traditional food production and distribution practices are unable to feed the world’s 6.3+ billion...
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http://www.pbs.org/emptyoceans/
• Traditional food production and distribution practices are unable to feed the world’s 6.3+ billion people
• Will resources in the sea be able to provide enough food to alleviate future problems of malnutrition and starvation ?
Most valuable living marine resources:• Demersal fish• Pelagic fish• Crustaceans• Mollusks• Marine mammals
Location of the world’s major commercial fisheries
upwellingcoastal areas
Commercial fishing:• 500 species regularly caught• Employs 200 million people worldwide• In 2002 the world fishing fleet numbered
about four million vessels. In 2005:• 100 million tons taken• $70 billion
Global Fish Catch
World Commercial Catch of Marine Fishes, Crustaceans, and Mollusks (1995) cod
Species Group Millions of Metric Tons, Live Wt.Herrings, sardines, anchovies 22.0Jacks, mullets, sauries 11.2Mollusks 11.0Cods, hake, haddock 10.6 Redfish, basses, conger eels 7.0Crustaceans 4.8Tunas, bonitos, billfish 4.7Mackerel, snooks, cutlass fishes 4.7Flounders, halibut, soles 0.9Miscellaneous marine fishes 17.7Total (excluding marine mammals) 94.6
Non-Food Products from the Sea
• Bioactive Compounds
• Algin & Agar: products from seaweed
• Whales: Oil for lubrication, in cosmetics, bones for fertilizer
• Seals and sea lions: furs
Food from the Sea
• Seaweeds
• Invertebrates (e.g., oysters, clams, crabs, lobster, squid, etc.)
• Fish (herring, mackerel, haddock, cod, tuna, mahi-mahi, etc.)
• Whales
Fisheries management• Fisheries management
seeks to maintain a long-term fishery by: – Assessing ecosystem health– Determining fish stocks– Analyzing fishing practices– Enforcing catch limits
• Fisheries management does not regulate the number of fishing vessels
Fisheries Mismanagement
Fisheries mismanagement• Overfishing• Commercial extinction• Bycatch (27 million metric tons annually)• Targeting smaller species on the low end of
the food chain
Bycatch by Gear Type for 2002/2003
Euphausia superba
Who eats Krill?
Krill & the Antarctic Food WebCritical components of Antarctic food webs
Krill Fishery• Annual consumption by natural predators =
470 million MT• 1972: Japan and Russia began harvesting
krill
Krill Fishery…Krill Fishery…
• Potential harvest = 25-30 million MT/yr
• Economic cost of fishery high• Patchy distribution complicates
location• Depths may be 150-200m• Single net haul may collect 10 MT• Ecological consequences of
removal poorly understood
Peru Anchovy Fishery
Peru Anchovy Fishery
• Upwelling zone off Peru
• Fishery began 1950
• Greatest fish catches for any single species
• Fish exported for domestic animal feed
• Fishery collapsed due to El Niño and overfishing
= El Niño19571965197219761982-83
Peru Anchovy Fishery
Peru Anchovy Fishery
Normal Year
El Niño Year
Collapse of New England Fisheries
• Cod, haddock, ocean perch, herring, mackerel, blue fin tuna
• George’s Bank- highly productive, nutrient rich environment
• Prior to 1976, Russia, Japan, Norway, & West Germany fished in Georges Bank
Collapse of New England Fisheries
Magnuson Act passed & prevented foreigners from fishing in U.S. waters
Fishery technology intensified and resulted in overfishing
Harvests were beyond the max. sustainable yield
Georges Bank closes after collapseSome fish stocks begin to rebound
Fisheries Management Council
The Magnuson Act created 8 regional fisheries management councils for U.S. waters and regions:
North Pacific FMC
(Anchorage, AK)
Pacific FMC
(Portland, OR)
Western Pacific FMC
(Honolulu, HI)
New England FMC
(Saugus, MA)
Mid-Atlantic FMC
(Dover, DE)
South Atlantic
(Charleston, SC)
Gulf of Mexico FMC
(Tampa, FL)
Caribbean
(San Juan, PR)
Fisheries Management Plans
Congress directed the Councils to manage federal fisheries by creating
