On June 14 Redwood Chapter’s Lake Group submitted comments to the California Department of Fish and Wildlife expressing strong support for the proposed listing of the Clear Lake hitch (lavinia exilicauda chi) under the state endangered species act. The hitch, which is endemic to Clear Lake and one of the few native fish remaining in the lake, used to be found in enormous numbers but has experienced dramatic population declines in recent years.
The Lake Group letter is quoted below.
“The Sierra Club Lake Group represents some 400 Sierra Club members living in Lake County, and is a branch of the 9,000-member Redwood Chapter. Preservation of biological diversity is, as it has always been, central to the Club’s core mission to “Enjoy, Explore, and Protect the Planet,” and we therefore strongly support the listing of the Clear Lake hitch (lavinia exilicauda chi) under the California Endangered Species Act (CESA).
“Lake Group has been actively involved in local efforts to preserve this endemic fish since 2004, when an informal group of Sierra Club volunteers began monitoring the annual spawning migration. This effort led to the creation of the Chi Council later that year. Subsequently we have played an important role in the recruitment of volunteers, and have done a great deal to spread awareness of the plight of the hitch and the activities of the Chi Council, local tribes, and other stakeholders to halt or reverse their population decline.
“Alas, it appears that these well-intended local actions have been inadequate to the task. It was already obvious in 2004 that hitch populations were dramatically reduced from their historic levels, but at that time substantial spawning runs were nonetheless still observed in Clear Lake tributaries far distant from the creeks in the Big Valley watershed. In particular, viable spawning cohorts numbering in the thousands were regularly seen in the Middle, Scotts, and Clover creek complex at the north end of the lake. Aside from a few scattered sightings, this population seems to have completely disappeared subsequent to 2006. This distressing loss has taken place despite investment of considerable monetary and human resources by the County of Lake in habitat improvements, especially the installation of a series of weirs to allow fish passage at a barrier at the Rancheria Road bridge that prevented the hitch from accessing some ten miles of their historic spawning grounds on Middle Creek.
“Additionally, fish capture during the course of tribal tagging projects has revealed that the remaining spawning adults are heavily infested with parasites and nearly universally subject to skin lesions of unknown origin—indications that the species is under extreme stress.
“The causes of hitch population decline are not definitively understood: indeed, one of the significant advantages of CESA listing would be potential access to the funding sources needed for authoritative scientific studies of their biology and their position in the ecology of Clear Lake. Nonetheless, a number of contributing factors seem obvious. Barriers to migration that artificially restrict spawning territory—barriers present on every major Clear Lake tributary to a greater or lesser extent—have received the most public attention, though they are probably not the most important limiting factor. Dramatic loss of wetland habitat, especially the tule marshes that shelter juvenile fish, food competition from introduced fish such as silversides and threadfin shad, predation from other introduced fish such as largemouth bass, especially the voracious Florida strain, and impairments to water quality from heavy metal pollution and excessive sedimentation all are likely to have played a role in hitch decline.
“On top of this diverse array of longstanding stressors the last few years have been characterized by anomalous weather patterns, sparse spring rains, and dramatically reduced stream flows during the migration season. In the winter of 2013, removal of riparian vegetation along a key segment of Adobe Creek—along with Kelsey, one of the two creeks where hitch have been known to spawn in substantial numbers in recent years—may also have had a dramatically negative effect on adult survival and reproductive success.
“The consequence of this perfect storm has been a sparse spawning run in 2012 and a nearly nonexistent spawning run in 2013. Adverse climatic conditions and absence of normal spawning behavior have been known in the past without apparently causing irreversible harm, but that was when Clear Lake’s hitch population was abundant and thriving, a description that certainly does not apply today.
“This fish is under extreme stress, and may indeed have already passed the point of possible recovery. But according to the mandate expressed by both the state and federal Endangered Species Act, it is our responsibility as citizens to use every means in our power to prevent extinction, because every extinction impoverishes us all, and impoverishes the planet as a whole. Listing the hitch under CESA cannot guarantee its long term survival, but listing is the only plausible means available to provide the resources needed to support a good faith effort to restore the population of this iconic fish to a viable level. As an additional benefit, the improvements likely to improve the longterm survival chances of the hitch—wetland restoration in particular—will also benefit the entire ecosystem of Clear Lake and the communities that surround it.
“The evidence clearly demonstrates that after barely surviving for a number of years this species is now declining with terrifying rapidity. Its plight is dire, and the need for action urgent, with CESA listing offering its only hope of survival. The Sierra Club therefore urges the staff of the California Department of Fish and Wildlife to recommend listing to the Fish and Game Commission in the most strenuous terms possible.”