intertidal communities part of chapters: 2, 4, 5, 11, 13, 20

INTERTIDAL COMMUNITIES

Part of Chapters:2, 4, 5, 11, 13, 20

Study of Ecology Environment: All of the living and non-

living factors of an area. biotic factors: living factors (animals, plants,

fungi, ect) abiotic factors: non-living factors (wind,

temp, currents, salinity, ect) Habitat: a place where an organism lives Niche: the role an organism plays in their

environment. No two species can have the exact same niche.

Populations and Communities Population : A group of the same species

in a specified area.

Community : Many different populations in a specified area.

Populations and Communities

Population growth there are many ways in which a population

can increase in size Birth and immigration

exponential growth: drastic growth in a short period of time.

carrying capacity: the amount of organisms a specific area can support without running out or degrading resources.


Distribution of marine communities pelagic division: all the water in the oceans

neritic zone: water above the continental shelf. pelagic zone (oceanic zone): all the water pass

the neritic zone (covers the deep areas) photic zone: where sunlight can penetrate and

support photosynthesis disphotic zone: minimal sunlight can reach. Not

enough for photosynthesis aphotic zone: no sunlight

Plankton: organisms that drift with currents Nekton: organisms that can swim against

currents


Benthic division: The ground below the water in the oceans

Shelf zone: area that extends from high tide line to the continental slope

Bathyal zone: Below the shelf zone Abyssal zone: Below the Bathyal zone (the deep)

Hadal zone: Below the Abyssal zone. Deepest areas in the oceans. Usually found in trenches.

Epifauna: Organisms that live on the sea bottom

Infauna: Organism that live in the sediment of the sea bottom

Characteristics of the Intertidal Zone Daily fluctuations of the environment

organisms must tolerate radical changes in temperature, salinity and moisture, and endure the crushing force of waves

Inhabitants are most active during high tide, when area is submerged water provides food for filter feeders

As the tide retreats, organisms adjust to exposure to air and sunlight

Environmental Factors Affect Organism Distribution

Maintaining homeostasis (internal balance) Affected by changes in external environment internal adjustments made to maintain a

stable internal environment homeostasis and the distribution of marine

organisms Optimal range:

Zone of stress:

Zones of intolerance:

Environmental Factors Affect Organism Distribution Physical environment

sunlight Photosynthesis Vision Desiccation

temperature Ectotherms:

Endotherms:


Salinity: Solutes:

Osmosis:

Isotonic:

Hypertonic:

Hypotonic:


metabolic requirements nutrients and limiting nutrients oxygen as a requirement for metabolism anaerobic and aerobic organisms Eutrophication:

metabolic wastes carbon dioxide is a common byproduct of

metabolism

Environmental Factors Affect Organism Distribution Biological environment

Competition interspecific: intraspecific: competitive exclusion: resource partitioning:

predator-prey relationships balance of abundance of prey vs. predators keystone predators:

Tides

Why tides occur tides result from the gravitational pull of

the moon and the sun though smaller, the moon is closer to earth,

so its gravitational pull is greater water moves toward the moon, forming a

bulge at the point directly under it the centrifugal force opposite the moon

forms another bulge areas of low water form between bulges

Tides

Spring and neap tides during spring tides, the times of highest

and lowest tides, the earth, moon and sun are in a line, combining the pull of the sun and moon

when the sun and moon are at right angles, the sun’s pull offsets the moon’s, resulting in neap tides, which have the smallest change between high and low tide

Tides

Types of Tides: Diurnal:

Semidiurnal:

mixed semidiurnal:

Tidal range:

Waves

Wave formation Wave:

Generating force:

most common = wind also geological events, falling objects, ships

Restoring force:

Waves

deepwater and shallow-water waves deepwater waves:

breakers deepwater waves become shallow-water waves

when they move into shallow water surf zone:

breakers form when the wave’s bottom slows but its crest continues at a faster speed

plungers form when the beach slope is steep spillers are found on flatter beaches

Waves

tsunamis seismic sea waves are formed by earthquakes tsunamis have long wavelengths, long periods

and low height compression of the wave’s energy into a

smaller volume upon approaching a coast or island causes a dramatic increase in height

Intertidal Zonation

Zonation—separation of organisms into prominent horizontal bands defined by color or distribution of organisms

As tide retreats... upper regions exposed to air, changing

temperatures, solar radiation, dissication lower regions exposed only a short time

before tide returns to cover them

Intertidal Zonation

Supralittoral (maritime) zone:

