newfoundland and Labrador, and they entered the Gulf of St. Lawrence in pur­suit of right whales, humpbacks, and possibly bowheads. Occasional incursions by American whalers continued into the middle 1800s, but their activities were discouraged by Canadian authorities and ended soon thereafter.

Meantime, several Loyalist families that settled on the Gaspe coast of southern Quebec started their own whaling industry. As many as a dozen Gaspe schooners were active at times during the 19th century. They cruised throughout much of the St. Lawrence and along the Labrador coast, taking right whales and possibly a few bowheads when they found them, but more often catching humpbacks and some fin whales and blue whales. This enterprise lasted until 1893.

Arctic Whaling Native people in Canada's arctic regions

historically depended on bowheads, belugas, and narwhals for subsistence. They hunted from skin boats and used hand-thrown implements to capture these animals. Later, they assisted the commercial whalers from Great Britain and the United States who came, beginning in the first half of the 19th century, to hunt bowheads (Figure 6) and,

I

A number of terms, many of them coined by whalers, are used to describe the behavior of whales at the surface. As a whale surfaces after a dive, it exhales. This is called blowing, and the visible column of vapor that results is called a blow. Usually the whale will make shallow dives, or simply sink below the surface, between the blows in a series. At the end of a series, however, the whale makes a sounding dive; when a whale sounded, the whalers did not expect to see it at the surface again for some time. The back and tail stock are usually arched high, and some whales begin a sounding dive by jluking-up. When a whale flukes-up, its tail flukes break the surface, sometimes rising vertically to show the undersides in full view.

Figure 6. One of two bowhead whales killed near Cape Fullerton, western Hudson Bay, in 1918 or 1919. Photograph courtesy Public Archives Canada, RG 85, Vol. 1045, File 540-3, Part 3.

Lobtailing is when a whale uses its flukes to slap the surface of the water. Flippering is when it rolls onto its side and slaps the surface with a flipper, or simply causes a flipper to wave in the air (Figure 5). Breaching (not "breeching" or "broaching") is when a whale jumps above the surface. The purpose of lobtailing, flippering, and breaching is not known.

HISTORY OF WHALING IN CANADA Early Commercial Whaling

The Basques were the first people to hunt

6 Underwater World

Table 1. Whale catch at Canadian Blue Fin Hump Sei Sperm Minke Pilot Killer Bottlenose' Other2

shore stations since World British Columbia War II. Sources: International 1948 37 115 2 28 Whaling Statistics; Pike and 1949 2 105 76 3 69 MacAskie (1969); Mitchell ~n 1950 4 150 95 24 40 Schevill [ed.], 1974}; Mercer~n 1951 9 216 51 5 153 1G,1R Mitchell [ed.], 1975}. 1952 16 240 61 22 126

1953 8 181 47 14 275 4 10G 1954 11 150 106 134 226 3 1955 11 120 37 139 320 3 1956 14 168 28 37 127 1 1957 15 284 49 93 190 4 1958 8 573 40 39 112 2 1959 28 369 27 185 260 1962 27 157 16 340 172 1963 30 220 24 154 147 3 1964 12 140 10 613 105

less intensively, belugas, narwhals, and bot- 1965 9 83 18 604 151 tlenose whales. The activities of these com- 1966 134 354 231 2 merciaf whalers had a severe impact on the 1967 102 89 304 stocks of bowheads. In addition, the

Newfoundland-Labrador presence of the whalers profoundly affected native settlement patterns, hunting tech- 1946 11 502 5 11 nology, and health. The Hudson's Bay 1947 14 413 6 4 18 Company took an early interest in whaling, 1948 57 669 15 4 14 215 49 too . This interest led to the establishment of 1949 30 425 11 23 53 intensive beluga fisheries near certain trading 1950 15 409 16 16 29 172 posts in Canada. 1951 24 483 29 39 12 55 3102

/ 1952 1 1 17 3155 Modern Commercial Whaling on the 1953 1 20 3584 Atlantic Coast 1954 32 2298

Modern shore whaling began in New- 1955 2 13 6612 13 foundland in 1898 with the establishment by 1956 7 2 13 57 9794 Norwegian interests of a station at Snooks 1957 23 5 14 37 7831

Arm on Notre Dame Bay along the north- 1958 55 4 7 42 789 east coast. The whaling season was limited 1959 14 5 1 18 1725 by ice conditions to the summer months, so 1960 1 1 11 1957 within a year an additional plant was opened 1961 22 6262

by the same company on Hermitage Bay 1962 45 150 1963

,

along the island's south coast. There whal- 18 221

ing could be done year-round. 1964 1 1 35 2849 Although the whaling initiative was 1965 6 2 29 1520

appreciated by those_ local residents for 1966 164 2 28 887 whom it provided employment, it also 1967 436 7 25 739 incurred hostility. Some Newfoundland 1968 438 4 311 fishermen believed whaling would lead to a 1969 376 5 3 5 50 123

decrease in fish landings; these men thought 1970 406 14 1 2 86 155 whales were responsible for driving bait fish 1971 301 16 73 4 toward shore, so any reduction in whale 1972 265 2 97 2 numbers was expected to result in a commen- Nova ScoUa surate decrease in the availability of bait. 1962 5 70 40 They also feared that whales would collide 1963 22 with and ruin nets while being chased. People 1964 56 4 19 2 14 living near rendering plants complained of 1965 135 12 6 the stench. Conservation officials worried 1966 263 8 that the same pattern of overexploitation and 1967 309 55 2 15 5 depletion of whale stocks that had occurred 1968 1 262 100 in Norway would emerge in eastern Canada. 1969 1 157 2 149 Largely in response to these concerns, the 1970 170 1 93 25 Whaling Industry Act was implemented in 1971 117 4 235 37 Newfoundland in April 1902. It created a 1972 95 183 41 licensing system intended to limit entry into the whale "fishery" and set in place an ' "Bottlenose" whales from British Columbia are Baird's beaked whales; those from inspection and reporting system to monitor east coast stations are northern bottlenose whales. whaling activities. 2 G = gray whale; R = right whale.

Underwater World

Figure 7. A 39-ft male humpback whale on the flensing deck at Coal Harbour, B.C., 1950. Photograph by G.C. Pike.

The legislation did not slow the develop­ment of the industry, however. During the period December 1902 to November 1903, there were 25 new applications for whaling licenses, most of which were granted. Fourteen new stations began operating in Newfoundland in 1904; five more in 1905. In addition, 13 whaling stations were active on the coast of Labrador from the Strait of Belle Isle north to Cartwright. Only five or six stations survived through the 1910 season. By 1915, well over 7,600 whales, most of them blue, fin, and humpback, had been landed in Newfoundland and Labrador.

A station at Seven Islands {Sept-lies) in the St. Lawrence Estuary operated from 1905 to 1915, accounting for at least 659 whales of three or more species. This was the only modern whaling station ever established in the St. Lawrence, other than a few on the west coast of Newfoundland.

After 1915, whaling was episodic in New­foundland and Labrador. The Rose-au-Rue station in Placentia Bay had the longest period of continuous operation, from 1902 to 1946 (except 1908). After the Second World War, whaling on the east coast centered at four sites: Hawke Harbour, Labrador (1947-1950, 1957-1958); Williams­port (1947-1951,1967-1972) and South Dildo (1947-1972), Newfoundland; and Blandford, Nova Scotia (1964-1972). Catch statistics for 1946-1972 are given in Table I.

Modern Commercial Whaling on the Pacific Coast

The first modern shore whaling station on the Pacific coast of North America was established in 1905 at Sechart, in Barclay Sound on the west side of Vancouver Island. A second station began operations in 1907 at Kyuquot, 160 km north of Sechart. During the winter season of 1907, catcher boats from these two stations transferred to Page's Lagoon, near Nanaimo on Georgia Strait. Winter whaling in British Columbia proved unprofitable, however, and this practice ceased after 1909. Two additional

stations were set up in 1911 on the Queen Charlotte Islands: one at Rose Harbour in the extreme south of the islands; the other at Naden Harbour in the extreme north. Thus, for several years (1911-1914) four whaling stations were active on the shores of British Columbia.

However, the Sechart station no longer operated after 1914, and the Kyuquot station closed permanently after the 1925 season. The stations in the Queen Charlotte Islands operated sporadically through the early years of the Second World War, but their activi­ties ceased after 1943. Although they were backed by Canadian, American and Norwegian capital, the crews on board the catcher boats of all four stations were almost entirely Norwegian.

After the war, a new whaling station was built at Coal Harbour in Quatsino Sound on the northwest coast of Vancouver Island. Whale meat, much of it exported to Japan, quickly became the major product of the Coal Harbour facility. The station was active from 1948 through 1967 (Figure 7), the only break being for the years 1960-61 when product markets sagged and operations came to a halt. Catch statistics for 1948-1967 are given in Table I.

The apparent reason for Coal Harbour's shutdown after 1967 was a sharp decline in the catch of fin and sei whales. Their meat is more valuable than that of the sperm whale which, by 1967, had become the predomi­nant species brought in by the Coal Harbour catcher boats.

In addition to modern shore whaling, a major non-Canadian pelagic whale fishery, based on the use of highly mechanized factory ships and their attendant fleets of catcher boats, existed in the eastern North Pacific until as recently as 1979.

Regulation of Whaling Canada signed the International Whaling

Convention of 1946, and Canada's Whaling Convention Act of 1951 provided a new framework for domestic regulation of the

7

whaling industry. Membership and partici­pation in the International Whaling Com­mission (IWC) from 1949 meant that species protection, minimum length limits, and (after 1967) catch quotas were applied to whale stocks exploited commercially in Canadian waters.

The Minister of Fisheries declared a mora­torium on commercial whaling in Canada in 1972, after the whaling seasons at Williams­port, South Dildo, and Blandford had ended. This ban remains in effect. However, in 1981 Canada announced the withdrawal of its membership in the IWe. The Whaling Convention Act was repealed in 1982, and in its place the Cetacean Protection Regu­lations, issued under the Fisheries Act, came into force in July 1982. These regulations (which do not apply to belugas and narwhals) require that anyone, other than Indians and Inuit, wishing to hunt cetaceans must obtain a license from the Minister of Fisheries before doing so. Indians and Inuit are allowed to hunt all cetaceans, except "right whales" (balaenids), without a license if the products are used for local consumption. Separate federal regulations apply to narwhals and belugas.

SPECIES ACCOUNTS Right Whale (Eubalaena glacialis)

This whale was given its English vernacu­lar name by whalers who considered it the preferred quarry. It was the right whale to hunt because of the relative ease with which it could be taken and its high yield of valuable products, notably oil and whale­bone (baleen). Right whales formerly occurred worldwide between cold temperate and subtropical latitudes. Overhunting caused them to disappear from some areas and to become very rare in others. Today there are only a few thousand right whales worldwide, most of them in the Southern Hemisphere. No more than a few hundred survive in the western North Atlantic, and the present population in the eastern North Pacific is believed to number less than 100.

Right whales are robust animals, whose girth can be more than 4/5 the body length. Large females reach lengths of 18 m and weights of 100 t or more; males are some­what smaller. The head comprises up to one­third of the body length. There is no dorsal fin or ridge. The flippers are broad and up to 1.7 m long. The flukes, up to 6 m wide, tip to tip, have a deeply-notched rear margin.

The right whale's narrow, curved rostrum (top of the head) is enfolded on either side by the massive lower lips (Figure 8), which are usually scalloped along their upper edges. Patches of cornified skin, called callosities, occur on certain parts of the head. There is always a relatively large callosity, or network

8

Figure 8. A close-up, face-on view of a right whale in the lower Bay of Fundy. The callosities on the rostrum and chin are evident, as is the smooth back which lacks a dorsal fin. Photograph by Porter Turnbull.

of callosities, on the rostrum. Callosities also occur on the chin, around the blowholes, and above the eyes. Most callosities are colonized by large numbers of white, yellow, orange, or pinkish "whale lice" (cyamid crusta­ceans). Since each right whale has a dis­tinctive arrangement of callosities, these structures are carefully photographed by researchers and used to identify and recog­nize individual whales.

Right whales are basically dark gray or black, although piebald individuals are not unusual. White patches on the ventral sur­face are common and can cover the entire throat region and much of the belly. Except for the callosities, the skin of right whales is relatively free of ectoparasites. Although frequently described as being heavily infested with barnacles, right whales in the Northern Hemisphere usually carry fewer barnacles than do gray whales and humpbacks.

Right whales have considerably longer baleen (up to 2.7 m) than any other species except the bowhead. There are about 230-250 dark gray, finely-fringed plates per side. Right whale baleen is supple, a quality which made it valuable in the manufacture of such things as skirt hoops, buggy whips, and parasols - it was the "spring-steel" of its time. At least 600 kg of baleen could be extracted from a large right whale.

There is a gap at the front of the mouth between the two rows of baleen. As the whale feeds with its mouth partially open, seawater

Underwater World

streams through this gap and passes out through the fringes of baleen, leaving behind the small organisms trapped against the screen of baleen. Small crustaceans, prin­cipally copepods and euphausiids, form the diet of right whales. There is no evidence that they eat fish.

Right whales have a distinctly V-shaped blow. They sometimes spend long periods lying motionless at the surface, with only the broad back and blowholes exposed. At other times, they lobtail or flipper. Right whales breach occasionally, propelling their entire bodies clear of the water. These whales are slow swimmers. When chased, they can achieve speeds of close to 20 km per hour for short periods, but they seldom move faster than about 5-10 km per hour.

