Back in 1983, it seemed like a good idea.
Local populations of California white seabass, prized by recreational and commercial fishermen for its mild, flaky white flesh, were declining. While a fishery management plan didn’t exist back then, sport fishermen had noticed a decline in their catches and asked officials for help. State lawmakers then reached out to the marine biologists at Hubbs-SeaWorld Research Institute in San Diego to see if they could boost stocks by trying something unusual — raising the fish in a hatchery and releasing them into the sea.
It wasn’t an entirely new idea. Americans have been attempting to raise fish in hatcheries in some form or another for at least 150 years. But this would be the first time scientists tried it with white seabass, launching a program that would become a model for other states hoping to bolster waning populations of wild fish, a process known as marine enhancement.
But as is often the case, things weren’t so simple.
Some 35 years and nearly $40 million later, the future of the Ocean Resources Enhancement and Hatchery Program (as it’s formally called) is in jeopardy: The first formal scientific evaluation has concluded that the program increased white seabass populations by less than 1 percent — a stunningly low success rate. Compare that to Alaska’s salmon hatchery program, which typically accounts for a third of the state’s total harvest.
It turns out that if you’re going to enhance stocks using a hatchery, species matters, and white seabass may not have been the best starting point. The hatchery-grown seabass suffered from high mortality rates within the first few months of being released into the wild. Even with tiny tags embedded in their heads, tracking them in the open ocean proved difficult. Of the more than 2 million fish that have been released since the program’s start, only 199 adults and just over 1,770 juvenile white seabass have been recaptured as of 2016.
Unlike salmon, which are hardwired to return to their original spawning grounds (or in many cases, their original hatchery stream), making them easy to count, white seabass roam without returning. And over the years, there were plenty of significant challenges to overcome: developing broodstock; caring for fish in their most sensitive larval stages; determining when and how to successfully release young fish into the wild; figuring out the best temperatures and feed mix to produce thriving fish; and trying to understand why exactly the breeding program continued to see malformed fish — a factor that also likely contributed to low survival numbers.
But in 1983, the idea to grow and release white seabass was a bold one. Even to this day, the white seabass program is considered a pioneer of marine enhancement efforts. The program itself falls under the authority of the California Department of Fish and Wildlife, but much of the work and expertise come from researchers at Hubbs.
“Should we have started the project with a different fish? It’s something we talk about quite a bit,” says Mark Drawbridge, a senior research scientist at the Institute, who joined the program in 1989. “I think halibut [a fish that was considered in the program’s early stages] would have been easier in a lot of ways. But the halibut research was discontinued because there wasn’t enough funding to go around.”
An enhancement program that garners less than a 1-percent bump in white seabass stocks might easily be dismissed as a failure. But officials from state and federal governments, as well as researchers from California Sea Grant and the science advisory committee that performed the evaluation, all say not so fast.
“Was the ultimate goal scientific knowledge? No, it was to enhance the wild populations. But there’s a lot of [scientific] value from what we gained, even if we didn’t reach that ultimate goal,” says Kathryn Johnson, an environmental scientist at the California Department of Fish and Wildlife.
Michael Rust, a science adviser for NOAA Fisheries Office of Aquaculture, says information from the program is in some ways as valuable as the fish.
“With stock enhancement programs, you have the opportunity to tag a whole group of fish, put them in the ecosystem, see where they go, what they eat, and how they grow at different temperatures. The value is in the information you get. From NOAA’s perspective, the enhancement is a bonus,” says Rust.
While marine enhancement programs may not capture the public’s attention or media spotlight in the way that oyster and salmon farming do, there are several programs in operation around the country. Alaska’s salmon fishery enhancement program might be the best known, but there are also marine enhancement programs in Texas, Floridaand South Carolina hatching and releasing economically important species like red drum, snook, spotted sea trout, southern flounder and cobia. The Texas red drum marine enhancement program, for example, is considered a success, with return rates that vary from just .2 percent to 17 percent, depending on the bay where samples were taken, the year and the season.
But measuring success can be tricky, when perhaps the more pointed question should be: Do marine enhancement programs actually do anything to fix the underlying problem of why a stock needs a boost in the first place? In the case of white seabass, the answer is no. A 2016 stock assessment of California white seabass showed stocks are currently considered depleted.
Kai Lorenzen, a professor of integrative fisheries science at the University of Florida, says there’s been a shift in thinking about the way marine enhancement programs might best be used.
“When the white seabass program was conceived, there was the idea [that] enhancing a fishery would be a good thing as long as you applied careful genetic management. But since then, our understanding of enhancement programs has evolved,” he says.
Using these programs to sustain or rebuild a very small population that would be lost would be a good use, he says. Stocking fish to be recaptured rather than to enhance the natural population — like Alaska’s program — could also be considered a good use. And, as climate change brings with it changes in ocean conditions, enhancement programs might become a critical tool for fisheries managers, especially for species that are sensitive to water temperature changes in their early lives.
But, according to some of Lorenzen’s research, many marine enhancement programs simply fail to deliver.
“Having looked at many, maybe one-third of enhancement [programs] would be successful on some criteria,” he says.
The findings in the new report will likely prompt other states to reassess their own marine enhancement efforts.
Whether California will decide to end its program and close the hatchery or move forward with a different species is yet to be decided. The state’s Department of Fish and Wildlife is planning to hold a set of regional public meetings in the coming months to gather input.
That input — from scientists, fishermen and the public — will be critical to the future of marine enhancement programs, says Theresa Sinicrope Talley, a coastal specialist with California Sea Grant who led the review of the seabass program. She says, “Whether enhancement programs like this are considered a success or not, depends on the goals — what the state and society decide they really want out of these programs.”
Top image: Captured wild adult white seabass are being readied for transport from Santa Catalina Island to the marine fish hatchery in Carlsbad.
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