Hotspots and bright spots in functional and taxonomic fish diversity

Planning for freshwater conservation is often secondary to that for terrestrial protected areas and rarely considers all aspects of biodiversity, such as functional biodiversity. To illustrate the application of functional diversity in conservation planning, we used data from a large-scale monitoring program to characterize patterns in functional and taxonomic fish biodiversity across coastal freshwater wetlands in northern Laurentian Great Lakes. We assessed the relationship between these 2 types of diversity to identify areas most likely to maximize conservation benefits in terms of these dimensions of biodiversity. In addition, we used an outlier analysis to find areas with unexpectedly high taxonomic or functional diversity in highly impacted watersheds, or bright spots. Taxonomic and functional fish diversity metrics were not closely related, and different areas across the basin supported highest taxonomic and functional diversities. Several bright spots had either very high taxonomic richness or functional diversity despite intensive anthropogenic land use, possibly indicating high resilience and conservation potential. These findings are relevant in the context of freshwater protected area prioritization because there are few guidelines available for nomination and selection of new freshwater protected areas.