Ballast water release from ocean vessels has introduced hundreds of invasive species to coastal ecosystems worldwide, causing major disruptions to fisheries and biodiversity. Attempts to control aquatic invasions have met with mixed success in general. However, a new study suggests that a bi-national regulation targeting ships entering the Great Lakes since the mid-2000s has been remarkably effective in reducing a large proportion of the invasive species in the world’s largest freshwater ecosystem.

Rising global maritime traffic could lead to sharp increases in invasive species around the world over the next 30 years, according to a new study by McGill University researchers.

The findings, published in the journal Nature Sustainability, suggest that shipping growth will far outweigh climate change in the spread of non-indigenous pests to new environments in coming decades.

A mussel never reported in Canada was identified in the port of Montreal, a soft shell clam never seen in the Arctic was discovered in the Hudson Bay in Churchill, Manitoba, and a barnacle that was not thought to occur north of San Francisco was detected in Nanaimo, British Columbia. These are invasive species and researchers from McGill University detected 24 of these non-indigenous species across 16 major ports in Canada, including 11 that were identified in previously unreported locations. Their findings were published Biodiversity Research.

The Great Lakes have been invaded by more non-native species than any other freshwater ecosystem in the world. In spite of increasing efforts to stem the tide of invasion threats, the lakes remain vulnerable, according to scientists from McGill University and colleagues in Canada and the United States.