The public has heard the message of the health benefits of omega-3 fatty acids, which are found in abundance in seafood. Increased consumption of these fish has created concern about overfishing of various popular fish, and limits have been placed on the take for both commercial and sport fishermen. Nature also plays a significant role in determining when and where seafood will thrive. Water temperatures in the oceans have been changing. Measurements taken by the National Oceanic and Atmospheric Administration (NOAA) along the Pacific Coast indicate that water temperature recently has been rising faster than it did at the beginning and during much of the past century.
Fishermen are reporting changes in the types and numbers of seafood in their locales. Humboldt squid and marlin, normally found in waters off Baja California, are now being caught as far north as Washington; the squid population found near San Francisco is increasing rapidly. San Diego fishermen are reporting reduced numbers of albacore, but more yellowfin tuna (the kind valued for making sushi). Fishermen off the coast of Oregon and Washington have been dealing with significant limits on the salmon they can take home; the good news is that more albacore tuna are found in this region as warmer waters have promoted their movement northward.
In the East, some people blame the warming water in Chesapeake Bay for causing an illness (mycobacteriosis) in bass living there. Algae are flourishing and taking some oxygen from the water, which may be a factor in the health of the bass population. Reduced oxygen content in the water is a potential problem in coastal waters and can cause a drop in the number of fish on both coasts in the future.
Predictions on the extent of glacial melt and the long-term effects on sea level suggest that present marshlands along the coast may disappear as the water gets deeper, and the area is transformed into open sea. When this happens, the population of crabs, shrimp, and menhaden, as well as some other types of sea life that reproduce in the sheltered marshy setting, will be reduced. These are some of the problems that need to be monitored and alleviated as much as possible to avoid losing valuable variety and quantities of seafood to feed the nation.
Quite a different environmental problem is developing for fish in the Great Lakes. The current situation has evolved from importing of some Asian carp by a fish farmer in Arkansas in 1972. The imported carp were effective in keeping holding pens clean and caused no concern until flooding in the 1990s released them into local streams. Unlike the common carp, which were already there and weighed around 25 pounds, the Asian carp ate voraciously and displaced most of the native fish as they worked their way north in streams and rivers. These giant fish may weigh as much as 100 pounds, and they are so strong that they can injure people in small boats when they soar as high as 8 feet out of the water. Not only are these giant carp badly behaved, they don’t even taste good and are full of bones, all of which removes them from the risk of appearing on dining tables. In other words, they are a menace to the edible fish supply and to hapless boaters. Now giant carp have arrived in Chicago, where vigorous and costly efforts are being made to keep them from escaping into Lake Michigan. This effort amounts to environmentalists’ last chance to protect all of the Great Lakes from giant Asian carp. Failure to stop them will have a devastating impact on the fishing industry and sport fishing in all of these lakes.