Supralittoral fringe (splash zone):

Intetidal Zonation

Zone system (continued) Midlittoral zone:

Infralittoral fringe:

Subtidal (infralittoral) zone:

Intertidal Fishes

Resident species typically have special adaptations for

surviving harsh intertidal conditions small size; absent, reduced or firmly attached

scales; compressed/elongate or depressed body shape; absent or reduced swim bladder; greater body density

tolerant of temperature and salinity changes some intertidal fish can leave the water to feed

Temporary inhabitants tidal, seasonal and accidental visitors

Rocky Shores and Sandy Shores

Rocky shores are found on the west coast from Alaska south and on the east coast cape cod north. Have all 5 intertidal zones. Organisms attach to

rocky surfaces and create a visiable zoning.

Sandy Shores are found mainly on the east coast, cape cod south and along gulf coast. Only have 3 zones (Supralittoral zone, Midlittoral,

Infralittoral zone). Does not show zonation because most organisms are found in the sand.

Role of Waves and Sediments Sediment particle size influences the

beach’s nature, porosity of sediments, ability of animals to burrow

Wave action influences sediment type: heavy wave action = coarse sediments little wave action = fine sediments

Beach slope results from interaction of waves, sediment particle size, and relationship of swash and backwash

Role of Waves and Sediments

Swash:

Backwash:

Types of beaches: dissipative beach:

usually flat with fine sediment reflective beach:

usually steep with course sediment

Role of Waves and Sediments On all sandy beaches, a cushion of water

separates the grains of sand below a certain depth especially true on beaches with fine sand

where capillary action is greatest Fine sand beaches have a greater

abundance of organisms greater water retention sediment is more suitable for burrowing

Meiofauna

Meiofauna: Characteristics of the meiofauna

invertebrates from many phyla generally elongated with few lateral projections many are armored to protect them from being

crushed by moving sand grains include predators, herbivores, suspension feeders

and detrivores

Linnaeus and Biological Classification Binomial system of naming

binomial nomenclature:

introduced by Swedish botanist Karl von Linné (Carolus Linnaeus) in 1750

e.g. Chaetodon longirostris (long-nose butterflyfish) and Chaetodon ocellata (spotfin butterflyfish) are both in the same genus

Linnaeus and Biological Classification Taxonomic categories

Early schemes of classification all living things were classified into 1 of 2

kingdoms, Animalia and Plantae, until 1960s Modern classification

major categories: domain, kingdom, phylum, class, order, family, genus, and species

Domains: Archaea, Eubacteria, Eukarya Kingdoms: Eukarya contains 4 kingdoms, Fungi,

Plantae and Animalia, Protista protists—eukaryotic organisms that do not fit

the definition of animal, plant or fungus

Marine Reptiles

Reptiles adapted for success on land, then used the same characteristics to return to the sea and gain success there as well

Modern-day reptiles include: crocodilians turtles lizards snakes

Amniotic Egg

An amniotic egg is covered by a protective shell and contains: Amnion: yolk sac: Allantois: Chorion:

Copulatory organs allow efficient internal fertilization

Physiological Adaptations

Advanced circulatory system in which circulation through the lungs is nearly completely separate from circulation through the rest of the body more efficient method of supplying oxygen

Kidneys are efficient in eliminating wastes while conserving water

Skin covered with scales and lacking glands decreases water loss

Marine Crocodiles

Best adapted to the marine environment is the Asian saltwater crocodile (Crocodylus porosus)

Large animals (up to 6 m long) Feed mainly on fishes Drink salt water and eliminate excess

salt through salt glands on their tongues Lives along the shore, where it nests

Sea Turtles

Adaptations to life at sea protective shells that are fused to the

skeleton and fill in the spaces between the vertebrae and ribs protect their bodies outer layer of shell composed of keratin inner layer composed of bone Carapace:

Plastron:

leatherback turtle lacks shell and has a thick hide containing small bony plates

Sea Turtles

Adaptations to life at sea (continued) shell is flattened, streamlined,d reduced in

size and weight, for buoyancy/swimming large fatty deposits beneath the skin and

light, spongy bones add buoyancy front limbs are modified into large flippers back limbs are paddle shaped and used for

steering and digging nests

Sea Turtles

Behavior generally solitary, don’t interact remain submerged while at sea; breathe air

but can stay under water for as long as 3 hours

alternate between feeding and resting during the day

sleep on the bottom under rocks or coral

Sea Turtles

Feeding and nutrition have a beak-like structure instead of teeth green sea turtle is the only herbivore leatherback sea turtles eat jellyfish

pharynx is lined with sharp spines to hold slippery prey

digestive system adapted to withstand stings large amounts of salt consumed with food

and water are eliminated as concentrated tears through salt glands above the eyes

