Magnetic Island Lagoon

Sites And Species Lists

Magnetic Island Lagoon - Australia

Physical features
Physiographic type	Subtropical lagoon
Area	-
Maximum lenght	5 km
Bathymetry	0.7 m
Wave exposure	-
Tidal stream	Semi-diurnal with diurnal inequlity
Tidal range	0.8 - 2.5 m
Salinity	20 - 36 ‰

Magnetic Island is situated 8km off the coast, from Townsville, Queensland’s largest regional city. (9). Originally named Magnetical Island by James Cook in 1770, it was thought that the topography caused his ship's compass to behave erratically. The granite spine of the island (Mount Cook's elevation is 497 m) suggests a magnetic influence, but tests have not revealed it (10). It islocated within the dry tropics region of north Queensland and the Great Barrier Reef World Heritage Area (GBRWHA) and is part of the Townsville City local government area.

The island is about 5184 ha in size, contains around 40 km of coastline and is the seventh largest and the fourth highest of the 600 continental islands in the GBRWHA. About half of the island (2533 ha) and much of the elevated country is protected (under the Queensland Nature Conservation Act 1992) as the Magnetic Island National Park and there are also two small areas designated as Conservation Parks. There are five matters of national environmental significance relevant to Magnetic Island. Specifically, the island is:

• home or habitat to listed threatened species and a threatened ecological community

• habitat to listed migratory species

• part of the Great Barrier Reef World Heritage Area

• part of the Great Barrier Reef National Heritage place, and

• surrounded by the Great Barrier Reef Marine Park (11).

However, the island boasts a huge diversity of habitat types and environmentally significant areas and features. Freshwater creeks meander through pockets of rainforest and woodland. Where the rocky headlands meet the sea many secluded beaches and bays have been formed. The rocky headlands with magnificent granite boulders keep watch over the tropical waters of the Great Barrier Reef Marine Park and GBR World Heritage Area. Impressive coral communities cluster around the rocky headlands. A range of well-developed nears hore fringing reefs in the bays surrounding the island provide superb habitat for a myriad of marine fauna species. Extensive mangrove habitat on the leeward side of the island forms integral habitat for the refuge and breeding

of numerous terrestrial and marine species. Wide inter -tidal mud flats support a huge variety and abundance of marine organisms and provide exceptional foraging ground for wading birds. Seagrass meadows flourish in the sheltered waters on the western side of the island, forming essential habitat for the Dugong, and support numerous species of marine flora, and other wildlife. These features are just some of the reasons that Magnetic Island was listed as a World Heritage Area in 1981. Situated on the cusp of Queensland’s wet tropics and the semi-arid tropics of the Townsville area, Magnetic Island is a refuge for biodiversity, by virtue of it’s isolation from many threatening processes prevalent on the mainland. Boasting an incredible diversity of permanent, nomadic and migratory wildlife species, many of which are of local, regional, national and even international conservation significance, Magnetic Island provides a unique and outstanding opportunity for wildlife conservation and research.

The island also supports some highly significant wildlife species. An overview follows:

Magnetic Island is home to almost 200 bird species, many of which are noteworthy from a conservation perspective;
Terrestrial mammals, of which 19 species have been recorded so far, such as the allied Rock-wallaby, Koala and one species of microbat listed as vulnerable, call Magnetic Island home;
At least 34 species of reptile have also been recorded on the island, including the rare Sadlier’s Dwarf Skink (Menetia sadlieri), a small skink species recorded only on Magnetic Island;
At least 13 species of amphibian occur within the varied forest habitats of this small island environment;
In addition, approximately 600 native plant species are also know to occur on the island;
A number of marine wildlife species of conservation significance also occur in the waters of the Great Barrier Reef surrounding the Island, such as the vulnerable Green Turtle (Chelonia mydas), the rare Snubfin Dolphin (Orcaella heinsohni) and vulnerable Indo-Pacific Humpback Dolphin (Sousa chinensis);
The variety of marine environments surrounding Magnetic Island provide habitat for over 140 species of fish from at least 33 families. The currently healthy condition of the island’s coral reefs supports an intact fish community from all trophic levels.

Even though research on the wildlife of Magnetic Island is relatively limited to date, the above includes an impressive diversity of wildlife species (9) (12). References (1) http://www.ga.gov.au/education/geoscience-basics/dimensions/australias-size-compared.html

(2) http://www.ga.gov.au/education/geoscience-basics/dimensions/climatic-extremes.html

(3) http://www.ga.gov.au/education/geoscience-basics/dimensions/coastline-lengths.html

(4) http://www.ga.gov.au/education/geoscience-basics/dimensions/oceans-and-seas.html

(5) http://www.ga.gov.au/education/geoscience-basics/dimensions/remote-offshore-territories.html)

(6) http://www.ga.gov.au/education/geoscience-basics/dimensions/remote-offshore-territories/coral-sea-islands.html

(7) http://www.ga.gov.au/education/geoscience-basics/landforms/islands.html

(8) http://www.ga.gov.au/education/geoscience-basics/dimensions.html

(9) Lyndall Harvey, Environmental Scientist, C&R Consulting Pty Ltd. (2008). A suburb of National Parks and World Heritage status – Wildlife Conservation on Magnetic Island.

(10) http://queenslandplaces.com.au/magnetic-island

(11) Australian government. Department of Sustainability, Environment, Water, Population and Communities, 2010. EPBC Act policy statement 5.1 Magnetic Island, Queensland Region

(12) Members of Magnetic Island Community Development Assoc. Inc. and Magnetic Island Nature Care Assoc. Inc. (2004). Magnetic Island’s World Heritage Values. A Preliminary Assessment.