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Published byLouise Newton Modified over 9 years ago
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Resources From the Sea1 Fisheries
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Resources From the Sea2 Food from the sea The animals that are harvested vary widely from culture to culture Polychaetes, and sea turtles Finfish constitute 84% of the total catch Most of the worlds food is grown on land Only 1% of the food eaten is from the sea Still marine resources are an important protein source Cheap source of protein in developing countries Japan eats 152 lb. per person and the US eats 42 lb.
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Resources From the Sea3 Fishing Efficiency We have become much more efficient in harvesting fish from the ocean putting a greater strain on the resources Through the use of satellites, larger fishing boats, factory ships many species are overexploited or exhausted Most fishing areas are found on the continental shelf and include both demersal and pelagic fisheries
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Resources From the Sea4 World Landings
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Resources From the Sea5 Landings The largest catches come from the clupeoid fishes Anchovies, menhaden and sardines These fishes travel in large schools and are captured by purse seines Used to produce fish protein concentrate (FPC) a protein supplement Most is made into fish meal for livestock or pressed into fish oil for cosmetics, margarine and paints
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Resources From the Sea6 Landings Cods, pollock, haddock, and hakes are an important fisheries (demersal) caught using trawls The cod fishery today is non existent on the Grand banks in the New England area Jacks and basses along with mackerels and flatfishes provide cheap protein Open water fisheries include several species of tuna eaten by more affluent countries raw
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Resources From the Sea7 Overfishing and Fisheries Management Fisheries are considered renewable resources, oil and gas are considered nonrenewable resources The first step in effective management is to understand the stock size Fish stocks grow fastest when there are neither too few nor too many individuals in a population If too small there are not enough potential parents, if too large competition and overcrowding slow down the growth rate
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Resources From the Sea8 Overfishing and Fisheries Management Sustainable yield = the number that can be harvested and still balance the growth of the population The highest catch that can be made without adversely affecting the population is called the maximum sustainable yield To be effective a fisheries manager must know the growth rate and the stock size Lastly, fishing effort must be actively regulated to allow for the maximum harvest
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Resources From the Sea9 Examples of Overexploitation Sardines on the west coast The Peruvian anchovy Northern Bluefin Tuna Less than 10% of their former numbers in the northern Atlantic Swordfish is close to commercial extinction In 1995 88% of the fish caught by the US fishing fleet were too young to have reproduced
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Resources From the Sea10 New Fisheries With all this pressure on traditional fisheries many new fisheries are being discovered Dolphinfish changed to mahi mahi, squid changed to calamari Surimi, changing unappealing fish through spices and preseratives into imitation crab, lobster, crabs, shrimp, and scallops The fish which is commonly used is Alaskan Pollock Yet to be exploited fisheries include lantern fishes, pelagic crabs and other cephalopods
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