Climate Change Threatening California Trout?

North America’s native trout populations continue to face serious threats, and some species are perilously close to extinction, according to a comprehensive new report released today by Trout Unlimited.

“The State of the Trout” describes the status of 28 separate species and subspecies of trout and char native to the United States. Three of these are already extinct, and more than half of the remaining trout and char populations now occupy less than 25 percent of their native waters. While the state of trout in America is tenuous, there are success stories that prove native trout recovery is possible–the report lays out a roadmap for that recovery.

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⤥ Summer Fun Starts Here ⤦

⤥ Summer Fun Starts Here ⤦

⤥ Summer Fun Starts Here ⤦

“Native trout are in trouble in the United States,” said Chris Wood, Trout Unlimited’s president and CEO in the report’s foreword. “But we are making a difference and with help, involvement and action can promise a future of recovery, not one of loss, for our children.”

Trout and other members of the fish family salmonidae require cold, clean water to thrive. Today, those requisite habitat conditions are increasingly under pressure. Native trout face a long list of challenges, chief among them non-native species and climate change but also increased demand on the nation’s water resources, loss and degradation of habitat, and different types of human development. Trout Unlimited’s staff of scientists spent more than a year preparing the detailed report with input from TU’s field staff and independent, federal and state fisheries experts. The full report is available in digital form at tu.org.

Threats

In California, climate change and hybridization with non-native species are primary threats. Ten species of trout native to California are profiled in the report. Of these, eight are at high risk due to climate change, and six — the California golden, Eagle Lake rainbow, Lahontan and Paiute cutthroat trout, coastal rainbow and Klamath redband trout — are at high risk from non-natives.

Hatcheries have also played a significant role in the dilution of native trout genetics in California. A recent study completed by Trout Unlimited and NOAA-Fisheries examined rainbow trout from 27 streams in southern California and found only three that still contain predominantly pure native trout — the trout in most others were a mix of hatchery and native genes. Such studies help focus recovery efforts where there is still a predominance of native fish.

In addition, drought and reduced streamflows are increasingly hard on California’s native trout. The state is now in the fourth year of one of the most severe droughts on record. And the adverse effects of the drought on trout are compounded by the warming climate — the year 2014 was the warmest on record for California, 4.1oF above the 20th Century average, while December through February of 2015 were the warmest in the state’s recorded history, and the snowpack in April 2015 was 5% of historical average for the date.

Successes

While California’s trout face many challenges, there are also heartening examples of success in protecting and restoring their habitat. One of these is in the headwaters of Pine Creek, historic spawning habitat for the Eagle Lake rainbow trout. Montane meadows provide habitat for a diverse array of species, reduce stream temperatures in summer and serve as vital groundwater recharge and storage zones (research suggests that restored meadows in the Sierra Nevada could store and release between 50,000 and 500,000 acre-feet of water annually). While there has been widespread degradation of montane meadows in California over the last century, for the past 20 years scientists have successfully applied a range of restoration methods to bolster water retention and slow runoff in these areas. In Pine Creek, a partnership including Trout Unlimited is prioritizing the sequence of events necessary for successful meadow restoration to help recover self-sustaining populations of Eagle Lake rainbow trout and avert the listing of the subspecies under the Endangered Species Act. Key proposed actions include the eradication of non-native brook trout, monitoring of key habitat variables and assessment of trends over time.

Trout Unlimited’s partners in native trout conservation say the report offers a course for future efforts, but also a chance to reflect on what has worked thus far.

“The State of the Trout report provides a comprehensive, yet accessible overview of conservation success stories and lays out a road map for challenges that lie ahead,” said Jason Dunham, supervisory aquatic ecologist with the U.S. Geological Survey out of Corvallis, Oregon. “Reading this report gave me the chance to look up from my own daily struggles to address conservation of native trout and look back on the success that we’ve been able to realize over the past 20 years.  We owe many of these successes to the broad influence of Trout Unlimited as a key player in developing new science, management partnerships, and actions on the ground to recover native trout in North America.”

Fishing is inherently an exercise in positive thinking. As long as hope remains, Wood says Trout Unlimited will work to protect and restore native trout.

“People who fish are eternal optimists,” Wood said. “Even the most cynical among us, on the last cast of the day, are confident we will catch the biggest fish of the day.

“That optimism and hope for the future breathes through this report.”

Trout Unlimited is the nation’s oldest and largest coldwater fisheries conservation organization dedicated to conserving, protecting and restoring North America’s trout and salmon and their watersheds.