Protecting and predicting genetic diversity of whole communities – a case study of Hawaiian reefs

Conservation strategies increasingly call for preserving areas of high genetic diversity. This shift necessitates a look beyond single-species studies toward methods to predict and map community-level trends in genetic diversity. Theory suggests that genetic diversity primarily responds to habitat area and isolation, but ecology particular to each species nevertheless modify spatial patterns across co-distributed species. The balance and sources of convergent and divergent forces shaping genetic diversity of a community are largely unexplored.  With data for 47 reef species sampled across 16 Hawaiian Islands, we test a suite of hypotheses about drivers of biodiversity with a novel metric representing the emergent genetic diversity of the community. Results reassuringly support foundational theory on the relationship of diversity to habitat, but also suggest intriguing eco-genetic feedbacks and concerning signs that thermal stress has effected the genetic resilience of the whole reef community. I discuss the implications of these results for managing and protecting genetic diversity at the community level.

Kimberley Selkoe

Center Associate, NCEAS, UCSB /
Associate Research Biologist, Marine Science Institute, UCSB