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Commercial fishing on the Great Lakes was built on lake whitefish, but for the past two decades, that species has been on the decline. It's now on the brink of collapse in parts of two of the lakes. Scientists are hoping they can get the fish to spawn in Northern Michigan's rivers. The fish have not spawned well in those places in over a century. Environment reporter Ellie Katz with member station Interlochen Public Radio tagged along on a fish stocking expedition in the woods of Northern Michigan and has this report.
ELLIE KATZ, BYLINE: Standing alongside Michigan's Jordan River, Kris Dey holds up a plastic bag full of water and thousands of little fish eggs.
KRIS DEY: Well, you can see all their little beady eyes. You can see their little tails. You should be able - if you look close to them, you should be able to see their heartbeat.
KATZ: These whitefish are only partially developed, but you can see impossibly tiny fish starting to take shape - all curled up inside each egg with two black eyes staring out.
How many are there in there?
DEY: Twenty-five thousand, two hundred and nine.
KATZ: Dey is the hatchery manager at the Little Traverse Bay Bands of Odawa Indians. The tribe has teamed up with two other tribes, along with the Michigan Department of Natural Resources and The Nature Conservancy. They want to see if stocking whitefish in rivers can help the dwindling species rebound. Here's the problem right now - lake whitefish lay their eggs on rocky, shallow reefs in lakes Michigan and Huron. Those eggs hatch, and the babies stay in the shallow water, eating zooplankton. But invasive quagga mussels have slurped up a lot of those zooplankton, and baby whitefish have very little left to eat these days. Scientists like Matt Herbert with The Nature Conservancy think that's where rivers can come in.
MATT HERBERT: These rivers feed into more nutrient-rich habitats. They'll have a lot of zooplankton. At first, they'll hatch, and they'll just basically be passive. For the most part, they're just going to drift down in the current, and they'll basically - wherever the river delivers them, that's where they'll hang out. And then once they get there, then they'll start looking for food.
KATZ: These eggs the team plants in the Jordan River today should float down into a nearby lake, then return to these same waters to spawn several years from now. At least, that's the idea. But stocking the eggs in the past has been a challenge. Take last year, for example, when they planted thousands of eggs into incubators, which ended up full of fungus and sand.
(SOUNDBITE OF WATER RUSHING)
ANGEL GUERRERO: So obviously, that did not work.
KATZ: That's Angel Guerrero, also with the Little Traverse Bay Bands.
GUERRERO: So I'm more for - the proponent of trying something different.
KATZ: Today is that something different. They're testing out a new strategy. Instead of using incubators, the eggs'll get spread directly onto the rocky river bottom, like how they would in the wild. The team tilts a long PVC pipe down into different spots in the river.
DEY: So we use the pipe to kind of aim them down into the water.
KATZ: That's Kris Dey again. They pour the eggs into the pipe, and like people at a water park, the little whitefish go sliding down to the riverbed and disperse.
(SOUNDBITE OF WATER SPLASHING)
KATZ: The whole process only takes about 15 minutes.
How's it feel doing another year a different way?
DEY: I'm excited to see how this turns out. I think this should do really well.
KATZ: Underlying all this, though, is a ticking timer for whitefish. The 25,000 eggs they planted today might seem like a lot, but it's a fraction of the amount they planted last year. The reason for that? There just aren't a lot of whitefish out there to collect eggs from anymore.
DEY: In a place that we normally catch 400 or more fish, we only caught probably 32 - quite a decline.
KATZ: But Angel Guerrero says that's what keeps him passionate about the project.
GUERRERO: Honestly, a lot of hatchery work is working yourself out of a job. Your hope and goal is to that they can just take care of themselves, and you don't have to take care of them anymore.
KATZ: It'll be years before they'll truly know if this works - before they can see whether whitefish are returning to the river to spawn. But for now, they'll wait, gather more data and keep trying.
For NPR News, I'm Ellie Katz in Mancelona, Michigan. Transcript provided by NPR, Copyright NPR.
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