Right whales were formerly abundant in Canadian waters. However, their migrations are poorly understood. In the eastern North Pacific, right whales occur in winter as far south as Baja California and Hawaii; in summer, as far north as the Gulf of Alaska and Bering Sea. In other parts of the world, sheltered embayments serve as winter nur­series for females with calves; but off the west coast of North America, no such nursery areas have been identified. A major nineteenth century whaling ground, called the Kodiak Ground, extended from Van­couver Island across the Gulf of Alaska to the Aleutian Islands. Right whales were caught there mostly from May through July.

In the western North Atlantic, the right whale's winter range is between Cape Cod and Florida. At least a part of the population migrates north in spring, reaching the Bay of Fundy and Scotian Shelf during summer and fall. Formerly, right whales were present during summer east of the Grand Banks, in much of the Gulf of St. Lawrence and Strait of Belle Isle, and along the outer coasts of Newfoundland and Labrador.

During recent years the lower Bay of Fundy has become recognized as a feeding ground for right whales in summer and autumn. The area of Browns Bank (60 km south of Cape Sable, N.S.) and the vicinity of Grand Manan Island (N.B.) are visited by a population of approximately 200 right whales. Females and calves tend to congre­gate inshore, beginning in July. Throughout the rest of summer and well into October, they can be observed in Head Harbour Passage and Grand Manan Channel and along the edges of Grand Manan Basin. Dramatic bouts of courtship, sometimes involving seven or eight males clustered around a single female, occur here as well. At the same time, right whales, generally unaccompanied by calves, are present on the Scotian Shelf, especially in or near Roseway Basin between Browns and Baccaro banks. Photodocumentation has demonstrated the

movement of animals between the summer feeding grounds off southeastern Canada and a winter calving ground off Georgia and Florida in the southeast US. They probably comprise a separate stock from the one on the European side of the North Atlantic, which is believed to be almost extinct.

There is little definite information about the life history of right whales. Most calves are born in winter or spring at lengths of 4.5-6.0 m. Lactation continues through the first summer and possibly into the second year after birth. Judging by resightings of known adult females in the South Atlantic and others in the Northwest Atlantic, the mean interval between births is at least 3 years.

Bowhead (Balaena mysticetus) The bowhead, or Greenland whale, is the

only baleen species which lives year-round in the Arctic. In historic times the bowhead's distribution was nearly circumpolar, broken only by the land mass of Greenland, the ice­choked Northwest Passage in the central Canadian Arctic, and a probable hiatus in the vicinity of the Laptev Sea, north of central Asia. Well over 50,000 bowheads existed before their discovery and exploi­tation by Europeans began in the sixteenth or seventeenth century. Today the world population is probably no more than about 5,000 individuals. Northern Canadian waters provide seasonal habitat for most of the remaining world population.

Bowheads closely resemble right whales in general body shape and size. Most are black with varying amounts of white on the chin and caudal peduncle (tail stock). The white zone on the peduncle and fluke region may increase in extent as the animal grows older. Newborn bowheads are light gray.

The baleen of the bowhead can be nearly twice as long as the right whale's. Lengths of more than 4 m have been reliably reported. The bowhead's dark baleen is highly elastic, and the fringes are long and fine. Like the right whale, the bowhead has a bushy, sometimes V -shaped blow, and it often flukes-up as it dives.

The bowhead maintains a close association with sea ice, although during summer and fall it can be found in completely open water. Bowheads are known to be capable of break­ing through new ice 22 cm thick. Their ability to navigate and subsist in heavy ice conditions offers several advantages. For one, they can reach feeding areas generally inaccessible to other mysticetes. For another, it forestalls frequent contact with killer whales, whose movements appear to be con­siderably limited by ice. The bowhead appears capable of longer sub mergences than other mysticetes. How the whales manage to detect and anticipate small patches of open

water in huge expanses of ice is a mystery. There are few documented records of ice entrapment.

Although they do not eat fish, bowheads are fairly versatile in their food habits. They skim-feed much like right whales at times, taking copepods and euphausiids near the surface, but they also feed at or near the bottom on benthic crustaceans such as gammarid amphipods and cumaceans. Bowheads are sometimes seen near the surface with clouds of mud streaming from the sides of the mouth.

Roes Welcome Sound, Repulse Bay, and Lyon Inlet were important whaling grounds for bowheads during the nineteenth century. Some are still found in these and other parts of Hudson Bay and Foxe Basin during summer. There is movement through Hudson Strait, but also some evidence of wintering in Hudson Bay and western Hudson Strait.

Many of the bowheads that winter at the mouth of Hudson Strait and along the ice edge in southern Davis Strait migrate north in spring to the floe edge off Pond Inlet and Lancaster Sound. In summer, bowheads occur in low numbers in Barrow Strait, Prince Regent Inlet, Admiralty Inlet, and Navy Board Inlet as well as in Pond Inlet and Lancaster Sound and along the east coast of Baffin Island. Virtually all the navigable channels and sounds in Canada's High Arctic were searched by the British arctic whalers of the nineteenth and early twentieth centuries. Large numbers of females and calves were killed, and the fishery finally collapsed as the Davis Strait stock became severely depleted.

American whalers who had opened the North Pacific right whale fishery in the Gulf of Alaska and Bering Sea discovered the last great bowhead whaling grounds in the Bering Strait region in 1848. During the 1880s, American whalers penetrated the western Canadian Arctic, the bowhead's last stronghold, by means of steam-powered whaling vessels. By wintering on Herschel Island and in sheltered harbors as far east as Langton Bay, the whalers could manage a few weeks of good hunting in the eastern Beaufort Sea and Amundsen Gulf during summer. Areas off Cape Bathurst and western Banks Island were especially productive whaling grounds. During the last years of the commercial fishery, the bottom fell out of the whalebone market, and the pursuit of the bowhead by pelagic whalers ended in all areas by about 1915.

Severe damage was done by commercial whaling to all the bowhead stocks, but the Bering Sea stock, which migrates in summer into the western Canadian Arctic, was left with the largest remnant population. It was also the only stock still supporting a major

Underwater World

aboriginal subsistence whale fishery when commercial whaling ended. Alaskan Eskimos increased their hunting effort sub­stantially during the 1970s, and their bowhead fishery, conducted mainly as the animals migrate along the north coast of Alaska in spring and fall, was subjected to close international scrutiny. An annual catch quota set by the IWC is now enforced by the Alaska Eskimo Whaling Commission, a group of Alaskan whaling captains.

Native people in Canada's Arctic hunted bowheads historically, but this activity virtually ceased in the west once the com­mercial whalers stopped visiting the Beaufort Sea in the early twentieth century. In the eastern Canadian Arctic, desultory hunting of bowheads continued at some settlements into the 1970s. Today, there is no regular or systematic hunt for bowheads in Canada, and the Inuit are not well equipped to catch bowheads or accustomed to utilize bowhead carcasses efficiently. Although hunters in several arctic communities have requested licenses to hunt bowheads under the Cetacean Protection Regulations, no licenses have been issued owing to concern about the bowhead's population status.

In spite of the large numbers killed by commercial whalers, little was learned about the bowhead's basic biology during the com­mercial whaling era. As a consequence, the urgent need for information is now being met by data and samples from the Alaska fishery. Unfortunately, the data collection and sampling are done under difficult field con­ditions, and relatively little new information

9

is provided by each additional whale that is killed. The best available scientific opinion is that bowheads breed mainly between March and August. Most calves are probably born during this period as well, at a mean length of 4.0-4.5 m. Females reach sexual maturity at a length of 14 m or somewhat less. The calving interval, natural mor­tality rate, and other aspects of bowhead population biology remain unknown.

Gray Whale (Eschrichtius robustus) The gray whale is one of the few mysticetes

whose present-day range is limited to a single ocean basin. A population inhabited the North Atlantic until as recently as the seven­teenth or eighteenth century, but it is now extinct, possibly as a result of overhunting. There are two stocks in the North Pacific. One, called the Korean stock, winters off Korea and southern Japan and summers in the Sea of Okhotsk. This stock is close to extinction. The eastern Pacific stock, also called the California stock, migrates along the west coast of North America, where it is a major tourist attraction.

Gray whales have no dorsal fin, but there is a pronounced hump followed by a series of bumps along the back. The rostrum and thus the mouthline is notably curved (Figure 9), and there are two or more deep furrows on the throat. Upon diving, the flukes are sometimes lifted clear of the surface; they are convex along the trailing edge and separated by a deep notch. Maximum length is about 15 m; a 13.4 m femaie weighed over 31 tons. At birth, gray

Figure 9. One of ten gray whales taken under special scientific permit at Coal Harbour, B.C., in 1953. Photograph by G.C. Pike.

10

whales are about 4.5 m long and weigh about 500 kg.

Gray whales are mottled gray. Their skin is infested with large numbers of barnacles, especially on the head, lips, sides of the neck, flippers, and tail. Orange patches on the skin are caused by "whale lice" - small crus­taceans which colonize wounds and other irregularities on the bodies of whales.

Gray whales have short, coarse, yellowish­white baleen. The anterior plates on the right side of the mouth are generally shorter than those on the left, presumably because the whales turn onto the right side more often than the left as they forage along the bottom, causing the baleen to wear unevenly.

Most gray whales winter in or near three lagoons on the outer coast of the Baja California peninsula - Ojo de Liebre (Scammon's) Lagoon, San Ignacio Lagoon, and Magdalena Bay - or along the mainland coast of Mexico. In early spring the northward migration takes them close along the coasts of California, Oregon, Washington, and British Columbia. Early arrivals begin to appear along the west coasts of Vancouver Island and the Queen Charlotte Islands in February or March. Peak numbers pass during the first two weeks of April, and the migration is essen­tially complete by late Mayor June. Most gray whales reach the Bering'Sea by way of Unimak Pass in the eastern Aleutian Islands; their concentrated movement through this pass during fall has facilitated attempts to census the population. Many remain in the Bering Sea for the summer to feed; others proceed through Bering Strait into the Chukchi Sea. A few enter the Beaufort Sea and feed in the Mackenzie Delta. On their way south, gray whales pass the Queen Charlotte Islands and Vancouver Island, mainly during December and January.

The gra~ whale's diet in the Bering and Chukchi seas consists mainly of small, bottom-dwelling crustaceans called gamma­rid amphipods. One of the best ways of locating gray whales on their summer feeding grounds is to watch for mud plumes in the water, made as the whales feed on or near the sea floor.

Of special interest to Canadians are the gray whales that do not participate in the entire 18,000 km round-trip migration. Gray whales are present year-round in the vicinity of Wickaninnish Bay, on the west coast of Vancouver Island, and there are small, sum­mering concentrations elsewhere along the shores of Vancouver Island. The animals spend much of their time feeding, probably on mysid crustaceans and polychaete worms which are locally abundant. Some of the gray whale feeding areas are in Pacific Rim National Park.

Sexual maturity is reached by both males

Underwater World

and females at a length of 11-12 m. Most conceptions occur during the southward migration in late fall or early winter, and calves are born after 14 months of gestation, in or near the Mexican lagoons. They are weaned on the summering grounds at an age of about 7 months.

Gray whales were traditionally hunted by several Northwest Coast Indian tribes, including the Nootka, Makah, Quilleute, and Quinault. The whale hunt remained a part of the Nootka and Makah cultures until as recently as the early twentieth century. American commercial whalers also killed gray whales, although they preferred right and sperm whales. An estimated 8,100 gray whales were killed between 1846 and 1874, mainly for their oil. Although badly depleted by the 18705, the eastern Pacific population has recovered well. It now numbers about 16,000 whales.

Blue Whale (Balaenoptera musculus) No known animal, living or extinct, equals

the blue whale in body size. This whale is cosmopolitan, inhabiting all areas from the tropics to the polar regions. The largest blue whales live in the southern ocean and rely on the vast swarms of krill available in the Antarctic during summer. One female killed in the Antarctic was slightly less than 30 m long; another 27 m female taken in the Antarctic weighed more than 150 tons. These are the largest whales on record and were probably close to the maximum size for the species. Blue whales up to 23.5 m long have been caught off Newfoundland; 26.2 m, off British Columbia.

The body shape of blue whales and their close relatives has been widely misconstrued by artists whose observations were limited to dead animals on a beach or fiensing deck. In life, these whales appear surprisingly long and slender, almost serpentine. Only while feeding does the throat expand to accom-

modate large amounts of zooplankton and seawater, giving the whale a tadpole-like appearance. The blue whale has a broad, flat rostrum (Figure 10), sickle-shaped flippers, and a small dorsal fin set relatively far back on the body. As the animal surfaces to breathe, the head clears the water first, and the explosive blow rises in a single vertical column, perhaps 9 m high. The head dis­appears, and all that remains visible is a long expanse of back. This may then dis­appear as the animal rolls forward to dive, and then the dorsal fin appears, followed by the large flukes (up to 5 m, tip to tip). The sighting of the fin long after the back breaks the surface is a feature that helps identify this species in the field. Blue whales do not always fluke-up before diving.

