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
Invertebrate fauna
Common invertebrate grazers found on Point Hick reefs include blacklip abalone Haliotis
rubra, the eastern temperate gastropod Astralium tentoriformis, warrener Turbo undulates
and sea urchin Heliocidaris erythrogramma. Predatory invertebrates include dogwhelks
Dicathais orbita, eastern rock lobster Jasus verreauxi, octopus Octopus moarum and a wide
variety of seastar species (Williams et al. 2007; Edmunds et al. 2010b). The cunjevoi Pyura
stolonifera is an obvious invertebrate on the reef close to shore (Ball and Blake 2007). In
general, Point Hicks shallow subtidal reefs are characterised by high abundances of the
predatory gastropod Cabestana spengleri, 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. 2010b). Point Hicks MNP invertebrate assemblage is distinct
from Cape Howe and Beware Reef regions (Edmunds et al. 2010b).
The long-spined black sea urchin Centrostephanus rodgersii (Figure 24) does occur in Point
Hicks MNP (Williams et al. 2007). Centrostephanus forms large grazing aggregations which
denude the reef of erect algal species, forming ‘sea urchin barrens’ and these have been
observed in the MNP (O'Hara 2000; Holmes et al. 2007a; Edmunds et al. 2010b). The
occurrence of urchin barren habitat reflects the influence of species from the east coast of
Australia on the MNP (Williams et al. 2007). Removal of large seaweeds by
Centrostephanus causes substantial changes to subtidal reef community structure (Williams
et al. 2007).
Figure 24. Black urchins Centrostephanus rodgersii and butterfly perch Caesioperca lepidoptera in
Point Hicks Marine National Park. Photo by Mark Norman Museum of Victoria.
Deep subtidal reefs (> 20 m) are dominated by sessile invertebrates. From 15 – 20 m to
approximately 40 m depth, the Ecklonia canopy thins out and is gradually replaced by a
‘garden’ of massive erect sponges, encrusting sponges, gorgonian coral Mopsella zimmeri,
sea-whip coral Primnoella australasiae, and basket star Conocladus australis (Ball and
Blake 2007).
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