A three-year study looking into the genetic diversity of Rainy River’s sturgeon population is underway by Rainy River First Nations, with a Ph.D. student scheduled to come in and run it this fall.
Jen Mercer, head of the band’s program on the Rainy River watershed, said the main thrust of the study now is collecting DNA data from both live sturgeon and sturgeon cartilage at various archeological sites along the river.
Mercer said this should allow them to compare the sturgeon’s genetic diversity now to that of 200-300 years ago.
“Over the past 100 years, we’ve seen two sturgeon population crashes,” she noted, crashes which would have “funnelled” the diversity down each time.
Knowing how different the genetics of the current population is will give the band and the area a better idea of how to manage the sturgeon. If the diversity is low, it’s wiser to keep a higher population of fish in the river.
If it’s high, the number of sturgeon harvested can be increased.
“Lake sturgeon have been culturally important to us for thousands of years,” Chief Jim Leonard remarked. “We are funding this genetic study in order to protect, conserve, and revitalize lake sturgeon in the Rainy River watershed.”
Mercer said the band also will be trying to maximize the genetic diversity of the sturgeon at its hatchery. Lorraine Cupp, an aquacultural technician there, said they’re combining the eggs of 10 female sturgeons with the sperm of 30 males this year.
Eggs from each female are divided up into three different bowls, with the sperm from a different male added to each bowl, she explained. This is repeated for all 10 females.
All the sturgeon have been tagged, and each batch of eggs is kept separate and marked with who their parents were, Cupp added. So if any breed stock comes from those eggs, they won’t be used to breed sister to brother.
A natural sturgeon hormone is used to help get the fish to the right phase when it comes time to collect the eggs and sperm. “This way, we can say when they’re going spawn instead of 3 a.m.,” Cupp said.
Meanwhile, the hatchery still has a tank of six-year-old sturgeon plus the few survivors of last year’s spawn.
“They really don’t know what happened [last year],” Cupp admitted, noting several factors had to be dealt with. “That’s why we built a new incubator for the eggs.”
She said the sturgeon have been fairly easy to work with. But handling a six-foot long fish out of water does have its drawbacks.
“I got hit in the face [Monday] night,” Cupp said. “It’s still tender.”