%0 Journal Article
%T Cyanobacteria in Coral Reef Ecosystems: A Review
%A L. Charpy
%A B. E. Casareto
%A M. J. Langlade
%A Y. Suzuki
%J Journal of Marine Biology
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/259571
%X Cyanobacteria have dominated marine environments and have been reef builders on Earth for more than three million years (myr). Cyanobacteria still play an essential role in modern coral reef ecosystems by forming a major component of epiphytic, epilithic, and endolithic communities as well as of microbial mats. Cyanobacteria are grazed by reef organisms and also provide nitrogen to the coral reef ecosystems through nitrogen fixation. Recently, new unicellular cyanobacteria that express nitrogenase were found in the open ocean and in coral reef lagoons. Furthermore, cyanobacteria are important in calcification and decalcification. All limestone surfaces have a layer of boring algae in which cyanobacteria often play a dominant role. Cyanobacterial symbioses are abundant in coral reefs; the most common hosts are sponges and ascidians. Cyanobacteria use tactics beyond space occupation to inhibit coral recruitment. Cyanobacteria can also form pathogenic microbial consortia in association with other microbes on living coral tissues, causing coral tissue lysis and death, and considerable declines in coral reefs. In deep lagoons, coccoid cyanobacteria are abundant and are grazed by ciliates, heteroflagellates, and the benthic coral reef community. Cyanobacteria produce metabolites that act as attractants for some species and deterrents for some grazers of the reef communities. 1. Cyanobacteria Cyanobacteria are oxy-photosynthetic bacteria. One of the characteristics of cyanobacteria is their thylakoids, the seats of photosynthesis, respiration, and in some species, molecular nitrogen fixation. One of the earliest signs of life on Earth was the formation of stromatolite reefs, which exist now as fossil structures in the oldest rocks known [1]. This cyanobacterial fossil record is among the oldest of any group of organism, possibly reaching back to 3500 million years (myr) ago. Throughout the succeeding 3000£¿myr, many shallow reefs arose and provided a habitat for cyanobacteria. Modern corals are a relatively recent phenomenon; indeed, scleractinian corals first appeared 230£¿myr ago in the Triassic [2]. Although cyanobacteria have been supplanted to an extent by eukaryotic algae on modern coral reefs, especially by the dinoflagellate Symbiodinium sp. (zooxanthellae) and coralline red and green algae, they play an essential role in the ecology of modern reefs. Nowadays, cyanobacteria are present in the benthos and plankton compartments of coral reef ecosystems. In this paper, we discuss the contribution of cyanobacteria to photosynthetic biomass and their role in
%U http://www.hindawi.com/journals/jmb/2012/259571/