Caring for and Healing the Earth


Are Gamefish Always Welcome?

Dana Griffin III

(reproduced from Colorado Streamside, Colorado Trout Unlimited, Spring 1986)

Here, fellow anglers, is a question for us. Should gamefish (trout, salmon, bass, or what have you) be planted in every lake and stream capable of supporting a population? The answer, I submit, is not simple. It most certainly is not an unqualified yes and may be, in fact, an emphatic no! Now if that opinion generates any hate mail, for heaven's sake send it to the author and not to the editor of this jour­nal. Before any foaming vitriol is put to paper however, please hear me out. You might decide to save the stamp for something better.

Another way of dealing with this matter is to frame our question somewhat differently. What exactly do we need to know about a stream or lake before stocking is proposed, much less carried out? The question, whatever its form, is more than fair, it's downright urgent if we are to relate to the gamefish environment in a rational way. "A rational way" will be defined as an attitude and policy, individual or cor­porate, that values and strives to preserve biological diversity.

There are any number of "events” that threaten the diver­sity of gamefish or, for that matter, any other group of organisms. The threats can be called environmental stresses. When stress exceeds tolerance, the individual, the popula­tion or, more ominously, the species disappears. So here is a beginning to an answer to our second question. Ob­viously. we need to know a lot about what stresses impinge upon a species and how much stress the populations of that species can cope with and still flourish.

Some stress is clear and unequivocable -- destruction of suitable habitat. You can put that kind of stress at the top of the list of factors explaining the severe contraction In the range of the brook trout and the Atlantic salmon in eastern North America, and loss of habitat can be blamed for the elimination of populations of other kinds of gamefish all over the country. It likely was one of the causes behind the elimination of the American grayling from the Upper Penin­sula of Michigan. I wonder If anyone living presently in Grayling, Michigan, can remember when their town's namesake swam in the waters of the U.P. Fishing pressure, to be sure, constituted another stress. No, it doesn't require an advanced degree to appreciate that fouling up the aquatic environment with chemical garbage, silt, thermal discharges, and deforestation won't do fish or fishermen any good. This is so obvious that I see no reason to elaborate any further on the topic.

Where I'd like to spend a bit more time and ink is in pondering another environmental stress that may not be quite as obvious. The stress I refer to obtains from the in­discriminate stocking of hatchery-raised gamefish into waters containing rare or otherwise fragile populations of other fish, including other gamefish. We wouldn't be pull­ing any punches to call this stress biological pollution for that is what it is, and its effects can be just as deadly to its victims as the most nauseous chemical imaginable. Extinc­tion, after all, is extinction, and only vested interest lawyers will get any kicks out of arguing over the modus operandi. Planting thousands of hatchery-reared fish (or fertilized eggs) into the aquatic world of a rare or endangered race of gamefish shows an immense insensitivity to the natural world and can have an impact on native fishes that, in human terms, could be compared to an act of war. Yet wholesale stocking of engineered, pellet-raised fish into any lake or stream reachable by hatchery truck or helicopter proceeds apace, both here and abroad.

Bob Behnke (a CSU professor), in several of his scholarly publications, has placed on the record the cold facts of what happens to first one rare race of trout, then another, when these natives are forced to coexist with hoards of stocked competitors. Gone is the sunapee golden trout from its New England home in Sunapee Lake, out competed by a mixed bag of introduced salmonids, hybridized into genetic oblivion by matings with lake trout. Gone is yellowfin cutthroat trout, endemic to Twin lakes, Colorado, genetically diluted into nothingness by breeding with stocked rainbows and other cutts -- this in spite of a vigorous program of propaga­tion by the Leadville National Fish Hatchery around the turn of the century. The yellowfin's one refuge, Twin Lakes, where it existed only with its own kind, had been biologically despoiled and there was nowhere else that its genetic in­tegrity could be maintained. Another Colorado endemic, the greenback cutthroat, is in about the position the yellowfin found itself in when President McKinley sat in the oval office, that is to say -- desperate. Efforts have been made to build up the numbers of pure greenbacks, but as to the final outcome, the jury is still out.

Those wanting a ride on an emotional roller coaster should curl up with a copy of Robert H. Smith's Native Trout of North America. This extraordinary pictorial and descrip­tive status report on the various races of our native trout will fill any sensitive reader with alarm over the prospects for survival for several of the rarer types. Any trout fisher­man worth his salt and sincerity cannot possibly finish this book without rushing to pen and paper and writing his (or her) congressman to insist that the delicate watersheds in which these endangered trout are holding out be given all possible protection, protection from physical destruction of their habitat and from biological assault from mindless stocking efforts.

