Regional classification of Tasmanian coastal waters

Abstract

Analysis of the distribution of reef plants and animals at over 150 sites around the Tasmanian coastline and Bass Strait islands indicated that Bass Strait reef communities were distinctly different from those occurring further south. This major division in reef ecosystems reflected a boundary near Cape Grim and Little Musselroe Bay between two biogeographical provinces. Each of the two bioprovinces was divisible into four biogeographical regions (bioregions), which occurred along the northern Tasmanian coast and at the Kent Group, Furneaux Group and King Island in Bass Strait, and along the northeastern, southeastern, southern and western coasts of Tasmania. In contrast to these patterns identified using data on coastal reef communities, regional classifications for estuarine and soft-sediment faunas (based on the distribution of beach-washed shells and beach-seined fishes) were less clearly defined. In order to manage and protect Tasmanian inshore plants and animals in accordance with the principle of ecologically sustainable development, an integrated system of representative marine protected areas is considered a necessary adjunct to appropriate regulations concerning individual marine species. The benefits of a marine reserve system include (i) the provision of fish propagation areas, (ii) insurance against the possibility of fishery stock collapses, (iii) the formation of areas where natural ecosystem processes can be scientifically investigated, (iv) the maintenance of reservoirs of genetic diversity, (v) the provision of recreational sites for divers and naturalists, and (vi) areas of focus for public education about coastal life. An integrated Tasmanian system of marine protected areas should include at least one area within each bioregion extending for approximately 10 km of coast where plants and animals are protected from exploitation. The recommended locations where representative marine reserves should be declared are Maria Island, Port Arthur or Tinderbox, Port Davey, Sloop Rocks or Point Hibbs, New Year Islands (King Island), the Kent Group, western Franklin Sound (Flinders Island), Rocky Cape and Macquarie Island. Because no Tasmanian marine reserve presently exists within the Bassian bioprovince, the immediate priority is to declare a marine reserve in the Bass Strait region. The species diversity protected within Tasmanian marine reserves will be maximised if that reserve is located in the vicinity of Deal Island. The identification and declaration of estuarine protected areas was not considered in the present report but should also be addressed as a matter of urgency.