The skin of blue whales is blue gray to light gray in color, with light gray mottling. Only the undersides of the flippers are truly white. The blue whale has a pleated throat, with 80 or more longitudinal grooves extending back along the belly at least to the umbilicus. The relatively coarse bristles of the blue whale's baleen are efficient for filtering euphausiids, its principal prey. The entire oral cavity -tongue, palate, and baleen - is inky black.

Except in areas where food is highly con­centrated, blue whales are usually encoun­tered alone or in small groups. Thus, they are not considered particularly social. However, they make high-intensity sounds of very low frequency (20 Hz or less), some so low that they are outside the hearing range of most humans. Such calls may well be used for communication. Since it is known that these sounds can travel several hundred kilometers underwater, blue whales may coordinate their activities over great distances even when individuals are not observed in close physical proximity.

Sexual maturity is attained at an age of about 10 years. Breeding occurs mainly at low latitudes during late fall and winter, and

Figure 10. Two blue whales surfacing near a whale-watChing boat in the St. Lawrence River near Tadoussac, September 1983. Note that the mouth of the lung­ing individual is closed. Photograph by P.F. Macfarlane.

Figure 11. A mother fin whale and her calf in the lower Bay of Fundy, viewed from the air in August 1980. Note how the white on the right lower jaw sweeps onto the neck behind the blowholes to form part of the pigmenta­tion "chevron." Photograph by R.R. Reeves.

gestation lasts about a year. Thus, the blue whale's reproductive cycle is closely attuned to its migration schedule. Most adult females probably bear a calf every second or third year.

Blue whales are about 7-8 m long and weigh 2-3 tons at birth. Seven months later, at weaning, they are 16 m long and weigh 25 tons. This prodigious increase in size is made possible by the rich milk, 35-50 percent fat, provided by the mother. It has been estimated that she supplies about 250 litres of milk per day, and that the calf gains over 90 kg of weight per day, or some 4 kg per hour.

Because of their size, power, and speed, blue whales would seem immune to natural predation. However, in a well-documented event off southern Baja California, a pod of about 30 killer whales attacked and badly mauled an 18 m blue whale. The attack

Underwater World

ended inconclusively, but the blue whale's injuries were probably serious and may have been enough to kill it.

Many of the blue whales that visit waters along the east coast of Canada probably belong to a wide-ranging western North Atlantic stock. An October stranding in New Jersey and a kill in January in the Panama Canal are among the few pubished records of blue whales south of Nova Scotia on the west side of the North Atlantic. In summer, some blue whales migrate into Davis Strait and Denmark Strait. They have been caught north of 80 0 N near the edge of pack ice in the Northeast Atlantic in June, but they probably do not regularly move so far north as Baffin Bay in the west.

Of special interest to Canadians are the blue whales that feed in summer along the north shore of the River and Gulf of St. Lawrence, as far upstream as the mouth of the Saguenay River near Tadoussac. They begin arriving in the Gulf in April or May, as soon as substantial open water becomes available. Where deep water comes close to the coast, blue whales can easily be observed from shore, particularly from headlands and cliffs. The best time for seeing blue whales in the St. Lawrence is August through September, when the density of whales in upstream areas reaches a peak. Most blue whales probably enter the Gulf through Cabot Strait in spring. Some remain in St. Lawrence waters until at least December, and occasionally they become trapped by ice along the southwest coast of Newfoundland in mid-winter (February or March).

In British Columbia, blue whales rarely approach the coast, but they can be found in small numbers weil offshore. These whales may belong to an eastern North Pacific stock that winters off Baja California and heads north in May, reaching waters off Vancouver Island in June. Many of the animals probably continue migrating north until reaching the main summer feeding grounds in the Gulf of Alaska or south of the eastern Aleutian Islands. By late August, they begin returning south, and a second peak in abundance occurs off Vancouver Island in September. The whales begin to reappear in Baja California waters in October.

The blue whale became fully protected from commercial exploitation in the North Pacific after the 1965 season. The hunting of blue whales in the North Atlantic and Arctic was prohibited by the IWC from the beginning of the 1955 season for a period of five years. Iceland and Denmark objected to the ban and continued hunting blue whales through 1959. When the prohibition was extended for a further five years beginning in 1960, all member states agreed to adhere to it, and since that time the species has been

11

fully protected in the North Atlantic and Arctic.

There may have been more than 200,000 blue whales in the world's oceans at the turn of the century, of which some 6,000 would have inhabited the eastern North Pacific and 1,100-1,500 the western North Atlantic. Today, only a few thousand remain world­wide. There could still be as many as 1,500 in the North Pacific, but only hundreds are believed to survive in the North Atlantic. Continued protection will be necessary for many years if blue whales are to recover fully.

Fin Whale (Baiaenoptera physaius) The fin whale, second in size only to the

blue whale, has a wider distribution and is considerably more abundant than its larger relative. Groups of fin whales, sometimes numbering up to 20 individuals, were his tor­icaily common in coastal and inshore waters at temperate latitudes. Decades of intensive exploitation have greatly reduced most fin whale populations, but these large, fast­swimming animals are still a common sight in Canadian coastal waters.

Fin whales range widely in the North Atlantic, from the Mediterranean Sea to Norway in the east and from Florida to Davis Strait in the west. They are abundant around Iceland and off the east and west coasts of Greenland. In the North Pacific, fin whales occur from the Chukchi Sea in the north, south to the Gulf of California in the east and Japan in the west. They have also been reported from the mid-Pacific.

It is difficult for an inexperienced observer to distinguish between the fin whale and the sei whale. The fin whale's asymmetric head coloration is its most reliable and least subtle field mark (Figure 11). The right lower jaw and right front third of the baleen are white; the rest of the head and baleen, darker. Behavioral differences can also help in making an identification. The fin whale has a characteristic roll. The head usually breaks the surface first, and the animal blows just before the dorsal fin appears. The fin whale usually arches its back high out of the water on the terminal dive of a series, but it almost never flukes-up. The sei whale usually approaches the surface at a flatter angle, and its prominent dorsal fin can some­times be seen while the whale is blowing. Sei whales usually do not arch the back high as they dive.

Fin whales have a varied diet. In some areas or at certain times of year, they feed heavily on pelagic crustaceans, mainly euphausiids but also copepods occasionally. In other areas or at other times, small school­ing fishes such as capelin, herring, sand lance, and anchovies are the staple fare. Cod, whiting, mackerel, and squid are sometimes eaten.

12

Tagging data and morphological differ­ences suggest the existence of at least two separate populations of fin whales off eastern Canada, one of which summers on the Scotian Shelf and in the Gulf of St. Lawrence, and the other in the Labrador Sea. There may be a small degree of mixing between these two populations. Fin whales share much of the same habitat with blue whales in the St. Lawrence, arriving in large numbers by July and feeding along the North Shore throughout summer and fall. They also are regularly seen in the lower Bay of Fundy, where they sometimes enter and damage inshore herring weirs.

In British Columbia, fin whales are usually found well offshore but are sometimes seen in exposed coastal seas such as Hecate Strait and Queen Charlotte Sound, and less often in protected waters such as Queen Charlotte Strait. Some fin whales, mainly young individuals, remain to feed throughout the summer. Others migrate past the British Columbia coast.

Because of their large size and ready avail­ability, fin whales figured significantly in the catches of all modern Canadian shore whaling stations. Beginning with the 1967 season, a Canadian national quota was set on fin whales hunted from the east coast whaling stations. As additional information became available on stock identity and popu­lation size, this quota was steadily lowe~ed. Canada's east coast fin whale population has been unexploited since 1972.

Sei Whale (Balaenoptera borealis) The sei whale (Norwegian, pronounced

say) is an oceanic species rarely encountered in protected, inshore waters or near the coast. The vernacular name was given to the species because its arrival off Finnmark (Norway) used to coincide with that of the seje or coalfish (Pollachius virens). Obser­vations by whalers, particularly in the North Atlantic, led them to suggest that sei whales follow a less consistent migration schedule than do most other rorquals. Their appear­ance on a local whaling ground, such as off Iceland, can be "unpredictable" from one year to the next.

The difficulty of identifying sei whales at sea often makes it hard to evaluate reports of sightings. Under the best of circum­stances, the symmetrical pigmentation of the sei whale's head and the single ridge along the midline of the slightly arched, pointed rostrum can be seen clearly. Like right whales, sei whales are usually classified as "skim" feeders. When feeding near the sur­face, their blows are evenly spaced over long intervals. Their head breaks the surface at a shallow angle, and the dorsal fin and back are exposed for a comparatively long time (Figure 12). The sei whale's baleen is grayish,

Underwater World

with long, silky fringes similar to the right whale's. It can filter very small organisms, such as copepods, amphipods, and juvenile euphausiids. The sei whale gulps as well as skims its prey, and it eats schooling fishes in addition to zooplankton.

It is not uncommon to find sei whales in multispecies feeding aggregations, in the close company of other balaenopterids as well as right whales. In some parts of the world, sei whales are believed to have increased in numbers because of the removal or reduction of right whales, their apparent competitors for copepods and other small planktonic forms.

Sei whales in the Northern Hemisphere breed and give birth primarily during winter months, in the southern half of their range. The mean length at birth is about 4.5 m; calves are weaned at 5-9 months of age. Both males and females reach sexual maturity at lengths of 12.8-14 m, which probably cor­respond to ages of 5-10 years. Maximum length is about 18 m. The calving interval is 2-3 years.

There are believed to be two stocks of sei whales in the western North Atlantic with non-overlapping distributions, one on the Scotian Shelf, the other in the Labrador Sea. The Nova Scotia stock migrates north along the continental slope from wintering grounds off the eastern U.S., consistently reaching waters off Nova Scotia by June and July. Sei whales largely disappear from this area for a period during late summer, then reappear in substantial numbers during a regular southward fall migration from mid­September to mid-November. The Labrador Sea stock is present in the Labrador Sea by early June. Animals from this stock appar­ently cross Davis Strait to the west coast of Greenland during summer, and their range may extend east to Denmark Strait and Iceland.

The sei whales which appear in large num-

bers off Vancouver Island in June, July, and August probably belong to a stock that migrates along the American west coast. A sei whale tagged off southern California in November 1962 was killed off Vancouver Island in August 1966.

Minke Whale (Balaenoptera acutorostrata) The minke whale is the smallest of the

baleen whales inhabiting Canadian waters. It is widely distributed on the continental shelf and usually encountered alone or in small groups, often amongst pods of fin whales. The blow is low and bushy, and thus difficult to spot in rough seas. Young minke whales sometimes approach stationary ves­sels, swimming under and around them close alongside. However, they are not easy to chase or follow due to their irregular sur­facing pattern and frequent changes of swimming direction.

The basic color pattern is black on the dorsal surface and white on the ventral surface, but like fin whales, most minke whales have a complex array of subtler mark­ings on the sides and back (Figure 13). These take the form mainly of light gray patches and swirls. The most distinctive marking is a bold white patch on the otherwise-dark flippers (Figure 14). Newborn minkes are about 2.8 m long, and maximum adult length is about 10 m.

Minke whales engage in aerial displays much more often than their Balaenoptera cousins. They make clean, arcuate leaps as well as twisting breaches after circling rapidly and tightly around a school of prey. They use their short, mainly white baleen to cap­ture a wide variety of organisms, including fish, zooplankton, and squid. During sum­mer months, dense concentrations of spawn­ing capelin attract minke whales into bays along the east coast of Newfoundland. They are present there as early as May, and most have left by early August.

Figure 12. The tall, scythe-shaped dorsal fin characteristic of a sei whale is clearly seen in this photograph taken during a whale tagging cruise in the North Atlantic sponsored by the Canadian government. Photograph by E. Mitchell.

Underwater World

Figure 13. A minke whale surfacing off Cap Gaspe in Forillon National Park, August 1981. Note how the dark back shades into light gray blazes on the sides. Variation in this trunk pigmentation has been used to identify individual whales off the west coast. Photograph by Diane Attendu.

Female minke whales reach sexual matu­rity at 7.3 m, males at 6.7-7.0 m. Breeding in the Northern Hemisphere occurs mainly during winter and spring. Gestation is assumed to last 1O-IOYz months, and calves are probably weaned before reaching 6 months of age. A high proportion (800,10 or more) of adult females taken in some whale fisheries have been found to be pregnant; so the calving interval is probably one year in many instances.

Minke whales are common during summer in Ungava Bay, along the entire Atlantic coasts of Labrador and Newfoundland, and in the Gulf of St. Lawrence and Bay of Fundy. Winter sightings in the Caribbean Sea suggest that some minke whales migrate to lower latitudes at that season. Stranded minke whales are reported with some regularity along much of the eastern sea­board. They are accidentally trapped from time to time in herring weirs in the Bay of Fundy, and pieces of netting have been found entangled in the baleen of some stranded specimens.

In 1947 a fishery for small whales was begun in eastern Newfoundland. Some of the meat of minke whales was saved for human consumption, but after 1954 most of it was used to feed ranch mink. This fishery ended in 1972. Between 1969 and 1972 Norwegian pelagic whaling vessels hunted minke whales in coastal waters off Labrador and Newfoundland.

The distribution of minke whales along the west coast of Canada is not as well known, but they are present in most nearshore and inshore areas during summer. Here, too, they occasionally blunder into fishing gear, such as salmon traps.

Humpback Whale (Megaptera novaeangliae) Humpback whales are cosmopolitan

animals. They were abundant in all oceans until whaling drove some populations to dan­gerously low levels. Today, the Northwest Atlantic and Northeast Pacific are among the few areas where sizeable humpback popula­tions remain.

