Sturgeon studies examine spawning, bring science to school

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Capital News Service
LANSING — Researchers at Black Lake are studying threats to sturgeon and using their findings to teach biology to students from kindergarten through high school.

A young sturgeon. Photo: U.S. Fish and Wildlife Service.

A young sturgeon. Photo: U.S. Fish and Wildlife Service.

Among the questions being examined at the 10,130-acre lake in Cheboygan and Presque Isle counties is why the prehistoric fish hasn’t reproduced in the wild as much as scientists would like.
There are some working hypotheses, said Edward Baker, one of the lead investigators on the project. One is theory is that the habitat isn’t ideal for sturgeon.

“The habitat has changed sufficiently from what it was before Europeans extensively settled the state that the larvae, once they hatch and start to grow, just aren’t surviving,” said Baker, the lake sturgeon coordinator at the Department of Natural Resources (DNR).
“Pollution and water quality issues were probably a problem back around the turn of the century when the sturgeon initially declined,” he said.
Nowadays, people don’t pollute as much and water quality is much better, he said. The biggest habitat challenge is that many rivers where the sturgeon spawn have dams.
Dams change a river’s flow and block traditional spawning grounds. Complicating the matter is the sturgeon’s unique reproduction, said Kim Scribner, another lead investigator.
When most people think of fish spawning, they think of species that make nests; where an area is carved out, the female lays the eggs, the male fertilizes them and there is some level of parental care, said Scribner, a fisheries and wildlife professor at Michigan State University.
But sturgeon release sperm and eggs that are distributed over large areas of water, he said. “It’s a very inefficient system. It requires a lot of individuals.”
With fewer fish, the process is even less efficient. Sturgeon require up to 20 years to reach sexual maturity.
Invasive species may also be a persistent problem, Scribner said. “One of the largest predators of larvae and juvenile lake sturgeon are invasive rusty crayfish. They are voracious predators on sturgeon, even at older age levels where the individuals are large enough to be beyond the threat of predation by most fish predators.”
But the researchers aren’t letting sturgeon go down without a fight. They also run a sturgeon hatchery near Black Lake.
Research there provides valuable information about how genetic diversity may help preserve the species, said Dave Borgeson, supervisor for the Northern Lake Huron Management Unit of DNR’s fisheries division.
If there’s a lot of genetic diversity in a population, it allows that population to respond better and more quickly to a change in the environment, Baker said. If a population is very close genetically, it could be especially susceptible to a particular disease that could wipe out the whole population.
The project also develops K-12 curricula derived from actual data that scientists gather sturgeon. It includes lesson plans that educators have used in their own science classes.
For Scribner, that aspect of the project is about giving students an experience with real biology.
“Kids can get really excited learning about science, technology, engineering and math types of work but in the context of a very charismatic species,” Scribner said. The sturgeon, with its huge, 6-foot body and shark-like tail, inspires students to look into the data and interpret graphs to see what they say about the sturgeon and their environment.
Lesson plans include instruction about the scientific method, egg survival, capturing juveniles and spawning behavior.
Beyond the science, the classes also instill children with a sense of attachment to the environment, and as future voters, a sense of responsibility.
Baker said, “I don’t think it’s any secret that, over time, we’re becoming a more urbanized society and students are less and less exposed to the natural world.
“It’s important to give students an understanding that there is a natural world around them that does provide benefits for us, and if we don’t take care of it, those benefits will disappear,” he said.
Matthew Hall writes for Great Lakes Echo.

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