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Traditional food production and distribution practices are unable to feed the world’s 7+ billion people Will resources in the sea be able to provide enough food to alleviate future problems of malnutrition and starvation ?
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Most valuable living marine resources: Demersal fish (bottom dwellers) Pelagic fish (free-swimming mid/upper dwellers) Crustaceans Mollusks Marine mammals
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Location of the world’s major commercial fisheries upwelling coastal areas
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Non-Food Products from the Sea Bioactive Compounds (drugs and insecticides) Algin & Agar: products from seaweed use for promoting gel formation Whales: Oil for lubrication, in cosmetics, bones for fertilizer Seals and sea lions: furs
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Food from the Sea Seaweeds Invertebrates (e.g., oysters, clams, crabs, lobster, squid, etc.) Fish (herring, mackerel, haddock, cod, tuna, mahi-mahi, etc.) Whales – international moratorium imposed in 1987; no commercial whaling permitted since with limited exceptions
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Case Study: 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 and has NEVER recovered
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= El Niño 1957 1965 1972 1976 1982-83 Peru Anchovy Fishery
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Normal Year El Niño Year
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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 Case Study: Collapse of New England Fisheries
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Magnuson-Stevens Act of 1976 prevented foreigners from fishing in U.S. waters Fishery technology intensified and resulted in overfishing – yields well beyond sustainable levels Georges Bank closed indefinitely after collapse in ~1994 Some fish stocks have begun to rebound Collapse of New England Fisheries
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Fisheries Management Council The revised Magnuson Act in 2007 created 8 regional fisheries management councils. Overfished stocks as of 2010
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Fisheries Management Plans Congress directed the Councils to create Fisheries Management Plans or “FMPs” for each species Primarily concerned with balancing growth of stocks with commercial needs Established annual catch limits or acceptable biological catch Attempted to end overfishing and help stocks recover Major critics say that the fisheries are still about to crash and that the Councils are mismanaged and ineffective Heavily revised in 2010 to be community-based initiatives and saw increased prices with less but more responsible catches as a result in experimental areas
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Fishing Techniques
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Fishing Methods Longline – baited hooks (100’s to many thousands) along a long line; used for swordfish, tuna (pelagic); cod, halibut (bottom) Trolling – many lines with single hooks slowly dragged through the water; use for salmon, albacore, mahi-mahi
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Fishing Methods Drift (gill) netting – vertical nets hung in the water to trap passing fish highly controversial! banned by UN, US limits length to ~1.7 miles used to catch various pelagic fish
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Drift Net net size: 20 m x 65 km
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Fishing Methods Trawl – large “pouch” dragged through water/across bottom; used for anchovies (pelagic); cod, halibut (bottom) Purse seine – net is wrapped around a school of surfacing or near surfacing fish; used for sardines, herring, mackerel, tends to accidentally snare any predators like dolphins
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Trawl midwater bottom
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Before trawl After trawl
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Fishing Methods Traps and Pots - Crabs, lobster, rock fish Main problem with most methods is “bycatch” – nontarget species caught and usually killed
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Exclusive Economic Zone (EEZ) 1.200 nautical miles (230 land miles) 2.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
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Exclusive Economic Zone of the United States
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Mariculture or Aquaculture (marine agriculture)- farming finfish, shellfish and algae under favorable conditions Big Island, Kona, Tilapia
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Aquaculture also produces: Bait fish Ornamental or aquarium fish Aquatic animals used to augment natural populations Algae for chemical extraction Pearl oysters
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Criteria for selecting species for farming: -inexpensive to grow - grows quickly -high sales price -resistant to disease and parasites tilapia barramundicatfish
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Problems associated with Mariculture: Won’t make a dent in the shortfall in food supply Fish food- fish meal Pollution Escapees High stress overcrowding pens High concentration of pathogens/parasites
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Overcrowded Pens
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