The Great Lakes BWMS Regulation Scrum

There hasn’t been an invasives species introduced to the Great Lakes from ballast water since 2006. So, what’s the problem now?

As far as Transport Canada is concerned: “Scientific sampling to date consistently shows that ballast water management systems (BWMS) used in the Great Lakes reduce organism densities in ballast water discharges by over 99%, consistent with global evidence. As crews gain experience in operating these systems, performance continues to improve, contributing to the ongoing protection of Canada’s waters from invasive species.”

However, a 2025 publication supported by Transport Canada and Fisheries and Oceans Canada reported that nearly half of discharge samples studied did not comply with the IMO Convention D-2 performance standard. The Convention, like the USCG ballast water regulations, includes organism discharge standards - not reduction percentage levels.

BWMS are not working, says James Weakley, President of the Lake Carriers’ Association (LCA). The association is working with various research organizations, the EPA and the US Coast Guard to test systems. “There's no equipment that will work on a US-flag Laker under the American rules,” he says.

Currently, compliance testing doesn’t involve ensuring treatment efficacy in the waters of the Great Lakes which have high tannin and