5. Risk Assessment of a Proposed Introduction of Pacific Salmon
61
reported (Fausch and White 1981; Waters 1983; Taylor et al. 1984; Kennedy and
Strange 1986; Fausch 1988), the Brown Trout is generally considered a fisheries
management success story (Courtenay and Kohler 1986).
At least 70 fish species have been introduced from outside the United States;
most of these were introduced within the past 50 years (Fig. 5.1; OTA 1993); more
than 168 species have been transplanted within the United States (Courtenay and
Taylor 1984). The proportion of intentionally introduced or transplanted fishes
causing harm (46%) is slightly higher than the percentage of unintentionally
introduced species causing harm (38%), and intentional introductions outnumber
unintentional introductions nearly three to one (OTA 1993). These findings suggest that researchers and resource managers have been ineffective in identifying
and preventing the intentional introduction of harmful nonindigenous fish. Magnuson (1976) described intentional introductions of fish as a game of chance.
Although the odds that an introduction will produce no harmful results may
appear better than even, the alternative outcomes are, in fact, incommensurable,
because introductions can lead to irreversible adverse effects on indigenous flora
and fauna.
It was not until 1969 that the American Fisheries Society and the American
Society of Ichthyologists and Herpetologists addressed exotic fish as an issue of
concern (McCann 1984). Since that time, attitudes and approaches for dealing
with exotic fish have slowly evolved. At its annual meeting in 1972, the American
Fisheries Society adopted a position statement on introductions of exotic species
(AFS 1972). The position statement called for an assessment of need, alternatives,
and impacts and, if appropriate, experimental research prior to any introduction.
The position statement received little attention, and it was rarely followed (Kohler
and Courtenay 1986).
Figure 5.1. Cumulative number of fish species of foreign origin in the United States.
Figure only includes those species with known introduction dates. (From OTA 1993.)
61
reported (Fausch and White 1981; Waters 1983; Taylor et al. 1984; Kennedy and
Strange 1986; Fausch 1988), the Brown Trout is generally considered a fisheries
management success story (Courtenay and Kohler 1986).
At least 70 fish species have been introduced from outside the United States;
most of these were introduced within the past 50 years (Fig. 5.1; OTA 1993); more
than 168 species have been transplanted within the United States (Courtenay and
Taylor 1984). The proportion of intentionally introduced or transplanted fishes
causing harm (46%) is slightly higher than the percentage of unintentionally
introduced species causing harm (38%), and intentional introductions outnumber
unintentional introductions nearly three to one (OTA 1993). These findings suggest that researchers and resource managers have been ineffective in identifying
and preventing the intentional introduction of harmful nonindigenous fish. Magnuson (1976) described intentional introductions of fish as a game of chance.
Although the odds that an introduction will produce no harmful results may
appear better than even, the alternative outcomes are, in fact, incommensurable,
because introductions can lead to irreversible adverse effects on indigenous flora
and fauna.
It was not until 1969 that the American Fisheries Society and the American
Society of Ichthyologists and Herpetologists addressed exotic fish as an issue of
concern (McCann 1984). Since that time, attitudes and approaches for dealing
with exotic fish have slowly evolved. At its annual meeting in 1972, the American
Fisheries Society adopted a position statement on introductions of exotic species
(AFS 1972). The position statement called for an assessment of need, alternatives,
and impacts and, if appropriate, experimental research prior to any introduction.
The position statement received little attention, and it was rarely followed (Kohler
and Courtenay 1986).
Figure 5.1. Cumulative number of fish species of foreign origin in the United States.
Figure only includes those species with known introduction dates. (From OTA 1993.)