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
reefs of all the MPAs except Ninety Mile Beach MNP, which has no intertidal reef. 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 could have serious
ecological consequences for subtidal reef communities if it spreads into the Flinders and
Twofold Shelf bioregions.
Recreational boating has also been identified as posing a threat to seagrass beds, soft
sediments and shallow subtidal reefs through propeller scour or anchors. Disturbance of
wildlife, shore birds by vehicles, people or dogs; or breeding colonies of seals by boats are
also a threat in the MPAs, as is poaching of abalone or fish. Commercial vessels also pose a
threat due to the risk of oil spills. Water quality in the MPAs may be threatened by increased
nutrients and sediments from land use or waste discharge.
Climate change represents a serious threat but the specific ecological consequences are not
well understood in temperate 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, 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 would be particularly vulnerable to climate change. In contrast, the urchin
Centrostephanus rodgersii range increase 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.
Intertidal reef monitoring is not conducted in either bioregion as this habitat is limited. Other
statewide projects are currently underway to determine which MPAs are most at risk from
introduced species, to document and photograph marine natural values, and to detect
poaching.
Since declaration considerable advancement has been made in identifying and
understanding the marine natural values of the Flinders and Twofold Shelf bioregions. There
are still major gaps in our knowledge. Comprehensive knowledge of basic habitats, their
distribution and extent, is limited to shallow waters except in Point Hicks and Cape Howe.
Monitoring changes in flora and fauna over time is limited to shallow subtidal reef. There is
limited knowledge of the bioregion’s intertidal and subtidal soft sediment and open waters.
Whilst general and individual threats to the MPAs have been identified we have limited
knowledge of how those threats will affect marine natural values.
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