RESOURCES FROMEARTH’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 TechniquesPurse 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 FISHOpen Water Fish

• Billfish (Striped marlin, Blue marlin, Black marlin Sailfish, Swordfish)

• Tuna (Yellowfin, Skipjack, Bonito)

• Jacks (Yellowtail, Amberjack)

• Dolphinfish (Dorado)

• Mako shark

Tuna

TUNASkipjack, yellow fin, big eye, albacore, blue fin

Eaten raw in sashamiCaught in gill nets, large sienes and long linesBlue fin can sell for up to $350.00 a poundTuna 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 FishPelagic Fish are caught using large seines,

surface longlines and gill nets.

COMMERCIAL FISHINGIN 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 355-377Questions on Resources from

the Sea Chapter.

Total Marine Catches from 1990 to 1995

Total Marine Catches

(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 STATESENDANGERED 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 PastSardines

• 1940-Pacific Sardine fishery collapsed due to heavy fishing that coincided with a low point in their reproductive cycle.

Problems of TodayBluefin 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 TodaySwordfish

• 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.

AquacultureFish 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