Investigation of an introduced subtropical alga (Lyngbya wollei) in Whiteshell Provincial Park, Manitoba

Abstract

Nuisance growth of a filamentous cyanobacterium, Lyngbya wollei, was studied in lakes of Whiteshell Provincial Park in eastern Manitoba. Its increasing abundance in two lakes, White and Betula over the last half dozen years has heightened awareness and concern by cottagers and recreational users that nearby lakes may become infested. L. wollei is typically found in the southeastern United States, and this is the only known occurrence in Canada. Desiccation experiments used to assess the ability of L. wollei to survive inter-lake transfer on recreational watercraft showed it can remain viable after short-term drying and stagnant conditions. Comparisons of lake basin morphology, land use, water and sediment chemistry of the infested lakes to those of other Whiteshell lakes showed that all lakes with shallow littoral areas and a photic depth greater than two and a half meters possess potential L. wollei habitat. Intensively used lakes such as Falcon, Caddy, Brereton, and Big Whiteshell are most susceptible to L. wollei inoculation. Principle Component Analysis based on water and sediment chemisty identified Jessica, Red Rock, Florence, and Madge Lakes as having the most similar conditions to the infested lakes. Consequently, these lakes may develop the greatest biomass and adverse effects of L. wollei growth. It is imperative that all clothing, footwear and recreational watercraft be cleaned thoroughly after being removed from infested lakes to prevent the further spread of L. wollei in the lakes of Whiteshell Provincial Park.