A new report from the Cooperative Science and Monitoring Initiative (CSMI) has found that the ecosystem in Lake Huron has undergone significant changes in recent decades; in particular, the density of benthic organisms – those that live at the bottom of the lake – has dramatically decreased. These studies also looked at other aspects of the Lake Huron ecosystem, including primary production and contaminants and investigated using new technologies to improve assessments.
The Lake Huron benthic community has been assessed as part of CSMI studies since the early 2000s. In 2017, the U.S. Environmental Protection Agency’s (U.S. EPA) Great Lakes Biology Monitoring Program (GLBMP), in collaboration with SUNY Buffalo State University, led an extensive lakewide survey as part of the CSMI sampling effort. Results indicate that since earlier studies in the 1970s, the density of benthic organisms has dramatically declined in the lake, likely in response to the introduction of invasive mussels, Dreissena spp., starting with zebra mussels in 1989 and followed by quagga mussels in 1996.
In addition, researchers investigated Saginaw Bay to determine how primary production was being affected by high nutrient-loading tributaries, particularly in nearshore areas. From zooplankton to fish, researchers found little evidence that tributary nutrient loading had direct effects on primary and secondary production in Lake Huron open waters.
The study also investigated contaminants at two sites in Lake Huron using a variety of markers. The U.S. EPA’s Great Lakes Fish Monitoring and Surveillance Program (GLFMSP) assessed contaminants in lake trout and lower food web components for various contaminants, such as PCBs and dioxin and dioxin-like compounds. Researchers found they have decreased steadily but are still above Canadian wildlife protection values.
Finally, CSMI partners piloted several remote video approaches to enhance assessments of biological communities. One goal was to improve estimates of invasive Dreissenids spp. and round goby densities, which often occupy rocky surfaces that are difficult to assess using standard sampling methods. They found video image analysis for Dreissenid spp. populations in Lake Huron provided substantially improved information and estimates compared to Ponar grab sampling. Videos collected from tripod mounted cameras and autonomous underwater vehicles also hold promise for estimating round goby abundance.
Since 2002, environmental organizations from the United States and Canada have teamed up to assess conditions in the five Great Lakes. The team working on Lake Huron is a collaborative team of natural resource managers led by the U.S. Environmental Protection Agency and Environment Climate Change Canada with participation from federal, state, provincial, Indigenous, and local governmental agencies.
This binational program, CSMI, coordinates science and monitoring activities in one of the five Great Lakes each year to generate data and information for environmental management agencies. CSMI works on a 5-year cycle of priority setting, planning, in-the-field research and monitoring, data analysis, and reporting. The CSMI provides lake managers with science and monitoring information to make informed, science-based decisions on each lake. Sea Grants in the Great Lakes region support reporting and communications efforts for this research, ensuring the results reach the groups and people that need them. For more information: greatlakescsmi.org