For her master’s thesis five years ago, Brennan Dow went fishing.
But his initial project – seeking to determine if yellow perch spawned in Milwaukee Harbor – would soon become a larger search for aquatic life across the city. Dow and his professor at UW-Milwaukee School of Freshwater Sciences, John Janssen, dived deep – literally – into Milwaukee’s harbor and rivers in search of fish, and used bathymetry and sonar. to map the underwater landscape. Their two-year fishing trip captured some of Wisconsin‘s most prized game species – often in healthier-than-expected populations given the legacy of waterway pollution.
Such information is of interest to far more than their fellow researchers and experts in the field, so Dow and Janssen have sought to educate the public about their fish discoveries in a bid to reverse the script on Milwaukee‘s long-distressed urban waterways. Living, and in many cases prosperous, creatures could help transform the city’s waters from industrial casualties to civic goods.
Dow and Janssen have teamed up with UWM arts professor Kim Beckmann to create a series of luxuriously designed maps and accompanying videos that describe and explain the city’s aquatic ecosystems and wildlife.
The maps were released last fall, available online and printed on canvas for Milwaukee Public Schools, while also hanging at Discovery World. The team hopes they will also be displayed in stores, used as placemats in riverside restaurants, and carried by kayakers.
The maps and the research behind them are also used by an alliance of agencies to inform the city’s vast project to clean up, rehabilitate and develop the port and rivers. Dow, who published his thesis in 2018, now works as the Department of Natural Resources coordinator for this effort.
The map-guided work would help address one of the “deficiencies” that led to a federal designation of “area of ââconcern”: the degradation of fish and wildlife populations. The specific recommendations that Dow made in his thesis are now part of the official clean-up plan, including connecting the habitat “hot spots” that are shown on the maps – often in man-made detritus like concrete that sinks. collapsing, bent metal, or thrown household items. Creating habitat paths through the arid places between these ‘islands’ could allow, for example, baby fish to move safely between a popular spawning ground in the Summerfest Lagoon and a location near the Breeze Wall. from the harbor where they could feast on tiny invasive bloody reds. shrimp.
Consult and download the map here.
âObviously, a fish living in paradise will not cross the desert to get to another paradise,â explains Dow. “Connecting these spots so that the fish get from point A to point B was part of the recommendations.”
The cards represent 51 species of fish, including northern pike, lake sturgeon, coho salmon, chinook salmon, bluegill and rainbow trout. The invasive black-spotted goby was also found in abundance, along with swarms of bloody red shrimp.
Dow got his scuba diving certification for the job, and scuba diving in the harbor helped him and Janssen get a bird’s eye view. Janssen described a descent through about 10 feet of murky green water near the surface, then a dip into a cooler, clearer water level, “where you get a shock of cold and all of a sudden you can see 30 to 40 feet “below, and” look at the green ceiling above you.
He said they knew the layers of water from the temperature probes, “but swimming through it gives you a whole different perspective. Salmon that like cold water can swim in that cold, clear water but seek fish in the hot water above, soar in the hot water and then rush to relax, like an inverted sauna.
The Lake Michigan Fund, which supported the Milwaukee work, funded the team for similar mapping projects at four other Lake Michigan ports: Port Washington, Sheboygan, Manitowoc, and Two Rivers.
âDuring the pandemic, one of the things people have realized and found comfort in is the environment,â says Beckmann. âWe turn our homes into urban jungles because there is something to nurture, care for and see things flourish and grow. Maps are a way to help people really understand what’s going on underwater. Some people are absolutely afraid of what’s going on underwater, so if they can truly understand that there is a vibrant ecological system there, we can help support and nurture it.