RESOURCES FROM EARTH’S WATERS OCEANS, BAYS, LAKES,RIVERS PONDS, STREAMS ETC.
WORLD POPULATION
How Much of Our Food Supply Comes from Earth’s Water 1% of food comes from the sea Earth’s Waters Supply 10% of the protein consumed by humans
Kinds of Food From Earth’s Waters Finfish – make up 85% of world catch followed by shellfish (mollusk and crustaceans) Finfish come from - 86% ocean, 14% freshwater Shellfish- 15% mostly from the ocean
Kinds of Food From Earth’s Water cont’d Freshwater fisheris comprise 18% of the global catch, and it is growing! Seafood accounts for 15% of the total animal protein consumed worldwide!! (a very large number considering only1% of food comes from the sea/rivers/lakes.
Types of Fish and Shellfish Benthic and Demersal – live at or near the bottom of the sea in COLD Waters (ex. Flounder, lobsters, crabs, whiting) Clupeoid – live in schools near surface on continental shelf ex. Herrings (sardines), Menhaden, Shads Pelagic – Open water fish (ex. Squid, Tuna, Swordfish)
Benthic Fish KING CRAB Live at or near the bottom of the sea
COLD WATER DEMERSAL FISH Live near or around the bottom of the continental shelf Examples Cod, Pollack, haddock, hakes, whiting Caught in trawls
COD
WHITING
POLLACK
Benthic Fish Flounder Flat fish Eyes on one side Camouflage to match color of the sand
Benthic Fishing Techniques Caught with trawls-dragged along the bottom of the sea. TRAWLING
FISHING TECHNIQUES TRAWLING
Cod Fishery-Threatened!! 1992-Grand Banks placed moratorium (ended) the cod fishery to save them from extinction. 1994-Georges Bank fishery off New England closed their operations also. Experts predict the cod will NEVER recover!!!
CLUPEOID FISH SARDINES – travel in schools near the surface & along continental shelf
CONTINENTAL SHELF
CLUPEOID FISH Sardines, shad, herring, menhaden etc. Live in schools Found over continental shelf Caught using purse seines Eaten fresh, canned or pickled Ground into fish flour or Fish Protein Concentrate
Fishing Techniques Purse Seine Nets
FISHING TECHNIQUES PURSE SEINE
CLUPEOID FISH Used to produce fish oil Used to make fish meal for poultry feed Used to make fertilizer Industrial catches may result in overfishing because they naturally fluctuate in population and fisherman are unaware of their low cycles 1940’s sardine fishery collapsed
Purse Seine Catches
CLUPEOID FISH HERRINGS
CLUPEOID FISH MENHADEN
Sardines and Anchovies
PELAGIC FISH Open Water Fish Billfish (Striped marlin, Blue marlin, Black marlin Sailfish, Swordfish) Tuna (Yellowfin, Skipjack, Bonito) Jacks (Yellowtail, Amberjack) Dolphinfish (Dorado) Mako shark
Tuna
TUNA Skipjack, yellow fin, big eye, albacore, blue fin Eaten raw in sashami Caught in gill nets, large sienes and long lines Blue fin can sell for up to $350.00 a pound Tuna population is down 10% Fish nations would not declare it an endangered species, but in 1995 agreed to restrict catches to 50% of current catches
Fishing Techniques-Pelagic Fish Pelagic Fish are caught using large seines, surface longlines and gill nets.
COMMERCIAL FISHING IN THE PAST Early fishing methods
FISHING TECHNIQUES
FISHING TECHNIQUES LONG LINES-Pelagic Fish
LONG LINES-Pelagic Fish
FISH NET
GILL NET-Benthic/Demersal Fish
Marlin
SKIPJACK TUNA
Blue Fin Tuna
YELLOW FIN TUNA
YELLOWFIN TUNA
ALBACORE TUNA
SWORDFISH
MAKO SHARK
FINNING Many sharks Are caught and Killed ONLY For their fins!! Then thrown Back into the Water to drown/die at sea. Fins sold to China for Shark Fin Soup
HW-Textbook pages 355-377 Questions on Resources from the Sea Chapter.
Total Marine Catches from 1990 to 1995 (million tons) 1990 (million tons) 1995 Fishes 69.36 73.07 Mollusks 7.73 10.61 Crustaceans 4.50 5.65 TOTALS 97.97 112.91
MOLLUSK Second to finfish, mollusks are the most valuable food source Mollusks-Soft-body protected by a calcium carbonate shell. Largest catches include clams, scallops mussels, oysters, abalone, squid, and octopus
MOLLUSKS
Fishing for Mollusks Shellfish-clams, oysters, scallops are caught using a scallop dredge or traps sitting on the seafloor.
SCALLOP DREDGE
Pink Spiny Lobster
LOBSTERS, CRABS AND SHRIMP
CRUSTACEANS Crabs Lobster Shrimp Caught in traps and trawls that are dragged along the seafloor.
LOBSTER TRAP
LOBSTER IN TRAP Lobster and Crab Fishing Today
SEAWEED Varieties of freshwater and marine algae are popular as a food source in the far east Often used in sushi, sashimi, and soup
SEAWEEDS Seaweed is used in many cultures. It can be consumed raw, cooked, dried. Contains substantial amounts of protein
SEA URCHIN (UNI) Roe (eggs and organs that make the eggs) demands an incredibly high price in $$ Japan
Caviar Caviar is an expensive delicacy consisting of the unfertilized eggs (roe) of sturgeon brined with a salt solution .
