The Geography of Mediterranean Benthic Communities Under Climate Change

Area of Science:

• Marine Ecology
• Climate Change Biology
• Biodiversity Informatics

Background:

• Seafloor ecosystems provide critical functions and services, supporting diverse benthic organisms essential to marine life.
• Benthic species are highly vulnerable to climate change impacts like rising temperatures and ocean acidification.
• Limited assessments exist on the future distribution and diversity changes of benthic species under climate change scenarios.

Purpose of the Study:

• To project the current and future distributions of approximately 350 Mediterranean benthic species.
• To assess predicted changes in alpha-diversity (α-diversity) and beta-diversity (β-diversity) of benthic communities.
• To identify areas critical for conservation planning based on predicted species distribution shifts and diversity changes.

Main Methods:

• Trained species distribution models using over 100,000 species occurrence records.
• Incorporated predictors from state-of-the-art physical and biogeochemical marine models.
• Projected species distributions and diversity changes across the Mediterranean Sea under various future climate scenarios.

Main Results:

• Most species are predicted to shift distribution northwards, with up to 60% experiencing range contraction and 77% moving north.
• Significant changes include range fragmentation (20%) and shifts towards deeper waters (30%), with cold-adapted species most affected.
• Alpha-diversity is projected to increase in the North and decrease in the South Mediterranean; beta-diversity changes indicate significant species turnover in specific regions.

Conclusions:

• Climate change necessitates adaptive conservation strategies for vulnerable Mediterranean benthic species.
• Marine spatial planning should prioritize connectivity in high turnover areas and protected areas in stable diversity zones.
• Ecosystem-based management informed by these projections is crucial for effective marine conservation.