Susana Simancas

Evaluation of Octocoral Physiological Responses to Ocean Acidification Conditions

Coral reefs are among the most important ecosystems on earth providing a wide variety of ecological services of high importance for human development and survival. However, these ecosystems are under constant transitions and continue to decline alarmingly given anthropogenic influences and climate change phenomena. According to records, important global factors of climate change are ocean acidification and warming, where these stressors have posed challenging scenarios for most coral reef benthic species. In particular, octocorals are a key component of the benthic communities in coral reefs in the Caribbean and the Tropical Eastern Pacific, where they enhance habitat complexity and three-dimensional structure. However, despite their high importance, octocorals have been strongly neglected in comparison to hard corals in evaluating their responses to climate change stressors. In general, global and local stressors have been widely documented to have negative effects on scleractinian corals, compromising their metabolic, physiological and reproductive processes. Nevertheless, there is still limited information on how octocorals will behave under such stressors scenarios.

This project aims to evaluate in a comprehensive way the physiological responses of octocorals to ocean acidification and other likely interacting global and local stressors. I will study key physiological response parameters (including photosynthesis, respiration, nitrogen fixation, organic and inorganic matter fluxes, skeleton formation, pump rates, and growth) of a selected model octocoral in response to ocean acidification and factors such as warming and eutrophication. In addition, a range of octocorals and hexacorals will be comparatively assessed through laboratory experiments in order to detect potential physiological differences, whilst the in-situ relevance of our laboratory findings will be finally assessed at appropriate natural laboratories (i.e. CO₂ vent sites). This project targets to improve our understanding on climate change effects on classical and novel reef communities.