Marine Natural Values Study Summary - Parks Victoria

Beaches and intertidal soft sedimentsare restricted to pockets at the base ofcliffs. A number of shorebirds are alsofound in or near the park, includingsome of conservation significance.Subtidal soft sediments (presentas a gently sloping sandy basin in thecentre of the park) are usually devoidof visible biota although the deeperregions have areas of reef beneatha thin veneer of sand allowing sessileinvertebrates to grow.Crustaceans are the most dominantgroup found in the soft sedimentsincluding amphipods, isopodsand cumaceans. Sparse seagrassHeterozostera spp. also growsin 10 metres to 30 metres on theshallow sandy plain providing habitatfor fish and invertebrates.Bull Kelp Durvillaea potatorum growson the intertidal reef edge and canbe seen at the base of the limestonerock stacks. The kelp Ecklonia radiataand the green algae Caulerpa spp.grow in depths less than 40 metresand red algae is found at all depthsincluding: Phacelocarpuspeperocarpus, Melanthalia obtusata,Gelidium asperum, Sonderopeltacoriacea and Haliptilon roseum.Smaller brown algae includingCarpomitra costatum grow in moresandy areas.Coastline of Twelve Apostles Marine National Park.Photo by NRE.Mobile invertebrates on the subtidalreefs include seastars such asPlectaster decanus, and the SouthernRock Lobster Jasus edwardsii.Subtidal reef fish in the park aretypical of the region and include theblue-throated Notolabrus tetricus,rosy Pseudolabrus psittaculus andsenator wrasses Pictilabrus laticlavius;the magpie perch Cheilodactylusnigripes and dusky morwongsDactylophora nigricans; sea sweepScorpis aequipinnis; barberCaesioperca rasor and butterflyperches C. lepidoptera; marble fishAplodactylus arctidens; and thebullseye Pempheris multiradiata.The deep reefs (more than 40 metres)are dominated by sessile invertebrates(e.g. erect sponges, gorgonians andthe large hydroid fan Solanderia fusca)and are an important natural value.The water column is home to a varietyof planktonic and pelagic organisms.Those that make their permanenthome in the water column includesea jellies, salps, many fish, andphytoplankton and zooplankton.A number of marine mammals andseabirds are also found in or use thewater column in the park.Species and Communitiesof Conservation SignificanceThe water column of the park isimportant habitat for threatened fishincluding the migratory southernbluefin tuna Thunnus maccoyii and islikely to be used by two shark species:the grey nurse shark Charchariastaurus and the great white sharkCarcharodon carcharias.The park provides important feedingand roosting habitat for eleventhreatened bird species includingthe wandering albatross Diomedeaexulans, little egret Egretta garzetta,and Australasian bittern Botauruspoiciloptilus.A large breeding colony of littlepenguins Eudyptula minor betweenthe Twelve Apostles and LondonBridge is considered a significant site,and two significant hooded ploverThinornis rubricollis nesting sites existon Clifton and Rivernook beaches.Mutton Bird Island also supportsa breeding colony of short-tailedshearwaters Puffinus tenuirostris.The park is important for a numberof resident and migrating marinemammals including Southern rightwhales Eubalaena australis, humpbackwhales Megaptera novaeangliae, NewZealand fur seals Arctophoca forsteri,and Australian fur seals Arctocephaluspusillus doriferus.Major ThreatsMeasures to address or minimisethreats identified for Twelve ApostlesMarine National Park form part of the14