Lisa Scott column

Invasive mussels are becoming a growing concern in British Columbia.

A type of mussel found in Okanagan Lake will not be declared as endangered by the federal government.

Local water managers hope the decision paves the way for a full return of the rototilling of Eurasian milfoil, slimy lake weeds that harm the ecosystem and make swimming unpleasant.

"We're very pleased with this decision of the federal government," Anna Warwick Sears of the Okanagan Basin Water Board said Thursday.

"It's a step forward, but the full return of rototilling will still depend on the provincial government changing their regulations," Sears said.

If the feds had decided to declare the Rocky Mountain ridged mussel to be endangered, that would likely have led to the complete cessation of milfoil rototilling. The practice, which involves the weeds being yanked out by their roots by a mechanical harvester during the winter, has been used since the 1970s.

Last year, the provincial government began prohibiting the OBWB from rototilling the weeds in areas where the mussel has been found. Bans now exist at the north end of Okanagan Lake, in areas of West Kelowna and Summerland and part of Osoyoos Lake.

Local officials have been concerned the ever-wider implementation of rototilling bans could see milfoil spread back to the kind of extensive conditions that existed decades ago. That could cause serious harm to the Valley's tourist industry, they say, as well as significantly degrade the aquatic ecosystem.

The OBWB and Valley politicians say the provincial government has never presented solid evidence that rototilling imperils the mussel. To the contrary, they say, it's likely that the mussel would be among the many aquatic species that could be jeopardized by a widespread resurgence of milfoil in Valley lakes.

The federal government said Thursday more study is needed before the mussel can be reclassified from a "species of special concern" to an endangered species.

"Additional consideration on potential reclassification of the Rocky Mountain ridged mussel will be done, and this will also take into account socio-economic impacts and effects on the broader Okanagan Basin system," Minister of Fisheries Jonathan Wilkinson said in a news release.

Kelowna-Lake Country Liberal MP Stephen Fuhr said there were "too many unanswered questions" for the mussel to be declared to be endangered.

"Such (a declaration) could have the potential to make it difficult to control Eurasian watermilfoil, an invasive species that has the potential to wreak havoc in our beautiful local lakes," Fuhr said in the government release.

In Canada, the Rocky Mountain ridged mussel only exists in the Okanagan basin, but it is found in many parts of the U.S.