Sunday, June 6, 2010

Arctic char, rotenone, and geo-engineering

This past May the Portland Maine Sunday telegram had an article about returning a tasty gamefish, the Arctic char, to a pond in Northern Maine. Here is a link to this article.

The body of water in question, Reed Pond, was long a home for the char -- one of the few in the "lower 48" -- until someone illegally introduced a far less "valuable" species, the rainbow smelt. The smelt fairly quickly monopolized the pond, nearly driving out the char and eliminating the place as a mecca -- well, that's overstating the case for a relatively inaccessible body of water in extreme northern Maine -- for fly fishing.

A Maine wildlife biologist and several local residents decided bring back the char. They found several of the remaining fish and bred them in captivity for several years until they had hundreds of fingerlings and some larger fish. They plan to reintroduce them into Reed Pond in the near future.

But now comes the dicey part. In order to allow the char to restock the lake, they have to remove the smelt. The plan is to introduce rotenone, a well-known insect and fish poison, into the waters.

Here is a quote from an article appearing on the website of the Center for Biological Diversity about a successful attempt to prevent a similar use of rotenone in California:

"Rotenone use poses the potential for irreversible damage to stream ecosystems and loss of other non-target native species. Studies show that Rotenone causes significant long-term effects on aquatic invertebrates, the food source for trout and other aquatic life. A study conducted after a 1991-1993 poisoning of Silver King Creek shows that the diversity of invertebrates was significantly lower even three years after the project was completed. There is also the potential for severe reductions in food supply to animals such as bats, flycatchers, warblers, amphibians, other fish, and fish-eating birds. This watershed is historic habitat for the mountain yellow-legged frog, a species in serious decline. Silver King Creek was treated with Rotenone in 1964, 1977 and in the early 1990s - the Forest Service has failed to analyze or discuss why non-native trout still persist there before proceeding with another poisoning."

I think that the Reed Pond plan is yet a another example of the failure of many well-meaning people to understand the complexities of ecology and evolution. Just as you can't blithely introduce new species into ecosystems without the risk of unintended consequences, you can't kill off whole segments of an established -- albeit compromised -- ecosystem without a risk of great damage. Rotenone will kill off vast numbers of small fish and insects in various stages of development. What kind of ecological mix will remain when the Arctic char are reintroduced, and what will be the long-term future of aquatic life in the greatly reorganized pond?

Reed Pond is a small deal, but the thinking involved in the plan is scarily evident in new schemes to "geo-engineer" the earth to combat global warming. All sorts of plans are surfacing to spray chemicals into the upper atmosphere or the ocean to reflect sunlight or remove carbon dioxide. Here is the article from Science News that reminded me of the Reed Pond story: Engineering a Cooler Earth.

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