Laura Heironimus thinks of white sturgeon as the Columbia River's living dinosaur. Fossil records show they existed more than 100 million years ago, and maybe twice as long, or even longer. Today, white sturgeon are the largest and longest-lived freshwater fish in North America.
"Some of our oldest are probably over 100 years old. And we know from historical photos that they were 15 to 20 feet long, although we rarely see fish that large today," Heironimus said.
Heironimus leads the sturgeon, smelt and lamprey unit for the Washington Department of Fish and Wildlife. She and sturgeon managers representing Oregon and Columbia Basin tribes are pushing to retain and restore funding for white sturgeon surveys in the lower Snake and Columbia rivers, and to expand studies and develop a rearing facility to enhance certain population segments of this ancient fish.
On May 12, they presented a status report on white sturgeon to the Northwest Power and Conservation Council's Fish and Wildlife Committee, noting some populations are doing relatively well, while others are struggling. And the status of others is uncertain due to scarce information from intermittent surveys.
Heironimus said that without the dams, these fragmented groups of white sturgeon that live and spawn between the dams would be one large Columbia River population. Now, she said, they rarely move between the dams as fish ladders aren't designed for them, although some juvenile sturgeon get washed downstream to other pools.
"Some of these fish are likely as old or older than the dams that exist on the Snake River," Heironimus told the Council panel. "I think it's our job to make sure we are taking care of them." But reduced funding resulted in cutbacks to some of the survey work, and an unfinished scientific review of several projects leaves the fate of future survey work uncertain.
This year, the Bonneville Power Administration is funding the stock assessments in the pools between Bonneville and McNary dams at about $1.3 million, according to Mark Fritsch, the Council's project implementation managers. But surveys in the Snake River and the pool above McNary Dam have been sporadic at best. Each of four pools—above McNary, Ice Harbor, Lower Monumental and Lower Granite dams—were surveyed two or three times since 1995, Heironimus said.
"In recent years, we've only had funding for a few weeks of work and we have to use the same boats used for work in other sections of the river so it's been limited to August and September," she said in an email. Earlier sampling included surveys from April through September, she noted.
For the past two years, Ice Harbor and Lower Monumental sampling was funded at $195,000 in 2018, and $157,000 in 2019 through the Bonneville Power Administration's cost savings program.
Funding will depend on the outcome of an Independent Scientific Review Panel review of 44 different resident fish and sturgeon projects. The ISRP released a preliminary review in April. Fritsch said a final recommendation is slated for an October decision.
With no funding currently available along with travel restrictions and social distancing recommendations due to the COVID-19 pandemic, it's unlikely any of the assessments will happen this year, Heironimus said. She said WDFW is under a state-mandated hiring freeze, and non-essential workers can only be hired on a case-by-case basis. "Funding would have to be made available very soon to have gear and staff prepared to start this August," she said.
"We feel strongly that baseline monitoring is needed, whether on a three-year or even up to a five-year basis. It's important to have some form of consistent sampling in order to adaptively manage them," she said.
Because of the lack of information, and sampling information that suggests a lack of successful spawning, there is no sturgeon fishing in the Snake River, or in the pool above McNary Dam on the Columbia River.
BPA-funded surveys below McNary Dam have been more consistent, and ongoing since 1997. Blaine Parker, sturgeon program lead for the Columbia River Inter-Tribal Fish Commission, told the Council committee that stock assessments are now on a three-year rotation in the pools above Bonneville, The Dalles and John Day dams, and include winter tagging, and summer tagging and recapture. In the fall, young sturgeon are monitored.
Recent surveys show the population above Bonneville is healthy and stable after going from about 100,000 fish to over 300,000 in 2008, and then dropping back to 200,000 in most recent surveys. "That population is where it should be right now," he said.
In The Dalles pool, spawning conditions are not as good, and the overall percentage of adults spawning there is less than 1 percent. He characterized that population of about 100,000 white sturgeon as stable.
The white sturgeon in John Day reservoir is the smallest of the three populations, with about 30,000 fish, he said. This population is not replacing itself and studies have not explained why, Parker said. CRITFC is seeking approval for white sturgeon supplementation, and John Day pool would be a good candidate for that, he said.
Peter Stevens, Columbia River white sturgeon project lead for the Oregon Department of Fish and Wildlife, provided assessment results for white sturgeon below Bonneville Dam. That project received funding from states and a federal grant, and not from BPA, he said.
Stevens noted that the adult abundance of 9,000 fish exceeded the managers' desired status for the first time since 2012. "Exact numbers vary from year to year, but it's been on an upward trend. That's good news for the future," he said.
However, the abundance of white sturgeon measuring between 38 and 54 inches has dropped in recent years. In addition, the age classes are not at desired percentages. Fish managers like surveys to show about 95 percent of the population is juvenile, indicating successful spawning. Instead, 2019 surveys found 54 percent of the population is in the juvenile class, he said, dipping below the conservation status of 60 percent, he said.
Stevens said poor spawning success might be related to sea lion consumption and harassment. White sturgeon do not reach sexual maturity until they are between 15 and 24 years old, and females will absorb their eggs instead of spawning when conditions aren't right. It's physically stressful for them to absorb their eggs, he said. The lack of population growth could be due to either less-than-optimal habitat, or to harassment by sea lions, he said. They could also be spawning in other locations, such as the Willamette or Sandy rivers.
"This is a population that's not ideally where we'd like to see it, but it isn't in imminent short-term risk," he concluded.
White sturgeon are not listed as threatened or endangered in the lower Snake or lower Columbia rivers, but they are considered an emerging priority in the Council's Fish and Wildlife Program. They are highly migratory, and before the dams, could travel miles up and down river to feed and spawn. Heironimus said they've been highly impacted by the dams, as they are unable to navigate the fish ladders. They prefer a free-flowing river with larger cobble rather than deep reservoirs with sand and silt, she said. The healthiest populations are in the lower estuary, because they have access to the ocean, and the richer marine environment.
"Maybe salmon and steelhead get the spotlight, but I think that sturgeon are a pretty charismatic megafauna here," she added.