Elucidating the effects of global climate change on macroalgae: effects of marine heat waves on populations of Hypnea pseudomusciformis (Gigartinales, Rhodophyta)

Abstract

Global climate change (GCM) has profound implications for marine ecosystems and for the economic and social systems that depend on them. GCMs will have a significant effect on the distributions of a wide variety of species, causing extinctions or population expansions. Although marine macroalgae play critical ecological roles in coastal regions, their responses to climate change are not well understood. The Brazilian coast, which is about 8000 km long and with a latitudinal gradient of 5°N to 33°S, comprises tropical and subtropical ficogeographic environments, and thus meets the criteria for studies on the effect of GCM on marine biodiversity. In this project we propose a case study with the species of red alga Hypnea pseudomusciformis. Using different populations with different thermal characteristics under a temperature and heat wave gradient, we can predict how the impacts of climate change (for example, warming) will affect the distribution of this important species in the Brazilian coast. For this, analysis of representatives of five populations along the Brazilian coast (certified by using molecular tool), combined with physiological data, may provide a large-scale perspective of how different populations respond in their physiological thermal limits, especially in wave events caused by global climate change.