Washington, DC
The most endangered ecosystems in the US - and the ones with the highest proportion of endangered species - are our fresh water ecosystems. They are also the ecosystems least well protected by existing laws. In fresh water ecosystems, according to The Nature Conservancy, 28% of all amphibian species are at risk of extinction, along with 34% of all fish species, 65% of crayfish, and 73% of unionid mussels, and very few of these are on the endangered species list. The government is very slow to list these species, compared to mammals and birds. And we also do a poor job of aiding recovery of those fresh water species that do manage to get listed. For example, only 3% of endangered mussels for which there are recovery plans exhibit stable or increasing populations.
Fresh water aquatic ecosystems in the arid portions of the West are analogous to island situations in that they have localized populations, tend to be isolated, and their species may lack anti-predator defenses. For freshwater ecosystems in general, habitat destruction, including modification of waterways by dams and diversions, is the number one threat, followed closely by exotic species. In some cases, exotic species may be a more serious threat than habitat loss.
About 70 species of foreign fish are now established in the US and an additional 160 or so have been transported within the US outside of their native ranges, mostly for sport fishing. Fisheries managers continue to pursue an aggressive policy of stocking and introductions, which is harming native aquatic biodiversity.
In 1991, there were 86 species of freshwater fish listed as threatened or endangered in the US. At least 44 of these were listed in part due to introduced fish, and at least 29 of those introductions were made for sport fishing, with 11 due to trout alone.
Introduced fish are also partly responsible for the dramatic decline of amphibians in much of the West because the introduced sport and bait fish eat the eggs and tadpoles of native frogs. Also, many hatchery fish contain a fungus which destroys the eggs of amphibians. State agencies are responsible for the introductions and each state is free to set its own policy with regard to species introductions. Who pays for these introductions? We, the taxpayers do.
In 1950, Congress passed the Sport Fish Restoration Tax, an excise tax on boat fuel, fishing tackle, etc., which is given to states for the purpose of sport fish enhancement. A lot of money is being spent on this. In fiscal year 1990, $154.7 million was spent, and in FY 1991, $184 million was spent. A significant fraction of this money is spent on stocking non-native species. In fact, more money is spent stocking non-native sport fish than is spent on restoration of threatened and endangered species of fish, mussels, and crustaceans.
A unified national policy is needed on aquatic introductions based on 4 principles: 1) baseline study prior to introductions, 2) liability for control efforts if there are negative impacts, 3) funding for follow- up studies, 4) neighbor state's approval for introductions. Opportunities should be sought to marry the objectives of fishing interests with restoration and protection of aquatic ecosystems.
For more information, see the report by the Environmental Defense Fund entitled "The Big Kill," available for $20 from Environmental Defense Fund, 1875 Connecticut Avenue NW, Washington, DC 20009 (Attention: Publications).