Dangerous Numbers for Winter-Run Chinook Salmon
Winter-run Chinook salmon are teetering on the edge of extinction as scientists revealed yesterday that the salmon’s numbers are dangerously low for the second year in a row. Only 3 percent of the juvenile salmon run made it to the sea and drought is the major culprit, the San Francisco Chronicle reported. Both warm water temperatures and shallow waters were to blame. Last year only 5 percent made the migration.
The fish need plentiful cold water in the rivers and creeks in the summer to protect their incubating eggs. Officials last year tried to release more water into the Sacramento River from Shasta Lake at critical times for the salmon, a tactic that drew ire from downstream agricultural interests who had water rights curtailed in last year’s drought. But it proved to be too little water to make a significant impact for the fish.
The dwindling population of winter-run Chinook in the Sacramento River is the last vestige of what was once a robust population that thrived in Northern California rivers. But dams cut off access to the Little Sacramento, McCloud and Pit Rivers, and drought has further endangered what’s left of the Sacramento River population.
The National Marine Fisheries Service also reported that the winter-run Chinook salmon are impacted by “water withdrawals, predation by non-native species, lack of quality rearing habitat in the Delta, and commercial and recreational fisheries.”
Scientists are learning more about the salmon’s migration in the past year since they starting outfitting hundreds of smolts raised in hatcheries with tracking devices. Soon 570 smolts will begin their journey toward the sea and biologists will follow their tracking devices to understand if the salmon are being impacted by water pumping in the Delta.
“With real-time data on the location of migrating Chinook salmon, water managers can close the gates and reduce pumping while the bulk of the fish migrate past,” writes Rich Press for NOAA Fisheries. “The reverse is also true: If a rare storm rolls in and the fish aren’t nearby, water managers can take advantage of the opportunity to increase water exports.”
Important Drought Numbers Today
After the wettest February in years, California officials are poised today to announce whether or not they will extend the mandatory conservation mandate put in place last year by Gov. Jerry Brown.
Later today, California will also have its second snow survey of the year after a promising start to the wet season. But despite above-average precipitation so far this year, there are still a few months to go before the most telling snow survey on April 1. Groundwater remains critically low in many places and most major reservoirs are still low as well.
“We’re at halftime,” Felicia Marcus, chair of the State Water Resources Control Board, told the Associated Press. “We’re not doing too badly, but we certainly haven’t won the game yet.”
Drought Impacts Felt in Forests
New research from the University of California Santa Cruz shows that California’s drought is affecting forests, but not just the trees. Native ferns that grow beneath coastal redwoods are beginning to suffer.
Jarmila Pittermann, associate professor of ecology and evolutionary biology at U.C. Santa Cruz, studied two kinds of ferns between 2013 and 2014 and found that extreme drought conditions have caused dieback.
The ferns are adapted to periods of dry summers and drought, but the current extended drought has limited the plants’ ability to store energy, the research found.
“These plants are not accumulating enough carbon to support new growth in the spring,” she said. “The implications are that they may not make enough spores to reproduce, and they may be more vulnerable to pests.”
The research points to a bigger problem, which is not limited just to the ferns that grow in coastal forests.
“These understory species are important in themselves, but also serve as indicators of how climate change may affect our redwood forests,” Pittermann said. “Considering that these plants are adapted to persist through a typical summer dry season, the dieback emphasizes just how unprecedented this drought has been over the past three years.”
Top image: Biologist Kari Burr holds a smolt, a younger version of a Chinook salmon, in Vallejo, Calif. Scientists revealed critically low numbers yesterday for winter-run Chinook salmon. (Marcio Jose Sanchez, Associated Press)