By Allan Britnell
Flamborough resident Paul D. Smith has turned the beach-vacation hobby of collecting interesting shells into an innovative biodiversity study. Each year since 2007, he has searched for freshwater mussel shells along the muddy shoreline of Cootes Paradise, an 800-hectare wetland sanctuary managed by the Royal Botanical Gardens (RBG), at the western end of Hamilton Harbour. And what he has found is changing our understanding of the variety of life in this long-abused watershed.
Specifically, he has discovered a species of mussel never before recorded in that part of the province, a diminutive creature dubbed the Lilliput mussel. More accurately, he has found their shells, discarded onshore by muskrats and other predators.
“I’ve found about a hundred shells in a single stretch of shoreline, so [Lilliput mussels] are there in significant numbers,” concludes Smith.
The species is fairly common in the United States from Michigan to Texas. In Canada, however, there were only a few records of this species, all from the Kitchener-Waterloo area.
Aside from being discovered in an unexpected location, the shells have revealed a surprising detail: their size. Unlike their namesake, the tiny characters in Gulliver’s Travels, these are, as Smith puts it, “giant Lilliputs.” Normally the shells reach a maximum length of 35 millimetres, but the ones Smith has been gathering are up to 55 millimetres long.
Smith’s search has also turned up shells of other provincially rare species, including the eastern pondmussel (which the Committee on the Status of Endangered Wildlife in Canada lists as endangered) and paper pondshell (with the delightfully derogatory scientific name Utterbackia imbecillis).
“Freshwater mussel populations are in widespread decline for a number of reasons, including pollution, damming of rivers and habitat degradation. It’s reassuring to hear that, even in 2011, there are new populations to be discovered,” says Ontario Nature’s conservation science manager, Mark Carabetta. The Ministry of Natural Resources estimates, however, that two-thirds of the 41 species of freshwater mussels found in the province are at risk.
Along with being a food source for a variety of fish, birds and mammals, the mussels’ own feeding habits make them an important water filtration system.
For Smith, the findings help boost ongoing efforts to clean up and rehabilitate the watershed, including the RBG’s Project Paradise. “It reinforces that the west end of Hamilton Harbour is a biodiversity hotspot that has been overlooked.”