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
Abalone viral ganglioneuritus has been slowly spreading on the west coast killing a large
percentage of abalone in infected areas from Discovery Bay MNP to Cape Otway. It is not
present in Flinders or Twofold Shelf bioregions but could have serious long term ecological
consequences for subtidal reef communities if it spreads into the bioregions. Recreational
and commercial boats and diving can be a vector for this virus.
Specific threats to individual MPAs have been identified. Generally recreational boating, as
well as being a vector for introduced species and diseases, has been identified as posing a
threat to seagrass beds, soft sediments and shallow subtidal reefs through propeller scour or
anchors. Disturbance of wildlife are also a threat, e.g. shore birds by vehicles, people or
dogs; or breeding colonies of seals by boats in Wilsons Promontory MNP. Poaching of
abalone or fish is a threat within the MPAs. Commercial vessels that pass near or through
the waters of the MPAs also pose a threat due to the risk of oil spills. Increased nutrients and
sediments through land use or waste discharge pose a threat to water quality in the MPAs.
Climate change represents a serious threat to marine ecosystems but the specific ecological
consequences are not well understood in marine systems. Increased sea levels, water and
air temperature, cloud cover, ultraviolet light exposure and frequency of extreme weather
events are predicted. Changes in the chemical composition (salinity, acidity and carbonate
saturation), circulation and productivity of the seas are also predicted. These predicted
changes have the potential to impact all marine habitats, causing loss of habitats, decreases
in productivity and reproduction and distribution of species. A number of species are at the
limit of their distributional range in both bioregions and such species would be particularly
vulnerable to climate change. In contrast, the increased range of the urchin Centrostephanus
rodgersii, is thought to be linked to climate change with the EAC extending further south.
Parks Victoria has established extensive marine monitoring and research programs for the
MPAs that address important management challenges, focussing both on improving
baseline knowledge of the MPAs as well as applied management questions not being
addressed by others. This knowledge will continue to enhance Parks Victoria’s capacity to
implement evidence-based management through addressing critical knowledge gaps. The
research and monitoring programs have been guided by the research themes outlined as
part of Parks Victoria’s Research Partners Panel (RPP) program, a Marine Research and
Monitoring Strategy 2007 - 2012 and Marine National Park and Marine Sanctuary Monitoring
Plan 2007 - 2012 (Power and Boxshall 2007). Much of the research has been undertaken as
part of the RPP program involving collaboration with various research institutions. Subtidal
reef monitoring occurs in all MPAs in the bioregions except Ninety Mile Beach MNP. No
intertidal monitoring is conducted in the bioregions due to limited or no intertidal reef and low
human pressure. Other statewide projects are currently underway to photograph and
document their marine natural values, and also to determine which MPAs are most at risk
from introduced species and to detect poaching.
Detailed bathymetry mapping has been done for shallow waters in all MPAs, and for all of
Point Hicks and Cape Howe MNPs. In Point Hicks and Cape Howe mapping has been done
that allows predictive modelling of the distribution and extent of habitats for the entire MPA.
For the remaining three MPAs our knowledge of their basic habitats, their distribution and
extent, is generally limited, although Friends of Beware Reef have significantly added to our
understanding of knowledge of habitats for the MS. Most of our knowledge about the flora
and fauna of the MPAs is from the shallow subtidal reef marine monitoring program. There
have been limted surveys of the intertidal reefs, which are a relatively small habitat in the
MPAs. Technological improvements have increased our ability to explore and describe deep
habitats, as has been done for reefs in Wilsons Promontory and soft sediments and reefs in
Point Hicks and Cape Howe. There are significant knowledge gaps with regard to our
understanding of the natural values associated with intertidal and subtidal soft sediments,
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