Using Environmental DNA to Find Lake Sturgeon

Photo Credit

USDA Forest Service Photo.

Vern St. John and Jeremy Hubbard hold a sturgeon on Indian Lake.

Since 2020, NRS scientists have been using eDNA analysis to map lake sturgeon populations in three rivers that cross the Hiawatha National Forest in Michigan. These rivers historically harbored lake sturgeon, a secretive fish species, but their current distribution is unknown.

Lake sturgeon are long-lived fish that can grow to 8 feet long and 300 pounds. As many as 15 million lake sturgeon were once found in the Great Lakes but, starting in the early 1900s, their numbers were decimated by logging and commercial fishing. Today, their total population is thought to be less than 150,000.

The lake sturgeon is a regional forester sensitive species and has been petitioned for listing as a federally threatened species. Sturgeon populations are declining throughout their native range and sturgeon are listed as threatened in all but one of the 20 states where it lives.

There is concern that a lack of high-quality spawning habitat may be contributing to lake sturgeon population declines. The fish migrate up riverways from the Great Lakes to spawn, but it is currently unknown where specifically they spawn. Environmental DNA sampling during the spawning season will provide critical information about where sturgeon are spawning (and not spawning). Scientists can then identify and calculate the amount of potentially suitable spawning habitat on the landscape and use this to guide restoration efforts.

Key Findings

Early research results indicate that lake sturgeon are traveling much further upstream than previously thought. Future sampling efforts are planned to map the extent of their distribution in the Hiawatha National Forest.

Environmental DNA

Where aquatic and land-based wildlife species are located (and where they are not) is a challenging question for natural resource managers to answer, especially for species that are rare, new to the area, or secretive.

Environmental DNA is an emerging technology that relies on detecting tiny amounts of DNA that organisms shed into the environment through, for example, skin cells, hair, or urine. By extracting DNA from water, soil, or sediment samples and looking for species-specific DNA segments, scientists can determine if a particular species is present or absent at sampling locations. Doing this repeatedly over time helps scientists determine if a species is moving around, maybe in response to management activities on the land or in the water.

Understanding species’ locations and distributions, when analyzed together with habitat and environmental data, can help scientists understand species’ living requirements and identify key areas of habitat. All of this can help guide conservation and restoration efforts.

Expected Results

Expected Outcomes

This eDNA research collaboration will allow managers, foresters, and biologists on the Hiawatha National Forest to monitor lake sturgeon through time and plan habitat restoration activities.

This research is ongoing, and no scientific articles have been published about it to date.