All Roads Lead to the Great Lakes: How Invasive Species Get Here & Ways You Can Help

Photo courtesy of © Shedd Aquarium/Brenna Hernandez

We're wrapping up the last days of National Invasive Species Awareness Week for 2015. More than 180 invasive species have adopted the Great Lakes ecosystem as their home. Asian carp might be some of the most prominent invaders we hear about in the Great Lakes region and are currently stalled in the Chicago Area Waterway System just 55 miles away from Lake Michigan near Shedd Aquarium's home in Chicago.

These now notorious fish made their way into the Mississippi and Illinois rivers by escaping aquaculture facilities in the 1970s, but there are a number of invasive species who have successfully infiltrated the entire Great Lakes basin and St. Lawrence Seaway through other pathways.

  • Pet Release: When people think of the scary invaders threatening native species in the Great Lakes, they probably don't think of the friendly, familiar goldfish. But when pet owners empty their aquariums into the lakes, they unleash a non-native species that has managed to take up residence in the shallower, warmer and more populated areas of the Great Lakes basin, competing with native forage fish like darters and minnows for food and habitat. By not releasing aquarium fish into the Great Lakes, rivers or streams, you can help prevent future invasions of goldfish and other popular pet species.

  • Bait Dumping: For anglers, sometimes bait is the key to a catch, but did you ever stop to think that your bait could become an invader? Bait fish used for sport fishing can come from waters around the world and these small or young fish are often indistinguishable from native minnow species. If unused bait is dumped into the Great Lakes, these small invaders can displace native fish there. The rudd, a small silvery fish originally from Western Europe, has established populations in southern Lake Michigan, Lakes Ontario, Erie and the St. Lawrence Seaway due to bait dumping. Though bait policies can vary between states and provinces in the Great Lakes region, many have regulations prohibiting the sale of invasive bait species and bait dumping. You can do your part by disposing of bait fish responsibly.
  • Ballast Water: Species like quagga and zebra mussels--some of the Great Lakes' smallest yet most costly invasive species--found a foothold in North America after transoceanic ships pulled them in with ballast water in Europe and flushed that water into the lakes when the boats picked up new freight. These tiny bivalves have caused millions of dollars' worth of damage, spreading rapidly to encrust surfaces of submerged objects and clogging intake pipes at water treatment and power plants. Governments across the Great Lakes basin have taken action, working to pass strict regulations requiring any oceangoing ships to dump their ballast water before entering the lakes or St. Lawrence Seaway. Boaters can help stymie these aquatic hitchhikers by cleaning, draining, and drying their vessels and equipment before moving into the lakes or other waters.
  • Across the basin, organizations, concerned residents and governments are working together to mitigate and reverse, when possible, the damage caused by invasive species. Here at Shedd, we focus our efforts on native habitat restoration, monitoring research utilizing the power of citizen scientists and educating the more than 2 million guests who visit us each year about ways they can help prevent the spread of invasive species.

    We dream of the day that the Great Lakes regions' 3,500 native plant and animal species, from mudpuppies to sturgeon, flourish. Let us know how you're helping make that dream a reality. Share your stories with us by tweeting @Shedd_GL or leave a comment below.