parks victoria technical series marine natural values study vol 2 ...

Parks Victoria Technical Series No. 79
Flinders and Twofold Shelf Bioregions Marine Natural Values Study
2.3 Point Hicks MNP – Twofold Shelf Bioregion
Point Hicks is one of three Marine National Parks in the Twofold Shelf bioregion, which also
contains Ninety Mile Beach and Cape Howe MNP. Other conservation areas are Gippsland
Lakes and Cape Conran Coastal Parks. Point Hicks MNP is approximately 450 km east of
Melbourne, 68 km east of Orborst and 25 km south-east of Cann River. It adjoins Point Hicks
Lighthouse Reserve and the Croajingolong National Park. It extends offshore to state limits
from high water mark along 9.6 km of coastline from two kilometres east of Clinton Rocks to
Stable Bay (Figure 17). It includes Whaleback Rock and Sensation Reef. Point Hicks MNP is
accessible by a short walk from Point Hicks Road, or less readily by boat (Parks Victoria
2006f). The reef directly below Point Hicks (formerly known as Cape Everard), Whaleback
Rock and Satisfaction Reef are the best-known geological features of the park (Parks
Victoria 2006f). The area of coast between Point Hicks and Thurra River is a site of State
geological and/or geomorphological significance because of its important dune stratigraphic
sequence.
Aboriginal tradition indicates that the Point Hicks MNP is part of the Country of the Bidawal
people and Gunai/Kurnai people and that other Aboriginal people including the Monero-
Ngarigo people also have an association with the coastal region of this area (Parks Victoria
2006e).
Important natural values of Point Hicks MNP are its granite intertidal and shallow and deep
subtidal rocky reefs, sandy shores and open oceans that provide habitat for a diversity of
marine flora and fauna species, including sessile invertebrates, algae, fish and transient
whales (Parks Victoria 2006f). Shallow rocky reef habitats have varied forms, from flat
platform reefs bordered by sand, pinnacles and bombies, gutters, large boulders rising to six
metres to clusters of smaller rocks and stones (ECC 2000; Carey et al. 2007b; Edmunds et
al. 2010a). They are highly exposed, which is reflected in the types of kelp habitats present
(Edmunds et al. 2010a). Deep subtidal reef characteristics have not been fully described
(Edmunds et al. 2010a). The MNP also has extensive subtidal soft sediments of variable
grainsize, with a low carbonate content (Carey et al. 2007b). Very high faunal species
richness, including intertidal and shallow subtidal invertebrates have been recorded in the
MNP (ECC 2000). Eastern temperate and southern cosmopolitan species co-occur, as a
result of the mixing of warm eastern and cool southern waters (Parks Victoria 2006f). The
marine flora and fauna of the subtidal reefs are spectacular with colourful and diverse sessile
invertebrates (Carey et al. 2007b). A notable feature are the front reefs and Whaleback
Rock, which have high relief gutters of 1 - 15 m and a high area of sessile invertebrate
habitat on the vertical walls (O'Hara 2000).
An important characteristic of Point Hicks MNP is its canopy forming algae and small
understorey algae (ECC 2000; Carey et al. 2007b). The stands of canopy forming algae are
generally a mixture of crayweed Phyllospora comosa and common kelp Ecklonia radiata,
with the proportions of these two species varying according to the habitat, depth and location
(Williams et al. 2007; Edmunds et al. 2010b). The reef beneath the canopy varies from
encrusting and erect sponges to small fleshy red algae (Parks Victoria 2003). The
Phyllospora invertebrate community includes relatively high abundances of the predatory
whelk Cabestana spengleri and the seastar Patiriella calcar, and moderate abundances of
blacklip abalone Haliotis rubra and the red bait crab Plagusia chabrus (Parks Victoria 2003;
Edmunds et al. 2005; Williams et al. 2007). The herbivorous sea urchin Centrostephanus
rodgersii can remove all erect algae to create ‘urchin barrens’ on the reefs in the MNP
(Williams et al. 2007).
Fish assemblages at Point Hicks MNP are a mixture of cool southern and warm eastern
species. They are dominated by large numbers blue throat wrasse Notolabrus tetricus and
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