Combining citizen science and environmental DNA for monitoring coastal marine species

The world is in an era in which direct and indirect consequences of human activities are the primary drivers of environmental change. Although carbon dioxide emissions arise primarily from terrestrial sources, the ocean is facing numerous resulting consequences, such as rising sea levels, acidification, changes to circulation patterns, and an overall increase in water temperatures. As ocean temperatures warm, many marine species are on the move, typically redistributing toward higher latitudes. These species shifts may cause profound alterations in established ecosystems, with changes to food web interactions and ecosystem services as new species move into an area or familiar species move out. While not every species shift is expected to have a profound negative impact on the local ecosystem, they are nonetheless important to monitor, especially in regions highly dependent on the ocean, whether culturally, economically, or both.

Nova Scotia, Canada, fits these criteria—connected to the rest of North America only through a narrow land bridge, its near-insular nature spans over 13,000 km of coastline supporting substantial biodiversity, and the ocean environment provides the province with recreational, tourism, and economic opportunities. Since time immemorial, the Mi’kmaq have served as the primary ocean stewards of Mi’kma’ki (current day Atlantic Canada, which encompasses Nova Scotia). Through the practice of Netukulimk, they maintain a tradition of sustainable, respectful ocean interaction that predates and transcends the challenges brought by European settlement and resource commodification. In the centuries since contact and settlement, the ocean has continued to play a central role in the lives and employment of those residing here. A high importance is placed on contemporary provincial fisheries, particularly American lobster Homarus americanus, Nova Scotia’s most valuable seafood export. Meanwhile, the legacy of the collapse of the Canadian fishery for Atlantic Cod Gadus morhua remains a heavy reminder that the benefits derived from the ocean can rapidly disappear in the face of mismanagement or environmental change.