by Patrick Burns
Population & Habitat Program
National Audubon Society

With world population expected to grow by 3 billion over the course of the next 50 years, managing wild ocean fish populations and decreasing the environmental consequences of aquaculture production will become increasingly important issues.

For an excellent piece about the subsidized nature of the ruination of the world's ocean bottoms and fish stocks, see "Subsidies and the Decline of the World's Fisheries" at http://newsroom.wri.org/wrifeatures_text.cfm?ContentID=1500.

Another piece worth reading is an article in the current edition of "Fly Rod and Reel" at http://www.flyrodreel.com/conservation.html, in which author Ted Williams notes that U.S. fisheries policy is largely to blame for the ruination of U.S. fish stocks: "[T]he Magnuson Fishery Conservation and Management Act of 1976 ... assured the continued depletion of these stocks [of mackerel, herring, billfish, sharks, tunas and groundfish] by subsidizing the U.S. commercial fleet, which doubled in size from 1977 to 1983..."

Williams notes that the recent Pew Oceans commission report makes a very important contribution to the fisheries debate because it examines "how we fish instead of just how many fish we extract from the sea. All but two percent of the 235,000 known sea animals live in or on the bottom. So it may do less harm to a fish stock to kill four times the quota with longlines than a quarter of the quota with bottom trawls that clearcut or crush habitat, leveling all structure including cobles, rocks, corals, sponges, sea fans, mussels, seagrass and kelp... Clearcuts via bottom trawl have been estimated ... to exceed the area of forest clearcuts by a factor of 150," with "each square foot of the world's continental shelves getting razed by bottom trawls every two years."

One of the results of over-harvesting and mismanagement of the world's wild oceans fisheries is the growth in aquaculture, especially in-land aquaculture of carp, tilapia, catfish, eel and shrimp in Asia. See: http://www.fao.org/docrep/005/y7300e/y7300e04.htm#P1204_53110 for more information, including per capita increases in worldwide fish consumption. Figure 9 shows the rapid increase in per-capita fish availability in China. This growth is partly a function of relative economic prosperity, partly a function of new and improved wild-capture fish production, and partly due to explosive growth in inland fisheries (i.e. fresh water pond) fisheries production.

The rapid growth in aquaculture all over the world, and especially in Asia, is truly astounding. From a base of almost zero in 1976, fin fish production has grown by leaps and bounds, with an average compounded rate of 9.2 percent per year since 1970, compared with only 1.4 percent for captured (wild) fisheries and 2.8 percent for terrestrial farmed meat production systems. Worldwide aquaculture is now believed to surpass beef production (when compared by weight), and about 30% of the world's seafood is now produced through aquaculture.

Much of the recent growth in aquaculture production is from closed-system pond, tank and paddy production of carp, tilapia and eel, but over 120 different food stuffs -- including shrimp, flounder, catfish, tuna, trout, perch, turbot, striped bass, bluegill and mussels -- are now commercially grown in aquaculture facilities. Today approximately 98% of all Atlantic salmon comes from aquaculture net pen operations in Canada, Chile, Norway and other producer countries.

In the U.S. the Atlantic Salmon has been decimated, not by over-fishing, but by dams. As Audubon magazine has noted, in Maine "there are more dams than salmon" and today farmed Atlantic salmon outnumber wild Atlantic salmon 85 to one.

Patrick Burns, Director
Population & Habitat Program
National Audubon Society
PBurns@audubon.org