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.