“Arrrgh!” A falsely throaty voice sends a humorous shock above the sound of Celtic flute and drum song. The serenity of the fields is replaced with the energy of an Irish pub on Capitol Square in Madison, Wisconsin. This energy is matched by a gathering of a unique kind of independent conservationists; Here, there be “slough pirates.”
Dave Marshall, a consulting aquatic biologist and owner of “Underwater Habitat Investigations, LLC,” sits amidst a small group of his colleagues. This is more than a casual meeting over a black-and-tan (a stratified beverage of light and dark beer, for those uninitiated) at the local pub. This is where one warms up after a long cold day trudging through the back-waters, or sloughs, of Southern Wisconsin’s river systems. Marshall is studying the species in these less traveled places.
“These were thought to be lost places; just a spot for rivers to overflow and carp to breed. Or maybe at best a cleansing mechanism for the river,” begins Marshall.
According to Marshall, for decades, sloughs have been described in the prevailing scientific literature as “brackish” areas with low oxygen; insignificant to people or wildlife. Yet, there were few scientists that actually stepped into the slough to collect any meaningful data. Marshall has spent the last several years surveying this type of unique aquatic habitat – specifically on the Wisconsin and Sugar River systems. His findings are surprising, even to him.
“What I think I am rediscovering is that these places are a habitat in their own right – not just a support system for the river,” continues Marshall.
Instead of just finding a carp breeding ground, Marshall has found numerous and abundant other fish species. Some sloughs include relatively common game panfish, such as blue gill, pumpkin seed and sun fish. These fish actually eat the young of the carp, controlling the population of the less desired fish before it leaves for the river system.
Others sloughs have proved to be a refuge to rare species. One such species, the Starhead Topminnow, was thought to be extinct in Southern Wisconsin, before Marshall rediscovered it harbored in a slough along the Sugar River in Green County.
It hasn’t been all good news however, on a trip to the sloughs of the Sugar River, Marshall discovered a Mosquito Fish – an invasive species likely dumped from someone’s neglected fish tank. Like carp, this small silver fish survives, even thrives, in areas of poor water quality. Sadly, return trips have proved that it did not die off over winter. On a bright note, it doesn’t appear to be taking over this particular slough either.
Marshall’s theory is that because the slough is otherwise healthy, the other native fish are consuming the Mosquito Fish eggs. Marshall, who has also studied the effects of agricultural practices on adjacent waterways, feels buffer strips may be a significant reason the slough remains healthy. This particular slough was located adjacent to an area where buffers are preventing the surrounding agricultural runoff from reaching the water.
While Marshall’s surveys are a start, what he really hopes will happen is that a comprehensive study of Wisconsin’s sloughs will one day be possible. Of course, this means that the sloughs must remain protected in some way, until funding and staff can be put in place.
“We really don’t know the full value to place on it [buffer protected sloughs and oxbow lakes]” admits Marshall. “I hope to find out.”
Torque Writer (TM) This work is protected by US Copyright law, and may not be reproduced (wholly or partially) without the written consent and signature of the author, Rebecca L. Olson.
No comments:
Post a Comment