Mass die-off of salmon in California predicted this year

editorial staff

Allocations of water for the environment must be prioritised say scientists.

In drought-stricken California, competition for the state’s precious water pits fishing and environmental interests against agriculture and residential communities.

This year, as wildfires rage across the state, Gov. Gavin Newsom is asking for statewide conservation of 15 per cent and farmers are facing water cutbacks.

But according to an article co-authored by Julie Zimmerman, lead freshwater scientist at The Nature Conservancy in California, mandated flows have not been sufficient to enable species, such as Sacramento and San Joaquin river salmon to change their trajectory toward extinction.

Meanwhile, the article warns, planned releases this year from Shasta Dam will result in river temperatures being too warm to sustain the eggs that will be laid this autumn, risking an entire year’s worth of fish. The state Department of Fish and Wildlife predicts that close to 100 per cent of eggs could be lost.

To improve the chances of survival for chinook or king salmon the state has already transported thousands of hatchery-raised salmon smolts to release in the San Francisco Bay. It means that the bulk of salmon returning to their spawning grounds in several years will likely be hatchery fish, putting at risk genetic diversity and thousands of years of evolution.