Fisheries Management Plans or “FMPs” by:
1. Identifying fish species that need management
2. Analyzing the biological, environmental, economic and social factors that affect the fishery
3. Preparing (and modifying, as necessary) an FMP to protect fishery resources while maintaining opportunities for domestic commercial and recreational fishing
Salmon• Anadromous fish that
migrate from sw to fw to spawn
• Spawning grounds affected by dam construction
• Aquaculture and restocking efforts
Fish Ladders
Alaska Fisheries
• Halibut and sablefish • IFQ• Limited entry c1930’s
Shark Overfishing
• Slow growth• Low reproductive rate• Late sexual maturity
Orange Roughy
• Distribution: world wide, high concentrations in New Zealand
• Found: 700-1000m depth• Life span: slow-growing, long-lived, ~150 years• Size: 30-40 cm• Diet: prawns, fish, & squid• Reproductive age: 25-30 years old
Fishing Techniques
Fishing Methods • Harpoon - whales, swordfish, bluefin tuna • Pole and line - mahi-mahi and used for tuna
extensively in the 50‘s • Longline - swordfish, tuna (pelagic); cod,
halibut (bottom) • Trolling - salmon, albacore, mahi-mahi • Drift (gill) netting - various pelagic fish • Trawl - anchovies (pelagic); cod, halibut
(bottom) • Purse seine - sardines, herring, mackerel • Traps and Pots - Crabs, lobster, rock fish
Drift Net
net size: 20 m x 65 km
Longlining
Gill net
Bottom-dwelling fish
Purse seine
Trawl
midwater
bottom
http://www.youtube.com/watch?v=bUHcD_jTgVA
Before trawl
After trawl
Trawl from space
Gulf of Mexico, near Louisiana coast. Individual vessels can be seen as bright spots at end of sediment trails. Other bright spots are fixed oil and gas production platforms. One sediment trail can be traced for 27 km. Assuming a standard trawling speed of 2.5 knots, sediment from this trawl is visibly persistent for nearly 6 hours. Water depth <20m. Large, indistinct bright blue patches at lower left and upper right are cloud/haze. (Credit: Landsat)
Exclusive Economic Zone (EEZ)1. 200 nautical miles2. under direct control of the country that owns the
nearest land
Allow nations to claim jurisdiction over their territorial seas (contiguous sea beds and their waters that extend off shore by 12 nautical miles)
Regulates continental shelf resources:• Fishing• Mineral exploration• Scientific research
Exclusive Economic Zone of the United States
Fisheries Problems & Solutions A. Maximum sustainable yield: maximum amount of
fish that can be harvested without depleting future stocks
B. World‘s maximum sustainable yield estimated at 100 to 135 million metric tons
C. Present harvests are at about 100 million metric tons
D. For fisheries where numbers available, estimated that 45% are currently over-fished
E. A number of fisheries have already collapsed (Anchovy fishery off Peru, Cod fishery in the N. Atlantic)
Fisheries Problems & Solutions F. Bycatch (or bykill): animals unintentionally killed during
harvest of the target species Trawling: Bycatch in shrimp trawling is very high (125 to 830% of the catch is discarded as bycatch), turtles often caught in trawls. SOLUTION: trawls with trap doors to let turtles escape
Dolphins caught in tuna net
Purse seine: Tuna known to hang out under pods of dolphins, nets set around pods of dolphins would result in many drowning.
SOLUTIONS: Nets not set around dolphin pods and/or employ — “backing down”, a technique that lowers upper edge of net letting dolphins escape
Fisheries Problems & Solutions
Driftnets: indiscriminate entangling of many sorts of marine animals SOLUTION: banned in oceanic fisheries (but some countries still using them)
Fisheries Problems & Solutions Long lining: Many albatross drown trying to snatch bait from long lines being deployed. snagged on hooks and pulled under. SOLUTION: deploy in the dark or with special rig to let line out under water.
