OVERVIEW
The biggest threats to the Island at present are those posed by people.
Over 400,000 people visit K'gari each year.
Many visitors travel in 4x4 vehicles to camp in coastal dunes that fringe the ocean beaches and to fish in the surf.
These activities are of immense social and economic significance to people, but they also impact many physical and biological properties of the surf-beach-dune area.
Vehicle access tracks change the physical structure of foredunes and alter the distribution and diversity of dune plants and animals (e.g. ghost crabs).
The use of 4x4 vehicles on beaches has a direct impact on the abundance, diversity and behaviour of animals, and indirect effects on the fitness of many other species including beach birds (e.g. pied oystercatchers, crested terns and invertebrates (e.g. surf clams).
Human activities, particularly those associated with recreation, have already left their imprint on lake water quality, lake water biota and ecosystem processes.
Visitors affect the ecology of the Island's freshwater ecosystems through direct physical disturbance of sediment and vegetation, and the addition of nutrients and other chemicals into the water column.
Perched lakes are particularly susceptible to visitor impacts given that have low nutrient concentrations and are essentially closed systems (no throughflow to/from the watertable and no streams leading in or out). The result is thatthe water stays there, as opposed to the natural flushing systemof other waterbodies.
Recreational anglers catch large numbers of fish from the beaches of K'Garieach year, which modifies the abundance and diversity of fish in the surf and alters the foraging behavior of dingoes.
Interactions with boats alters the behaviour of whales in Hervey Bay and are a common cause of mortality for sea turtles.
Pests such as feral animals, weeds and pathogens such as myrtle rust impact the flora and fauna of the Island. It's essential that visitors do not bring soil, plants or domestic animals on the Island. All vehicles need an underbody wash before landing on K'gari.
Future climate changes are projected for the broader K'gari and Wide Bay region. Projections indicate the potential for increasing warming and evaporation, and a likely decrease in rainfall. It is anticipated that there will be periods of extreme drought and intense rainfall events.
Current projections for rainfall suggest wetter summers and significantly drier autumns, winters and springs. These changes in rainfall patterns, particularly the extended dry spells, are likely to threaten the perennial nature of many of the shallow perched dune lakes.
Perched dune lakes may also experience changing hydrology, rising water temperature, rising human-generated nutrient levels, and changes to the carbon cycle. The lowering and raising of lake water levels from predicted rainfall patterns will drive pulses of lake productivity, stimulated by tourist-derived nutrients, that will likely lead to increased algal production in the near shore areas. Excessive algae may have negative consequences both for the lake food web and for the visitors who find the lakes unattractive.
Bushfires and intense cyclones are also set to increase. The characteristics of the Island make it particularly vulnerable to climate changeimpactsincluding sea level rise and increased storm frequency and intensity.
Many tropical species are moving towards the poles with rising sea temperatures, and their arrival in cooler waters is altering the structure and functioning of subtropical and temperate ecosystems. The coastal waters of Hervey Bay are a hotspot for species range shifts and are recognised as a potential refuge for tropical species that are migrating south with climate change.
More information: Hadwen W.L., Arthington A.H. and Mosisch T.D. (2003). The impact of tourism on dune lakes on Fraser Island, Australia. Lakes and Reservoirs: Research and Management, Vol. 8, pp. 15-26.
Schlacher, T. A., Nielsen, T. and Weston, M.A. (2013a).
Estuarine, Coastal and Shelf Science, Vol, 118, pp 31-42.
Gontz, A. M., Moss, P. T., Sloss, C. R. Petherick, L. M., McCallum, A., and Shapland, F., (2015). Understanding past climate variations and environmental change for the future of an iconic landscape - K'gari Fraser Island, Queensland, Australia. Australian Journal of Environmental Management, Vol. 22, pp. 105-123.