Learning from Lake Sturgeon with WCS Canada
Rachel Doornekamp | November 7, 2019
Throughout the month of October, a lake sturgeon research project put the DTG3 to work as they performed research on lake sturgeon ecology in the Moose River Basin watershed in Moose Cree First Nation traditional territory.
This collaborative research project between Wildlife Conservation Society Canada (WCS) and Moose Cree First Nation Resource Protection, was established to learn more about the movement and behaviour of lake sturgeon in natural and hydroelectrically dammed rivers of the Moose Cree Homeland.
Lake sturgeon, Canada’s largest freshwater fish, are unfortunately a threatened species. Lake sturgeon populations collapsed after overfishing due to the global demand for caviar. However, currently lake sturgeon still face threats of habitat loss, fragmentation, and declining water quality. These massive fish are incredibly important to the Moose Cree as both a food source and a species of significant cultural importance. It is therefore crucial that we learn as much as possible about lake sturgeon to help them recover, and to make the best management and planning decisions to help this unique species.
Lake Sturgeon Tracking
In order to learn about lake sturgeon health, habitat use and behaviour, the team has been catching and tagging fish with small transmitters which broadcast a unique “ping”: an acoustic message with a unique ID number. Acoustic receivers are then placed underwater by the group, anchored to the riverbed, and tethered on-shore. These receivers log the “pings” from transmitters whenever a tagged lake sturgeon swims by. It is important to note that the transmitter does not harm the fish: tagged fish go on to live completely normal lives with their internal transmitters. The data from the transmitters is logged and then downloaded from the receivers, not the transmitters in the fish. So, the fish does not need to be caught or disturbed again.
The team has two specific study areas: the North French River and Lower Mattagami River. The North French River is an undammed, natural system while the Lower Mattagami River is a dammed river, containing multiple dams, as part of a hydroelectric system.
By tracking the lake sturgeon, the team is learning how the fish use and respond to different river systems. This information can then be used to understand what factors are most important to lake sturgeon, and those that impact fish health and behaviour.
While the DTG3 allowed researchers to observe other fish during testing in clear Lake Superior waters; they were not able to get a glimpse of the lake sturgeon using the ROV. The ROV was primarily used to handle the underwater receivers.
During the spring, one of the receiver’s on-shore steel cable tethers was no longer locatable. Using the ROV, the team searched the riverbed for the cable or for the receiver. After recovering the receiver and changing its batteries, the receiver was redeployed so that it can continue the important work of monitoring lake sturgeon.
With receivers needing to be retrieved on a biannual basis for battery replacements, inspections and data downloads, the use of an ROV has proven to be incredibly handy for the lake sturgeon research team.
In addition to using the DTG3 to move and monitor receivers, the group incorporated the ROV into their Youth Program. The lake sturgeon research crew brought along Moose Cree youth on their field work to give the youth real fieldwork and science experience while also taking them parts of their traditional territory. The ROV brought an added level of excitement to the trip, while allowing youth to learn even more about what’s going on underwater in rivers.
During their last week with the ROV, the lake sturgeon team in Thunder Bay took the ROV to a grade nine science class at Dennis Franklin Cromarty First Nations High School. Here, they talked about the amazing species that lake sturgeon is, about the lake sturgeon research project, and ended the talk with a not-so-dry-land ROV demonstration in a large container filled with water, right in the middle of the classroom! This kind of novel, high-tech, hands-on science like the ROV deserves to be shared as much as possible.
Deep Trekker is absolutely thrilled to have helped out WCS Canada with such an awesome mission!