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  • The West Coast of the United States was once teeming with salmon populations from Baja

  • California to Alaska. 75 years ago, up to 400,000 coho salmon would return to spawn

  • in California streams.

  • But in the last 20 years, those numbers have dropped to as low as 3000 in the 1990s, and

  • we sometimes less than 1000.

  • These fish are not only an incredible symbol of the region.

  • They're also an important indicator for the health of their entire ecosystem.

  • Now, in order to save them from the brink of extinction, a group of experts devised a

  • fish matchmaking service of sorts, complete with DNA profiles and tiny barcodes.

  • Coho are a real iconic species, well salmon in general, are iconic species of California and

  • the Pacific Northwest and California has some of the most southern populations of salmon

  • and steelhead in the United States.

  • They are kind of an indicator of water quality and habitat availability, not just for themselves

  • but for all animals and plants that rely on these coastal watersheds in California.

  • But for such an important species, the human race hasn't been too kind to them,

  • there has been a long history of land management practices that have been really harmful to

  • them over the years we've built dams that have blocked them from a lot of their historical

  • habitat.

  • We're diverting water that they need to survive in the summertime and a lot of watersheds.

  • There's kind of a laundry list of things insults that have been foisted upon them over the

  • last hundred years.

  • Part of what has made salmon such an icon for California is that they're ridiculously heart animal.

  • Starting their lives in a river, they can migrate more than 1000 miles to the ocean,

  • only to return all the way back to their home river, about a year and a half later.

  • They survive predators from bears to sharks to fishermen and shift easily from freshwater

  • to saltwater, warm coastal waters to the frigid ocean.

  • It's only with these more recent land management practices and overfishing that they've lost

  • such substantial numbers.

  • And here in Northern California coho salmon populations have dropped to a dangerous level.

  • So now the fight is on not only to increase their numbers, but ensure they're healthy

  • and strong enough to make the annual journey to and from the Pacific Ocean.

  • And to do this.

  • Many groups from around the state came together to help with an innovative breeding program

  • sequencing salmon DNA.

  • We're collecting DNA from them so that we can sequence their DNA and create a profile

  • for each individual, and then every individual in the population will be kind of stacked

  • up against each other.

  • We're going

  • to be looking to help breed

  • the males and females that are most distantly related to maximize the amount of outbreeding

  • and genetic diversity in the population.

  • So, picture an online dating website crossed with a DNA sequencing service, but you know, for

  • fish.

  • And it all starts with a collecting expedition.

  • In this project,

  • once the wild fish had been born in the watershed, and they're probably around...

  • Yeah, they're about six or seven months old.

  • We're going out and looking for those fish and capturing some portion of the young wild

  • fish that are out there, and bringing them into the hatchery.

  • The teams will carry these young coho down the mountain on their backs and bring them

  • here, where their DNA information will be taken and eventually matched with an unrelated

  • mate.

  • So they sequence all the DNA and then look at the different alleles, and they use that

  • information to create kind of metrics of relatedness between individual fish in the same way that

  • if you submitted a DNA sample and your mom and your mom's sister and your mom's brother

  • did they would be able to figure out how you were related it's the same kind of process

  • really.

  • So we're able to identify brothers and sisters, full siblings, half siblings, first cousins,

  • etc using that information, and then every individual in the population will be kind

  • of stacked up against each other.

  • And we're going to be looking to help breed the males and females that are most distantly

  • related to maximize the amount of outbreeding and genetic diversity in the population.

  • This might sound like an awful lot of work just to breed some fish, but genetic diversity

  • is the only chance the species has for survival.

  • When populations shrink, so does the amount of mates to choose from, which will eventually

  • lead to inbreeding and inbreeding could result in passing on harmful recessive genes to future

  • populations.

  • That's a bad thing because if brothers and sisters or first cousins are reproducing

  • together, it really reduces the fitness of the offspring so they can have deformities

  • like problems with their fins, they can be more vulnerable to disease, it just really

  • dramatically reduces their ability to make it to an adult and reproduce themselves.

  • And without salmon, the multiple ecosystems where they live could suffer because not only

  • have they been historically important food source for us humans, but their lives and

  • deaths by a vital role in the survival of both flora and fauna.

  • When they come back as adults, they spawn in rivers coho salmon die pretty shortly thereafter,

  • and they're a really important source of nutrients to the terrestrial forest environment.

  • So in order to protect this critical species, and really, all critical species.

  • We need to help grow the population in a healthy way teams are raising a few generations of

  • young coho here at the hatchery and will start returning fish to the wild this winter genetically

  • diverse partners will be released together to breed in the wild naturally, hopefully

  • increasing the fitness and survival of their offspring.

  • The hope is that this DNA program will be the thing that eventually revitalizes these

  • vital fish.

  • The goal is to get this population back up to their original numbers, and that may take

  • decades.

  • In the meantime, we can try to do our part.

  • People can certainly support conservation organizations that are working to rehabilitate

  • these species and their habitats, and also take your kids out to see them in the wild,

  • and help kids develop a passion for nature and for salmon and protecting them

  • in the future.

The West Coast of the United States was once teeming with salmon populations from Baja

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Online Dating Could Save Coho Salmon

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    Summer posted on 2020/11/11
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