STURGEON
SEA CUCUMBERS Called TREPANG OR BECHE-DE-MER are dried, smoked, or eaten raw in orient
JELLIES Jellies are dried and eaten in China
POLYCHEATE WORMS Eaten in South Pacific
Lab-Medicines from the Sea p.176
SEA TURTLES Sea Turtles and their eggs are eaten wherever found
SEALS AND WHALES Still eaten, particularly in Arctic, West Indies, and South Pacific
MINKE WHALES
BELUGA WHALES
NEW YORK STATES ENDANGERED FISH SPECIES Shortnose Sturgeon Silver Chub Pugnose Shiner Round Whitefish Bluebreast Darter Gilt Darter Spoonhead Sculpin Deepwater Sculpin
How Much Fishing is Too Much? Optimal Catch vs. Over-fishing Renewable Resources are composed of living organisms that can reproduce and replace individuals lost to disease and predators including humans. Nonrenewable resources would not be replaced naturally and would include oil and minerals.
Over-Fishing Catch them faster than they reproduce. A population of fishes are over-fished and the stock ( size of population) is reduced to a level which can still reproduce successfully, fisheries will cease to exist for a short time, then rebound.
Successful Reproduction Depends on a Proper Stocking Too many organisms lead to overcrowding, excessive competition, and depletion of food resources. Too few organisms produce too few young to maintain a proper self-sustaining stock. Fish do best when there are not too many and not too few. OPTIMAL *
MAXIMUM SUSTAINABLE YIELD The amount of fish that can be caught and just balance the growth of the population. Catch just enough fish to prevent population growth, but not enough to reduce the population.
Maximum Sustainable Yield Graph
PROBLEMS WITH MAINTAINING MAXIMUM SUSTAINABLE YIELD Fisheries strive to exceed maximal sustainable yield or optimal catch. Overfishing has already affected almost all commercial fisheries. Stocks of cod, haddock, herring, halibut, shark, and wild salmon are in danger. Fish stocks are damaged by pollution from oil spills, sewage, and toxic chemicals.
Problems Determining Maximum Sustainable Yield Not easy to determine Variation caused by catching fish when they are too young or catching them before or after breeding season may make all the difference. No exact science about regulating stocks of fish
Problems from the Past Sardines 1940-Pacific Sardine fishery collapsed due to heavy fishing that coincided with a low point in their reproductive cycle.
Problems of Today Bluefin Tuna Tunas-Northern bluefin tuna; one of the largest bony fish is very valuable. Their popluation is down to less than 10% of their former numbers in the Western Atlantic. Nations are slow to respond, refusing to list it as endangered. 1995-Agreed to reduce catch limits by 1/2
Problems of Today Swordfish Swordfish-Close to commercial extinction. Stocks fallen 70% since 1960. 88% of swordfish caught in 1995 were too young to reproduce!!!
Other Threats Pollution: Oil spills Sewage overflow Toxic Chemicals Fertilizer/pesticide runoff into oceans/lakes Habitat loss Destruction of breeding grounds
Possible Remedies Set fishing limits below what we think is the optimal catch Limit the length of fishing season Restricting the size or number of boats Regulating the size and the sex of fish caught Certain methods of fishing can be eliminated (ex. Trawls) or size of nets
MORE REMEDIES Control the areas of the sea to be fished Safe fish farming
Fishing and Life Many people are effected by the success or failure of fisheries Cannery Dock workers Boating and fishing gear industries Bankers Fisherman Local businesses
Regulations 1989 United Nations Convention on the Law of the Sea established a 200 nautical mile ( 1 nm = 1.15 miles) exclusive economic zone. (EEZ) Within this zone each country controls fishing, oil, and mineral resources.
New Fisheries Create a market to use “junk fish” or “Bycatch” such as Alaskan Pollack, Monkfish, Croakers, and Sea Robins will be consumed. They are presently used to make fish flour, fish sticks and enrich processed food.
Industrial Fisheries Catch is used for purposes other than human consumption (fish oil, margarine, paint, pet food, fertilizer) Industrial fisheries account for over 1/3 worlds total fish. Most clupeoid fish are used for FPC or fish flour.
Aquaculture Fish Farming Can reduce pressure on the oceans for protein It is the commercial breeding and raising of fish for human consumption. Chinese have farmed freshwater fish for thousands of years Romans have raised oysters Videos\Aquaculture safer method.asf
Fish Farm
Catfish Farming
Fish Farming Benefits Provide a plentiful inexpensive source of food specifically protein for a large population Easier and can be less expensive than catching wild fish May help prevent extinction of some species
Limitations and Problems with Fish Farming Only a small number of fish species can be farm raised Clupeoid fishes need open ocean spaces and would not survive on a farm Parasites and diseases are a concern Cannibalism Need expensive filters and pools free of pollution
Limitations and Problems of Fish Farming Use of artificial feed sources (ex. Chicken feed or Junk Fish) Concentration of Carcinogens (ex. PCP ) in some populations. Effect on local environment
Salmon Farming Hatch in freshwater habitats from 0-18months At 18months they are moved offshore into pens in the ocean. Stimulates normal lifecycle.
Salmon Farming-Problems Waste concentrates and builds up in surrounding water. Disease spread quickly and easily to other fish and fish that are not in the pen. Chemicals given to salmon (antibiotics) may affect humans. Farmed salmon have higher levels of PCB, toxic to humans!
Salmon Farming Problems Sea lice-parasites on fish
Video Clips Videos\Fish_Farms.asf Videos\Fish_Farming_.asf