parks victoria technical series marine natural values study vol 2 ...
parks victoria technical series marine natural values study vol 2 ...
parks victoria technical series marine natural values study vol 2 ...
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Parks Victoria Technical Series No. 79<br />
Flinders and Twofold Shelf Bioregions Marine Natural Values Study<br />
Victoria 2003). However, this region is subject to high current flows and high winds, with<br />
some influences from local and regional upwellings and current boundaries (e.g. East<br />
Australian Current, EAC). The winds can create substantial surface waves, affect local<br />
currents and cause turbidity (Parks Victoria 2003). Wave exposure is moderate but higher on<br />
the western side of Wilsons Promontory than on the eastern side. The tidal range is<br />
macrotidal. The coastline is predominantly granite headlands and promontories with long<br />
sandy beaches in between. Shores plunge steeply onto a sandy sea floor (IMCRA 2006).<br />
The reefs (Figure 3) consist of a variety of forms: smooth, featureless reef; deep vertical<br />
walls; fissures and pinnacles; boulder fields (with boulders ranging from 1 to 5 m in size)<br />
creating extensive overhang and cavern spaces; and rubble beds (0.1–1 m cobble and<br />
boulders) (Parks Victoria 2003). There are extensive deepwater and shallow sandy beds.<br />
The biota is cool temperate with low numbers of warm-temperate species that are commonly<br />
found in New South Wales (IMCRA 2006). Although the dominant biota of this region<br />
consists of a mixture of species from all of the adjacent biogeographical provinces, the<br />
eastern and southern provincial species appear to be more prevalent than the western<br />
province species (Parks Victoria 2003).<br />
Figure 3. Algal beds on subtidal reef at Wilsons Promontory Marine National Park in the Flinders<br />
bioregion<br />
The Twofold Shelf bioregion extends east of Wilsons Promontory (including the Kent Group<br />
Islands in Tasmania) to Tathra in southern New South Wales (Figure 1, IMCRA 2006).<br />
Within Victorian waters there are three MNPs, Ninety Mile Beach, Point Hicks and Cape<br />
Howe, and one MS, Beware Reef (Figure 2). Its climate is moist cool temperate. Water<br />
temperatures are generally warmer than elsewhere on the Victorian open coast due to the<br />
influence of the EAC (Parks Victoria 2003). These waters are also seasonally and<br />
periodically influenced by the boundary of the EAC with the more southern subtropical<br />
convergence (Harris et al. 1987). The continental slope is quite close to the far eastern<br />
Victorian shore and cold-water upwellings are frequent (Parks Victoria 2003). These<br />
upwellings provide nutrients to inshore ecosystems, contributing to higher productivity. The<br />
continental shelf becomes broader and shallower in the west. Wave energy in this bioregion<br />
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