The presence of Dreissenid mussels has been confirmed by the Ontario Ministry of Natural Resources in the northern part of Black Bay on Lake Superior, representing a recent occurrence of the invasive species along the lake’s northern coastline. Although the exact species has not been identified yet, the mussels were initially noted earlier this month via a post on the iNaturalist app, an online platform where nature enthusiasts share validated observations. The ministry has verified the mussels’ existence on the bay’s north side but has not detected them on the south side.
Quagga mussels and zebra mussels fall under the category of Dreissenid mussels and were previously reported in nearby Thunder Bay and Nipigon Bay but not in Black Bay. Brook Shryer, Program Advisor for Ontario’s Invading Species Awareness Program, mentioned that quagga mussels entered the Great Lakes in the late 1980s, closely following zebra mussels’ introduction.
According to Shryer, the transportation and introduction of these invasive species to the Great Lakes were facilitated through ships’ ballast water in the past when regulations were not in place. He emphasized the unregulated nature of ballast water before 2006 as a significant method of transport for these harmful species.
Quagga mussels, which share similarities with zebra mussels but possess distinctive characteristics such as the ability to survive on both hard and soft surfaces, were discussed by Shryer. He highlighted that quagga mussels can thrive on various surfaces, unlike zebra mussels, which primarily survive on hard surfaces. Shryer also mentioned that due to their preference for deep waters, reaching depths of up to 130 meters, encountering quagga mussels may be rare for most individuals.
The Ministry of Natural Resources warns that quagga and zebra mussels’ filter feeding activities deplete phytoplankton, essential algae forming the foundation of the aquatic food chain, consequently reducing the food supply for species like whitefish and lake trout. Shryer emphasized that while the filtering actions of the mussels may initially lead to clearer water, the long-term ecological consequences could be disruptive, especially in the warmer and cloudier Black Bay.
The spread of these mussels primarily occurs through boats and fishing equipment, highlighting the importance of cleaning, draining, and drying all gear as mandated by Ontario’s Invasive Species Act when moving between water bodies. Shryer stressed the significance of public awareness as a crucial defense measure against the spread of these invasive species, underscoring the importance of education and outreach efforts.
Despite some northern lakes having low calcium levels that naturally inhibit mussel survival, Shryer emphasized the necessity of prevention measures. He encouraged individuals who encounter invasive species to report them promptly through the Invading Species hotline or the online reporting platform. The Ministry of Natural Resources will continue monitoring Black Bay, with no reported presence of mussels in the south end to date.