On a bright August day, Lake Namekagon is alive with sound. Standing on the shores in the early morning, three Northland student scientists and I hear the call of a loon, the splash of a fish, and the buzz of dawn insects. As we prepare our research equipment at the Forest Lodge Boathouse, these murmurs give way to the roar of boats cruising past, the laughter of children in the water, and the quiet chatter of anglers. Lake Namekagon, as reflected in the chorus of natural and human sounds we hear, is both a vibrant ecosystem and a gem for recreation. This morning, we are here to listen to the lake.
The Mary Griggs Burke Center for Freshwater Innovation has launched three research buoys as an initiative to understand the natural dynamics of Lake Namekagon, Garden Lake, and Jackson Lake. The buoys have sensors attached that collect measurements on the physical and biological characteristics of the lake, including temperature, oxygen concentrations, abundance of algae, and more. By tracking the changes in the water and lake life through time, we are able to listen to the lake as an ecosystem; hourly measurements provide us with the data to tell Namekagon’s changing scientific story.
The lake’s rhythm can be seen in the subtle undulations of water temperature, which naturally increase as the calls of loons give way to shouts of children and the surface water absorbs the morning sun. Water temperature peaks in late afternoon and retreats overnight, gradually warming throughout the summer. While water temperature will be of high interest to the families and anglers that gather at Lake Namekagon, we will be exploring the daily changes in a suite of additional measurements to assess the overall health and quality of the lakes.
One of these measurements will be monitoring algae levels. In lakes, daily peaks and valleys of oxygen reflect the health and production of the ecosystem. Algae, which produces oxygen as a byproduct of photosynthesis, is the foundation of the lake food web, yet too much algae production signals that the lake is impaired. A lake flush with algae can choke other aquatic life and is less inviting to those seeking a refreshing swim.
Globally, lakes are changing rapidly due to disruptions to the Earth’s climate. Our research will feed into a global database of buoys monitoring lakes on five other continents, providing an opportunity to compare Lake Namekagon side-by-side with similar bodies of water in forested areas or in far more human-dominated landscapes. In time, we will also be able to compare Lake Namekagon to itself as we collect a long-term data set on the water quality and health of this signature northwest Wisconsin lake.
Lakes are unique sentinels on the landscape, providing insight into the health and integrity of the freshwater ecosystem itself as well as the surrounding water- shed across years and decades. With its wide biodiversity, robust walleye fishery, long history as a social and cultural center, and location in the Mississippi River watershed, Lake Namekagon’s significance extends far beyond its shores. The lake is an ever-changing ecosystem with an intriguing story to share. As researchers, it is our job to capture this story, interpret it, and then write it down.
Peter Levi is a freshwater ecosystem ecologist passionate about teaching, field and laboratory research, and science communication and outreach. He and his family enjoy exploring the woods and waters of the south shore region.
