Updated on 12/12/12
This week, The Center for Biological Diversity petitioned the U.S. and California state governments to protect a large minnow called the Clear Lake hitch as an endangered species. According to the Center, the subspecies* of fish is found only in Northern California’s Clear Lake and its tributaries.
A popular recreational area, Clear Lake is north of San Francisco and slightly inland. It is located in Lake County, which is bordered by Napa, Sonoma, Mendocino, Glenn, Colusa, and Yolo counties. The lake is the largest body of freshwater entirely in California and is possibly the oldest lake in North America, with an estimated age of 2.5 million years.
The Center for Biological Diversity says the Clear Lake hitch was once very plentiful in the region, and had served as an important food source both for wildlife and indigenous people. But in recent years “they have declined precipitously as their habitat has been degraded and destroyed,” reports the Center.
“Clear Lake hitch have long been an important part of the natural and cultural heritage of Clear Lake, but if they’re going to be around for future generations, we need to protect and restore their habitat to put them on the path to recovery,” said the Center’s Jeff Miller. “Hitch now spawn regularly in only two streams, and the entire population is vulnerable to water diversion and pumping, drought, invasive species and pollutants.”
Clear Lake hitch (a subspecies of Lavinia exilicauda) are silver, though the young have a dark spot at the base of their tail. They are omnivores that eat algae, insects, and zooplankton.
The small fish migrate, though not as far as some species like salmon. Each spring, adults swim up streams to spawn before they return to Clear Lake. Millions of them used to jam the lake’s tributaries, but now only a few thousand of the fish remain. The survivors have lost access to the best spawning streams, and many have to make do with temporary flooded ditches and other marginal areas, reports the Center.
According to the group, the hitch’s closet relative, the Clear Lake splittail, was already driven to extinction in the 1970s by barriers and development that dried out streams. Clear Lake also suffers mercury pollution from nearby mines, as well as the usual polluted runoff from lawns, farms, and other human activities.
*In response to a reader comment about Lavinia exilicauda being more widely distributed, we asked Tierra Curry of the Center for Biological Diversity to explain. She said via email that the Clear Lake hitch is a subspecies:
“The Clear Lake subspecies was first described by Hopkirk (1973) as a lake-adapted form,primarily because of its greater number of fine gill-rakers. Clear Lake hitch differ from other hitch physiologically by having larger eyes, small mouths, a slightly extended lower jaw, a decurved lateral line, deeper, rounder bodies, and more gill rakers (Hopkirk 1973).
“Analysis of 10 microsatellite loci supported subspecific designation of Clear Lake hitch
(Aguilar and Jones 2009). Here is a link to the petition.”
Brian Clark Howard covers the environment for National Geographic. He previously served as an editor for TheDailyGreen.com and E/The Environmental Magazine, and has written for Popular Science, TheAtlantic.com, FastCompany.com, PopularMechanics.com, Yahoo!, MSN, and elsewhere. He is the co-author of six books, including Geothermal HVAC, Green Lighting, Build Your Own Small Wind Power System, and Rock Your Ugly Christmas Sweater.