Endangered Species Petition: Coho Salmon
California Endangered Species Act
Submitted July, 2000
California Fish and Game Commission
The Salmon and Steehead Recovery Coalition (SSRC) is formally petitioning the California Fish and Game Commission to list coho salmon populations as an endangered species, pursuant to the California Code of Regulations. Coho salmon living in Californias coastal streams are specially adapted to each stream and best suited to its conditions by genetics, behavior and physical adaptability. This adaptability has enabled coho salmon to survive for many thousand of years in the presence of man.
The coho salmon populations in California have declined at an alarming rate in the last 40 years. In this period, over 40% of the streams have completely lost their historic coho runs; 25 streams have intermittent runs of very few fish and only a few streams still retain self sustaining runs of this once abundant salmon species.
This petition is warranted because the populations of coho salmon (North of San Francisco Bay) that have not been listed, have declined by an estimated 90% in the last 30 years, and now stand at 1% of their estimated historical populations. The SSRC believes that efforts taken by the State of California must be quickly expanded to the entire range of Californias stocks of coho salmon, as soon as possible, if we are to have a chance of saving important coho genetics and restoring native runs of coho salmon.
Some of the present threats that must be dealt with are habitat degradation, migration barriers, water diversion, and disease. Commercial and recreational harvests have been curtailed with little effect on the species. This evidence points to freshwater and ocean habitat as the primary factors restricting coho recovery. The SSRC petitions the State of California to use the special protections afforded by the California Endangered Species Act to protect and restore our streams and watersheds. Habitat recovery for coho salmon will benefit many vanishing aquatic species, restore an important coastal economy, and improve drinking water quality and recreational opportunities for the citizens of the State.
SPECIES DESCRIPTION AND BIOLOGY
COHO SALMON Oncorhynchus kisutch
Coho Salmon are widely distributed in steams along the California coast and are important to sport and commercial fisheries. Their life history is well known from numerous studies that have been conducted over the years, including the classic life history study by Shapovalov and Taft, 1954. They have adapted to the unpredictable conditions present in most California coastal streams. Coho salmon, nevertheless, have demanding habitat requirements and are most abundant in least disturbed, heavily forested watersheds. They move upstream in response to an increase in stream flows caused by fall storms, especially in small streams when water temperatures are 39-57 degrees F. Spawning sites are typically at the head of riffles or tail of pools where there ideally are beds of loose, silt free gravel and where cover exists nearby for adults. Optimal temperatures for development of the embryos in the gravel are 43-50 degrees F. Juveniles prefer deep (greater than 3 feet) well shaded pools with plenty of overhead cover. Juveniles prefer water temperatures of 50-59 degrees F and demand high oxygen and food (invertebrates) levels. High turbidity is detrimental to emergence, feeding and growth of young coho.
Description: Coho are fairly large salmon, with spawning adults typically attaining 22 to 28 inches in length and weighing 6.5-13.2 pounds. They have 9-12 dorsal fin rays, 12-17 anal fin rays, and 9-11 pelvic fin rays. Lateral line scales number from 121-148 and the scales are pored. There are 11-15 branchiostegal rays on either side of the jaw. Gill rakers are rough and widely spaced, with 12-16 in the lower half of the first arch (Moyle 1976).
Spawning adults are dark and drab. The head and back are dark green, the sides are dull maroon to brown, and the belly is gray to black. Females are paler than males. Spawning males are ch