Humpbacks are well known to the pub­lic. Photographs of breaching individuals or of mothers and calves underwater often appear on posters and magazine covers. Humpbacks grow to a maximum length of about 16 m, and they are 4.5-5.0 m long at birth. The humpback's head is marked by rows of fleshy knobs, and there is a lumpy protuberance at the front of the lower jaw. The flippers, which have a scalloped lead­ing edge, are very long; they can be almost a third as long as the animal's entire body. The flukes are distinctively shaped, with a serrated rear margin divided by a deep notch. The dorsal fin is what gives the humpback its vernacular name. Although the fin can vary greatly in shape, it sits on a hummock or "hump" (Figure 15).

The humpback's skin is colonized by large "acorn" barnacles (Coronula), especially on the flukes, flippers, and chin. The general body color is black. Many humpbacks have all-white or mainly white flippers. Humpbacks often fluke-up as they dive, so it is possible to get photographs of the undersides of the flukes. The variable black­and-white pigmentation pattern on the flukes is distinctive for every individual and, espe­cially when augmented by scars and deformi­ties, provides a reliable means of individual recognition.

13

In all parts of their range, humpbacks migrate between high-latitude summer feed­ing grounds and subtropical winter breed­ing grounds. Most of the humpbacks that feed in summer off eastern Canada spend the winter in the West Indies, principally on Silver and Navidad banks north of Hispaniola. Some visit Bermuda on their way north in spring. Although much of the Northwest Atlantic humpback population appears to mix on the breeding grounds, groups of individuals seem to congregate on separate feeding grounds year after year. One of these feeding "substocks" apparently does not go much farther north than the Gulf of Maine and Scotian Shelf, but another large "substock" occurs along the coasts of Newfoundland and Labrador. Several hundred humpbacks go to Davis Strait in summer, and another group (which may be related to the Davis Strait "substock") occurs in Denmark Strait between Greenland and Iceland.

In the eastern and central North Pacific there are two major wintering areas. One is along the coast of Baja California and around the Revillagigedo Islands off Mexico. The other is in Hawaii, where most of the underwater photography of hump­backs has taken place. Individual whales are known to use either of these grounds in a given winter. One known individual traveled from Hawaii to the coast of Van­couver Island, and another found in British Columbia waters one summer was seen off

Figure 14. The distinctive white flipper patch and the sharply pointed snout of the minke whale are seen as this animal surfaces in the lower Bay of Fundy. The white flip­per appears to be part of a disruptive pigmentation pat­tern on this, the smallest of the balaenopterine group. Photograph by Porter Turnbull.

14 Underwater World

Figure 15. The "hump" comprising the base of the small dorsal fin on the hump­back whale is clearly evident in this photograph taken in the North Pacific. Photograph by G.C. Pike.

southeast Alaska the next. The humpback's North Pacific summering grounds extend from British Columbia to much of the coastal Gulf of Alaska, the Bering Sea, and the southern Chukchi Sea. Formerly, hump­backs were abundant along the west coast of Vancouver Island as well as in protected waters, including the Strait of Georgia.

In general, humpbacks are denizens of the continental shelf and offshore banks. They take advantage of concentrations of spawn­ing fish such as capelin, herring, anchovies, and sand lance, but they also prey heavily on euphausiids and occasionally squid. At times, they repeatedly lunge at the sur­face, exposing the front third of the body as they capture their prey. Frequently, hump­backs create clouds or "nets" of bubbles underwater to corral their prey; such maneu­vers often end with the whale's mouth wide open above the surface, the coarse black baleen and pink palate plainly showing. Small fish jump in many directions, to be snatched up by attending seabirds.

Humpbacks are unrivaled among the mysticetes as aerial acrobats. Bouts of breaching, lobtailing, and flippering are common on both the breeding grounds and feeding grounds. On the breeding grounds, adult males sometimes interact aggressively, beating one another with the flukes, even slamming and scraping against each other so boisterously that the dorsal fins and fleshy knobs on the head become ragged and bloody.

Both sexes attain sexual maturity at a length of about 11-12 m. Studies of living humpbacks, using photo-identification tech­niques, have shown that calves are sometimes born to adult females in successive years. The average calving interval is more likely two years, however. Most births in the Northern Hemisphere occur in winter (J anuary­March), after about one year of gestation.

Calves are suckled for about 10 months and thus are fully weaned before the breeding season following their birth. During the first few weeks of life, humpback calves are rarely separated from their mothers by a distance of more than 10 m.

The International Whaling Commission has given humpback whales in the North Atlantic full protection from commercial whaling since 1955, and in the North Pacific since 1965. Today, there are at least 2,000 humpbacks in the Northeast Pacific, with about 1,000 wintering in Hawaii each year. In the Northwest Atlantic, there are at least 3,000, perhaps many more, humpbacks today. This population appears to be recovering.

Sperm Whale (Physeter catodon) If there is an archetypal whale, it is the

sperm whale, the largest of the odontocetes and the most widely distributed, most abun­dant of the great whales. Moby Dick, the legendary antagonist of Herman Melville's classic novel, was a bull sperm whale. Sperm whales are generally found in deep water, so they are most likely to be found along the edge of the continental shelf or over canyons and deep basins between banks, as well as on the high seas.

The sperm whale is the only living whale whose nostrils are not situated in a position well behind the snout. Its single blowhole, an S-shaped slit, is at the front of the snout, distinctly left of center. The position of the blowhole causes the bushy blow to angle for­ward and to the left, which makes it possible to identify sperm whales even at a distance of some miles. The body is dominated by the huge head, which is squarish in profile. Functional teeth are present only in the nar­row, underslung lower jaw (Figure 16). These massive chunks of were smoothed, engraved, and decorated with intricate pat-

terns or scenes by nineteenth-century whale­men, a traditional American art form known as scrimshaw.

There is a substantial difference in size between male and female sperm whales. Males grow to lengths of 18 m or more, while females are rarely more than 12 m long. Old bulls can weigh in excess of 50 tons. Length at birth is about 3.5-5.0 m; weight, 750-1,000 kg.

Sperm whales are basically brownish gray to black. Calves are lightly pigmented but soon darken to the adult color. Most sperm whales have a white zone around the mouth, as well as a light gray or whitish region on the ventrum. Adult males are heavily scarred on the head, evidence of aggressive encoun­ters with one another and with large squid.

Sperm whales subsist on squid, octopuses, deepsea fishes, and a variety of other fishes. Only adult bulls are likely to attack the giant squid (Architeuthis sp.) which lives at great depths. Yankee sperm whalers sometimes confirmed that they had arrived on the whal­ing grounds by noting pieces of squid float­ing on the sea surface.

The basic social unit of sperm whales is the mixed school, which contains up to 50 or more individuals. Adult females accom­panied by their offspring, including young whales of both sexes, are found in such schools. Bachelor schools formed by matur­ing males remain apart from the mixed schools, and adult males travel alone or in small, loosely associated bands. Large males associate with mixed schools during part of the year, presumably for breeding purposes. Usually only one of these "schoolmasters" or "harem masters" is present in the mixed school at a given time.

This segregated social structure allows sperm whales to partition the food resources on which they depend. Females and juveniles rarely venture north of about SOON latitude except in areas influenced by warm currents. Bulls, on the other hand, migrate during summer into subarctic and even arctic regions, where their foraging efforts are not in direct competition with those of the females and young.

Length at sexual maturity is about 9 m for females and 12 m for males. The latter, however, probably are not socially mature (i.e. successful in reproduction) until some time well after the attainment of sexual maturity. Breeding can occur any time between late winter and late summer, but generally peaks during late spring or sum­mer. The gestation period is 14-16 months, and lactation lasts for 1-2 years. Adult females give birth at 3 to 5-year intervals. Sperm whales are long-lived and may reach ages of 45-60 years.

Sperm whales are common off both coasts

of Canada during summer and fall. In the Atlantic, some bulls migrate along the continental slope at least as far north as Hudson Strait, where local concentrations can be found off Resolution Island. This migration consists almost entirely of large males. Sperm whales seem not to enter the Gulf of St. Lawrence in large numbers. Long-distance movements across the North Atlantic, between southern Nova Scotia and the coast of Spain and between Iceland and the Azores, have been documented.

Off British Columbia, mixed and bachelor schools occur seasonally on the old whaling grounds as far north as SooN, apparently tied to the ISoC surface isotherm. Mixed aggre­gations of 50-ISO sperm whales have been seen there during April, May, and early June. Females with near-term fetuses some­times re-appear in August and early Septem­ber. Bulls are present year-round in deep waters off the British Columbia coast. Small numbers of sperm whales enter Hecate Strait, Dixon Entrance, Queen Charlotte Sound, and some of the broad waterways of the Inside Passage.

The sperm whale is of great commercial interest. Its oil differs from baleen whale oil in that it consists chiefly of waxes rather than fats. Sperm oil's viscosity is less affected by temperature variations tfian are those of fatty oils, so it is valuable as a lubricant. Spermaceti, a waxy liquid found in the head, has been widely used in the manufacture of certain cosmetics and wax candles. As much as 150 barrels of spermaceti and sperm oil has been rendered from a very large bull. Ambergris, a substance produced in the alimentary tract of some sperm whales and occasionally discovered as a waxy lump floating on the sea surface or washed up on beaches, is used as a fixative in making long-lasting perfumes.

An intensive hunt for sperm whales began from sailing vessels out of New England ports during the early eighteenth century, and by the middle of the nineteenth century it had spread throughout the southern ocean and the North Pacific. This worldwide chase, which eventually came to include a fleet of large modern factory ships, has all but ended now. Only a few shore stations continue to catch significant numbers of sperm whales.

There are two species of small cetacean, closely related to the sperm whale, which should be mentioned here briefly. Neither grows longer than about 4 m; both resem­ble the sperm whale in that they have a short underslung lower jaw and a squarish or bulbous head. The pygmy sperm whale (Kogia breviceps) and the dwarf sperm whale (K. simus) live mainly in the temperate and tropical regions of the world oceans, and there is little evidence of their frequent

Underwater World 15

Figure 16. A 16.85 m sperm whale landed at the South Dildo, Newfoundland, whaling station, 18 June 1972. Note the sockets for lower teeth in the toothless upper jaw. The few throat creases are typical of sperm whales. The scarring on the head may be from battles with other large males. Photograph by James G. Mead.

presence in Canada. Their occurrence along the Canadian coast is known mainly from strandings. A dead pygmy sperm whale was found under the ice in Halifax harbour in January 1920, and another decayed carcass was found on Sable Island in January 1969. A female dwarf sperm whale stranded alive on the coast of Pachena Bay, Vancouver Island, in September 1981.

Beaked Whales (Ziphiidae) This diverse family of whales is repre­

sented in Canadian waters by four genera: Berardius, Hyperoodon, Ziphius, and Mesoplodon. Ziphiids, or beaked whales, are typically pelagic in distribution and rarely sighted on the continental shelf. Most appear to be deep divers, and squid or deep-sea fish comprise the bulk of their diet.

All beaked whales in the Northern Hemisphere have a pair of deep grooves on the throat, which partially converge to form a forward-pointing V. Their flukes are not normally separated from each other by a well-formed notch. The beak, which can be short and ill-defined as in Cuvier's beaked whale (Ziphius cavirostris) or long and cylin­drical as in Baird's beaked whale (Berardius bairdii), is equipped with usually 2 but no more than 4 functional teeth, situated toward the front of the lower jaw. In Mesoplodon, only adult males have erupted teeth, and in some of these the teeth protrude outside the closed mouth, serving as formidable tusks that are probably used during fights between males.

Baird's beaked whale, measuring nearly 13 m in length, is the largest of the beaked whales. It lives only in the North Pacific, where it is known from as far south as north­ern Baja California, Mexico, to as far north as the central Bering Sea. Shore-based whalers frequently encountered groups of 10-20 Baird's beaked whales, mainly adult males, on the grounds west of Vancouver Island. The whales were seen dur­ing all months from May to September, but most regularly in August.

The only other beaked whale that has been of any commercial significance in Canada is the northern bottlenose whale (Hyperoodon ampullatus). It is endemic in the North Atlantic, where it is widely distributed in cold temperate and subarctic regions. Off North America, the two best-known areas of con­centration are at the mouth of Hudson Strait and in a deep canyon east of Sable Island, called The Gully. It is in the latter area that 67 bottlenose whales were caught during the 1960s by whalers out of Blandford, Nova Scotia. Bottlenose whales were also hunted in Davis Strait by British arctic whalers dur­ing the nineteenth century, and 818 of them were taken off Labrador during 1969-1971 by Norwegian pelagic whalers. Bottlenose whales dive for longer periods than most other whales; timed dives lasting 90 minutes or more have been reported.

The other beaked whales that occur in Canadian waters have not been hunted here, and they are rarely seen alive at sea. Most of what is known about their distribution in

16

Canada comes from the few stranded speci­mens which have come to the attention of scientists. Cuvier's beaked whale and Blain­ville's beaked whale (Mesoplodon densiros­tris) are cosmopolitan in temperate and tropical seas, and they can be expected to occur irregularly on both the Atlantic and Pacific coasts of southern Canada. In addi­tion, Sowerby's beaked whale (M. bidens) and Gervais' beaked whale (M. mirus) are known from the east coast; Hubbs' beaked whale (M. carlhubbsi) and Stejneger's beaked whale (M. stejnegeri), from the west coast.

