Data/hora: 16/06/2024 03:14:15

Provedor de dados: | 5
País: | France
Título: | Internal bioerosion of Acropora formosa in Reunion (Indian Ocean): microborer and macroborer activities
Autores: | Zubia, M; Peyrot-clausade, M.
Data: | 2001-05
Ano: | 2001
Palavras-chave: | Acropora; Bioérosion; Organismes perforants; Récifs coralliens; Océan Indien; Acropora; Bioerosion; Boring organisms; Coral reef; Indian Ocean.
Resumo: | Bioerosion by grazing and boring organisms is one of the major destructive forces operating on reef. The aim of this study was to estimate the intensity of internal bioerosion by both microflora and fauna of Acropora, a branching scleractinian, on the reef flat at La Saline (Reunion, Indian Ocean). Internal bioerosion was estimated at two sites, varying in degrees of eutrophication. At each site, dead Acropora subjected to heavy grazing or covered by algal turf were examined. Acropora formosa is subjected to high bioerosion due to its high porosity and its branching form, which facilitates colonisation by boring organisms. Three endolithic microflora species, Plectonema terebrans, Mastigocoleus testarum and Ostreobium queckettii colonised the branches. The mean density of polychaetes was high (72 individuals cm(-3)), and all were regarded as meiofauna (diameter &lt; 0.5 mm). The main agents of bioerosion of Acropora formosa were boring microflora whose baring activities were four times greater (0.29 g cm(-3) of CaCO3) than that recorded by the boring fauna (0.07 g cm(-3) of CaCO3). Under high levels of eutrophication, the microflora were responsible for high bioerosion (30.8% of the surface of the substrate). In contrast, the composition of the fauna changed under these conditions but not the rate of bioerosion (4.4% maximum of the volume of dead Acropora). At the undisturbed site, the substrate covered by algae (within damselfish territory and therefore not subjected to grazing) had low levels of bioerosion caused by microflora (18.9% of the surface) and high bioerosion by fauna (9.5% maximum of the volume of dead Acropora) and in addition the composition of boring fauna was different to that found at the disturbed site with sipunculans being the dominant agent of bioerosion (6 individuals cm(-3) maximum).
Tipo: | Text
Idioma: | Inglês

Identificador:

http://archimer.ifremer.fr/doc/00322/43353/42860.pdf

DOI:10.1016/S0399-1784(01)01144-6

http://archimer.ifremer.fr/doc/00322/43353/

Editor: | Gauthier-villars/editions Elsevier
Formato: | application/pdf
Fonte: | Oceanologica Acta (0399-1784) (Gauthier-villars/editions Elsevier), 2001-05 , Vol. 24 , N. 3 , P. 251-262

Fonte:

2001 Ifremer/CNRS/IRD/Éditions scientifiques et médicales Elsevier SAS

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