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

channel or from the shoreline of a standing body of water. Designated critical habitat
areas include the Columbia River from a straight line connecting the west end of the
Clatsop jetty (Oregon side) and the west end of the Peacock jetty (Washington side), all
river reaches from the estuary upstream to the confluence of the SR, and all SR reaches
upstream to the confluence of the Salmon River; all Salmon River reaches to Alturas
Lake Creek; Stanley, Redfish, yellow Belly, Pettit, and Alturas Lakes (including their
inlet and outlet creeks); Alturas Lake Creek and that portion of Valley Creek between
Stanley Lake Creek; and the Salmon River. Limiting factors identified for SR sockeye
include: (1) Reduced tributary stream flow, (2) impaired tributary passage and blocks to
migration, (3) degraded water quality; and (4) mainstem Columbia River hydropower
system mortality.
Steelhead
Description of the Species
Steelhead are native to Pacific Coast streams extending from Alaska south to
northwestern Mexico (Moyle 1976; Gustafson, Wainwright et al. 1997; Good, Waples et
al. 2005). We discuss the distribution, life history diversity, status, and critical habitat of
the 11 endangered and threatened steelhead species separately.
Steelhead can be divided into two basic run-types: the stream-maturing type, or summer
steelhead and the ocean-maturing type, or winter steelhead. The stream-maturing type or
summer steelhead enters fresh water in a sexually immature condition. It requires several
months in freshwater to mature and spawn. The ocean-maturing type or winter steelhead
enters freshwater with well-developed gonads and spawns shortly after river entry.
Variations in migration timing exist between populations. Some river basins have both
summer and winter steelhead, while others only have one run-type.
Summer steelhead enter freshwater between May and October in the Pacific Northwest
(Nickelsen, Nicholas et al. 1992; Busby, Wainwright et al. 1996). They require cool,
deep holding pools during summer and fall, prior to spawning (Nickelsen, Nicholas et al.
1992). They migrate inland toward spawning areas, overwinter in the larger rivers,
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