Climate-change refugia: shading reef corals by turbidity.

Area of Science:

• Marine Biology
• Climate Change Science
• Ecology

Background:

• Coral reefs face unprecedented decline due to rising ocean temperatures.
• Ocean warming is heterogeneous, prompting a search for climate change refuges.
• Turbid nearshore environments may offer refuge by reducing high sea-surface temperatures and irradiance.

Purpose of the Study:

• To identify potential climate change refuges for corals in turbid nearshore environments.
• To predict the distribution of 12 coral species under future climate scenarios (RCP 8.5) by 2100.
• To assess the protective role of turbidity against thermal stress and its impact on coral growth.

Main Methods:

• Hierarchical Bayesian modeling approach.
• Analysis of coral species distribution in the Indian and Pacific Oceans (37°N to 37°S).
• Evaluation of Representative Concentration Pathway 8.5 (RCP 8.5) climate projections.

Main Results:

• Turbid nearshore refuges identified between 20-30°N and 15-25°S latitudes.
• Turbidity predicted to mitigate high-temperature bleaching for 9% of shallow reef habitat (<30m depth).
• Turbidity may protect some coral species more than others; high turbidity can also inhibit coral growth.

Conclusions:

• Turbid nearshore habitats can serve as vital climate refuges for coral reefs.
• Strategic protection of identified refuges is essential for global coral reef persistence.
• Specific regions like the Hawaiian Islands, Philippines, and Australia are key areas for conservation efforts.