The California Department of Fish and Wildlife has closed rivers and creeks to fishing from San Mateo County to Big Sur in an effort to protect coho salmon and steelhead struggling to survive during California's record drought.
As we reported earlier this week, so little rain has fallen along the Central Coast this winter that the mouths of most coastal rivers are still blocked by sandbars. Spawning fish such as the steelhead and coho are thus massing offshore, waiting for a pulse of freshwater that may never come.
The closures, effective until further notice, are intended to ensure that any adult fish that do make it into the region's rivers and creeks have as good a chance to spawn as possible rather than being caught by anglers.
The closures, announced by CDFW on Wednesday, include Pescadero Creek, the San Lorenzo River and all its tributaries, Aptos and Soquel creeks, the Pajaro River, the Carmel River, the Big Sur River, the Arroyo Seco River, and the Salinas River below its confluence with the Arroyo Seco. Anadromous reaches of other creeks between Big Sur and the San Mateo coast have also been closed.
CDFW will extend these closures to North Coast rivers and streams, including the Russian, Mattole, Smith, Van Duzen and Eel rivers, if flows in those streams drop below levels it considers safe for fish. The agency is urging the California Fish and Game Commission to adopt emergency measures closing portions of the American and Russian rivers, as well as all coastal streams west of Highway 1, at its February 5 meeting.
The move underscores the seriousness of the drought's potential effect on coastal fisheries. As we reported this week, the prognosis for central Coast coho is incredibly bleak, with two thirds of the already severely depleted population at immediate risk of extinction.
The steelhead, Oncorhynchus mykiss, is taxonomically identical to the rainbow trout: the central California coast population of steelhead is listed as Threatened under the federal Endangered Species Act. A Southern California population segment has Endangered status.
The relationship between the two kinds of fish is mindbogglingly complex. Essentially, steelhead are the rainbow trout that swim out to sea and return to freshwater to spawn, and rainbow trout are steelhead that stay in freshwater their entire lives. There are exceptions: so-called "landlocked" steelhead survive just fine in freshwater for their entire lives. Rainbow trout often mimic an anadromous lifestyle, swimming downstream to freshwater lakes and then back into cold trout streams to spawn.
Steelhead may be in a slightly better position with regard to the drought, as they have more flexibility in spawning than do coho. Coho salmon mainly return to their natal streams to spawn at three years of age, though some -- called "grilse" or "jacks" -- shave a year off that and return at age two.
Steelhead, on the other hand, can actually delay their spawning by a season if conditions don't permit heading upstream, or if upstream habitat turns out not to be suitable for spawning once they get there. Though the rigors of spawning usually claim 90 percent or more of adult steelhead in any given spawning season, it's not at all uncommon for surviving fish to head back downstream, and them to return another year to spawn once more.
One other factor that makes steelhead likelier than coho to survive extremely dry spawning seasons: steelhead routinely fortify themselves by eating the eggs the coho have given their lives to produce. Even in good spawning years, it's common to see steelhead lurking around coho "redds" -- the gravel bed nests in which the salmon lay their eggs.
Nonetheless, California's coastal steelhead is still severely threatened by the historic drought. "We fully understand the impact these closures will have on California anglers and the businesses related to fishing in California, and we really feel for them," said CDFW Director Charlton H. Bonham in a press release. "However the science is clear. Two-thirds of the wettest part of winter is now behind us and conditions are looking increasingly grim. Under these extreme drought conditions, it is prudent to conserve and protect as many adult fish as possible to help ensure the future of fishing in California."