Global swordfish catch
http://www.pifsc.noaa.gov/wpacfin/hi/dar/Pages/hi_fish_2.php
0
50
100
150
200
250
300
350
400
450
1817 1861 1900 1961
N. AtlanticSwordfish
Ave
. w
t. in
lbs
year
Mariculture or Aquaculture (marine agriculture)- farming finfish, shellfish and algae under favorable conditions
Big Island, Kona, Tilapia
One of every four fish eaten today was raised in either a fw or sw fish farm.
84% of the 6 million to 7 million tons of seafood consumed each year in the U.S. is imported . About ½ comes from aquaculture. H. Jones, Time, 2011.
Aquaculture also produces:• Bait fish• Ornamental or aquarium fish• Aquatic animals used to
augment natural populations• Algae for chemical extraction• Pearl oysters
• 2000 years ago in Egypt, Rome, China• <2000 years in Hawaii• 600 years ago France developed mussel
aquaculture• 500 years ago Europe developed the idea of
using pond fertilizer to promote plankton growth
• 400 years ago China discovered that oysters would grow on bamboo stakes
• 1960’s- Europe and U.S. catfish and salmon
History:
TheAhupua‘a
TheAhupua‘a
Molokai: South Coast• The pond’s walls were made from lava
boulders and coral.• Walls keep the fish inside while allowing the
sea water to ebb in and out.
Types of fish raised in ponds:
• ulua (papio)
• owama (goatfish)
• kahala (amberjack)
• manini (convict tang)
• palani (surgeon)
• oio (bonefish)
• uhu (parrotfish)
These fish were kept in a separate pond to breed and raised so they could easily be harvested by hand.
Criteria for selecting species for farming:
- inexpensive to grow
- grows quickly
- high sales price
- resistant to disease and parasites
tilapia barramundi catfish
Problems associated with Mariculture:
• Won’t make a dent in the shortfall in food supply
• Fish food- fish meal • Pollution • Escapees• Loss of natural habitat• Loss of genetic diversity• High stress overcrowding pens• High concentration of
pathogens/parasites
Overcrowded Pens
Salmon with lice
Parasites & Disease
Pollution Under a salmon farm cage
Fish Vaccination
Integrated Aquaculture
Aquaponics
Hawaii open ocean aquaculture
Mio, big eye tuna, yellow tail
$34.7 million in 2008
Artificial ReefsImprove the local marine bio-density
1. attract schools of fish 2. providing habitats for the colonization
of commercially valuable species3. improve the local inshore marine
harvest
May wash up on beaches
tires ship wrecks construction rubble
T
T
T
T
Papahānaumokuākea Marine National Monument
http://www.mbayaq.org/cr/cr_seafoodwatch/download.asp
HawaiiSeafood Guide
2007
Barramundi (U.S. farmed)Clams (farmed)Crab, dungenessHalibut (Pacific)Salmon(wild)Swordfish (Hawaii)Tilapia (farmed)Skip-jack tuna (troll/poll, handline)
HawaiiSeafood Guide
2007
Chilean SeabassCod, AtlanticMahi mahi (imported longline)Salmon (farmed)SharksShrimp (imported)Swordfish (imported)Orange roughyTuna, Albacore (worldwide except Hawaii)Tuna Bige Eye (longline)Tuna bluefin
Catfish (farmed imported)Crab, KonaGroupers (NWHI)Lobster (American/Maine)Octopus (Hawaii)SquidTrevally/Jack (Hawaii)Tuna, cannedTuna, Skipjack (Hawaii longline)
Inquiry
1. What problems are associated with aquaculture?
2. What does fisheries sustainability mean?
3. What occurred shortly after the Magnuson Act was passed?
4. Define the EEZ.5. What contributed to the demise of the
Peru anchovy fishery?6. Discuss technology changes in the
fishing industry in the last 100 years.