Marine Natural Values Study Summary - Parks Victoria

Marine Natural Values Study SummaryMushroom ReefMarine SanctuaryAustralia’s southern waters areunique. Ninety per cent of ourmarine plants and animals arefound nowhere else on earth.The system of Marine NationalParks and Sanctuaries hasbeen established to representthe diversity of Victoria’smarine environment, itshabitats and associatedflora and fauna.Victoria’s marine environmenthas been classified into fivebioregions according toa nationally agreed schemebased on physical andbiological attributes.Mushroom Reef MarineSanctuary is one of five marinesanctuaries and two marinenational parks in the CentralVictoria bioregion.Image left:The Anemone Phyctenanthus australis.Photo by Mark Norman, Museum Victoria.Image right:Intertidal reef and rockpools in Mushroom Reef MarineSanctuary. Photo by Mark Norman, Museum Victoria.DescriptionThe sanctuary covers 56.7 hectares,abutting the Mornington PeninsulaNational Park and extends from thehigh water mark to approximately1kilometres offshore. Close to thetownship of Flinders, the sanctuaryextends 702 metres along the FlindersOcean Beach from 300 metres eastof Kings Street to 500 metres westof the West Head car park.The sanctuary is accessible from thesigned car park off the golf courseor by adjoining beaches.Parks Victoria acknowledges theAboriginal Traditional Owners ofVictoria – including its parks andreserves. Indigenous tradition indicatesthat the park is part of Countryof Boonwurrung.Physical Parameters and ProcessesMushroom Reef Marine Sanctuaryis protected from large swells bynearby Bismark Reef and is influencedby the ocean waters of Bass Straitand by tidal flows from the westernentrance to Western Port Bay.The seafloor is predominantly lessthan 9 metres deep. Surface watertemperatures vary between anaverage 17.5°C in the summer and13.0°C in the winter. Tidal variationis 2.1 metres for spring tides and0.7 metres for neap tides.The geology of the sanctuary is basalt.The reefs are hexagonal fracturedcolumns formed by the coolingof lava, which weather and breakdown to form rounded cobblesand boulders.Mushroom Reef Marine Sanctuaryis named after the shape of its largestintertidal platform. Its large intertidalisthmus or ‘stalk’ has been formed byincoming waves refracting around thereef platform and depositing basaltcobbles into the gap between theplatform and the shore, an unusualcoastal landform known as a tombolo.Double Creek discharges 500 metreswest of the sanctuary and receivesstormwater from the townshipof Flinders.Marine Habitat Distributionand Ecological CommunitiesThe main habitats protected by thesanctuary include intertidal andsubtidal soft sediment (includingseagrass), intertidal and subtidalreefs, and the water column.The intertidal soft sediments provideimportant feeding and roostinghabitat for shorebirds such asSooty oystercatchers Haematopusfuliginosus, curlew sandpipers Calidrisferruginea, red-necked stints Calidrisruficollis, Ruddy turnstones Arenaria30