Killer Whale (Orcin us orca) The killer whale is a familiar sight to

mariners in British Columbia, where the spe­cies has been studied more closely than in any other part of the world. In 1973, Canadian scientists began compiling photographs of killer whales in the protected waters of southwest British Columbia and northwest Was-hington. Using naturally-occurring nicks, scars, and growth patterns on the dorsal fin, and the configuration of the lightly-pigmented "saddle patch" behind the dorsal fin, it proved nossible to identify individuals, track their movements, and monitor associations among the whales.

Killer whales are about 2.4 m long at birth. Males can grow to lengths of 9 m and weights of almost 5 tons, while females generally do not grow longer than 8 m or weigh more than 3 tons. Sexual maturity is generally reached in British Columbia males at a body length of 5.8 m and an age of at

Underwater World

least 12 years; females, 4.9 m and at least 6.7 years. Adult males are easily distin­guished from juveniles and adult females by the height and shape of the dorsal fin (Figure 17). By the time males reach sexual maturity, the fin is slightly over I m high; the fin of adult females is usually only 0.5-0.75 m high. The female's fin remains hooked, or curved, throughout life, but the adult male's loses its curved aspect and becomes triangular with straightened edges.

The flippers of killer whales are shaped like broad, rounded paddles. They are often visible as the whale breaches and falls onto its side with a loud smack. The killer whale's conical head is dominated by the large mouth, lined with piercing teeth used for gripping and tearing prey, but not for chew­ing. Like most other cetaceans, killer whales swallow their prey whole or in large pieces.

Gestation in killer whales lasts about 15 months, and females nurse their young for at least a year. Killer whales in British Columbia have a calving interval of 3 years or more. The population was judged in 1980 to be increasing at a rate of about 2.5 per­cent a year.

The public attitude toward killer whales changed dramatically during the 1960s. Before then, they were feared by many boaters and resented by fishermen who noticed the whales' appetite for herring and salmon. In 1964, the Vancouver Public Aquarium brought a young female into captivity that lived long enough to demon­strate the feasibility of maintaining killer whales in captivity. The next year another

Figure 17. Part of a pod of killer whales (J-pod) in Puget Sound, September 1978. Note the high, erect dorsal fin of the adult male in the foreground. Photograph by Randi Olsen.

whale accidentally caught in a gillnet at Namu, British Columbia, was towed to Seattle, Washington, where it was kept in a floating pen. During his year in confinement, "Namu" proved docile and trainable. Soon most major marine aquariums in North America and Europe had at least one killer whale on display. Killer whales live peaca­bly in tanks with bottlenose dolphins and other animals on which they prey in the wild.

A population of about 260 killer whales frequents coastal waters surrounding Van­couver Island. About 23 percent are mature males, 34 percent mature females, 39 percent juveniles, and the rest (4 percent) calves. This local population has a complex social struc­ture. There are 30 pods, or sets of related individuals, which remain together on a long-term basis. Pods can be as large as 50 animals, but usually number from 5 to 20. Several pods may travel together for a few days or weeks, but there is no permanent exchange of individuals. The British Colum­bia population is made up of three distinct communities. A southern community con­sists of three pods, code named J, K, and L, totalling about 80 animals. Their year-round range is limited to the inshore waters south of Discovery Passage and some offshore areas west of southern Vancouver Island. J-pod's range extends southward into Puget Sound. A northern community, consisting of 12 pods or about 135 animals, occurs mainly inshore north of Discovery Passage. The third community is comprised of 15 small transient, or non-resident, pods. These pods seem to have a less well-defined range than the resident pods.

Since the members of a pod are often dispersed while foraging for food, com­munication is apparently maintained largely through acoustic exchange. The three basic sound-types produced by killer whales are: (1) short, high-frequency pulses or clicks used mainly for echolocation; (2) somewhat lower-frequency "whistles"; and (3) pulsed "screams" which sound harsh and metallic to the human ear. The latter two groups of sounds are thought to playa role in commu­nication. At least in British Columbia, each killer whale pod has a slightly different acoustic repertoire, or dialect, which prob­ably facilitates pod integrity when the ranges of two or more pods overlap.

Killer whales are skilled predators. Their diet includes nearly anything that swims. Turtles, ducks, and many kinds of fish and squid are eaten, as are seals, sea lions, porpoises, and whales. The preferences of a given pod seem to depend on where it lives. For example, some of the resident pods in British Columbia and Washington subsist largely on salmon and herring. In the Antarc­tic, some killer whales regularly prey upon minke whales and seals. Although killer

whales in some areas attack the larger whales, such attacks do not always result in a kill. Like wolves, killer whales rely on coor­dinated movement and cooperative hunting techniques to kill their larger prey.

Although present on the Canadian east coast and in the Arctic, killer whales are seen less frequently and less predictably there than in British Columbia's inshore waters.

Long-finned Pilot Whale (Globicephala melaena)

This medium-size toothed whale, known locally as the pothead in Newfoundland and the black fish in some other areas, is espe­cially abundant along the Atlantic coast of Canada. A closely related species, the short­finned pilot whale (G. macrorhynchus), is present in the more tropical waters of the Atlantic. In the Pacific, it is present in trop­ical waters and occasionally reaches the shores of British Columbia and Alaska, associating with warm currents.

The most distinctive external features of the pilot whale are a high, rounded forehead (thus the vernacular name pothead) and a thick, broad-based dorsal fin which is unmistakable in profile. The short beak is overhung in large adults by the bulbous melon. Males are considerably larger than females; maximum lengths are 6.2 m and 5.4 m, respectively. Very large males may weigh close to 3 tons. At birth, most pilot whales are 1.65-1.9 m long.

Although at first glance adult pilot whales appear uniformly blackish-gray or blackish­brown, they do have certain consistent, if rather subtle markings. There is a wedge of speckled dark gray on the back behind the dorsal fin, often referred to as a saddle­mark. A dark gray streak, shaped like an elongate teardrop, is often present behind each eye. The ventral surface is marked by a gray-to-white patch along the midline which widens to form an anchor-shaped che­vron design on the throat. Calves are light gray, their markings muted.

Pilot whales are among the most gregari­ous of cetaceans. They often travel in herds of several hundred, closely coordinating their activities and movements. Squid, specifically short-finned squid (Illex illecebrosus) off Newfoundland, are the principal prey of pilot whales. The whales' distribution is thus governed largely by the squid migra­tions. Pilot whales live throughout the year in deep water, and are especially abundant on the continental slope. Their appearance on the shelf and in shallow coastal waters, particulary along the east coast of New­foundland in Trinity, Bonavista, Concep­tion, and Notre Dame bays during summer, is explained by the arrival there of dense swarms of squid.

Underwater World 17

Figure 18. Long-finned pilot whales stranded at River John, Nova Scotia, August 1918. Photograph by E. Clay Blair/Public Archives Canada, copyright (Call.) 1966-94, PA 30300.

The phenomenon of mass stranding has always puzzled those who study the habits of whales. This tendency to come ashore and die in groups is displayed mainly by the highly social odontocetes. On the east coast of Canada, nearly all mass strandings involve herds of pilot whales (Figure 18). There is no evidence that the whales involved in such mass strandings are diseased or afflicted by exceptionally heavy parasite burdens. It has been suggested that since strandings most often occur along gently shelving coasts, bottom topography plays a major role, perhaps reducing the effectiveness of the whales' biosonar navigation system. Strangely enough, however, attempts by well-meaning onlookers to refloat the animals by towing them clear of the beach are generally unsuccessful. More often than not, the whales simply return directly to shore. This may mean that social or psycho­logical factors, such as response to stress calls by animals still beached, are what trigger and maintain this strangely self-destructive behaviour. In addition to eastern Newfound­land, mass strandings of pilot whales have occurred on Sable and Cape Breton islands, Nova Scotia, and in the Gulf of St. Lawrence and Bay of Fundy.

Life-history parameters have been esti­mated from a large sample of pilot whales killed in Trinity Bay during the 1950s. Females reach sexual maturity at about 6 years of age and a mean length of 3.65 m; males at about 12 years and 4.9 m. The breeding season is prolonged, with most births occurring sometime between May and November after a gestation period of 15Yz-16 months. Although calves may begin taking solid food at 6 months, they may not be fully weaned until nearly 2 years of age.

The most popular and effective method of

capturing pilot whales in Newfoundland was driving. Beginning in late July, the whalers would look for herds of pilot whales follow­ing the squid inshore. In small vessels, they would intercept the herds of whales and drive them slowly toward shore. After driving them into shallow water, the whalers killed the animals with lances, then towed them ashore where the meat and oil could be processed. In these drives, entire herds, usually containing individuals of both sexes and various ages, were dispatched. The fishery for minke whales and other medium-size cetaceans established in eastern Newfoundland in 1947 soon came to depend mainly on pilot whales, the meat being sold to mink ranches.

During the period of organized and inten­sive catching at Newfoundland, 1947-1971, approximately 54,000 pilot whales were cap­tured. The highest catch in a single season was nearly 10,000 in 1956. A fairly consis­tent decline in the annual catch after 1956 has been interpreted as evidence that the local stock was depleted. An estimated 14,000 pilot whales were present off eastern Newfoundland within 150 km of shore in 1980, based on results of an aerial survey.

White Whale or Beluga (Delphinapterus leucas)

White whales, or belugas as they are often called, are among Canada's best-known whales. They are endemic to the Northern Hemisphere, where they occur in many dis­crete stocks throughout the Arctic and Subarctic regions. There are at least five stocks in Canada: the Mackenzie Delta stock, the Lancaster Sound stock, the Cumberland Sound stock, the Hudson Bay/ Hudson StraitiUngava Bay stock or stocks, and the St. Lawrence stock. The present

18

world population consists of at least several tens of thousands, although some stocks have been severely reduced by overhar­vesting.

The distribution and abundance of white whales in Canada are summarized in Table 2. The occurrence of belugas along the coast of British Columbia would be very exceptional. The nearest population is cen­tered in Cook Inlet, south-central Alaska. There are a few isolated records of individual belugas reaching coastal waters of Washing­ton, and a herd of 21 was seen several years ago during late May in Yakutat Bay, south­east Alaska. Presumably such animals are emigrants from the Cook Inlet stock, which numbers only a few hundred. Occasionally, solitary belugas or very small groups are reported along the coasts of Newfoundland, Nova Scotia, and New Brunswick, and south along the U.S. coast as far as Long Island, New York. Many of these "strays" are prob­ably from the St. Lawrence stock, although Newfoundland records may involve "strays" from stocks along the Labrador coast or farther north.

Male white whales, which are somewhat larger than females, can grow to lengths of 5 m and weigh more than 2,000 kg. However, the average adult size is smaller, perhaps 0.5-1.5 tons and 3.0-4.5 m. The

Underwater World

Table 2. Major stocks of white whales in Canada.

CENTER OF DISTRIBUTION Initial

Winter Summer Population

Bering Sea Mackenzie Delta, ? Beaufort Sea, Amundsen Gulf

West Greenland Lancaster Sound, ? Prince Regent Inlet

Davis Strait & Cumberland Sound 5,000 + Mouth of Hudson Strait?

Hudson Strait Ungava Bay 1,000 + Hudson Strait Eastern Hudson Bay 5,000 + Hudson Strait Western Hudson Bay ? St. Lawrence River St. Lawrence River 5,000 +

and Gulf and Gulf

* Applies only to a portion of stock's summer distribution.

1.5 m long newborns are generally gray or brownish. Juveniles are gray to bluish. After the attainment of sexual maturity, the body color changes to all white except for the edges of the flippers and flukes, which retain dark pigment.

Well-fed belugas have a lumpy appear­ance, with folds of fat along the sides of the

Current Population (Year)

7,000 (1979)

6,300-18,600 (1981)

600 (1979)

Low hundreds (1981) 350 or less' (1981) 5,000-10,000 (1965) 360-715 (1983)

Figure 19. A white whale surfacing in a crack during break-up in Lancaster Sound, July 1983. Photograph copyright Gregory Silber.

body. The flippers are broad and, in adult males, curl up at the tip. The flukes of adults have a convex rear margin. There is no dor­sal fin, but a low, serrated ridge is present along the midline where a fin occurs on other species. White whales can radically change the shape of their bulbous melon (Figure 19). The short, broad beak is cleft slightly in the center. There are 40-44 simple conical teeth evenly distributed in the jaws. Sharp initially, these teeth eventually become badly worn, and many are lost by injury or infection.

The sailors' term "sea canary" is appropriately applied to the beluga, as an underwater chorus of chirps and creaks is invariably heard in the presence of a pod. Experiments have shown them to be adept at echolocation, and judging by the variety of sounds they make, they are also highly communicative. Their sociable nature is manifest in the large size of herds, includ­ing up to several thousand individuals, that congregate in river mouths during summer.

