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Conservation of natural wilderness values in the Port Davey marine and estuarine protected area, South-Western Tasmania


Edgar, GJ and Last, P and Barrett, NS and Gowlett-Holmes, K and Driessen, M and Mooney, P, Conservation of natural wilderness values in the Port Davey marine and estuarine protected area, South-Western Tasmania, Aquatic Conservation: Marine and Freshwater Ecosystems, 20, (3) pp. 297-311. ISSN 1052-7613 (2010) [Refereed Article]

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DOI: doi:10.1002/aqc.1079


1. Port Davey and associated Bathurst Harbour in south-western Tasmania represent one of the world’s most anomalous estuarine systems owing to an unusual combination of environmental factors. These include: (i) large uninhabited catchment protected as a National Park; (ii) ria geomorphology but with fjord characteristics that include a shallow entrance and deep 12-km long channel connecting an almost land-locked harbour to the sea; (iii) high rainfall and riverine input that generate strongly-stratified estuarine conditions, with a low-salinity surface layer and marine bottom water; (iv) a deeply tannin-stained surface layer that blocks light penetration to depth; (v) very low levels of nutrients and low aquatic productivity; (vi) weak tidal influences; (vii) marine bottom water with stable temperature throughout the year; (viii) numerous endemic species; (ix) strongly depth-stratified benthic assemblages exhibiting high compositional variability over small spatial scales; (x) deepsea species present at anomalously shallow depths; (xi) no conspicuous introduced taxa; (xii) a predominance of fragile sessile invertebrates, including slow-growing fenestrate bryozoans; and (xiii) sponge spicule- and bryozoan-based sediments that are more characteristic of deep sea and polar environments than those inshore.2. Although this region has historically been protected by its isolation, seven major anthropogenic stressors now threaten its natural integrity: boating, fishing, dive tourism, nutrient enrichment, introduced species, onshore development, and global climate change. These threats are not randomly distributed but disproportionately affect particular habitat types. 3. For management of environmental risk, the Port Davey–Bathurst Harbour region is subdivided into six biophysical zones, each with different ecological characteristics, values, and types and levels of potential threat. In response to the various threats, the Tasmanian Government has enacted an adaptive management regime that includes a multi-zoned marine protected area and the largest ‘no-take’ estuarine protected area in Australia.

Item Details

Item Type:Refereed Article
Keywords:benthic invertebrates; climate change; diver impacts; fishes; introduced marine pests; World Heritage Area
Research Division:Environmental Sciences
Research Group:Environmental management
Research Field:Conservation and biodiversity
Objective Division:Environmental Management
Objective Group:Terrestrial systems and management
Objective Field:Assessment and management of terrestrial ecosystems
UTAS Author:Edgar, GJ (Professor Graham Edgar)
UTAS Author:Barrett, NS (Associate Professor Neville Barrett)
ID Code:66977
Year Published:2010
Web of Science® Times Cited:21
Deposited By:TAFI - Marine Research Laboratory
Deposited On:2011-02-22
Last Modified:2011-03-22

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