Some reef-building corals only disperse metres per generation.

Area of Science:

• Marine Biology
• Population Genetics
• Ecology

Background:

• Estimating dispersal potential is crucial for predicting species recovery and adaptation, especially for marine organisms like corals.
• Dispersal distances for scleractinian corals are challenging to measure due to their oceanic propagule dispersal.
• Understanding coral dispersal informs conservation strategies and predictions of range shifts.

Purpose of the Study:

• To indirectly infer generational dispersal distances for coral propagules using genomic and spatial data.
• To investigate dispersal patterns within the coral genus Agaricia in Curaçao.
• To identify cryptic taxa and assess their dispersal capabilities.

Main Methods:

• Utilized individual-based isolation-by-distance (IbD) analyses.
• Combined reduced-representation genomic sequencing with photogrammetric spatial mapping.
• Collected dense samples of Agaricia colonies across various locations and depths.

Main Results:

• Identified seven cryptic taxa within three nominal Agaricia species.
• Four taxa exhibited generational dispersal distances within meters (two in A. agaricites, two in A. humilis).
• Agaricia lamarcki taxa showed no isolation-by-distance signals, suggesting longer dispersal distances.

Conclusions:

• Agaricia agaricites and Agaricia humilis populations rely on localized replenishment due to short dispersal distances.
• Quantitative estimation of dispersal is vital for effective coral species management.
• The study highlights the importance of genetic methods for understanding marine dispersal.