Most belugas migrate, but the distance covered varies greatly among stocks. For example, the Mackenzie Delta stock, esti­mated to number about 7,000, leaves its win­tering grounds in the Bering Sea during late April to mid-June, heading north through Bering Strait and east along the north coast of Alaska. Some animals travel in leads through the pack ice far offshore. The first arrivals reach the Mackenzie Delta by mid­May. Numbers in the estuary build up through July, then decrease in August and September as the whales begin returning westward. In contrast, the St. Lawrence belugas are relatively stationary. At least some of them overwinter at the Saguenay River confluence; others find refuge in patches of open water and broken pack ice elsewhere in the estuary and gulf. The limits

of their summer distribution are from Ile­aux-Coudres in the west to Natashquan and Baie des Chaleurs in the east. There is no evi­dence for a seasonal migration out of the Gulf through either Cabot Strait or the Strait of Belle Isle.

Ice cover appears to be the decisive factor in the distribution of most white whale stocks. At the floe edge in Lancaster Sound during late spring, belugas (along with nar­whals, bowheads, and various pinnipeds) arrive with an apparent sense of urgency. They quickly penetrate the cracks and leads formed in the rotting ice. Belugas can break through thin ice to breathe, and they often rest in ice "domes" which form around their bodies while at the surface. Occasionally they miscalculate and are cut off from open water. Such entrapment can be fatal. If polar bears or native hunters do not find and kill the whales, they are likely to starve or suffo­cate. However, sometimes a shift in the wind direction or an early break-up allows the whales to escape.

Polar bears certainly hunt white whales, and sometimes kill them. Their success undoubtedly depends upon how confined the belugas are in a crack op pool of open water. Killer whales are probably a more serious and regular threat to belugas, but few eye­witness accounts of attacks have been pub­lished. Their close association with ice may give belugas some degree of protection because killer whales are unlikely to follow them far into the hazardous ice fields.

Belugas prey upon many kinds of fish, as well as squids, octopuses, marine worms, crustaceans, and mollusks. In a study of food habits in the St. Lawrence, at least 50 different species were identified in stomach contents. Belugas are known to prey on commercially valuable fishes such as salmon, cod, and herring, but contrary to the views expressed by local fishermen, St. Lawrence belugas are not a major pre­dator of cod or salmon. In the St. Lawrence they eat mainly capelin early in the summer, then switch to sand lance in August and September.

The St. Lawrence stock of white whales evidently was depleted as a result of over­hunting and today numbers only about 500 animals, compared to at least 5,000 in the late nineteenth century. The degree to which environmental factors such as the damming of important tributary rivers along the North Shore, pollution, or vessel traffic are affect­ing St. Lawrence belugas is unclear.

Several other Canadian stocks are in need of special protection. The Cumberland Sound stock, which contained at least 5,000 animals in the early 1920s, has been reduced to no more than about 500-700 individuals today. Other areas of concern are Ungava Bay, Hudson Strait, and eastern Hudson

Underwater World 19

Figure 20. About 80-90 white whales stranded at low tide after a whale drive in Clear­water Fiord, Cumberland Sound, early 1920s. Photograph courtesy Hudson's Bay Company Archives, D.FTRI19, fo. 432A, top.

Bay. There, too, the white whale stocks were greatly overtaxed by commercial drive fisheries earlier in the present century (Figure 20).

Belugas have always been an important subsistence resource for the Inuit and for cer­tain northern Indian tribes. Kittigaruit (also spelled Kittegazuit on modern maps), located at the mouth of East Channel, was appar­ently the largest Inuit village in the Macken­zie River area, and probably in all of Arctic Canada during the mid-nineteenth century. It had a summer population of 800 to 1,000 people, the Kittegaryumiut. The backbone of their economy and culture was the annual communal beluga hunt which took place from mid-July to early September. In the summer of 1848 the Arctic explorer Sir John Richardson was met by no less than 200 kayaks from Kittigaruit. This remarkably large fleet was used to drive herds of belugas onto sandbars where they could be slaugh­tered. After being killed, the whales were butchered on the beach, their meat smoked or air-dried, and their blubber rendered to oil by cooking over driftwood fires. Although the settlement site at Kittigaruit has been abandoned for many years, the present­day residents of the Mackenzie Delta still hunt white whales and process the meat in much the same way.

A unique method of catching white whales was developed by early French colonists along the shores of the St. Lawrence River. The peche aux marsouins (beluga fishery) was conducted using specially designed traps or weirs, strategically placed to intercept groups of whales as they moved close to shore. Rows of evenly spaced poles "guided" the whales into a cuI de sac, where the fisher­men could easily dispatch them with lances at low tide. Several hundred animals were sometimes taken in a single tide.

The Hudson's Bay Company maintained a lively interest in beluga fishing almost from the establishment of their first trading post in Canada during the seventeenth century. A shipment of 28 casks of beluga oil was made from Churchill to England in 1689. Thereafter, whaling was attempted at virtu-

ally every post situated near a concentration of white whales. If possible, the whales were driven into shallow water where they could be netted, shot, or harpooned.

Many white whales were also caught by the crews of Scottish and American commercial whaling vessels in Davis Strait and the Lan­caster Sound region. More than 20,000 were killed there during the period 1868-1911. Most of these were taken in drives conducted in Cumberland Sound or at Elwin Bay in Prince Regent Inlet. White whale hides and oil initially supplemented the bowhead oil and baleen which attracted the whalers to the Arctic in the first place. But as bowheads became more scarce, belugas and other smaller game increased in importance. Beluga hides can be tanned to produce a fine and durable leather. It was used to make bootlaces, carriage covers, and mailbags. The oil was used mainly for illumination and lubrication.

A plant erected at Churchill in 1949 processed white whales during the 6-week summer hunting season. Local Inuit, Cree, and Metis, as well as other residents, could purchase licenses to hunt; they were paid by the foot for whales delivered to the factory. The main product initially was minced, frozen of carcasses shipped by rail to mink ranches in the Prairie Provinces. A native-run commercial netting operation was begun at Whale Cove, northwest Hudson Bay, in 1961 to produce canned or frozen meat and muktuk (whale skin with a thin layer of adhering blubber), most of which was sold to Inuit settlements. In 1970, unacceptably high levels of mercury were discovered in the white whale meat, and the fishery was ordered to close.

Since 1962, white whale hunting in Canada has been controlled by Beluga Protection Regulations issued under the Fisheries Act. Only resident Indians and Inuit are allowed to hunt without a license. The killing of calves, and females by calves, is forbidden. Trade or barter of white whale

is allowed within the Northwest Territories, bur such products cannot be

are from

20 Underwater World

Table 3. Reported landed catch of white whales in Canada, 1974-1984.

Western Eastern Central Western Year Arctic Arctic Arctic Hudson Bay No. Que.1 Total 1974 239 668 1,0722

1975 184 140 101 471 896 1976 154 239 146 546 1,085 1977 148 286 191 682 1,307 1978 127 161 118 297 703 1979 144 200 105 435 884 1980 85 133 124 432 774 1981 218 232/2523 28 211 297 986/1006 3

1982 126 191 158 344 819 1983 85 116 15 268 294 778

423 286 941

1 Estimates of catch; Rep. into Whal. Commn 31:531-538; Taqralik July-August 1985; note that catches by Povungnituk and Ivujivik for 1974-1980 and by Povungnituk for 1981-1984 are not included in the estimates. 2 Exclusive of the catch in western Hudson Bay. 3 Reported catch for Igloolik was 60-80.

ail forms of hunting in the Gulf of St. Lawrence and in the St. Lawrence River and its tributaries. The St. Lawrence stock presently helps to sustain the whalewatching tourist industry in the e:;tuary.

tend to occupy deep bays and fiords; whereas, white whales congregate in shallow, relatively warm estuaries. The best-known and probably largest narwhal population in the world inhabits the deep inlets, sounds, and channels of the eastern Canadian Arctic and northwest Greenland.

The narwhal's highly modified dentition is its most distinctive attribute. Two adult teeth are rooted in the upper jaw. In females, both usually remain embedded, leaving the animal functionally toothless. In males, the left tooth erupts through the gum at the front of the jaw and grows into a straight, tapered, spiraled tusk up to 3 m long (Figure 21). Occasionally, females develop one or two external tusks, and a small percentage of males become "double-tuskers". The func­tion of the male narwhal's formidable tusk has long been debated. It is now generally agreed that the tusk serves a role in aggres­sive interaction among adult males, although details of the behavior involved in its use are unknown. Tusk-crossing or "fencing" above

and below the surface has been observed. In overall body size and shape, narwhals

resemble belugas. In the Canadian Arctic, males reach physical maturity at a length of about 4.7 m when they weigh about 1,600 kg; females at 4.15 m and 1,000 kg. Narwhals are about 1.6 m long and weigh just over 80 kg at birth. The body color changes with age, from evenly light gray at birth to dark gray or almost black in juvenile stages and mottled at maturity (Figure 22). Adults, especially males, become white ven­trally and laterally but retain dark pigment on the back, head, neck, and edges of the flippers and flukes. Very old bulls can be mostly white.

The narwhal's summer distribution in Canada is centered in Lancaster Sound and its adjacent waters, including Prince Regent Inlet, Barrow Strait, and Peel Sound, and in Jones Sound. Especially large numbers occur in Admiralty Inlet and the Pond Inlet­Eclipse Sound-Navy Board Inlet-Milne Inlet complex, where narwhals have long been hunted by the Inuit. During fall the Lan­caster Sound animals migrate south in Baffin Bay, and they overwinter in the broken pack ice or along the edges of fast ice as far south as Disko Bay on the east and Hudson Strait on the west. Narwhals are also found dur­ing summer in deep waters of northern Hud­son Bay, Hudson Strait, and Foxe Basin; it is not known whether the animals overwinter in these areas and thus comprise a separate resident stock. Rarely, narwhals wander as far south as the coast of Newfoundland. There is some fossil evidence that narwhals were present in the Gulf of St. Lawrence a few thousand years ago. 'Very few narwhals have been recorded in the western Canadian Arctic.

Narwhals are gregarious. Pods of three to four or sometimes as many as 20 individuals congregate in close proximity and in this way form herds of several hundred or even thou­sands of animals. Pods sometimes consist of individuals of the same sex and age, but

White whales were among the first ceta­cean species to be maintained in captivity. A number were exported alive during the second half of the nineteenth century. They came from the weir fisheries in the St. Lawrence, and most of them were destined for makeshift aquariums in Boston, New York, or London. Although survival was poor initially, it has improved greatly in recent years. Today, most specimens brought into captivity are from Churchill, Manitoba. Native hunters there have developed a tech­nique for isolating an individual from its pod, driving it into shallow water, and lassoing it by hand. Whales caught in this manner are cradled in a canvas stretcher and transported to shore alongside an outboard­powered freight canoe. They are then placed in a holding tank before being airlifted to the USA, Europe, or Japan. The Vancouver Public Aquarium is the ony facility in Canada with live belugas presently on display.

Figure 21. The long tusks of three narwhals silhouetted against the water and sky in Lancaster Sound, July 1983. Photograph copyright Gregory Silber.

The reported landed catch of white whales in Canada from 1974 to 1984 is shown in Table 3.

Narwhal (Monodon monoceros) Like the white whale, its closest relative,

the narwhal is confined to the northern extremes of the Northern Hemisphere. The narwhal's habitat requirements seem to be more specific than the beluga's, and thus its range is more restricted. Because both species prey on many of the same types of organisms, they are potential competitors. However, during summer at least, narwhals

Underwater World

Figure 22. Close view of a young narwhal with a short tusk at the floe edge in Lancaster Sound, July 1983. The more extensive white mottling on two whales nearby·suggests that they are larger, older individuals. Photograph copyright Gregory Silber.

mixed groups are also seen. During their westward spring migration in Pond Inlet and Lancaster Sound, groups of adult males head the procession, followed by females and young. Later in the summer, narwhals are segregated into groups of immature males, groups of mature females and calves, and groups of tusk-bearing adult males. There is some evidence that the bulls remain farther offshore, while females with calves penetrate far inside embayments where waters are relatively calm.

The size of the narwhal population in Canadian waters during summer has been estimated as over 13,000. There is currently no way of knowing how the present popula­tion size compares to that of earlier times.

In spring (June-July) at the Pond Inlet floe edge, narwhals dive under the fast ice in pur­suit of arctic cod, a staple item in their diet. Later, as they move through the inlet toward their main summering grounds, they prey on halibut, shrimp, and squid. Narwhals are deep divers, and the pursuit of squid and halibut probably takes them to depths well below 400 m.

Narwhals face many of the same ecologi­cal problems as belugas. Killer whales, polar bears, and rarely even walruses attack them. Ice entrapment makes them vulnerable to predation, starvation, or suffocation.

The life history of narwhals and belugas appears to be similar in some respects. In the absence of direct evidence, some scientists have estimated the narwhal's vital para­meters by inference from the beluga's, since the latter has been more extensively studied. Narwhals breed mainly in mid-April, and most calves are born in mid-July. Lactation probably lasts for well over a year, and the average calving interval is probably three years.

Several unsuccessful attempts were made in 1969-1970 to bring live narwhals into cap­tivity. A small ophaned calf from Grise Fiord was airlifted to the New York Aquarium but died after a month of confinement. The Van­couver Public Aquarium captured six nar­whals in 1970 and transported them across the continent. All died within a few months, mainly from bacterial or viral infections.

Narwhals have been hunted by the Inuit for many centuries, mainly for meat, muk­tuk, and sinew used as thread. During the eighteenth and nineteenth centuries, the arrival of European and American whalers and merchants made narwhal tusk ivory valuable as a trade commodity. The commer­cial whalers killed some narwhals themselves, but large amounts of ivory were also bartered from the natives, especially during the first quarter of the twentieth century on north Baffin Island.

