Carbaryl, Carbofuran, and Methomyl - National Marine Fisheries ...

Of the 21 populations in the Puget Sound ESU reviewed by Busby et al. (1996), 17 had
declining and four had increasing trends, with a range from 18% annual decline (Lake
Washington winter-run steelhead) to 7% annual increase (Skykomish River winter-run
steelhead). Eleven of these trends (nine negative, two positive) were significantly
different from zero. These trends were for the late-run naturally produced component of
winter-run steelhead populations. No adult trend data were available for summer-run
steelhead. Most of these trends were based on relatively short data series. The Skagit
and Snohomish River winter-run populations have been approximately three to five times
larger than the other populations in the DPS, with average annual spawning of
approximately 5,000 and 3,000 total adult spawners, respectively. These two basins
exhibited modest overall upward trends at the time of the Busby et al. (1996) report.
Busby et al. (1996) estimated five-year average natural escapements for streams with
adequate data range from less than 100 to 7,200, with corresponding total run sizes of
550 to 19,800.
Critical Habitat
Critical habitat is not currently designated for Puget Sound steelhead. However, factors
for essential habitat are under evaluation to designate future critical habitat.
Snake River Steelhead
Distribution
SR Basin steelhead is an inland species that occupies the SR basin of Idaho, northeast
Oregon, and southeast Washington. The SR Basin steelhead species includes all
naturally spawned populations of steelhead (and their progeny) in streams in the SR
Basin of Idaho, northeast Oregon, and southeast Washington SR Basin steelhead do not
include resident forms of O. mykiss (rainbow trout) co-occurring with these steelhead.
The historic spawning range of this species included the Salmon, Pahsimeroi, Lemhi,
Selway, Clearwater, Wallowa, Grande Ronde, Imnaha, and Tucannon Rivers.
Managers classify up-river summer steelhead runs into two groups based on ocean age
and adult size upon return to the Columbia River. A-run steelhead are predominately
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