The effects of ocean warming and acidification on Corallinaceae coralline algae

[Truncated] Coralline algae (Rhodophyta, Corallinaceae) are a ubiquitous group of calcifying red macroalgae, which form an integral component of a diverse range of ecosystems worldwide. The effects of environmental change on ecologically important taxa, such as the coralline algae, have major implications for the future fate of marine ecosystems. Understanding how particular habitats will be affected by environmental change is currently of great interest, as this knowledge will contribute to the effective protection and management of the marine environment in the coming decades. Coralline algae are sensitive to the increases in seawater temperature and CO2 predicted with global climate change due to the negative effects of these changes on the process of calcification. In contrast, fleshy (non-calcifying) algal species can respond in a positive manner to ocean warming and acidification. As such, a shift in dominance from calcifying to fleshy algal species is predicted for many marine communities. Since coralline and fleshy algae occupy many of the same benthic habitats, understanding how differential responses to environmental change will affect the interaction between them is important for predicting future changes in community structure. Thus, the general aims of this thesis were to assess the effects of ocean warming and acidification on 1) coralline algal metabolism and 2) the interaction between coralline algae and fleshy algae.