Resources from the Sea Shipley Marine Biology Summit High School

  Food  Products  Materials  Recreation Marine Resources are Utilized For:

  What types of organisms are harvested?  Finfish (about 90% of worldwide harvest)  Shellfish  Other species such as jellyfish, sea cucumbers, polychaetes and seaweed  While seafood represents only about 1% of the food consumed each year, it represents about 30% of total animal protein consumed Food From the Sea



  1950’s to present- there was a five-fold increase in fishing effort  1980’s to present- worldwide catches relatively constant despite the increased fishing effort  Many of world’s most important catches are overexploited or exhausted (especially in the Atlantic, Pacific and Mediterranean) The Fisheries Industry

 Worldwide Commercial Catches

 Worldwide Marine Catch and Mariculture

  Most located near coast over continental shelf  Easier to catch demersal species  High primary production in these areas means more species are present  Ex: Grand Banks of Newfoundland, North Sea and Bering Sea Major Fishing Areas



 Examples of Commercially Important Fishes Around the World

  Clupeoid fishes  Sardines, menhaden, shad and herrings  How they are used:  Eaten directly  Fish flour (powder used as a dietary supplement  Fish meal (ground fish used as protein supplement for poultry, livestock and aquaculture  Fish oil (used in manufacture of margarine, cosmetics, paints, omega-3 fatty acids Major Food Species

  Cods, haddock, hakes, pollock, whiting  Demersal, cold water species  Has been harvested for centuries  Sold fresh and frozen  Vital source of inexpensive protein in many parts of the world Major Food Species

  Fishery peaked in the 1960’s then began to decline  Moratorium declared in 1992 to attempt to save the fishery  Closure caused high unemployment in American and Canadian fishermen  The fishery may never recover  The cod is listed as endangered in that area even today Cod Fishery of the Grand Banks

  Jacks, Mullets, Rockfishes and Mackerels  Important in worldwide tonnage  Cheap protein in some parts of the world  In the United States, flounders and other flatfish are important  Salmon also remain important catch Major Food Species

  Tuna  Caught in open water  These fish command high prices  They are caught on long lines or in gillnets  Fishing boats are equipped with freezers so they can stay at sea longer Major Food Species

 280 lb Bigeye tuna

 120 lb. Swordfish

 Wahoo

 This is a Cobia

 Golden Tile Fish

  Molluscs  Second most valuable catch after finfish  Squids, cuttlefish, and octopus are particularly important in the Far East  Clams, oysters, mussels, scallops and abalones are important worldwide Major Food Species

  Crustaceans  Prized worldwide  Command high prices  Shrimp, lobster, crab Major Food Species

  These species contribute little to the worldwide catch  Sea weeds, jellyfish and sea urchins harvested in Far East, especially Japan  Gooseneck barnacles are harvested in Spain  Polychaete worms are harvested in South Pacific  Sea turtles and their eggs are harvested and eaten even where they are protected by law  Seals and whales are still eaten in some cultures despite laws to protect them Other Harvested Marine Life

  Sea-life species are renewable resources  However, for a fishery to last long-term, it must be fished in a sustainable way  The sustainable yield is the amount that can be caught and just maintain a constant population size  Maximum sustainable yield is the highest catch that can be maintained year after year without affecting the stock Optimal Yield and Overfishing

  If catches fall despite increased fishing effort, overfishing has occurred  Market forces often cause this to happen  If other fishermen are making money, other fishermen will be attracted to the fishery and cause overfishing to occur Exceeding Maximum Sustainable Yield

  It is estimated that about 70% of marine fishes are overfished  This is especially true for large species like tuna, swordfish and sharks  In many of these species, the fish that are harvested today are about half the size of those harvested 20 years ago  Ex: Bigeye tuna were two times as heavy and eight times more abundant in 1950’s than they are today Exceeding Maximum Sustainable Yield

  Swordfish  Catches of these fish fell 70% between the 1960’s and the late 1990’s  A campaign to reduce consumption of these fish was successful  Numbers of the fish are recovering Exceeding Maximum Sustainable Yield

  Habitat destruction  Critical breeding grounds like seagrass beds, estuaries and mangroves are destroyed each year  This is especially detrimental since 75% of commercially important species use estuarine areas as nursery areas  Trawls used in fisheries also damage the ocean floor which is detrimental to demersal species Other Dangers to Fisheries

  A fishery is regarded as collapsed if numbers fall to 10% of historic highs  It is estimated that one-third of fisheries are already collapsed  A 2006 study indicates that all major fisheries will collapse by 2050 if protective measure are not taken to better manage and protect these resources Collapse of a Fishery

  Management can be difficult for many reasons:  Maximum sustainable yield is difficult to calculate  Harvested species may compete with other species and fishing pressure may affect competitive balance  Real fisheries are more complex than models  High seas are “common property” Managing the Resources

  Limiting total catch and closing the fishery when the catch is reached  Limiting length of fishing season  Limiting areas open for fishing (to include marine reserves)  Limiting number of boats permitted to fish  Limiting gear size or gear type  Limiting size of fish caught  Limiting catches per boat  Limiting fishing methods Ways to Manage a Fishery

  Passed in 1996  Requires federal fisheries managers to develop plans to avoid overfishing, restore depleted stocks and reduce by-catch (species caught incidentally while fishing for a target species)  US fishermen must abide by rules as well as foreign fishermen with valid permits  In 2003, the Pews Ocean Commission calls for management of ecosystems as well United States- Sustainable Fisheries Act

  New fisheries may be available by increasing the use of by-catch  However, consumer tastes are fickle and these species may not be appealing to consumers  Some species may be able to be used in the manufacture of imitation crab (as pollocks are currently)  Other untapped potential fisheries – squid, flying fish and lanternfish New Fisheries

  Aquaculture is the application of farming techniques to the growth and harvesting of aquatic organisms  The term mariculture applies specifically to marine organisms  The column of marine organisms produced through mariculture has risen three-fold since 1990  As an example, farmed fish account for 25% of shrimp consumed each year  Other “farmed” species include milkfish, molluscs, seaweed, salmon and Pacific threadfish Mariculture and Aquaculture



 Commercial Mariculture Species

  Disease and parasites can be high due to many organisms in close proximity  Different food requirements may be present at different life stages  Species that require open water cannot be raised this way  Maintaining water quality may be difficult  If farmed species escape, they may breed with wild stocks and dilute genome of wild population  Pollution from farm ponds can leak into nearby waters  In some areas of the world, mangroves and other estuarine communities are destroyed to create farm ponds Problems Associated with Aquaculture/Mariculture

  Other items harvested for reasons other than direct consumption:  Mangroves – for timber and charcoal  Pearls, shells, coral and sea turtle shells for jewelry  Some species harvested for their chemical compounds that are used as “marine natural products” Marine Life as Items of Commerce and Recreation

  Amateur anglers – in general, marine resources caught by recreational anglers is only about 30% of the amount caught by commercial fishermen  However, for some species, the number of individuals caught each year may be solely from recreational anglers  Other species are harvested each year for the aquarium trade Marine Life as Items of Commerce and Recreation

  Oil and Gas  Sand and gravel for the construction industry  Freshwater via desalination process Non-Living Resources Harvested from the Marine Environment

  NaCl Non-Living Resources Harvested from the Marine Environment

 Tidal energy

Non-Living Resources Harvested from the Marine Environment  Polymetallic nodules – contain manganese, nickel, copper and cobalt