Environmental factors influencing urchin spatial distributions on disturbed coral reefs (New Caledonia, South Pacific)

Pascal Dumas; Michel Kulbicki; Sandrine Chifflet; Renaud Fichez; Jocelyne Ferraris

Environmental factors influencing urchin spatial distributions on disturbed coral reefs (New Caledonia, South Pacific)

Pascal Dumas ^{1, 2} Michel Kulbicki ^{1, 2} Sandrine Chifflet ^{3, 4} Renaud Fichez ^{3, 4} Jocelyne Ferraris ^{2, 1}

1 UR 128 CoRéUs-IRD

2 EPHE - École pratique des hautes études

3 UR 103 Camélia

4 COM - Centre d'océanologie de Marseille

Abstract : Few works have examined the relative contributions of habitat variables to the distribution of coral reef urchins. In the present study, the spatial distribution of two common urchin species (Diadema setosum and Echinometra mathaei) was studied in the fringing reefs of two urban bays in New Caledonia (South Pacific). Urchins were surveyed at 105 stations with contrasted habitat structure/anthropic disturbance levels; 32 environmental variables (water/sediment characteristics, reef structuring species) were considered. Moderate densities were generally observed at station scale (mean 0.5 individuals m(-2)). The combination of univariate and multivariate techniques highlighted patchy distributions for Diadema as well as Echinometra, with distinct species/habitat associations; environmental gradients occurring within the bays did not seem to influence the species patterns. For Diadema, the spatial variability was better explained by sediment type than by biotic cover; increasing densities occurred across habitats with larger sediment sizes and decreasing coral complexity/macrophytes cover. In contrast, the distribution of E. mathaei exhibited weak relationships with habitat variables. In coral reefs, small-scale heterogeneity may thus be responsible for most of urchins spatial variability.

Keywords : COASTAL ZONE MANAGEMENT SEA-URCHINS FRENCH-POLYNESIA BENTHIC MACROINVERTEBRATES MACROBENTHIC COMMUNITIES PARACENTROTUS-LIVIDUS DIADEMA-ANTILLARUM FISH COMMUNITIES DISCOVERY BAY FLORIDA-KEYS

Document type :

Journal articles

Domain :

Sciences of the Universe [physics] / Earth Sciences / Oceanography

Complete list of metadatas

https://hal.archives-ouvertes.fr/hal-01438811
Contributor : Renaud Fichez <>
Submitted on : Wednesday, January 18, 2017 - 10:17:49 AM
Last modification on : Saturday, April 20, 2019 - 2:05:13 AM

Environmental factors influencing urchin spatial distributions on disturbed coral reefs (New Caledonia, South Pacific)

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Environmental factors influencing urchin spatial distributions on disturbed coral reefs (New Caledonia, South Pacific)

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