Shallow reef associated echinoderm biodiversity and distribution on long-shore and cross-shelf surveys of the Kimberley, Western Australia

WA Museum Records and Supplements | Updated 9 months ago

ABSTRACT – This paper describes the echinoderm diversity and distribution arising from an extensive marine biological survey of the Kimberley region of Western Australia (the Kimberley Woodside Collection Project) which was a multi-taxon marine biodiversity survey program undertaken by the Western Australian Museum between 2009 and 2014. The study recorded a total of 203 species of echinoderms, plus a further 94 taxa with uncertain or no identification. The 203 species comprised 39 crinoids, 32 asteroids, 75 ophiuroids, 20 echinoids and 37 holothuroids. Forty-one of the species had not previously been recorded from among the 382 shallow water (<30 m) species known from the Kimberley. The 216 sites sampled were distributed among 5 sub regions; Inshore (110 sites), mid-shelf north (12), offshore south (48), offshore central (22) and offshore north (24). Diversity per site was lowest inshore (4.9 per site) and dominated by ophiuroids and crinoids reflecting the silt and rock habitats characteristic of the inshore subregion. In contrast the midshelf and offshore regions have predominantly coral reef/atoll habitats. The offshore north subregion had the highest number of species per site (10.3) and had 12 times as many asteroid and echinoid species per station than the inshore subregion. Nine species contributed strongly to spatial patterns in species assemblage structure. Overall there was a significant difference in echinoderm assemblages between the inshore subregion and all other subregions. There was no difference between the northern midshelf and the northern offshore subregions which along with significant differences between all of the offshore subregions, suggests the north-south gradient is more influential than the gradient between midshelf and offshore.