Ecological Temperature Metrics as Predictors of Climate Change Impacts on North American Freshwater Fish Communities

Habitat temperature is a major determinant of performance and activity in fish. We examined the relationship between six temperature metrics describing the growth (optimal growth temperature and final temperature preferendum), survival (upper incipient lethal temperature and critical thermal maximum), and reproduction (optimum spawning temperature and optimum egg development temperature) requirements of North American freshwater fish species. The results showed that all metrics were highly correlated, especially those within each life process. Values for different metrics fell into distinct groups that were associated with reported thermal preference classes, reproductive guilds, and spawning season. Phylogenetic analysis revealed no association between metrics within taxonomic families, but strong positive correlations between closely related families. Bayesian modeling based on these correlations was utilized to derive temperature values for species with incomplete data. These close associations suggest new ways in which thermal performance data can be used to predict climate change impacts on North American freshwater fish communities.