|
information on the growth rate or
<br />,makeup of the total fish population of
<br />restricted bodies of water. There is a
<br />vast difference, however, between this
<br />type of management and the indiscrim-
<br />inate application of highly toxic chemi-
<br />cals to hundreds of miles of our rivers,
<br />with resultant destruction not only of
<br />fishes but of associated aquatic: ani-
<br />mals that are so complexly and inti-
<br />mately interrelated to the total effici-
<br />ency of all organisms inhabiting the
<br />river even to the use of these re-
<br />sources by man himself. Moreover,
<br />because of the naturally complex re-
<br />lationship between different kinds of
<br />water life in different types of streams,
<br />it is not yet possible to make a
<br />biologically sound prediction of what
<br />may happen in one drainage based on
<br />what occurred in a different river.
<br />Extermination of Native Fishes
<br />The threat that fish management
<br />holds to native aquatic animals-in.
<br />sects and other invertebrates, as well
<br />as fishes-is particularly ominous in
<br />Western North America for several
<br />reasons. Throughout the West and
<br />Southwest there are numerous highly
<br />distinctive groups of associated fishes
<br />that often occupy relatively small areas,
<br />either single stream systems or just
<br />certain parts of the few larger drainage
<br />basins. Most of these native species
<br />fare poorly in competition with intro-
<br />duced kinds and with other changes
<br />that man imposes on them-such as the
<br />effects of over-grazing, deforestation,
<br />damming and diversions of water, and
<br />the lowering of the water table (Miller,
<br />1961) . Consequently, they are being
<br />threatened with extinction at an ever-
<br />increasing rate. Indeed, in the rela-
<br />tively few years since I have studied
<br />the kinds of fishes inhabiting the
<br />American Southwest (since 1938), no
<br />fewer than eight species have already
<br />become extinct, and the continued ex-
<br />istence of thirty-one others is in
<br />jeopardy. These thirty-nine species
<br />constitute nearly 40 percent of the
<br />known native, freshwater fishes of
<br />Western North America (north of
<br />Mexico). Attempts are now being
<br />made-we hope they are not too little
<br />or too late-to set aside segments
<br />of the range, or even the entire known
<br />distribution, of some of the more ur-
<br />gently threatened of these native fishes.
<br />This brings us to what is probably
<br />the most glaring example of misuse of
<br />rotenone yet carried out by State and
<br />federal conservation groups. I refer to
<br />the recent chemical eradication of
<br />fishes and aquatic insects in the Green
<br />River in Wyoming, Utah, and Colo-
<br />rado, including heavy losses in Dino-
<br />saur National Monument-an area set
<br />aside by Congress with directions that
<br />it be safeguarded and preserved as a
<br />complete, natural community of life.
<br />The Green River project was the most
<br />extensive eradication job of its kind
<br />ever undertaken, and since the poison
<br />travelled through three States it maj-
<br />justifiably be labeled as interstate pol-
<br />lution that was financed, albeit largely
<br />unwittingly, by American citizens. Be-
<br />tween September 4 and 8, 1962, more
<br />than 20,000 gallons of an emulsified
<br />rotenone preparation were applied to
<br />nearly 500 miles of this river by more
<br />than 100 men. The cost for the poison
<br />alone exceeded $157,000. Funds for
<br />the project were authorized by Con-
<br />gress in June, 1961, after full approval
<br />by the Bureau of Sport Fisheries and
<br />Wildlife, of the U. S. Fish and Wild-
<br />life Service, of the program proposed
<br />by Wyoming and Utah. It is admitted
<br />by the fish managers themselves that
<br />if only a minimum of six years of good
<br />trout fishing results from this project,
<br />their objective will have been met.
<br />The poison was introduced at the
<br />rate of five parts per million of 5 per-
<br />cent rotenone at 17 of 22 stations on
<br />the Green River, and was timed in
<br />such a way as to insure a continuous
<br />flow of toxicant for 86 hours. At sta-
<br />tions 18 to 21, the concentration was
<br />reduced to approximately 4 ppm and at
<br />station 22 to 2 ppm-but even the lat-
<br />ter strength is four times that required
<br />to kill most fishes. The chemical was
<br />also introduced into the drainage sys-
<br />tem at 15 tributary stations in W)'o-
<br />ming and Utah.
<br />Despite repeated warnings to respon-
<br />Dr. Miller is Curator of Fishes at
<br />the Uni%ersity of Michigan's Nlu.
<br />scum of Zoolo=v, in Ann Arbor.
<br />sible authorities by individuals and
<br />organizations concerned with the pos-
<br />sible downstream effects of rotenone
<br />on aquatic life-particular])' in Dino-
<br />saur National Monument-including a
<br />1961 resolution by the American So-
<br />ciety of Ichthyologists and Herpetolo-
<br />gists condemning, the proposed poison-
<br />ing, the operation was carried out
<br />without adequate safeguards and got
<br />out of control. This tragedy occurred
<br />even though this was stated to be the
<br />most thoroughly planned and re-
<br />hearsed operation of its kind ever un-
<br />dertaken and even though considerable
<br />funds ivere invested in pre-poisoning
<br />surveys and in test runs of the toxi-
<br />cant, and many persons from several
<br />agencies were involved in the round-
<br />the-clock activity. The general effect
<br />of this operation on aquatic animals
<br />in Dinosaur National Monument is
<br />known to the National Park Service
<br />from reports and photographs, and a
<br />research report has been released. The
<br />damage done is a matter of common
<br />knowledge among residents of the re-
<br />gion and is further indicated by. the
<br />information given me by George F.
<br />Edmunds and others (see below).
<br />"Rehabilitation" of the River
<br />The Green River treatment has been
<br />repeatedly hailed by the States and
<br />the federal government as a rehabili-
<br />tation project-but "rehabilitate"
<br />means to restore to a former status,
<br />and the establishment of an intro-
<br />duced rainbow-trout fishery does not
<br />fulfill the definition. Flaming Gorge
<br />Reservoir is now being impounded
<br />(since November 1, 1962) in a 91-
<br />mile section of the river behind Ashley
<br />Dam. extending from Dutch John,
<br />Utah, almost to Green River, Wyoming.
<br />Native trout are not known to have
<br />inhabited this sill-laden stream, al-
<br />though certain cold and clear tribu-
<br />taries once were populated by the
<br />Colorado River cutthroat trout, the
<br />only native trout in the drainage.
<br />That fish is now almost extinct. Elim-
<br />ination of native fishes (of which there
<br />are 10 species t and introduced kinds
<br />(9 species, including carp and chan-
<br />nel catfish) was felt necessar) in order
<br />to give the rainbow trout (to be
<br />planted this year) a chance to build up
<br />big populations in the absence of com-
<br />petition from the "trash fish." It is
<br />MAY 1963
<br />S
|