Drought May Force California to Move Salmon by Truck

Andy Clark/Reuters

The California drought is now so dire that the state government might move millions of salmon by truck to be nearer to the ocean next month.

Historically, state-run salmon hatcheries have trucked fish to different locations to protect them from hazards like pollution and predators. Now it's the dangerously low water levels in rivers that are posing a threat.

Millions of juvenile salmon are normally released from the state-run Coleman National Fish Hatchery into the Sacramento River in April and May, where they migrate along the river and into the ocean. Officials worry shallower riverbeds might pose a lethal threat to salmon by compromising their food supply and making them more susceptible to predators. The water, at such low levels, may be significantly warmed, which could also potentially kill the young salmon, The Sacramento Bee reported.

"The juvenile fish this year represent the adult fish that will support our fishery in 2016," John McManus, of the Golden Gate Salmon Association, told local station NBC 4. "If we get fish moved by truck, survival rate goes way up."

But trucking salmon to new habitats by tanker has its risks as well: Evidence has shown that trucked fish, unaccustomed to their new habitat, are more prone to "stray" into the wrong river when they return from the ocean to spawn as adults. The California Department of Fish and Wildlife is studying the effectiveness of the trucking method versus releasing the fish directly into the river, The Fresno Bee reports.

The salmon industry in California is a multibillion-dollar business. So is the almond industry, the wine industry and the produce industry, each of which has been hit hard by the more than three-year drought that still drags on. It remains to be seen how much havoc the drought might wreak, but scientists warn it may not get better anytime soon.

Ten years ago, University of California, Santa Cruz professor Lisa Sloan predicted the California drought. Well, almost: Her team didn't predict it would be quite this bad. Now, given the drought's severity and persistence, she says we should be prepared for it to get even worse.

Sloan and graduate student Jacob Sewall predicted that in some areas, average rainfall would drop by as much as 30 percent. Currently, the amount of snow and rain that has fallen on California's Northern Sierra is a whopping 56 percent less than the average precipitation for the area to date.

"Yes, sadly, I think we were correct in our findings, and it will only be worse with Arctic sea ice diminishing quickly," Sloan told Think Progress.

Back in 2004, Sloan and Sewall created a simulation of how melting Arctic sea ice would change weather patterns. The result was a "significant reduction in rain and snowfall in the American West," in a manner eerily similar to what is playing out over much of California now: reduced sea ice would trigger a heat transfer in the ocean, which would warm the atmosphere, forming a rising column of warm air off the West Coast of the U.S. The jet stream – which carries weather patterns like precipitation – would be forced over the warm air column onto a more northerly route, skipping large swaths of the West.

That's more or less exactly what California is experiencing now. A four-mile-high and 2,000-mile-long high-pressure zone is forcing the jet stream along a much more northerly route, effectively diverting rain- and snow-bringing storms that might otherwise fall on California up into Alaska and Canada. One researcher dubbed the high-pressure zone the "Ridiculously Resilient Ridge."

Now, Sloan tells Think Progress, climate change may be happening even more quickly than her paper calculated. Certain factors that are part of our current reality weren't accounted for in her model, which she says indicates that the drought may be worse than the team originally concluded:

Yes, in this case I hate that we (Sewall & Sloan) might be correct. And in fact, I think the actual situation in the next few decades could be even more dire that our study suggested.

Why do I say that? (1) we did not include changes in greenhouse gases other than carbon dioxide; (2) maybe we should have melted more sea ice and see what happens; (3) these atmospheric and precipitation estimates do not include changes in land use, in the U.S. and elsewhere. Changing crops, or urban sprawl increases, or melting Greenland and Northern Hemisphere glaciers will surely have an impact on precipitation patterns.

For major industries and small towns alike, this is terrible news.