Work

Role of elevated organic carbon levels and microbial activity in coral mortality

Year: 2006

Type: article

Abstract: Coral reefs are suffering a long-term global decline, yet the causes remain contentious.The role of poor water quality in this decline is particularly unclear, with most previous studies providing only weak correlations between elevated nutrient levels and coral mortality.Here we experimentally show that routinely measured components of water quality (nitrate, phosphate, ammonia) do not cause substantial coral mortality.In contrast, dissolved organic carbon (DOC), which is rarely measured on reefs, does.Elevated DOC levels also accelerate the growth rate of microbes living in the corals' surface mucopolysaccharide layer by an order of magnitude, suggesting that mortality occurs due to a disruption of the balance between the coral and its associated microbiota.We propose a model by which elevated DOC levels cause Caribbean reefs to shift further from coral to macroalgal dominance.Increasing DOC levels on coral reefs should be recognized as a threat and routinely monitored.

Source: Marine Ecology Progress Series

DOI: 10.3354/meps314119

Authors: DI Kline, NM Kuntz, M Breitbart, N Knowlton, F Rohwer

Institutions: Smithsonian Tropical Research Institute, Scripps Institution of Oceanography, San Diego State University, University of California San Diego

Language: English

Topic: Coral and Marine Ecosystems Studies

Subfield: Ecology

Field: Environmental Science

Domain: Physical Sciences

SDGs: Life below water, Clean water and sanitation

Open Access status: bronze