Quantifying functional consequences of habitat degradation on a Caribbean coral reef

Abstract. Coral reefs are declining worldwide. The abundance of corals has decreased alongside a rise filter feeders, turf, and algae in response to intensifying human pressures. This shift prevalence functional groups alters the biogeochemical processes tropical water ecosystems, thereby influencing reef functioning. An urgent challenge is understand consequences these shifts develop suitable management strategies that aim at preserving biological functions reefs. Here, we quantify supporting key (i.e. net community calcification (NCC) production (NCP) nutrient recycling) situ for five different benthic assemblages currently dominating shallow degraded Caribbean habitats. To this end, transparent custom-made enclosure was placed over communities dominated by either one – coral, turf macroalgae, bioeroding sponges, cyanobacterial mats, or sand determine chemical fluxes between overlying water, during both day night. account simultaneous influence distinct have on measured variables, rates were then derived solving model consisting differential equations describing contribution each process fluxes. Inferred low compared those known flats Reduced accretion potential recorded, with negative very modest all communities. Net also low, suggesting limited accumulation biomass through photosynthesis remineralisation organic matter night relatively high comparison, resulting heterotrophy survey period most Estimated recycling nitrification denitrification) but did not fully counterbalance release from aerobic mineralisation, rendering substrates sources nitrogen. Results suggest similar directions magnitudes Curaçaoan reef. We infer amount type released abundant algal turfs mats likely enhances heterotroph activity stimulates proliferation less diverse copiotrophic microbial populations, studied heterotrophic drawing “behaviour” closer other.