03097nas a2200373   4500008004100000020001400041245012400055210006900179260002800248300001200276490000800288520195100296653001502247653001302262653001502275653001502290653001202305653002302317653002302340653001202363653001102375653001602386653001102402653002402413653002702437653001302464653001702477653001602494653001202510653001602522100002302538700003002561856013202591       2002                        eng d  a0022-098100aThe distribution and abundance of boring species of polychaetes and sipunculans in coral substrates in French Polynesia0 adistribution and abundance of boring species of polychaetes and   aAMSTERDAMbElsevier B.V  a101-1210 v2693 aThe distribution and abundance of the dominant initial macroborers of dead coral substrate, sipunculans and polychactes were investigated over time at seven sites within French Polynesia. Sites were located in the lagoon of high islands and atolls, and varied from highly eutrophic to oligotrophic. Significant differences occurred between sites and patterns of recruitment varied over time and between sites. With increasing exposure, the densities of polychaetes increased but not the number of species present, whereas both the densities and number of species of sipunculans increased. The atoll sites tended to be dominated by suspension feeding polychaetes and the high island sites by deposit feeding polychactes. Sipunculans tended to dominate the high island sites in comparison to the atoll sites and they all fed by scraping algae and detritus from the substrate. We suggest that this distribution of feeding types is related to water quality and to land run off. In the atolls, the lagoonal waters are oligotrophic and little land run off occurs, whereas at the high island sites, high rates of land run off occur during the wet season with high levels of suspended material in the water column. These variations in densities of boring species, affect rates of bioerosion and have the potential to alter the equilibrium between reef growth and reef destruction. We suggest that it is critical for reef managers to try to maintain water quality and limit land-based terrestrial run off and associated nutrients into coastal waters. This is especially important if the reefs have been affected by bleaching events or Crown of Thorns plagues, resulting in extensive death of coral colonies and with it, the potential for a massive increase in the rate of bioerosion. The long-term maintenance of the reef structure is critical if coral recruitment and recovery of the reef are to occur. (C) 2002 Elsevier Science B.V. All rights reserved.10abioerosion10aBrackish10aCoral reef10aDead coral10aECOLOGY10aFRESHWATER BIOLOGY10aGREAT-BARRIER-REEF10aIslands10aMarine10aMARINE &amp10aMOOREA10aOligotrophic waters10aPaddle-footed annelids10aPATTERNS10aPeanut worms10apolychaetes10aPORITES10aSipunculans1 aHutchings, Pat, A.1 aPeyrot-Clausade, Mireille  uhttps://reefichno.myspecies.info/content/distribution-and-abundance-boring-species-polychaetes-and-sipunculans-coral-substrates02496nas a2200301   4500008004100000020001400041245012200055210006900177260002800246300001200274490000800286520149500294653001501789653002701804653001601831653001601847653001201863653001101875653002801886653002101914653002301935653001601958653001101974100001901985700003002004700002302034856013702057       2002                        eng d  a0022-098100aBioerosion of experimental substrates on high islands and atoll lagoons (French Polynesia) during 5 years of exposure0 aBioerosion of experimental substrates on high islands and atoll   aAMSTERDAMbElsevier B.V  a109-1270 v2763 aRates of loss of CaCO3 from bioerosion (grazing and boring) and gains from accretion were determined from experimental coral substrates exposed for 5 years, which were laid in the lagoons of high islands and atolls in French Polynesia. Significant differences in net rates of bioerosion occurred between sites with the highest rates of loss being recorded at one of the lagoonal sites. The processes contributing to these losses and gains varied between sites. The results were compared with those obtained at the same sites after 6 and 24 months exposure. Rates of bioerosion increased with increasing exposure as did rates of internal erosion as densities of borers increased and boring sponges began to colonise the experimental substrates. High rates of bioerosion were recorded at both eutrophic and pristine sites suggesting that environmental conditions only influence some of the factors controlling rates of bioerosion. Worldwide, the amount of dead coral substrate available for colonisation by boring organisms is increasing as reefs are being subjected to anthropogenic impacts. We discuss how this may change the balance between reef growth and reef destruction by borers and grazers. In cases where the impact may be short lived as in the case of bleaching, we suggest that the maintenance of water quality is especially important in trying to minimise the rates of increase of bioerosion and increases in density of grazers. © 2002 Elsevier Science B.V. All rights reserved.10abioerosion10aCalcium carbonate loss10acoral reefs10aCORAL-REEFS10aECOLOGY10aEXCESS10aExperimental substrates10aFrench Polynesia10aFRESHWATER BIOLOGY10aMARINE &amp10aMOOREA1 aPari, Nathalie1 aPeyrot-Clausade, Mireille1 aHutchings, Pat, A.  uhttps://reefichno.myspecies.info/content/bioerosion-experimental-substrates-high-islands-and-atoll-lagoons-french-polynesia-during-5