Watersheds and waterways face significant challenges, not only from chemical pollution and habitat manipulation but also from biological pollution caused by invasive species.  These invaders—plants, invertebrates, and fish—modify aquatic food webs and make it more difficult to support aquatic life as defined by the Clean Water Act and the State of Illinois.  The presentation will cover two important but lesser-known invasives that are appearing in local waterways.  Hydrilla, a fast-growing submerged aquatic plant, is considered one of the most aggressive invasive aquatic plant species in the world.  Hydrilla can reproduce by the thousands from both plant fragments and tubers, quickly forming dense mats and outcompeting native species.  It has the potential to alter fish and macroinvertebrate populations, zooplankton, and water chemistry.  The second species is Round Goby, an invasive fish that preys on the eggs and young of native fish and directly outcompetes native species like sculpin (which it resembles) and logperch for food, shelter, and nesting sites.  The Round Goby has a remarkable ability to climb over obstacles using its pelvic fins and can survive in degraded waterways.

The presentation will look at the presence of these invasives, identification, and what might be done to control them.

Presenters:

Alana Bartolai - Ecological Services Program Coordinator, Lake County Health Department and member of the Illinois Hydrilla Task Force

Chris Yoder - Technical Director, Midwest Biodiversity Institute, Ohio.