For each sampling trip or cruise, we had the following objectives: 1) characterize the estuarine fish assemblage by documenting the abundance, size, and condition of fishes (including juvenile salmon) present in the sampling area, and 2) collect 50 individuals of each of 4 juvenile salmon species and age classes (yearling Chinook, subyearling Chinook, and coho salmon
, and steelhead) for laboratory analyses; this number reflects a balance between restrictions on lethal sampling of ESA-listed species and the need for sufficient samples for statistical rigor.
Water was passed through spill gates at Mossyrock Dam during 2008, which resulted in substantial numbers of landlocked Coho Salmon
being passed downstream into Mayfield Lake.
Then, in 2007, six young-of-the-year coho salmon
were found in Reach 2, and in 2008 two one-year-old coho smolts were found in this reach (Figure 1) (Sparkman, CDFG, personal communication).
More recently, Scholz' team has shown that low concentrations of the insecticide chlorpyrifos can impair olfaction in coho salmon
and that the insecticide esfenvalerate can trigger abnormal neural signals in response to food scents.
Under pressure from the White House, Norton's Bureau of Reclamation slashed the river flow, returning much of the water to the irrigators, despite a report from a team of federal scientists warning this would place the coho salmon
in serious jeopardy (along with the commercial fishermen and Indian tribes who depend on them).
The death rate for Chilean coho salmon
infected with rickettsia is 90%.
District Court Judge Michael Hogan found that the ESA listing of Oregon coastal coho salmon
by the National Marine Fisheries Service (NMFS) was illegal.
Thousands of people rallied in support of desperate farmers and ranchers who have been battling for survival since April, when federal authorities cut off their water to benefit "endangered" sucker fish and Coho salmon
Grant recipients in California, meanwhile, are dip-netting juvenile coho salmon
from small streams that dry up in the summer and transporting them to larger creeks where they can continue their migration to the sea.
During peak seasons, the stream teems with coho salmon
and steelhead trout.
The dams helped to cause the extinction of the coho salmon
and to bring 25 other species of salmon and steelhead to the edge of extinction, reducing populations by 90%, according to American Rivers, an advocacy organization based in Washington, DC.
Pink and chum salmon are the most commonly reported Pacific salmon caught in Arctic waters, as they are more tolerant of low Arctic water temperatures than the rarer sockeye or rarest coho salmon
(Salonius, 1973; Craig and Haldorson, 1986).