Kimberley marine biota. History and environment

Abstract

The remote tropical Kimberley region of Western Australia is introduced, its physical marine environment, habitats and classifi cation into bioregions are described, and its marine science history is summarised. An introduction to the ongoing Western Australian Museum marine biological survey program and its objectives are also provided. The geology, metocean conditions and climate of the region are summarised. A primary division of the Kimberley coastline is noted with a northern section dominated by Proterozoic meta-sedimentary and igneous rocks (Kimberley and Bonaparte Gulf Bioregions) and a southern section dominated by Mesozoic and Cainozoic sedimentary rocks (King Sound and Canning Bioregions). In the former section inner shelf seabed sediments overlying the inundated Yampi Plateau are principally of terrestrial origin while in the Canning Bioregion they are principally marine carbonates. On the middle and outer shelf (Oceanic Shoals and North West Shelf Bioregions) sediments are primarily marine carbonates. Along the shelf margin the water is clear and oligotrophic and subject to the Indonesian Through Flow current that originates in the western Pacifi c. The coastal zone is macrotidal, currents are predominantly tide driven and the coastal water is turbid and probably nutrient rich. These environmental differences and the different connectivity regimes account for distinctive offshore and coastal reef communities.