Coho Salmon. Adult coho may measure more than two feet (60 centimeters (cm)) in length and can weigh up to 35 pounds (16 kilograms (kg)); however, the average weight of adult coho is about eight pounds (3.6 kg). Adult coho salmon have dark metallic blue or greenish backs with silver sides and a light belly; their back and the upper lobe of their tail fin have numerous small black spots. The gumline in the lower jaw has grey pigment, a feature that distinguishes coho from Chinook salmon, which have distinctive black gums. Spawning adult coho salmon in inland rivers are dark with reddish-maroon coloration on their sides. The life history of coho salmon in California has been well documented by Shapovalov and Xxxx (1954) and Xxxxxxx (1987). Coho salmon in California generally exhibit a relatively simple three year life cycle (Shapovalov and Xxxx 1954; Xxxxxxx 1987). Adult coho salmon typically begin the freshwater migration from the ocean to their natal streams after heavy late-fall or winter rains breach the sand bars at the mouths of coastal streams (Xxxxxxxxxx 1991). Adult migration continues into March, generally peaking in December and January, with spawning occurring shortly after the fish return to the spawning grounds (Shapovalov and Xxxx 1954). Female coho salmon choose spawning sites usually near the head of a xxxxxx, just below a pool, where water changes from a laminar to a turbulent flow and where there is small to medium gravel substrate. Preferred spawning grounds have nearby overhead and submerged cover for holding adults, and they have clean, loosely compacted gravel (1.3 to 12.7 cm diameter) with less than 20 percent fine silt or sand content. At suitable sites, the female creates a hollowed depression in the gravel into which she releases several hundred eggs. As they are deposited, the eggs are fertilized with xxxx from one or more attending males. The fertilized eggs are then covered with gravel by the female. Good spawning sites have subsurface flow that ensures good aeration of developing eggs and embryos, and the flushing of metabolic waste products. The lack of suitable gravel often limits successful spawning in many streams. Coho salmon are semelparous (spawn only once and then die). Coho salmon eggs generally incubate for four to eight weeks, depending on water temperature. Egg survival and development rates depend on temperature and dissolved oxygen (DO) levels within the xxxx. According to Xxxxx and Xxxxxxxx (1986), under optimum conditions, e...
Coho Salmon. The North American range of coho salmon extends from Point Hope, Alaska, south to streams in Santa Xxxx County, California. Within this coastal area, NMFS designated seven evolutionary significant units (“ESUs”) of coho salmon, each with its own distinct geographic range. The coho salmon in the vicinity of the XxxXxxxxx Ranch belong to the southernmost ESU, the CCC coho salmon, which are endemic to coastal California streams from Punta Gorda in southern coastal Humboldt County, California, south to Aptos Creek in Santa Xxxx County, California. The CCC coho salmon ESU also includes tributaries to the San Francisco Bay. The CCC coho salmon was listed under the Federal ESA as a threatened species in 1996 and as endangered in 2005 (70 FR 37160). Bjorkstedt et al. (2005) identified that each of the 12 largest coastal streams in this ESU have their own independent population of CCC coho salmon. Coho salmon are listed as Endangered under CESA. The Russian River is the largest river and near the geographic middle of the CCC coho salmon ESU. Bjorkstedt et al. (2005) indicates that the Russian River historically supported the largest population of coho salmon in the ESU; however, this species was nearly extirpated from the Russian River by the late 1990s. Between 2000 and 2003, the documented annual returns of adult coho to the Russian River were less than ten fish, and few of the watershed’s tributaries contained juveniles of this species. The RRCSCBP was initiated in 2001 to reestablish self-sustaining runs of coho salmon in tributary streams within the Russian River Basin (Obedzinski et al. 2007). Under this program, offspring of captive and wild Russian River coho salmon are reared in a conservation hatchery and then released as juveniles into tributaries historically supporting the species, with the expectation that a portion of them will return to these areas as adults to naturally reproduce. The program involves the conservation of the remaining native Russian River coho salmon genome through genetic management that optimizes the genetic diversity of the progeny of the captive broodstock.
Coho Salmon. This Chapter shall apply to the period from 2019 through 2028.
Coho Salmon. The provisions of this Chapter shall apply for the period 2009 through 2018.
Coho Salmon. It is apparent from the Reach 4 fish survey data (Table 4, Table 4a) that Big Indian Slough (Reaches 1-4, Figure 6) currently supports a reproducing population of Coho salmon. Coho salmon are always anadromous. Coho salmon distribution and behavior in Big Indian Slough is assumed to be typical of a Managed Watercourse With Headwaters (green) as described above in section A8-3. Suitable Coho salmon spawning habitat is only available in Reach 4. Adult Coho that enter Big Indian Slough from Xxxxxxx Bay migrate through Reaches 1, 2 and 3 to access the spawning habitat available in Reach 4. Juvenile Coho salmon originating from the spawning habitat in Reach 4 utilize Reaches 1, 2, 3, and 4 for rearing and migration to Xxxxxxx Bay. The fish utilization data and fish passage barrier data presented in Figure 4 is from WDFW’s Salmonscape database. Historically, Upper Xxxxxxx Slough included Reaches 3 and 4 of Big Indian Slough. Given that the historic watershed of Upper Xxxxxxx Slough included an area of sufficient size and gradient to support Coho salmon spawning habitat, it is reasonable to assume that Coho salmon historically reproduced in the watershed. However, it is impossible to determine whether the Coho salmon observed in Reach 4 of Big Indian Slough (Table 4, Table 4a) are a remnant of a historically reproducing population, the result of 20 years of WDFW and Swinomish Tribe Coho plants in the Swinomish Channel and at the mouth of Big Indian Slough, or a combination of the two. The historic fish planting records for the Swinomish Tribe and WDFW pertinent to Big Indian Slough are summarized below in Table 5. TABLE 5. SWINOMISH TRIBE AND WDFW FISH PLANTING HISTORY Year Species Fish/Lb. Release Date Release Location Party Releasing Fish 1977 Chum 1300 6/8/77 Swinomish Channel Swinomish Tribe 1978 Chum 1050 4/21/78 Swinomish Channel Swinomish Tribe 1979 Chum 1000 4/1/79 Swinomish Channel Swinomish Tribe 1980 Chum 1000 3/30/80 Swinomish Channel Swinomish Tribe 1985 Coho 15 6/14/85 Swinomish Channel Swinomish Tribe 1986 Coho 18 5/13/86 Swinomish Channel Swinomish Tribe 1987 Coho 17 5/15/87 Swinomish Channel Swinomish Tribe 1988 Coho 14 6/15/88 Swinomish Channel Swinomish Tribe 1989 Coho 17 5/19/89 Swinomish Channel Swinomish Tribe 1990 Coho 17 6/8/90 Swinomish Channel Swinomish Tribe 1991 Coho 17 6/4/91 Swinomish Channel Swinomish Tribe 1992 Coho 8-14 5/7/92, 6/1/92 Swinomish Channel Swinomish Tribe 1992 Chum 349 5/21/92 Swinomish Channel Swinomish Tribe 1992 Ch...