21

There are three types of hunt conducted by the narwhal hunters of Pond Inlet: the floe-edge hunt from mid-June to mid-July, the ice-crack hunt from late July to early August, and the open-water hunt in August and September. During the floe-edge and ice­crack hunts, the animals are shot by hunters standing on the ice. Carcasses that do not sink are retrieved with the aid of a boat or a harpoon and line. During the open-water hunt, narwhals are chased in outboard­powered boats and canoes. Once driven into shallow water, they are shot. Harpoons are sometimes attached to wounded animals to facilitate retrieval.

The Canadian government introduced interim Narwhal Protection Regulations under the Fisheries Act in 1971. These made hunting by anyone except the Inuit illegal and set a maximum catch limit of five narwhals per year for each subsistence hunter. In 1976 and 1978 the regulations were made more explicit. Now calves and females accompa­nied by calves cannot be killed legally, and any part of a narwhal carcass suitable for food is to be utilized fully. Hunters are now required to affix a tag to the carcass or tusk of any narwhal that is killed. The tags are issued to settlements on a quota basis and are intended to limit the harvest. It is illegal to possess or sell a tusk that is not accompa­nied by a tag. Because the narwhal is listed on Appendix II of the Convention on Inter­national Trade in Endangered Species of Wild Fauna and Flora, tusks exported from or imported into Canada must be covered by an export or import permit or are-export certificate.

The total narwhal quota has remained at 542 since 1981; Pond Inlet and Arctic Bay are allowed 100 narwhals each, and all other settlements have quotas of 50 or less. The reported landed catch of narwhals in Canada for the period 1975-1984 is given in Table 4.

Dolphins One diverse group of dolphins, the genus

Lagenorhynchus, has representative species on both coasts of Canada. When a large school of dolphins is sighted in inshore or nearshore waters of British Columbia and the Maritimes (including Newfoundland and Labrador), it is likely that they belong to one of these species or to the species De/phinus de/phis, the common dolphin. All indulge in breaching, somersaulting, and other aerial acrobatics. At times, they will approach the bow of a vessel under power and swim there for long periods in its pressure wave. Such behavior is called bow-riding.

In the temperate and subarctic regions of the North Atlantic there are two species of Lagenorhynchus: the whitebeaked dolphin (L. albirostris) and the Atlantic white-sided dolphin (L. acutus). They are similar in size

22 Underwater World

Table 4. Reported landed catch of narwhals in Canada, 1975-1984. 1 Quotas are shown in parentheses for the years when they were first imposed or changed.

Year

10 Year Community 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 Average

Arctic Bay 167 115 40(100) 65 33 100 100 80 100 89 Broughton Island 5 6 10(15) 26 0 49(50) 50 50 20 36 25 Cape Dorset 0 0 0(10) 2 1 1 0 0 0 0 1 Chesterfield Inlet 0 0 0 0 0 0 0(5) 0 0 0 0 Clyde River 15 15 35(15) 4 9 35(50) 37 19 46 49 26 Coral Harbour 0 0 0(15) 0 0 0(10) 6 0 0 0 1 Creswell Bay 0 15 0(12) 0 0 0 0 0 0 0 1 Frobisher Bay 0 0 0(10) 0 0 0 0 0 1 1 1 Gjoa Haven 0 0 0(10) 0 0 0 0 0 22 0 2 Grise Fiord 0 11 0(20) 0 12 0 0 28 3 2 6 Hall Beach 0 0 13(10) 0 2 11 173 7 1 0 5 Igloolik 0 0 0(10) 0 1202 14 36(25)4 25 18 0 21 Lake H arbou r 0 0 0(10) 0 0 0 0 0 0 0 0 Pangnirtung 0 10 1(15) 2 28 19 44(40) 49 2 32 19 Pelly Bay 7 0 0(10) 0 0 0 0 0 0 0 1 Pond Inlet 77 125 99(100) 150 94 96 82 100 104 45 97 Rankin Inlet 0 0 0 0 0 0 5(10) 0 2 2 1 Repulse Bay 0 8 8(10) 4 30(25) 25 29 21 11 25 16 Resolute Bay 0 0 2(20) 14 2 0 0 2 11 0 3 Spence Bay 0 0 0(10) 0 0 0 0 1 0 0 0 Whale Cove 0 0 0 0 0 0 0(5) 1 0 0 1

----- ----TOTALS 271 305 208 267 331 350 406 383 341 285 313 Quotas n/a n/a (402) (402) (417) (482) (542) (542) (542) (542)

1 Official DFO harvest statistics, from D. Goodman, DFO, Ottawa, personal communication. 2 Includes 108 animals taken from a savssat in Agu Bay. 3 Includes 1 taken from a savssat in Quilliam Bay. 4 Includes 7 taken from a savssat in Quiliiam Bay.

(maximum length of 2.7-3 m; maximum weight of over 230 kg) and overall appear­ance (short, thick beak; tall dorsal fin at mid-back). At sea, they can be distinguished by differences in pigmentation. As their name implies, most whitebeaked dolphins have a white, or at least light gray, beak. They also have zones of white to light gray on the sides, sweeping onto the upper sur­face of the tail. Atlantic white-sided dolphins have a vivid white patch on either side and a broad tan or yellow stripe along either flank (Figure 23). Both species eat squid, as well as many kinds of fish.

Although the ranges of the two species clearly overlap, the white beaked dolphin occurs in somewhat higher latitudes than the Atlantic white-sided dolphin. In Newfound­land, whitebeaked dolphins sometimes become trapped against the coast by wind­driven ice. There have been a number of mass strandings of Atlantic white-sided dol­phins on the eastern seaboard in recent years.

The Pacific white-sided dolphin (L. obli­quidens) is somewhat smaller than its North Atlantic relatives. Like them, it has a promi­nent dorsal fin and a short beak, as well as a complex pigmentation pattern. A long white or light gray stripe sweeps along the back on either side of the dorsal fin, a fea­ture most evident to a shipboard observer as the animal is bow-riding. In addition to forming herds of several hundred individ-

uals, the Pacific white-sided dolphin often associates with other small cetaceans. Large schools of Pacific white-sided dolphins, numbering 200-250 animals, are observed in inshore waters of British Columbia from October through January. During other months, smaller groups are more common inshore.

None of the Lagenorhynchus dolphins has been exploited on a large scale in Canada. In the past, when herds of pilot whales were driven ashore at Newfoundland (and on the beaches of Cape Cod in the United States), a few of these dolphins were sometimes mixed in the catch. On rare occasions, a hundred or more dolphins were captured in this way. Indian porpoise hunters in the Bay of Fundy have occasionally shot white beaked and Atlantic white-sided dolphins, but their principal quarry was and stilI is the harbor porpoise (see beloW).

A few white beaked dolphins and Atlantic white-sided dolphins that have been ice­entrapped or that stranded alive have been held for short periods in aquariums. However, of the three Canadian species, only the Pacific white-sided dolphin has been suc­cessfully captured and maintained for long periods in captivity.

Common dolphins are widely distributed on the high seas in herds of hundreds or even several thousand. These handsomely marked, acrobatic dolphins are abundant

during summer and fall on the Scotian Shelf and on the continental slope southeast of Newfoundland. A few strays have been observed inshore along the coast of New­foundland. On the west coast, a stranding at Victoria demonstrated that common dol­phins do occur there, at least sporadically.

The striped dolphin (Stenella coeru/eoalba) is similar in size and appearance to the com­mon dolphin, and it is also found in large herds, usually well offshore. A number of striped dolphins have been found freshly stranded on Sable Island, and skulls of several have been reported from Vancouver Island. However, striped dolphins appear to be quite scarce inshore, except possibly in association with incursions onto the con­tinental shelf and slope by warm oceanic currents (Figure 24).

Risso's dolphin (Grampus griseus), some­times known as the gray grampus, is a rare visitor to Canadian waters. It is a large dol­phin, reaching lengths up to 4 m. Because of the light gray, almost white appearance of adults, Risso's dolphins are sometimes confused with belugas (white whales). How­ever, their tall dorsal fin is in sharp contrast to the complete lack of such an appendage on belugas. Risso's dolphins are abundant in temperate and tropical waters of both the Atlantic and Pacific. They are only encoun­tered occasionally off the British Columbia, Nova Scotia, and Newfoundland coasts.

The gregarious northern right whale dolphin (Lissode/phis borealis) is endemic to the temperate North Pacific. It is a long, slender dolphin with no dorsal fin; the lack of such a fin gave it the vernacular name, for the right whale also has a smooth back with no dorsal fin. Although not as com­monly seen off British Columbia as in some areas to the south, northern right whale dol­phins range all the way from southern California to Alaska. They often associate with Pacific white-sided dolphins and thus should be looked for whenever a herd of the latter is encountered.

The bottlenose dolphin (Tursiops trunca­tus) is familiar to most Canadians because of its appearance in captive animal shows and marine aquariums. However, most individuals in such displays have been caught along the southeast coast of the United States or in the Gulf of Mexico. There is only one confirmed published record of this species in the wild in Canada - a female that strayed into the Petitcodiac River of southern New Brunswick in September 1950.

Porpoises Canada's smallest cetaceans are the har­

bor porpoise (Phocoena phocoena) and Dall's porpoise (Phocoenoides dalli). Although related to each other and of simi-

Underwater World

Figure 23. An Atlantic white-sided dolphin caught in mid-air off Cap-des-Rosiers, Gaspe Peninsula, August 1978. The subequal flank panels of white and yel/ow-ochre distinguish this species from aI/ others. Photograph by Maxime St-Amour.

for more than 10 years. Boaters in British Columbia sometimes

report sightings of "baby killer whales" which prove, on closer examination, to have been Dall's porpoises. The killer whale is cer­tainly found in the same areas as the simi­larly marked Dall's porpoise and the harbor porpoise, and it is known to attack both of them. In the Bay of Fundy and Gulf of Maine on the east coast, harbor porpoises are also preyed upon frequently by large sharks, including the great.. white shark (Carcharodon carcharias).

Both these porpoises may have a high

23

metabolic rate, which would mean they are extremely active and require relatively large amounts of food at frequent intervals. Several European institutions have success­fully maintained, and even trained, harbor porpoises in captivity, but in North America attempts to do so have been unsuccessful. The few Dall's porpoises brought into cap­tivity in California have proven to be high­strung and difficult to keep alive.

Because of their nearshore distribution, both harbor porpoises and Dall's porpoises were traditional targets of Indian hunters, who relished porpoise meat. During the nineteenth century the Micmac Indians of western Nova Scotia carried on a commer­cial porpoise fishery in the Bay of Fundy. Harbor porpoises were shot with shotguns and retrieved with long-handled hooks. Their blubber was rendered down, then sold in bar­rels at Halifax and Saint John for the soap­making industry. Local fishermen in the Gulf of St. Lawrence and in parts of Newfound­land and Labrador still hunt harbor por­poises for domestic consumption, and some hunting for meat is still done in the Bay of Fundy by the Passamaquoddy tribe living in Maine on the shores of Passamaquoddy Bay. At one time, harbor porpoises were hunted in the vicinity of Deer Island, New Brunswick, to supply food for ranch mink.

Harbor porpoises and Dall's porpoises, as well as other related species of phocoenids worldwide, face another threat in addition to natural predators and human hunters: many die in fishing gear intended to catch fish rather than porpoises. Each year, a number of harbor porpoises become trapped in herring weirs along the coasts of New Brunswick and Nova Scotia (Figure 25). In the Gulf of St. Lawrence and along the coast

lar body length (maximum of 2.0-2.2 m), the two species differ in' many important re­spects. Dall's porpoise is a chunkier, heav­ier animal than the harbor porpoise; its well defined, black-and-white markings are in sharp contrast to the drabber pigmentation of the harbor porpoise. Moreover, Dall's porpoise is a high-speed swimmer, known to dart back and forth across the bow of fast­moving vessels and to make distinctive splashes of seawater as it charges along the surface to breathe. The harbor porpoise usually behaves more cryptically. It does not bow-ride and usually surfaces with little splash; thus, in all but the calmest of seas, the harbor porpoise can be hard to detect.

The distribution of the two species also differs. Dall's porpoise is found only in the temperate to subarctic North Pacific. It is a deepwater animal and usually comes close to the coast only in areas where canyons or deep channels provide suitable inshore habitat. Sightings are especially common in Hecate Strait, Queen Charlotte Strait, Juan de Fuca Strait, and exposed seaways like Queen Charlotte Sound, Dixon Entrance, and Fitz­hugh Sound. Dall's porpoises eat squid, crustaceans, and many kinds of fish. The harbor porpoise inhabits both the North Pacific and North Atlantic, where it ranges regularly into bays and estuaries and over offshore banks. It eats mainly squid, herring, mackerel, and other schooling, nonspiny fishes. Harbor porpoises are especially abun­dant in the lower Bay of Fundy, where a team of researchers from the University of Guelph (Ontario) has been studying details of their behavior, ecology, and physiology

Figure 24. A striped dolphin on a wharf at Chester, Nova Scotia, 1926. Photograph courtesy J.C. Medcof.

