Spatial and Temporal Variation of Benthic Macrofaunal Communities in the Intermittently Closed Estuaries of the Solitary Islands Marine Park, Australia

Abstract

Intermittently closed estuaries comprise up to 92% of the estuaries along the New South Wales (NSW) coast. Despite being the most abundant estuary type in southeast Australia,intermittently closed estuaries are, ecologically, very poorly understood. This is a result of past estuarine research in Australia primarily having focussed on permanently open systems. Consequently, there is little scientific information on which to base management guidelines concerning intermittently closed estuaries, with the prevailing management approach giving little attention to their natural differences to other estuarine systems or their elevated sensitivity to anthropogenic influences. The overall objective of this work, therefore, was to develop a greater understanding of the ecology of intermittently closed estuaries by examining community variation within them, and comparing this with nearby permanently open estuaries. Conducted within the Solitary Islands Marine Park, the major proportion of the study comprised seasonal sampling of benthic macrofauna in six intermittently closed and three permanently open estuaries. This continued over a two-year period, with the aims of: 1) determining the degree of spatial variation within and between the two estuary types; 2) examining how the relationship between the two estuary types changed over time; and 3) investigating temporal variation within each estuary.