Tagging, diet and genetics research
“The technology we use to study lake sturgeon has increased tremendously in several different areas,” Scribner says. “How we track fish with tags is similar to what you’d put in your pet.”
A 12mm PIT tag used to actively monitor adults and juvenile lake sturgeon. Image courtesy of Doug Larson
Almost all of the 1,189 lake sturgeon in the Black River have been tagged with a passive integrated transponder, or PIT tag, inserted into the fish. PIT tags allow researchers to track individual fish and record biological information such as the fish’s weight, length, location and date of spawning. Researchers can also track their movement within the Black River system without a researcher ever having to touch the fish. Antennae arrays at the mouth of the Black River and along the riverbanks pick up the signals emitted from the PIT tags and record them.
MSU has been a leader in using DNA technology to look at the diets of lake sturgeon predators.
"We want to know if the predators are eating sturgeon or other things like insects because there isn’t enough sturgeon?” Scribner says. “We also monitor conditions like if there is a new moon with lots of light that can impact the number of sturgeons eaten. This has helped us gain tremendous insight into sturgeon predators.”
Researchers at the Black River facility are internationally known for their genetics research where they can look at the genetic makeup of the lake sturgeon that successfully spawned — at least once every three to four years — compared to fish that haven’t spawned. Thanks to the PIT tag technology, the researchers know which males most likely fertilized the females’ eggs. This means they can analyze the genetic data of the parents before lake sturgeon larvae grow into juveniles.
Like humans, sturgeon need time to grow up before they become parents. It takes male lake sturgeon approximately 15 years and females about 25 years before they are mature enough to spawn, which provides a large gap of time where the fish are vulnerable to predators and poachers.
“Lake sturgeon are uniquely susceptible to over-harvest and habitat loss,” Larson says. “We have developed outreach and volunteer programs to protect the fish.”
Hooking communities with outreach and education
Each year, 1,500 lake sturgeon are released into the Cheboygan River drainage system, including 500 fish released into the Black River, but not all of the fish survive.
Holding lake sturgeon juveniles from the Black River hatchery before releasing them into the Flint River as part of the Saginaw Bay sturgeon restoration effort. Image courtesy of Michigan Sea Grant
“Local groups like the Sturgeon for Tomorrow have developed the sturgeon watch program where hundreds of volunteers learn about lake sturgeon biology and guard the river during spawning to prevent poaching,” Scribner says. “It’s been a tremendously successful program.”
“Sturgeon are a charismatic fish that hook educators and youth, as well as their parents and communities, on being excited about the rearing of fish, which is part of the stocking program,” says Brandon Schroeder, a senior extension educator with Michigan Sea Grant, a program dedicated to the protection and sustainable use of the Great Lakes and coastal resources. “It also is a good way for us to have that conversation about human interactions with the environment, both the negative and the positive.”
Another community science program aimed at K-12 students is the Sturgeon in the Classroom program, where students help raise a lake sturgeon in an aquarium in their classroom during the school year and then return it to the hatchery or release it into a local river sturgeon call home.
“When these kids realize they are going to be adults before these fish are is really an ‘ah-ha’ moment for them,” says Meaghan Gass, an extension educator with Michigan Sea Grant. “They want to protect the fish so that they can be around for a long time.”