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
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
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
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