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A Truck-assisted Migration: Salmon Smolts Get a Helping Hand to Reach California Coast Amid Severe Drought by Harry Morse Idaho State Journal, June 15, 2021

While Idaho wrestles with how to restore salmon runs on the Snake and Columbia Rivers, California's Chinook salmon are faced with near disaster this year.

A mega drought has caused low flows and elevated water temperatures, creating conditions ripe for fish losses from disease and predation. Toss in California's complex water delivery systems, water rights, water transfers and storage problems and you get a set of circumstance that could decimate young salmon migrating downriver to the sea, jeopardizing future returns of adult fall-run Chinook salmon in the Sacramento River system.

Water is the crux of the issue for fish and people in California and in Idaho. Idaho ranks second only to California in the use of surface water, and Southeast Idaho according to recent reports is one Idaho's highest use areas. The future of salmon and water in both states are inseparably intertwined. Realizing this, Gov. Brad Little tasked 20 Idahoans in 2020 to develop an Idaho salmon recovery work group report. Members ranged from fish biologists to three tribes and industry representatives. The report was developed through 18 months and 16 meetings, ending in December 2020. The governor asked for consensus support.

The net result was a sped-up continuation of the natal habitat and hatchery measures that have been occurring for the previous decades.

Locally Rep. Mike Simpson, R-Idaho, felt that in order to recover Idaho's wild salmon and steelhead and prevent extinction, the lower Snake River dams must be breached. He recently presented a concept that included dam breaching along with a large suite of mitigation measures that he felt would ensure that agriculture, power, community waterfronts, etc that would be affected by dam breaching, would not be harmed.

The salmon and water dialogue continues but Mother Nature waits on no man.

The drought cometh and the trucks roll to save salmon in California

After year one of drought and heading into what's now being described as a "mega drought" in California, business as usual in the world of salmon shifted.

River conditions were going downhill rapidly. Low flows, rising temperatures, prospects of disease and high predation meant exceedingly low survival rates for young salmon migrating down the Sacramento River to the ocean. Reservoirs were at less than 50%, snow pack was close to all time lows. Rains were six to eight months away. There would be no extra water for fish or farmer.

In March, California Department of Fish and Wildlife took the proactive measure of starting the trucking of more than 17 million hatchery-raised Chinook salmon smolts from four hatcheries in Northern California, diverting them around perilous sections of the Sacramento River to the San Francisco and San Pablo Bays and seaside net pens.

The trucking operation was massive; it took 146 individual truckloads to transport 17 million young salmon. Truckers traveled over 30,580 mile between mid-April and early June delivering fish to eight different release sites. It was designed to insure the highest level of survival for young salmon on their hazardous journey to the Pacific Ocean.

I saw several of these releases in person. They were awe inspiring. Watching six or eight giant tanker trucks rumbling down the highway each containing 100,000 to 150,000 young salmon boggles the mind. Seeing thousands of young salmon flowing out of the pipes and tubes from tanker trucks into the bay or net pens at just one release site gives you an idea of how really big the operation was. And it went on day after day.

I asked the hatchery staff what they do to insure the fish made the trip safely. They told me that when temperatures soared, they added ice to the tanks. On one day in late May, for example, the temperature in Sacramento reached 105 degrees. Chillers were mandatory, oxygen levels were closely monitored and small levels of salt were added. Travel time from hatchery to release site varied from three to five hours. When possible they traveled during the cool of the early morning or toward dark depending on the outgoing tide.

Tides are critical. The outgoing tides in the bays sweep the little fish out to the ocean. Many of the releases took place in the dark on outgoing tides to minimize predation. That's when predators such as gulls and cormorants are sleeping, and without good light, sight predators such as seals, sea lions and many hungry fish species have trouble locating released salmon smolts.

Sport and commercial salmon anglers urged the California Department of Fish and Wildlife to do everything possible to save future salmon fishing from the drought conditions and assure that between 225,000 to 500,000 adult salmon return annually. In addition to providing sports fishing for thousands of anglers, the ocean and river salmon fishery is estimated by sports groups to generate close to $1 billion annually. Salmon advocates like the Golden Gate Salmon Association and numerous commercial organizations fully backed the salmon trucking.

Two, three and four years from now we will know the fate of these salmon smolts as they return to spawn and are caught by anglers in the ocean and rivers. Before being released, 25% of all these young salmon were implanted with coded wire tags identifying when and where they were released. These tags are read by biologists surveying salmon catches both commercially and sport caught. How many will return is uncertain. What is certain is that if they did not reached the ocean, there would be no return.