A long-term perspective is useful to distinguish natural ecosystem variability from human impacts, and to recognize the rates and magnitude of environmental change. This research aims to understand the causes and effects of nuisance growths (blooms) of the bottom-dwelling alga, Didymosphenia geminata (Didymo), in pristine salmon rivers in western (Vancouver Island, BC) and eastern (Gaspe region of QC and northern NB) regions of Canada.

By studying the information preserved in sediment records within regions currently experiencing nuisance Didymo blooms we will be able to assess the long-term environmental drivers that cause blooms to form and proliferate across these ecosystems. Our approach can recognize whether recent Didymo blooms are unprecedented over the last ~2000 years. Collaborators on this study include DFO scientist Dr. Dan Selbie and ECCC scientist Dr. Max Bothwell.

We will also conduct a modern ecological study of river habitats in two eastern Canadian rivers by sampling invertebrates, algae, and juvenile Atlantic salmon. A greater understanding of both the causes and effects of Didymo blooms will provide evidence-based knowledge to aid in the management of these iconic Canadian salmon rivers.