24 Underwater World

Figure 25. A harbor porpoise trapped in a herring weir in the lower Bay of Fundy, July 1973. Photograph by DE Gaskin.

of Newfoundland and various parts of the North American west coa~t, gillnets, cod and salmon traps, mackerel nets, trawls, and purse seines take their toll ot: harbor por­poises. The Japanese high-seas gillnet fish­ery for salmon in the North Pacific kills several thousand Dall's porpoises annually, as they become fatally entangled alongside sea lions, fur seals, seabirds, salmon, and many other marine organisms, in walls of netting several km long and about 6 m deep.

A crude estimate of the number of harbor porpoises present during summer in the approaches to the Bay of Fundy is 4,000, with a further 2,000 distributed in coastal waters of the Scotian Shelf. These porpoises are probably part of a stock whose winter range extends south along the U.S. coast to North Carolina and offshore to Georges Bank. There are no population estimates for harbor porpoises on the west coast. The aggregate population of Dall's porpoise in the North Pacific is probably close to a million. However, the degree to which coastal stocks intermingle with pelagic stocks is unknown.

Further Reading Allen, K.R. 1980. Conservation and

Management oj Whales. A Washington Sea Grant Publication, distributed by Univ. of Washington Press, Seattle; Butterworths, London. ix + 107 p.

Brodie, P.F. 1975. "Cetacean Energetics, an Overview of Intraspecific Size Variation." Ecology, 56(1): 152-161.

Chapman, J.A. and G.A. Feldhamer (eds.). 1982. Wild Mammals oj North America: Biology, Management, and Economics. The Johns Hopkins University Press, Baltimore and London. xiii + 1147 p.

Davis, R.A., K.J. Finley and W.J. Richard­son. 1980. The Present Status and Future Management oj Arctic Marine Mammals in Canada. Prepared for: Science Advisory Board of the Northwest Territories, Yel­lowknife, N.W.T. Published by: Depart­ment of Information, Government of the Northwest Territories, Yellowknife, Northwest Territories XIA 2L9. i-viii + 93 p.

Gaskin, D.E. 1982. The Ecology oj Whales and Dolphins. Heinemann, London and Exeter, New Hampshire. xii + 459 p.

Haley, D. (ed.). 1978. Marine Mammals oj eastern North Pacific and Arctic Waters. Pacific Search Press, Seattle, Washington. 256 p.

Herman, L.M. (ed.). 1980. Cetacean Behavior: Mechanisms and Functions. John Wiley & Sons, New York, Chichester, Brisbane, Toronto. xiii + 463 p.

Hoyt, E. 1981. The Whale Called Killer. E.P. Dutton, New York. xx + 226 p.

Hoyt, E. 1984. The Whale Watcher's Hand­book. Madison Press Books, Toronto, Ontario. 208 p.

International Whaling Commission. Annual Reports 1-35, 1950-1985; Special Issues 1-6, 1977-1984. Cambridge, England.

International Whaling Statistics. Ed. by Committee for Whaling Statistics, Oslo, Norway. Nos. 1 (1930) to 94 (1984) cur­rently available.

Jones, M.L., S.L. Swartz, and S. Leather­wood (eds.). 1984. The Gray Whale Eschrichtius robustus. Academic Press, Orlando, Florida. xxiv + 600 p.

Kanwisher, J.W. and S.H. Ridgway. 1983. "The Physiological Ecology of Whales and Porpoises." Scientific American, 248(6): 110-120.

Leatherwood, S. and R.R. Reeves. 1983. The Sierra Club Handbook oj Whales and Dolphins. Sierra Club Books, San Fran­cisco. xviii + 302 p.

Lubbock, B. 1937. The Arctic Whalers. Brown, Son & Ferguson, Glasgow. xi + 483 p.

Mitchell, E.D. 1973. "The Status of the World's Whales." Nature Canada, 2(4): 9-25.

Mitchell, E. 1975. Porpoise, Dolphin and Small Whale Fisheries oj the World. Status and Problems. International Union for Conservation of Nature and Natural Resources, Morges, Switzerland. IUCN Monograph No.3. 129 p.

Mitchell, E. (ed.). 1975. "Review of Biology and Fisheries for Smaller Cetaceans." J. Fish. Res. Board Can., 32(7): 889-983.

Payne, R. (ed.). 1983. Communication and Behavior oj Whales. AAAS Selected Sym­posium 76. Westview Press, Boulder, Colorado. xii + 643 p.

Pike, G.C. and LB. MacAskie. 1969. Marine Mammals oj British Columbia. Fish. Res. Board. Can., Bulletin 171. ix + 54 p.

Reeves, R.R. and E. Mitchell. 1984. "Catch History and Initial Population of White Whales (Delphinapterus teucas) in the River and Gulf of St. Lawrence." Naturaliste can. (Rev. Eco!. SysL), 111:63-121.

Reeves, R., E. Mitchell, A. Mansfield and M. McLaughlin. 1983. "Distribution and Migration of the Bowhead Whale, Balaena mysticetus, in the Eastern North Ameri­can Arctic." Arctic, 36(1): 5-64.

Rice, D.W. and A.A. Wolman. 1971. The Life History and Ecology oj the Gray Whale (Eschrichtius robustus). Amer. Soc. Mammal. Spec. Pub!. 3. viii + 142 p.

Ross, W.G. 1975. Whaling and Eskimos: Hudson Bay 1860-1915. National Museums of Canada, Publications in Ethnology, No. 10. 164 p.

SchevilI, W.E. (ed.). 1974. The Whale Problem: A Status Report. Harvard University Press, Cambridge, Massa­chusetts. x + 419 p.

Sergeant, D.E. 1962. The Biology oj the pilot or pothead whale Globicephala melaena (Traitl) in Newjoundland waters. Fish. Res. Board Can., Bulletin 132. vii + 84 p.

Sergeant, D.E., A. W. Mansfield and B. Beck. 1970. "Inshore records of Cetacea for Eastern Canada, 1949-68." 1. Fish. Res. Board Can., 27(11): 1903-1915.

Slijper, E.J. 1979. Whales. 2nd English edi­tion. Hutchinson of London. 511 p. [Orig. pub!, in Dutch, 1958]

Underwater World

Tomilin, A.G. 1967. Mammals oj the U.S.S.R. and Adjacent Countries. Cetacea, Vo!. 9. Trans!. from Russian by Israel Program for Scientific Translations, Jerusalem. xxii + 717 p. [Orig. pub!, in 1957]

Tcinnessen, J.N. and A.O. Johnsen. 1982. The History oj Modern Whaling. Trans­lated from Norwegian by R.I. Christophersen. C. Hurst & Co., London; Australian National Univ. Press, Canberra. xx + 798 p.

Winn, H.E. and B.L. Olla (eds.). 1979. Behavior oj Marine Animals. Current Perspectives in Research. Vol. 3: Ceta­ceans. Plenum Press, New York and London. xix + 438 p.

25

Appendix. Scientific and vernacular names of cetaceans of Canada. The preferred French-language usage is indicated by an asterisk (*).

North American Scientific English1 European French2 French3 Proposed Name

Euba/aena glacjali~ Right whale Baleine de Biscaye* Baleine franche ou ou Baleine des Baleine noire Basques

Ba/aena mysticetus Bowhead whale Baleine du Baleine boreale ou Groenland* Baleine franche du

Groenland Eschrichtius robustus Gray whale Baleine grise de Baleine grise*

Californie Ba/aenoptera musculus Blue whale Rorqual bleu* Rorqual bleu* ou

Baleine bleue Ba/aenoptera physalus Fin whale Rorqual commun* Rorqual commun* Ba/aenoptera borealis Sei whale Rorqual de Rudolphi* Rorqual boreal Ba/aenoptera Minke whale Rorqual a museau Petit rorqual*, acutorostrata pointu ou Petit Gibard, ou Rorqual

rorqual* nain Megaptera novaeangliae Humpback whale Megaptere ou Rorqual a bosse ou

Jubarte Baleine a bosse* Physeter catodon Sperm whale Cachalot* Cachalot

macrocephale Kogia breviceps Pygmy sperm whale Cachalot pygmee* Cachalot pygmee * Kogia simus Dwarf sperm whale Cachalot nain* Ziphius cavirostris Cuvier's beaked whale Ziphius Baleine a bec de

Cuvier* Berardius bairdii Baird's beaked whale Grande baleine a bec Baleine a bec de

Baird*

Hypero6don ampullatus Northern bottlenose Hyperoodon boreal * Baleine a bec whale commune

Mesop/odon Blainville's beaked Mesoplodon de Baleine a bec de densirostris whale Blainville Blainville* Mesoplodon bidens Sowerby's beaked Mesoplodon de Baleine a bec de

whale Sowerby Sowerby* Mesoplodon mirus True's beaked whale Mesoplodon de True Baleine a bec de

True* Mesoplodon carlhubbsi Hubbs' beaked whale Mesoplodon de Baleine a bec de Baleine a bec de

Hubbs Moore Hubbs* Mesoplodon stejnegeri Stejneger's beaked Mesoplodon de Baleine a bec de

whale Stejneger Stejneger*

26 Underwater World

Appendix (continued).

North American Scientific English1 European French2 French3

Orcinus orca Killer whale Orque ou Epaulard* Epaulard* ou Orque Globicephala melaena Long-finned pilot whale Globicephale noir Globicephale noir;

Globicephale noir de l'Atlantique

Globicephala Short-finned pilot Globicephale Globicephale du macrorhynchus whale tropical* Pacifique Delphinapterus leucas White whale or Beluga Belouga Beluga* ou Marsouin

blanc Monodon monoceros Narwhal Narval* Narval* Delphinus delphis Common dolphin Dauphin commun* Dauphin commun* Lagenorhynchus White-beaked dolphin Lagenorhynque a bec Dauphin a nez albirostris blanc blanc*, "Sauteur," ou

"Cochon de mer" Lagenorhynchus acutus Atlantic white-sided Lagenorhynque a Dauphin a flancs

dolphin flancs blancs blancs, "Sauteur" ou "Cochon de mer"

L.agenorhynchus Pacific white-sided Dauphin a flancs obliquidens dolphin blancs du Pacifique* Stenella coeruleoalba Striped dolphin Dauphin bleu et Dauphin bleu

blanc Grampus griseus Risso's dolphin or Grampus ou Dauphin Dauphin gris

Grampus de Risso* Lissodelphis borealis Northern right whale Dauphin ados lisse

dolphin Tursiops truncatus Bottlenose dolphin Grand dauphin ou Dauphin a gros nez

Souffleur Phocoena phocoena Harbor porpoise Marsouin Marsouin commun*

ou Pourcil Phocoenoides dalli Dall's porpoise Marsouin de Dall*

1 Following standard usage adopted by the International Whaling Commission and other agencies. 2 Following R. Duguy and D. Robineau. 1982. Guide des Mammiferes marins d'Europe.

Delachaux & Niestle, Eds, Neuchatel (Switzerland)-Paris. 200 pp. 3 Following J. Prescott and P. Richard. 1982. Mammiferes du Quebec et de I'est du Canada.

Proposed Name

Globicephale a nageoires longues*

Baleine blanche*

Dauphin a flancs blancs de l'Atlantique*

Dauphin raye*

Dauphin ados lisse boreal* Tursion*

Editions France-Amerique, Montreal. Vol. 2: XIII + 201-429; E. Mitchell. 1973. Les baleines dans Ie monde. Nature Canada 2(4); A.W.F. Banfield. 1977. Les Mammiferes du Canada. Deuxieme ed. Publie pour Ie Musee national des Sciences naturelles Musees nationaux du Canada par Les Presses de l'Universite Laval. xxv + 406 pp. + 46 planches-couleur.

Underwater World factsheets are brief illustrated accounts of fisheries re­sources and marine phenomena pre­pared for public information and edu­cation. They describe the life history, geographic distribution, utilization and population status of fish, shellfish and other living marine resources, and/or the nature, origin and impact of marine processes and phenomena.

Underwater World

Others in this series:

Alewife American Eel American Plaice American Shad American Smelt Arctic Char Arctic Cod Atlantic Cod Atlantic Groundfish Atlantic Halibut Atlantic Herring Atlantic Mackerel Atlantic Pelagic and Diadromous Fish Atlantic Salmon Atlantic Shellfish Atlantic Snow Crab Bluefin Tuna Capelin Cetaceans of Canada Crabs of the Atlantic Coast of Canada Dungeness Crab Grey Seal in Eastern Canada Haddock Harbour Seal in Canada Harp Seal Hooded Seal Irish Moss Lake Trout Lingcod Lobster

Lumpfish Marine Fish Eggs and Larvae Northern Shrimp Oyster Pacific Herring Pacific Salmon Pollock Red Hake Red Sea Urchin Red Tides Redfish (Ocean Perch) Rockfish Roundnose Grenadier Sand Lance Sea Cucumber Sea Scallop Selected Freshwater Fish

27

Selected Shrimps of British Columbia Soft-Shell Clam Spiny Dogfish Squid Thorny and Smooth Skates Trout in Canada's Atlantic Provinces Turbot (Greenland Halibut) Walleye White Hake Winter Flounder Witch Flounder Yellowtail Flounder

Published by:

Communications Directorate Department of Fisheries & Oceans Ottawa, Ontario KIA OE6

DFO/S12 UW/S9

© Minister of Supply and Services Canada 1987 Catalogue Number Fs 41-33/59-1987E ISBN 0-662-15085-6

"Egalement disponibte en fram;:ais sous Ie titre: LES CETACtS DU CANADA."