parks victoria technical series marine natural values study vol 2 ...
parks victoria technical series marine natural values study vol 2 ...
parks victoria technical series marine natural values study vol 2 ...
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Parks Victoria Technical Series No. 79<br />
Flinders and Twofold Shelf Bioregions Marine Natural Values Study<br />
Abalone viral ganglioneuritus has been slowly spreading on the west coast killing a large<br />
percentage of abalone in infected areas from Discovery Bay MNP to Cape Otway. It is not<br />
present in Flinders or Twofold Shelf bioregions but could have serious long term ecological<br />
consequences for subtidal reef communities if it spreads into the bioregions. Recreational<br />
and commercial boats and diving can be a vector for this virus.<br />
Specific threats to individual MPAs have been identified. Generally recreational boating, as<br />
well as being a vector for introduced species and diseases, has been identified as posing a<br />
threat to seagrass beds, soft sediments and shallow subtidal reefs through propeller scour or<br />
anchors. Disturbance of wildlife are also a threat, e.g. shore birds by vehicles, people or<br />
dogs; or breeding colonies of seals by boats in Wilsons Promontory MNP. Poaching of<br />
abalone or fish is a threat within the MPAs. Commercial vessels that pass near or through<br />
the waters of the MPAs also pose a threat due to the risk of oil spills. Increased nutrients and<br />
sediments through land use or waste discharge pose a threat to water quality in the MPAs.<br />
Climate change represents a serious threat to <strong>marine</strong> ecosystems but the specific ecological<br />
consequences are not well understood in <strong>marine</strong> systems. Increased sea levels, water and<br />
air temperature, cloud cover, ultraviolet light exposure and frequency of extreme weather<br />
events are predicted. Changes in the chemical composition (salinity, acidity and carbonate<br />
saturation), circulation and productivity of the seas are also predicted. These predicted<br />
changes have the potential to impact all <strong>marine</strong> habitats, causing loss of habitats, decreases<br />
in productivity and reproduction and distribution of species. A number of species are at the<br />
limit of their distributional range in both bioregions and such species would be particularly<br />
vulnerable to climate change. In contrast, the increased range of the urchin Centrostephanus<br />
rodgersii, is thought to be linked to climate change with the EAC extending further south.<br />
Parks Victoria has established extensive <strong>marine</strong> monitoring and research programs for the<br />
MPAs that address important management challenges, focussing both on improving<br />
baseline knowledge of the MPAs as well as applied management questions not being<br />
addressed by others. This knowledge will continue to enhance Parks Victoria’s capacity to<br />
implement evidence-based management through addressing critical knowledge gaps. The<br />
research and monitoring programs have been guided by the research themes outlined as<br />
part of Parks Victoria’s Research Partners Panel (RPP) program, a Marine Research and<br />
Monitoring Strategy 2007 - 2012 and Marine National Park and Marine Sanctuary Monitoring<br />
Plan 2007 - 2012 (Power and Boxshall 2007). Much of the research has been undertaken as<br />
part of the RPP program in<strong>vol</strong>ving collaboration with various research institutions. Subtidal<br />
reef monitoring occurs in all MPAs in the bioregions except Ninety Mile Beach MNP. No<br />
intertidal monitoring is conducted in the bioregions due to limited or no intertidal reef and low<br />
human pressure. Other statewide projects are currently underway to photograph and<br />
document their <strong>marine</strong> <strong>natural</strong> <strong>values</strong>, and also to determine which MPAs are most at risk<br />
from introduced species and to detect poaching.<br />
Detailed bathymetry mapping has been done for shallow waters in all MPAs, and for all of<br />
Point Hicks and Cape Howe MNPs. In Point Hicks and Cape Howe mapping has been done<br />
that allows predictive modelling of the distribution and extent of habitats for the entire MPA.<br />
For the remaining three MPAs our knowledge of their basic habitats, their distribution and<br />
extent, is generally limited, although Friends of Beware Reef have significantly added to our<br />
understanding of knowledge of habitats for the MS. Most of our knowledge about the flora<br />
and fauna of the MPAs is from the shallow subtidal reef <strong>marine</strong> monitoring program. There<br />
have been limted surveys of the intertidal reefs, which are a relatively small habitat in the<br />
MPAs. Technological improvements have increased our ability to explore and describe deep<br />
habitats, as has been done for reefs in Wilsons Promontory and soft sediments and reefs in<br />
Point Hicks and Cape Howe. There are significant knowledge gaps with regard to our<br />
understanding of the <strong>natural</strong> <strong>values</strong> associated with intertidal and subtidal soft sediments,<br />
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