Heterogeneous Predation, Community Asynchrony, and Metacommunity Stability in Cyanobacterial Mats

AbstractBenthic cyanobacterial mats are increasing in abundance on coral reefs, yet the processes governing their persistence across scales of ecological organization remain poorly resolved. Here, we integrated observational and experimental approaches to characterize the ecological processes driving the dynamics of these mats. Community- and metacommunity-scale dynamics of mats off the island of Bonaire, Caribbean Netherlands, were tracked for 47 days alongside quantification of predation pressure from fishes. We also tested the hypothesis that elevated predation would decrease mat persistence using an in situ coring experiment. Cyanobacterial mat metacommunity-scale cover was temporally stable across the study despite high community-level mortality, likely stabilized by asynchrony in community extinction. Natural mat communities had a median persistence time of 36 days, with experimentally disturbed mats exhibiting significantly longer persistence. Predation rates from diverse reef fishes varied among spatially distinct cyanobacterial mat communities within a reef site, but not among reef sites.