Global warming and overexploitation both threaten the integrity and resilience of marine ecosystems. However, a mechanistic understanding of the interactions of multiple stressors is generally lacking for habitat-forming species; preventing the development of sound conservation strategies.

This study examined the effectiveness of no-take marine protected areas (MPAs) at enhancing structural complexity and resilience to climate change on populations of an overexploited and long-lived species, the Mediterranean red coral Corallium rubrum. This was done by using long-term data over eight populations, subjected to varying levels of disturbances, and using Integral Projection Models to understand how the overfishing and mass-mortality events shape the stochastic dynamics of this species.

The results of the study show that MPAs largely reduced colony partial mortality, enhancing the structural complexity of coral populations. While warming had detrimental consequences for the long-term viability of red coral populations, driving steady declines and potential local extinctions. However, stochastic demographic models revealed only a weak compensatory effect of MPAs on the impacts of warming.

Taking into account the obtained results, the authors conclude that MPAs are an effective local conservation tool for enhancing the structural complexity of red coral populations, but they might not be enough to ensure red coral’s persistence under future increases in thermal stress. For this reason, the authors suggest that conservation strategies aiming to ensure the persistence and functional role of red coral populations should include management actions at both local (well-enforced MPAs) and global scales (reductions in greenhouse gas emissions).

Montero-Serra et al. (2019) Marine protected areas enhance structural complexity but do not buffer the consequences of ocean warming for an overexploited precious coral. Journal of Applied Ecology DOI: 10.1111/1365-2664.13321.