Worldwide the liberal seeding of exotic gamefish into diverse habitats has produced a mixed record of success and disaster. Readers interested in some of these stocking histories might wish to write to the Food and Agriculture Organization (FAO) of the United Nations and ask for FAO Fisheries Technical Paper No.213. This document, entitled the Register of International Transfers of Inland Fish Species, is a fascinating catalog of stocking attempts carried out across international borders with dates, purposes, and results.

Success, in socio-economic terms, could be qualified as the establishment of a gamefish in its new habitat with lit­tle or no obvious disturbance to the native biota, but with benefit to the human population. This measure of success is flawed from the outset since no one is prescient enough to know the impacts the introduction of a major predator will have on the ecosystem. We're involved here in one of life's many trade-offs. Still, the introduction of brown and rainbows into the streams and lakes of New Zealand seems to have been a qualified success. Technical papers on the subject discuss the reduction to low levels of at least one species of mayfly from some of the streams and the virtual elimination of a species of fresh-water crab from one of the lakes now inhabited by these trout. Other losses or perturbations may yet be discovered. However, on the surface it would seem the arrival of trout in New Zealand has brought more good than harm.

Elsewhere, the introduction of trout has had more negative repercussions. In high lakes of the Andes, most notably Lake Titicaca on the Bolivian-Peruvian border, ex­otic trout (mainly rainbows) have preyed to extinction or near extinction several species of Orestias, an endemic genus of killifish relatives. Lake Indians had netted these fish for centuries, finding them usually in bays and sloughs where the nets could reach. Trout, being great cruisers in lake environments, are more dispersed and often dive to depths beyond the reach of the nets.

Largemouth bass, introduced in the late '50s into Lake Atitlan in Guatemala, have basically wiped out the local fishes, decimating the age-old fishing industry of the lake Indians. The bass are not as catchable by net, and furthermore, are competing directly for the same food resources as the now endangered great pied-billed grebe, the world's largest and only flightless grebe. The trade-off here is highly questionable. The bass were to issue in a lucrative sports fishing industry as streams of bass fishermen lugged themselves up to lakeside, leaving greenbacks in the pockets of an appreciative populace. The hordes of anglers have yet to materialize, and in the meantime, the Indians and the great pied-billed grebe could well ask what they possibly did to deserve this wrenching change in their lives.

Most readers of outdoor mags are familiar with the ballyhoo surrounding the stocking of peacock bass in some of our southern states, nowhere more promoted than in Texas. This fish is not a bass, but a predaceous cichlid from Amazonia (smaller cichlids are often kept as aquarium curiosities). One has to wonder if the promoters of peacock bass stocking in the United States are aware of the havoc this species has wrought on the fish and shorebird popula­tions of Gatun Lake, Panama, where it was released by accident or ill-planning (take your pick). This aggressive predator has practically eliminated six species of native fish in the lake, including the silverside (Melaniris chagresi) which figured importantly in the diet or tarpon, terns, herons, and kingfishers.

Is Gatun Lake better off for having opened its doors to an introduced alien? Will Texas waters be better off if this fish slakes its appetite by tearing up populations of native species? Which sitting authority can assure us that there will be no negative fallout from this "experiment"?

Cases such as these might draw us to the conclusion that stocking programs should cease and desist, but that would be equally short-sighted. In the race of mushrooming fishing pressure on our lakes and streams, the future of breeding and stocking programs is completely safe. Hatchery managers need not start looking for other work.

The conclusion, to which most reasonable individuals will arrive, is that preservation of our native fauna and flora is a higher need than that of assuring every license holder of his limit every time he goes afield. The time scale used by Mother Nature to produce new species is such that we can just as well assume that what we've got on the planet now in the way of plants and animals is what we, our children, grandchildren, and so on, will have and not one more. We can only loose a species, not produce one. The loss of any species leaves a tear in the fabric of the natural world. To have produced that tear out of ignorance, when we should have known better, or out of greed, or some equally dark motive, is indefensible.

In his admirable book, Trees of the Great Basin, Ronald Lanner states that people need to develop feelings about forests, informed, sensitive feelings that will be reflected in the decisions made about the future of the forests, decisions that, alas, are political. Without any loss of validity, that thought can be applied to our native fishes and to the sport to which we all profess allegiance.


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