Community structure and zoogeographic affinities of the coastal fishes of the Dampier region of north-western Australia.

The inshore fish fauna of the Dampier region of tropical northwestern Australia has received little attention. The only data available are species lists in environmental impact statements by Woodside Petroleum and Dampier Salt, and unpublished reef fish surveys by the West Australian Museum. This study of the fishes of the Dampier area was undertaken to fill this gap and also for three specific reasons: (1) to assess interrelationships and possible interdependence between the inshore fauna and the commercially important deeper water fisheries of the North West Shelf (2) to compare the communities with other Indo-Pacific inshore faunas; and (3) to establish a data base for monitoring possible future changes in the fauna, as part of the research program of the Western Australian Department of Conservation and Environment (Chittleborough 1983). The coastal land is arid, lacking soil development, extensive vegetation and rivers. The lack of freshwater inflow, together with the presence of mangroves, open shores and coral reefs, provides a relatively unique range of shallow water habitats. How these unusual conditions influence the species composition and community structure was not known. Coral reefs were excluded from this study because of the specialized nature of their fauna, and attention was concentrated on the fishes of the mangroves, open shorelines and embayments of the mainland In order to obtain seasonal coverage and comparisons, fieldwork was undertaken in July and October 1983 and in January 1984, from a base laboratory of the Department of Conservation and Environment in Dampier. The mangrove sites were Cleaverville Creek, north Withnell Bay, and the West Intercourse Island complex, adjacent to the Dampier Salt Lease. The open shore sites were South Bay, No Name Bay and south Withnell Bay, all of which consisted of embayments with shelving sandy beaches flanked by rock promontories. Depth was down to 2 metres.