Coastwide evaluation and classification of Pacific Region estuaries based on anthropogenic activities and significant fish habitat

Abstract

Estuaries are highly productive and diverse ecosystems that represent a geographic bottleneck between marine and freshwater systems. Estuaries have been identified as ecologically and biologically significant areas (EBSAs) in Canada’s Pacific Region because of their importance for the aggregation, productivity, and fitness of anadromous fishes, including Pacific salmon. However, estuaries are also the site of many anthropogenic activities, and the degradation of estuarine habitats such as eelgrass beds has had corresponding impacts on many species of ecological, economic, and cultural importance. To support a regional request for information to aid integrated coastal planning, a coastwide classification of estuaries based on anthropogenic activities was completed. Anthropogenic activities and associated stressors relevant to estuary habitats were identified through a literature review and used to guide the compilation of spatial datasets. The spatial datasets were then used in a cluster analysis that identified estuaries that share similar activity types and levels of use. Ecological information was then compiled and mapped to highlight how estuarine fishes and fish habitats considered significant or sensitive relate to the results of the clustering analysis and individual estuaries. This broad-scale analysis represents an initial assessment of British Columbia’s estuaries that can help guide localized efforts and identify opportunities for management efficiencies among estuaries that face similar activities and stressors. Research needs for future evaluations at a finer-scale scale are detailed, as are linkages with projects underway within specific estuaries, to highlight opportunities for collaboration as priority estuaries are identified for management and conservation action.