Temperature Influences Herbivory and Algal Biomass in the Galápagos Islands

In the Galápagos Islands, temperature significantly influences herbivory and algal biomass, challenging the assumption that upwelling intensity alone controls macroalgal cover. Research reveals that grazing rates by urchins, fishes, turtles, and iguanas increase during warmer seasons, leading to reduced algal biomass when upwelling is weak. Conversely, strong upwelling with colder water can result in higher algal biomass despite increased herbivory. The study combined grazing assays, field surveys across ten sites over five years, and a herbivore exclusion experiment to demonstrate that temperature-driven changes in herbivore activity play a critical role in shaping subtidal ecosystems. This finding suggests that the relationship between upwelling and algal biomass is more complex than previously understood.

Carr, L. A., Gittman, R. K., & Bruno, J. F. (2018). Temperature Influences Herbivory and Algal Biomass in the Galápagos Islands. Frontiers in Marine Science, 5. https://doi.org/10.3389/fmars.2018.00279