Managing Great Lakes Invaders

The Great Lakes are a natural wonder – and are also some of the most heavily-invaded ecosystems in the world. Over the past few centuries, many non-native plants, animals, and microorganisms have entered the Great Lakes through bait buckets, cargo ships, and human-built canals. Once here, some of these species have caused significant damage to local ecosystems and economies. 

Today, nearly 200 non-native species are present in the Great Lakes -- and more are on the way. So how are federal, state, and local agencies addressing this environmental challenge?

This Story Map, created by the team behind the  Great Lakes Aquatic Nonindigenous Species Information System (GLANSIS)  and  Michigan Sea Grant , showcases the “ Managing Great Lakes Invaders ” animated video series, along with species distribution maps and additional resources about the organisms featured in these videos and their ongoing management.

Watch the videos, click through to the maps, and explore the links included in this Story Map to learn more about how researchers, elected officials, industry, and Great Lakes residents are working together to protect the region from aquatic invaders.

To better understand just how many aquatic nonindigenous species have been reported in the Great Lakes basin, click on this map, which displays all species reported through GLANSIS. Each point represents an individual sighting, and clicking on them will reveal details of the species and when it was found. Which species can you find in a waterway near you?

Learn more about each of these species through  GLANSIS , a one-stop shop for information about introduced aquatic species in the Great Lakes. GLANSIS is a Great Lakes-specific hub of USGS’s  Nonindigenous Aquatic Species (NAS)  database, funded through the  Great Lakes Restoration Initiative (GLRI) , hosted by  NOAA’s Great Lakes Environmental Research Lab (GLERL) , and staffed by  Michigan Sea Grant  and NOAA-GLERL. In addition to map data, GLANSIS profiles host information about identification, ecology, risk assessments, management, control, and much more for each of the 180+ introduced species present in the Great Lakes basin, as well as watchlist profiles for potential future invaders. Some of their stories continue below...

Every year, hundreds of ships transport millions of tons of cargo into and out of the Great Lakes, but in the late 1980s, scientists discovered that ocean-going ships were one of the main channels allowing invasive species to enter the region. The ballast water these ships used to balance the weight of their cargo often picked up aquatic organisms from other ports around the world, providing a pathway for them to enter the Great Lakes when the water was pumped out again.

To help stop the invasion, regulators and the shipping industry worked together to develop a procedure called ballast-water exchange that uses salt water to flush the tanks of these ships, and an additional method to rid them of the sandy sludge at the bottom of the tanks that could still be harboring stowaway species – a process that’s proved highly successful at preventing the introduction of new aquatic invaders.

Watch the video below to learn more about this invasion pathway and how effective cooperation between scientists, regulators, and the shipping industry shapes legislation and ship designs to continue protecting the Great Lakes.

This map shows reported sightings of species introduced or spread via ballast water, including the  round goby ,  spiny waterflea ,  zebra  and  quagga mussels , and many more. For the full list of species introduced to the Great Lakes via ballast water, use the  GLANSIS Species List Generator : selecting “Shipping” from the Pathway field will create a list of species transported through ballast water based on historical specimen records.

To learn more about ballast water regulations and the positive effects they’ve had on Great Lakes invasion rates, check out these resources from the  Great Lakes St. Lawrence Seaway System , the  Great Waters Research Collaborative , and  NOAA-GLERL .

The invasive sea lamprey (Petyromyzon marinus) is a parasitic, eel-like fish that has spent decades harming Great Lakes fisheries, but thanks to the hard work of scientists and environmental managers, populations of this aquatic invader are finally under control.

Accidentally introduced to the Great Lakes through human-built canals, invasive sea lamprey have adapted to survive in the region, where they latch on to other fish to suck their blood, often killing their prey in the process. Their presence devastated native species and the local economies that relied on them, and in the 1950s the situation got so bad that the international Great Lakes Fishery Commission was established to address the problem. Years of regional collaboration and research led to a breakthrough in the form of a lamprey-specific pesticide, and this new chemical tool, along with other strategies, allowed researchers to push back against the sea lamprey invasion.

Across the Great Lakes basin, sea lamprey populations have been reduced by 90 percent, and this reduction has held for nearly 60 years. Thanks to the persistence, dedication, and resources of government agencies, sea lamprey are currently under control in the Great Lakes.

This map shows sea lamprey sightings throughout the Great Lakes: learn more about this species through  their profile on GLANSIS . To view an interactive map of sea lamprey barriers and management actions, check out the Great Lakes Fishery Commission’s  Sea Lamprey Control Map .

