By Coggin Heeringa, Program Director/Naturalist, Crossroads at Big Creek
Crossroads at Big Creek will have another fish on the line. Or, more accurately, the second on-line lecture of the “Fish Tales Lecture Series: Presenting the Science of Great Lakes Fisheries.”
On Thursday, March 4, Dr. Dan Isermann, of the Wisconsin Cooperative Fishery Unit of the University of Wisconsin – Stevens Point, will present “Where Fish Wander in Green Bay: Tracking the Movements of Walleye and Whitefish.” Dr. Isermann will discuss the results of his research on the movement of walleye and lake whitefish throughout Green Bay using the latest acoustic telemetry technology as part of the Great Lakes Acoustic Telemetry Observation System.
For Zoom login info, visit the Door County Library Calendar and look for the “Virtual Fish Tales Lecture” on Thurs., March 4 at 7:00 pm.
I did quite a bit of wandering myself last summer. For decades, I had been leading nature hikes on trails, feeling rather like a mother duck being followed by a line of ducklings. With normal group programming canceled this year, I was able to venture beyond our established trail system and just wander aimlessly through the 200 acres that comprise Crossroads’ three preserves – Big Creek, The Cove and Ida Bay.
I’ve read that flocks of certain wild birds wander in winter. It seems true at Crossroads. For example, flocks of goldfinches, siskins, and waxwings suddenly will show up for a couple weeks and then, just as suddenly, disappear. So, are these irregular winter migrations just aimless wandering?
Most researchers think movement is purposeful, that these birds are looking for food. But more often than not, flocks will disappear when there is still plenty of food available.
I once heard a lecturer suggest that birds instinctively leave an area before they run out of food. If they stayed until everything was consumed and then got stuck in an ice storm or became grounded by high winds, they would perish. So they somehow know to move on. They wander.
But fish wandering? I wonder as I wander, but I also believe in science. So I turned to Mark Holey, the retired fisheries biologist who coordinates our Fish Tales Lecture Series.
According to Mark, “Fish movement is based primarily on eating, avoiding being eaten, and sex.” But, he added that there is an element of comfort involved as well. Some fish prefer cold water. Other species seem to like warmer water. So fish usually are found where they are comfortable, at least if there is adequate food.
Mark further explained, “They also react to alterations in their physical environment such as currents, pressure changes and wind events. The temperature tends to stratify in water (going deeper gets colder) but when a strong storm or wind comes through, the stratification gets disrupted and causes fish to move. Currents can change. Water that was calm can become raging, forcing fish to find refuge or simply hug the bottom as best they can. Current and temperature changes can be abrupt and significant in Green Bay, and that can cause fish to move great distances.”
So, to answer my question, Mark summarized, “Fish do wander (move), but I doubt they wander aimlessly, rather with a purpose. Being cold-blooded, their activities are more a function of their environment.” We certainly encourage wandering at Crossroads at Big Creek. Winter is a great time to explore, and we’ve found snowshoe and boot prints throughout the preserve. (Free preserve maps are available at the two trailheads at the Collins Learning Center parking lot on Michigan Street.) As long as the snow is adequate and the temperatures are appropriate, we will continue our Ski (and Snowshoe) For Free program on weekends.
Visit www.crossroadsatbigcreek.org for current information on trail conditions and hours of operation.
Crossroads at Big Creek Learning Center and Nature Preserve is located at 2041 Michigan Street, Sturgeon Bay, Wisconsin. Crossroads is a 501(c)3 organization committed to offering education, conducting research and providing outdoor experiences to inspire environmental stewardship in learners of all ages. We welcome your support! Become a member of Crossroads by mailing your support to P.O. Box 608, Sturgeon Bay, WI 54235, or donate online at www.crossroadsatbigcreek.org. Ski for Free availability and trail condition are updated on our website daily during ski season.