Sea Turtles

Reproduction courtship – males court females before

mating; males may compete for a female, or 1 female may mate with several males

nesting – females dig shallow pits on the beach, usually at night, and bury eggs

development and hatching temperature determines development time and

sex ratio hatchlings rush for the safety of the sea after

hatching

Sea Turtles

Turtle migrations females migrate from feeding grounds to

the beaches where they were born to nest green sea turtles feed on grasses in warm,

shallow continental waters, but breed on remote islands some breed on a 2- or 3-year cycle

method for navigation over long distances is unknown

Sea Turtles

Sea turtles in danger beach erosion artificial lighting near nesting beaches sea turtles are killed when trapped in

fishing nests, especially those used for shrimpers turtle exclusion devices can reduce turtle

mortality by as much as 95% when used for shrimp nets

turtles are hunted by humans for meat, eggs, leather and shells

Marine Iguana

The marine iguana of the Galápagos Islands off Ecuador is the only marine lizard

Most are black, but some are mottled red and black dark coloration is thought to allow more

absorption of heat energy raising body temperature allows them to

swim and feed in cold Pacific waters

Marine Iguana

Feeding and nutrition herbivores with a short, heavy snout for

grazing on dense mats of seaweed swallow small stones to reduce buoyancy

for feeding under water excess salt from consumed seawater is

extracted and excreted by specialized tear and nasal glands

Marine Iguana

Behaviors good swimmers, using lateral undulations

of the body and tail each male occupies a small territory on the

rocks, usually with 1 or 2 females intruders or challengers are attacked when

they enter the male’s territory fights between male iguanas rarely result in

serious injury

Sea Snakes

Adaptations to life in the sea scales are absent or greatly reduced for

streamlining tail is laterally compressed into a paddle nostrils are higher on the head

valves in the nostrils prevent water from entering when the snake is submerged

single lung reaches to the tail, and trachea is modified to act as an accessory lung by absorbing oxygen

Sea Snakes

Adaptations to life in the sea (cont.) can exchange gases through the skin while

under water can lower metabolic rate to use less O2

Feeding and nutrition eat mainly fish and eels, sometimes eggs most ambush prey and strike with

venomous fangs can swallow prey more than twice their

diameter

Sea Snakes

Sea snakes and humans sea snake venom is toxic to humans being timid, sea snakes rarely bite humans;

people eat them in Japan

Seabirds

250 of 8,500 bird species are adapted to live near or in the sea

Seabirds feed in the sea Some spend months away from land, but

all must return to land to breed Types of seabirds:

shorebirds gulls and their relatives pelicans and their relatives tubenoses penguins

Adaptations for Flight

Homeothermic:

Feathers aid in flight and insulate High rate of metabolism to supply

energy for active flight/nervous system Strong muscles, quick responses, great

deal of coordination Advanced respiratory system with 4-

chambered heart Keen senses

Adapting to Life in the Sea

Large amounts of salt are consumed with food and salt water salt glands above the eyes produce tears to

remove excess salt these tears have twice the salt

concentration of seawater

Shorebirds

Waders with long legs and thin, sharp bills used to feed on intertidal organisms

Oystercatchers, curlews & turnstones oystercatchers use long, blunt, vertically-

flattened orange bills to slice through adductor muscles of bivalve molluscs

long-billed curlew uses its bill like a forceps to extract shellfish from burrows

Shorebirds

heavyset turnstones use slightly upturned bills as crowbars to turn over stones, sticks and beach debris in search of food