The  Great Lakes Fishery Commission  and its partners, including the  U.S. Fish and Wildlife Service ,  Fisheries and Oceans Canada , the  U.S. Geological Survey , and many other agencies, keep a constant eye on sea lamprey populations and continue researching new ways to keep their numbers in check. Learn more about the Commission’s work with partners  here  and at the links above.

Zebra mussels (Dreissena polymorpha) and quagga mussels (Dreissena rostriformis bugensis) are invasive clam-like animals that attach themselves to underwater surfaces, and have radically altered the Great Lakes since their discovery in the 1980s. Both of these closely-related species now clog water intake pipes, colonize shipwrecks, and foul vessels throughout the region, where they also filter out nutrients needed by native species. Right now, no easy solution exists for removing these invaders from the Great Lakes. Instead, people are adapting to live with them through ongoing management strategies.

Power plants, drinking water facilities, and other utilities have developed chemical treatments, filters, special coatings, and other tactics to keep mussels from clogging their pipes, and sometimes hire divers to manually scrape away mussels. Meanwhile, scientists continue working on new chemical and biological tools that can help control mussel populations in specific sections of open water.

There are many people in the U.S. and Canada working hard to research zebra and quagga mussel solutions. Outreach campaigns like “ Stop Aquatic Hitchhikers! ” help educate boaters and anglers to clean, drain, and dry their boats and equipment before moving from one lake to another, so hitchhiking mussels don’t go along for the ride. Groups such as the binational  Invasive Mussel Collaborative  bring researchers, decision-makers, and other specialists together to build knowledge, share new techniques, and strategize for the future of invasive mussel control. 

Click on these maps to explore records of invasive mussels in the Great Lakes, and check out the species profiles for  zebra mussels  and  quagga mussels  on GLANSIS. For more information about how dreissenid mussels impact other species – and even displace each other –  see  this review  of zebra and quagga mussel research at NOAA-GLERL.

 The Invasive Mussel Collaborative  connects people, science, and management to advance technology for invasive mussel control. A map of ongoing mussel control projects can be found  here .

 Stop Aquatic Hitchhikers  is a national education campaign launched by the Aquatic Nuisance Species Task Force. It encourages boaters, anglers, and other people participating in waterway recreation to  clean, drain, and dry  their equipment to prevent the spread of aquatic invasive species like zebra and quagga mussels.

Invasive carp are actually four separate species of fish: bighead carp (Hypophthalmichthys nobilis), silver carp (Hypophthalmichthys molitrix), grass carp (Ctenopharyngodon idella), and black carp (Mylopharyngodon piceus). If invasive carp reach the Great Lakes, they could dramatically impact the region’s ecosystem, so scientists, environmental managers, and the public are working together to stop them in their tracks.

Researchers are hard at work developing and refining strategies for keeping invasive carp out of the Great Lakes -- and that means blocking their path. Technological solutions like electric barriers, sound waves, carbon dioxide, and even walls of bubbles help keep carp out of waterways, and techniques like eDNA and computer modeling can be used as an early warning system to predict where one or more species of carp might have reached the Great Lakes.

In some parts of the US, invasive carp are probably here to stay. But states, agencies, and groups like the Invasive Carp Regional Coordinating Committee can work together to help keep them from establishing themselves in the Great Lakes.

This map shows the distribution of invasive carp in waterways leading to the Great Lakes and throughout North America. You can learn more about  silver carp ,  bighead carp ,  grass carp , and  black carp  and other watchlist species through their species profiles at GLANSIS. You can also use the  GLANSIS Species List Generator  to see other species that pose a potential threat to the Great Lakes but aren’t here yet: simply choose “Watchlist Species” from the species category selector to create the list.

In addition to displaying reported sightings of these species and more, the  GLANSIS Map Explorer  allows users to display habitat suitability maps to show where silver, bighead, and grass carp may find environmental conditions that will allow them to survive in the basin, courtesy of the  Great Lakes Aquatic Habitat Framework . To view these maps, head to the Map Explorer and select any of the carp habitat suitability maps under the "Surface Layers" drop-down menu.

Many partner agencies working in the Great Lakes have created risk assessments for invasive carp, which can be viewed through the  GLANSIS Risk Assessment Clearinghouse . Using the  Risk Assessment Explorer , try comparing the risk assessments of different carp species side-by-side and view an interactive map showing regulations and restrictions on these fish and more.

 The Invasive Carp Regional Coordinating Committee  brings together federal, provincial, state, local partners to prevent invasive carp from becoming established in the Great Lakes and beyond. Learn more about their work at the link above.

While aquatic invasive species impact ecosystems, economies, and communities throughout the basin, the story of their effects – and on what’s being done to stop them – is still being told. By working together, scientists, industry, elected officials, and local residents continue to make a powerful difference in protecting the Great Lakes.