Coho Salmon Released in Marin County's Redwood Creek to Boost Spawning of Endangered Fish
12 Jan 2018 01:01 PM PST
In an effort to boost the population of spawning coho salmon in Marin County's Redwood Creek, biologists from the California Department of Fish and Wildlife (CDFW) and the National Park Service (NPS) today released nearly 200 adult coho salmon in the creek at Muir Beach.
The released coho salmon were collected as juveniles from Redwood Creek in the summer of 2015 at an age of 6 to 8 months and reared to adulthood at the Warm Springs Fish Hatchery in Geyserville at the base of the Lake Sonoma Dam.
The release of coho salmon this winter is the culmination of the Redwood Creek Coho Salmon Rescue and Captive Rearing Project. This project, a collaborative effort by CDFW, NPS, the National Oceanic and Atmospheric Administration (NOAA) Fisheries, the U.S. Army Corps of Engineers and the California Department of Parks and Recreation, was initiated in 2014 with the goal of preventing the extinction of the coho salmon, which is listed as an endangered species under both the California Endangered Species Act and the federal Endangered Species Act.
Prior to 2014, fewer than 10 adult coho salmon were estimated to have returned to Redwood Creek annually to spawn. The long decline of coho salmon in Redwood Creek has been accelerated by recent periods of poor ocean survival combined with the prolonged California drought. Coho salmon are more sensitive to habitat degradation and poor water quality than other Pacific salmon species since they rear as juveniles in freshwater for a year or more.
Biologists hope that the released fish will migrate upstream and spawn in the creek. NPS monitoring staff will survey the creek in the summer of 2018 and collect tissue samples from juvenile fish. Genetic analysis of the tissue samples will indicate how many of the released adult fish produced viable offspring.
The first major release of adult coho salmon in Redwood Creek occurred in the winter of 2016. A third and final release of adult coho salmon is planned for the winter of 2018-19.
More information about the Redwood Creek Coho Salmon Rescue and Captive Rearing Project can be found on the CDFW website at wildlife.ca.gov/Drought/Projects/Redwood-Creek-Coho. The Redwood Creek coho restoration project is part of a broader effort to sustain and restore coho salmon runs along the central and northern California coast.
Peter Tira, CDFW Communications, (916) 322-8908
Manfred Kittel, CDFW Bay Delta Region, (707) 944-5522
Dana Polk, Golden Gate National Recreation Area, National Park Service, (415) 786-8021
Darren Fong, Golden Gate National Recreation Area, National Park Service, (415) 289-1838
Bringing the Paiute Cutthroat Trout Home
The California Department of Fish and Wildlife (CDFW), U.S. Fish and Wildlife Service (FWS), and U.S. Forest Service (USFS) have returned a rare trout species to its home water after a 71-year absence.
In 1946, poachers were decimating the Paiute Cutthroat Trout (PCT), a species whose native range was limited to a nine-mile section of Silver King Creek (Alpine County). To ensure the species' survival, the USFS and Eastern Packers Association translocated 401 of these fish to North Fork Cottonwood Creek in Inyo County's White Mountains. This population has persisted in isolation from other forms of trout and has recently provided important restoration options for resource managers. None of this would have been possible without the foresight of concerned biologists seven decades ago.
The conservation history of this rare trout is complex. The initial "conservation" measure was entirely inadvertent. In the early 1900s, Basque sheepherders in the area caught and transported PCT into the previously fishless portion of Silver King Creek above Llewellyn Falls. This early within-basin transfer was the salvation of the PCT, since non-native species were later introduced below the falls. The falls prevented non-natives from reaching the habitat above and protected PCT from hybridization and competition.
The FWS listed PCT as endangered under the Endangered Species Preservation Act of 1966 the precursor to the federal Endangered Species Act (1973). The species was down-listed to threatened status in 1975, in order to facilitate management and restoration and to allow regulated angling. In 1994, CDFW, FWS and USFS began developing a restoration plan to remove non-native fishes from Silver King Creek and return the PCT to its native waters. From 2013 to 2015, the partner agencies treated 11 stream miles of Silver King Creek and three tributaries below Llewellyn Falls with a fish toxicant, rotenone, to remove all non-native fish species.
The PCT population in Upper Fish Valley, an area of Silver King Creek above the falls, has been considered a primary source for restocking the recovery area. Unfortunately, that population was heavily impacted by the extreme 2012-2016 drought. During this extended drought, lack of snow cover resulted in the stream freezing almost solid during cold snaps. In order to offset the resulting population decline, the partner agencies caught 86 pure PCT in North Fork Cottonwood Creek. On August 23, 2017, the fish were planted back into Silver King Creek above Llewellyn Falls.
Agency staff met in the White Mountain Wilderness (Inyo National Forest) and, along with volunteers and pack mules, hiked from their campsite to North Fork Cottonwood Creek. There, the team used electrofishers to retrieve descendants of the fish moved back in 1946. The fish were hauled out by mule, put in a specialized transport truck, and driven approximately 100 miles to the Carson Iceberg Wilderness. Another mule team then hauled them back to Silver King Creek. Thanks to careful handling by the collection and transport teams, every fish survived the trip home.
Due to its limited habitat, the Paiute Cutthroat Trout has been called the rarest, but most recoverable, form of trout in the United States. With the most recent success of this partnership, and due in large part to the foresight of conservationists in the past, the future looks bright for this beautiful native salmonid.