Shorebirds

Avocets, stilts, and sandpipers avocets and stilts have very long legs,

elongated necks, and slender bodies avocets wade through shallow water,

moving a partially opened beak from side to side through the water, to feed

stilts probe the mud for small animals (e.g. insects, crustaceans) with their bills

sociable sandpipers feed on small crustaceans and molluscs as the surf retreats

Shorebirds

Herons (e.g. egrets and bitterns) most stand still and wait for prey to come in

range to feed some stalk prey or stir up the bottom to

frighten prey into motion so it can be caught

Gulls and their Relatives

Gulls have webbed feet and oil glands to waterproof their feathers

They are not true ocean-going birds, and do not stray far from land

Have enormous appetites Are not very selective feeders Relatives of gulls include terns, skuas,

jaeger birds, skimmers and alcids


Gulls herring gulls are the most widespread, and

are vocal, gray and white, and travel in large groups

feeding noisy, aggressive, efficient predators and

scavengers may drop prey with hard shells on rocks or

parking lots to break the shell open highly successful at finding food and surviving


Gulls (continued) nesting

highly gregarious; gather in large colonies not picky about nesting sites or materials both sexes assist in incubating 2-3 eggs chicks hatch in 3-4 weeks, and remain in the

nest until almost fully grown, camouflaged by speckled down

chicks are vulnerable to predation by other animals and by other gulls


Terns small, graceful birds with brightly-colored and

delicately-sculpted bills, forked tails hunt by plunging into the water for fish and

invertebrates; will steal food usually gregarious nesters

Skuas and jaegers very aggressive omnivores and predators “hawks” or “vultures” of the sea jaegers will pursue other birds to steal their prey


Skimmers (scissorbills) small birds with pupils that are vertical slits

and a flexible lower jaw protruding much farther than the upper bill

fly over water and use the lower bill to create ripples at the water’s surface that attract fish

fish are then collected by flying along the same path over the water a second time


Alcids (e.g. auks, puffins, murres) look like penguins but are related to gulls

convergent evolution:

ecological equivalents:

major difference is that alcids can fly

Pelicans and their Relatives

E.g., gannets, boobies, cormorants, darters, frigatebirds, tropicbirds

Have webs between all 4 toes Upper mandible is hooked in pelicans,

cormorants and frigatebirds Many are brightly colored, or have head

adornments


Pelicans large birds preferring warm latitudes and

estuary, coastal and inland waters require a large fish population to support

colonies of large birds feed just under the water’s surface using

gular pouches as nets gular pouch—a sac of skin that hangs between

the flexible bones of the bird’s lower mandible


Boobies dive into the sea from 18-30 m up to fish species lay differing numbers of eggs; this

is thought to reflect the reliability of the food supply around where they nest

Cormorants swim along the surface scanning for fish,

then plunge deep to pursue them lacking oil glands, they must periodically

dry their wings in order to fly


Cormorants (continued) most are strong fliers, but the Galápagos

Island species is flightless guano cormorant of the coast of Peru

valued for its guano (bird manure) Frigatebirds

lightweight body and near 2 m wingspan lacking oil glands, they feed by skimming

with their bills pursue/attack other birds to steal prey

Tubenoses

E.g. petrels, albatrosses, shearwaters Have obvious tubular nostrils on their

beaks which join with large nasal cavities within the head

Nasal glands secrete concentrated salt solution

Stomachs contain a large gland that produces a yellow oil composed of liquefied fat and vitamin A, used for feeding hatchlings and defense

Tubenoses

Albatrosses gliders with wings nearly 3.5 m long most live in the Southern Hemisphere

where winds circle the earth without encountering land

usually come to land only to breed courtship displays precede mating 1 egg is incubated by both parents on a

volcano-shaped nest, and the young are fed on stomach oil, then regurgitated fish

Penguins

Bird most adapted to marine lifestyle Awkward on land, but swift swimmers

flap their wings to swim torpedo-shaped bodies are streamlined flat, webbed feet are used for steering leap from the water to breathe

Eat fishes, squid and krill Eaten by leopard seals and killer whales

Penguins

Reproduction in Antarctic species adelie penguins lay eggs in summer;

emperor penguins in mid-winter female emperor penguin lays 1 egg, which

the male incubates for 2 months while she visits her feeding grounds egg sits on his feet, covered by a fold of skin male can feed the chick a secretion from his

crop if it hatches before female’s return crop—a digestive organ that stores food before

it is processed

Penguins

female returns with food in her crop for the chick, and male can feed

both parents help to feed the chick once it reaches 6 weeks

by summer, the chick can feed itself, and is ready to enter the sea

intertidal communities part of chapters: 2, 4, 5, 11, 13, 20

Documents

shelf zone abyssal zone

zone of stress

deephadal zone

oceansshelf zone

oceansneritic zone

pelagic zone oceanic

continental slopebathyal

photosynthesis aphotic