AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS Aquatic Conserv: Mar. Freshw. Ecosyst. 20: 282–296 (2010) Published online 3 December 2009 in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/aqc.1082 Biotic affinities of rocky reef fishes, invertebrates and macroalgae in different zones of the Port Davey marine protected area, south-western Tasmania GRAHAM J. EDGAR Ã and NEVILLE S. BARRETT Tasmanian Aquaculture and Fisheries Institute, University of Tasmania, GPO Box 252-49, Hobart, Tasmania 7001, Australia ABSTRACT 1. Assemblages of fishes, invertebrates, and macroalgae showed strong and predictable distributional patterns within the newly declared Port Davey marine protected area (MPA) in south-western Tasmania. Biotic assemblages in the eastern estuarine section of the MPA within Bathurst Channel were extremely anomalous, both in relation to biota elsewhere in the Port Davey region and also to those present along the wider Tasmanian and Australian coasts. Much of this variation was due to the phenomenon of deepwater emergence, with species in 5 m water depth in eastern Bathurst Channel possessing a mean maximum recorded depth of 200 m, compared witho80 m for the same metric when calculated for sites studied elsewhere around Australia. Deepwater emergence in Bathurst Channel was particularly notable for sessile organisms, although also evident among fishes and mobile macro-invertebrates. 2. Quantitative baseline surveys of reef-associated species were undertaken at sites interspersed among MPA management zone types and biotic community types, thereby providing an appropriate benchmark for assessing ecological changes in different management zones within the Port Davey region through the long term. Distinctive biota present in eastern and western Bathurst Channel, and eastern Port Davey, are well protected within ‘no-take’ sanctuary zones; however, a bias in location of sanctuary zones towards areas with little fishery resources resulted in less protection for the western Port Davey biota, which also extends along the open coast. Although the lack of high level protection for sites with fishery resources detracts from conservation goals, the Port Davey MPA nevertheless represents a major advance in environmental protection because the ecologically unique, fully protected locations are a necessary inclusion within any comprehensive Australian MPA network. Copyright r 2009 John Wiley & Sons, Ltd. Received 4 February 2009; Revised 29 August 2009; Accepted 4 September 2009 KEY WORDS: deepwater emergence; effects of fishing; estuary; MPA management; World Heritage Area; wilderness INTRODUCTION In January 2005 the Tasmanian Government declared its second largest marine protected area (MPA), with the aim of safeguarding aquatic plant and animal populations off the south-western Tasmanian coast in a wilderness World Heritage Area (Resource Planning & Development Commission, 2002, 2003). The multi-zoned Port Davey MPA is fully contained within the South West National Park and extends approximately 20 km north–south and 30 km east–west (Figure 1), encompassing (i) the large coastal embayment of Port Davey, (ii) a large estuarine basin at Bathurst Harbour that is almost land-locked, (iii) the narrow 12 km long connecting passage of Bathurst Channel, and (iv) numerous adjacent inlets (Edgar et al., in press). Most scientific research within the greater Port Davey region has focused on sites within Bathurst Channel and Bathurst Harbour. These estuarine-influenced areas are particularly interesting scientifically because they possess faunal communities regarded as extremely unusual globally in terms of endemism and faunal composition, and because of the presence in diveable depths of taxa and biophysical processes that are more typical of the deep sea (Edgar et al., in press). A surface layer of tannin-stained low-salinity water *Correspondence to: Graham J. Edgar, Tasmanian Aquaculture and Fisheries Institute, University of Tasmania, GPO Box 252-49, Hobart, Tasmania 7001, Australia. E-mail: g.edgar@utas.edu.au Copyright r 2009 John Wiley & Sons, Ltd.