Dams and droughts are making it difficult for salmon to reproduce in California. Now hatchery programs are working to breed salmon in captivity but the process is flawed due to problems in keeping the fish DNA diverse.
CCTV’s Mark Niu reports one scientist claims he’s created a matchmaking service to alleviate the problem.
Genetics used to improve salmon hatcheriesDams and droughts are making it difficult for salmon to reproduce in California. Now hatchery programs are working to breed salmon in captivity but the process is flawed due to problems in keeping the fish DNA diverse. CCTV’s Mark Niu reports one scientist claims he’s created a matchmaking service to alleviate the problem.
At the Warm Springs Hatchery in Northern California, scientists tag and scan male Coho Salmon. Researchers need to know how often each one has been used to reproduce and which eggs will be their best match.
A three-hour drive away in Santa Cruz, California, 11,000 fish tissue samples arrive at the lab each year. Geneticist John Carlos Garza leads a team that extracts fish DNA, puts it on a chip, and then builds a matrix that determines which Coho Salmon are related in order to avoid inbreeding.
“We are determining on an individual fish basis, who mates with whom, we are essentially ranking partners for each individual female salmon It is in that sense, a matchmaking service,” said John Carlos Garza the research geneticist at the Southwest Fisheries Science Center.
The matrix is relayed to hatcheries, where the leading males are retrieved and sperm samples checked. The female salmon are killed but their eggs extracted and fertilized.
“Since we’ve started this program, we’ve seen the number of adults coming back to the watershed increase almost every year except for the past few drought years, so I would say that without this program there might not be any fish out there,” said Benjamin White a Fisheries Biologist.
Garza admitted when humans think they know better than nature, they usually don’t. But as researchers observe Coho Salmon populations go from near extinction to healthy levels, Garza said for now, they’ll keep working to mimic nature as best as humanly possible.
John Carlos Garza, Research Geneticist, Southwest Fisheries Science Center explains how hatcheries may have accelerated the decline of Salmon populations and how they’re working to change that.