Temperature, Growth, and Size at Maturity: Global Patterns and Implications for Crustacean Fisheries Under Climate Change

Understanding environmental drivers of growth is critical for commercially harvested species, as even small changes in growth rates and associated changes in body size can greatly affect mortality, reproduction, and fishery landings. Growth rates can be profoundly influenced by temperature, and the temperature-size rule predicts that organisms reared at a lower temperature grow more slowly but reach a larger body size. This relationship is estimated to occur in 80% of ectothermic species. Yet relationships between temperature, growth, and body size can be more complex in species exhibiting discontinuous growth due to potential effects of temperature on both the intermolt period (IMP) and growth-per-molt (GPM). Higher temperatures consistently decrease IMP, but effects on GPM can be quite variable, even among different life history stages of the same species. I examined relationships between temperature, growth, and size at maturity in a range of commercially harvested crustacean species (including crabs, lobsters, and shrimp), in the context of predicting population- and fishery-level responses to climate change. These population-level effects of temperature change are variable among species and regions and depend on the life history of the species in question, including reproductive strategy and presence or absence of a terminal molt.