Native to Eurasia, the round goby (Neogobius melanostomus) is considered one of the greatest invasive species threats to the Lake Champlain ecosystem. It was first found in the St. Clair River in 1990 and has expanded its distribution to many areas of the Great Lakes, Erie Canal, the interior of New York, and the St. Lawrence and Richelieu Rivers in Quebec. The goby is gray, four to ten inches in length, and is physically similar to other species native to U.S. waters, including the slimy sculpin.
Round gobies are benthic—or bottom dwelling—fish that outcompete native species like sculpin for food and habitat and prey on eggs and juveniles of other fish like largemouth bass. They thrive in poor water conditions and spawn multiple times each season. They eat zebra mussels—seemingly a benefit to the Lake—but in the process, ingest toxic substances like PCBs that bioaccumulate in predators like bass and walleye, posing a threat to other fish and potentially humans.
Scientists believe that Lake Champlain and the lower reaches of its tributaries are prime habitat for gobies. They are known to be a nuisance to recreational anglers, whose bait and lures attract the undesirable fish. They also have impacted commercial fisheries in the Great Lakes, resulting in seasonal restrictions on certain types of fish whose populations have been affected.
As of summer 2022, no round gobies have been found in Lake Champlain, north (upstream) of Lock 1 of the Champlain Canal near Troy, NY in the Hudson River, or south (upstream) of the St. Ours Dam in the Richelieu River (close to the St. Lawrence River).
Scientists from the U.S. Geological Survey (USGS) captured round gobies in the Hudson River for the first time in summer 2021 near the confluence with the Mohawk River. The find marks the eastern-most extent of the expansion of this invasive fish from the Great Lakes through the Erie Canal, and another step closer to Lake Champlain’s doorstep.
Scientists from the USGS, U.S. Fish and Wildlife Survey (USFWS), and the Quebec Ministry of Forests, Wildlife and Parks (QC MFFP) are conducting intensive monitoring in summer 2022 in the Hudson and Richelieu Rivers and in Lake Champlain.
Samples collected in 2021 by QC MFFP from the Richelieu River near the outlet of Lake Champlain for a grass carp survey showed the presence of goby DNA when analyzed this summer. These results were confirmed by a separate analysis by USFWS. However, analysis of subsequent samples collected in summer 2022 did not detect the presence of goby DNA at these sites in the upper Richelieu. Unlike those areas of the Hudson and Richelieu that have been determined to have goby present, no physical specimens have been collected to confirm the result of the e-DNA analysis. QC MFFP will continue e-DNA sampling and live fish collection through fall 2022.
The USGS has continued sampling for presence of DNA at multiple locations along the Hudson River and Champlain Canal from Albany to Whitehall, NY (the southern extent of Lake Champlain) in May and June of 2022, with no positive results above Lock 1 of the Champlain Canal. Physical specimens were collected in the Hudson and below Lock 1, confirming the 2021 finds. These results indicate that the goby has not made it any closer to Lake Champlain since summer 2021. Scientists will conduct additional sampling in early August and mid-September 2022.
The Champlain Canal is open for the Summer 2022 recreation season. The New York State Power Authority/Canal Corporation is “double flushing” locks C1 and C2 to reduce the likelihood that round goby will spread through the lock system as boats pass through. They also are practicing scheduled lockings to reduce the number of daily lockages or number of times round goby might challenge the lock system.
The NYS Power Authority/Canal Corporation and New York State Department of Environmental Conservation with input from the Lake Champlain AIS Rapid Response Task Force have drafted a Round Goby Rapid Response plan for the Champlain Canal that outlines actions to be taken under certain scenarios, based on detection or confirmation of round goby at different locations within the Champlain Canal. The plan is currently available here.
USFWS has initiated an e-DNA surveillance program at 70 locations on Lake Champlain (including sites in Quebec) that will allow for detection of e-DNA for multiple species, including round goby, other AIS, and for threatened and endangered species.