. Commercial fisheries review. Fisheries; Fish trade. 'SQUOXIN' IS A SELECTIVE TOXIN FOR SQUAWFISH A selective fish toxixi that will turn squaw- fish belly-side up--and leave trout, salmon, steelhead, and other desirable species un- harmed--is a management tool scientists have long been seeking, Squoxin, a nonchlo- rinated hydrocarbon that kills the highly pre- dacious squawfish and leaves other fish swim- ming happily, is a big step in this direction. Releases of young salmon and trout from fish hatcheries are especially vulnerable to squawfish. As many as 250 young salmon have been found in
. Commercial fisheries review. Fisheries; Fish trade. 'SQUOXIN' IS A SELECTIVE TOXIN FOR SQUAWFISH A selective fish toxixi that will turn squaw- fish belly-side up--and leave trout, salmon, steelhead, and other desirable species un- harmed--is a management tool scientists have long been seeking, Squoxin, a nonchlo- rinated hydrocarbon that kills the highly pre- dacious squawfish and leaves other fish swim- ming happily, is a big step in this direction. Releases of young salmon and trout from fish hatcheries are especially vulnerable to squawfish. As many as 250 young salmon have been found in the digestive tracts of squawfish. Squoxin Developed The squawf ish-killing chemical was devel- oped by Dr. Craig MacPhee, professor of fish- eries at the University of Idaho, after 4 years of research and testing. The search was sponsoredbyBCF's Columbia Fisheries Pro- gram Office. The selective toxin, Squoxin, acts on the squawfish's nervous system as a vaso-con- strictor; it prevents efficient use of oxygen and the proper function of the blood vessels. The chemical is applied to the stream or lake environment--.! part per million--and kills squawfish, while not harming salmon and trout. The toxin also kills a very few dace and shiners--an indicator that the proper amount of toxin is being metered into stream. It has no effect on aquatic insects or other fish foods, humans, or land animals. Slow-Working, Short-Lived Squoxin is a relatively slow-working but short-lived toxin. It becomes ineffective within hours. The first dead squawfish are seen 3 hours after squoxin is applied, and more are dying 24 hours later. Because of squoxin's short life, it must be applied over a long period. One amazing characteristic of the toxin is that squawfish apparently have no sense of danger, or are aware that they are being killed. With other fish-killing chemicals, such as rotenone, fish of all kinds try des- perately to escape with the very first whiff. Squawfish have moved miles downstream
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