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
Intertidal
Soft sediment
There is no intertidal soft sediment habitat in Beware Reef MS.
Reef
Intertidal reef biota is exposed to large changes in physical conditions such as temperature
and desiccation. There is great spatial and temporal variability in the life histories of the
organisms and the environmental processes in reef habitats (Underwood and Chapman
2004). The recruitment of new biota onto the reef, largely from plankton, strongly influences
the ecological patterns for individual species and assemblages. Interactions between biota
on the reef also influence biota distribution. Resources which are often in short supply on
intertidal reefs are space on which to live and food (Underwood and Chapman 2004).
The exposed intertidal reef is a 0.3 hectare gently rounded offshore granite platform, which
is wave-swept in high seas (Parks Victoria 2006a). Thick stands of bull kelp Durvillaea
potatorum dominate the lower intertidal reef, with coralline algae and fleshy green and brown
algae occurring elsewhere (Parks Victoria 2006a). Durvillaea is more abundant along the
exposed southern side of the island (Edmunds et al. 2005).The cunjevoi Pyura stolonifera is
the dominant invertebrate on the intertidal reef (Parks Victoria 2006a). Large barnacles and
mussels cover much of the rock, while other areas are bare (Parks Victoria 2006a).
As noted by Plummer et al. (2003) no specific data on the biota of intertidal reefs are
available for Beware Reef MS.
Subtidal
Soft sediment
Deep subtidal soft sandy sediment is widespread within the MS. No biological surveys have
been undertaken of this community within the sanctuary to date, but it probably supports
numerous polychaetes, isopods, gastropods, euphausiids, ophiuroids, bivalves, amphipods,
cumaceans and cephalopods (Plummer et al. 2003). A trawl survey conducted 10 km west
of the sanctuary indicates that the presence of some species of fish is seasonal. Common
species found included: sparsely spotted stingaree Urolophus paucimaculatus, gurnard
Lepidotrigla spp., flathead Platycephalus spp., common gurnard perch Neosebastes
scorpaenoides, banded stingaree Urolophus cruciatus and school whiting Sillago bassiensis
(Bird & Watson 1993 as reported in Plummer et al. 2003). Numerous shark species were
also found in the survey: swell Cephaloscyllium laticeps, angel Squatina australis, spotted
cat Asymbolus analis, southern saw Pristiophorus nudipinnis, elephant Callorhynchus milii,
gummy Mustelus antarcticus and Port Jackson Heterodontus portusjacksoni sharks.
Newborn pups of gummy sharks inhabit shallow inshore areas and there is some evidence
to suggest that the inshore sandy areas east of Wilsons Promontory, including Beware Reef
MS, may be important feeding areas for gummy shark pups (Plummer et al. 2003).
Reef
Subtidal reefs and the assemblages associated with them are strongly influenced by the
position of the reef, its orientation, slope, depth, exposure and topography (Connell 2007).
These physical parameters influence key physical processes such as light, water flow and
sedimentation, and biological processes such as foraging and recruitment (Connell 2007).
Biotic assemblages of algae and sessile invertebrates can form habitat and food sources for
invertebrates and fish. Shallow (< 15 m) subtidal reefs are known for their high biological
complexity, species diversity and productivity and in addition they have significant economic
value through commercial and recreational fishing (outside of MPAs), diving and other
tourism activities (Power and Boxshall 2007). Shallow subtidal reefs are often dominated by
canopy forming algae. Deep reefs, where light penetration is limited, are often dominated by
large sessile invertebrates such as massive sponges, whip corals, soft corals and colonial
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