This entry describes a GBRMPA Workshop Presentation on the status of dugong in the Torres Strait. Refer to the compiled report: Marsh, H.L. And Saalfeld. K. (1991) Status of Dugong in Torres Strait. In: D. Lawrence and T. Cansfield-Smith (eds) Sustainable development for traditional inhabitants of the Torres Strait region. Proceedings of the Torres Strait Baseline Study Conference. Kewarra Beach, Cairns, QLD, 19-23 November 1990. GBRMPA Workshop Series 16 : 187-194.

This record is derived from DEC Marine Policy Branch Endnote library and spatially referenced SIER Database.

Fishery Assessment Report (1994) on the Dugong Fishery in the Torres Strait. Compiled by H. Marsh and edited by the Southern Bluefin Tuna Fishery Stock Assessment Group, for AFMA: Marsh, H. (1995) The Torres Strait Dugong Fishery 1994, Fisheries Assessment Report, edited by the Southern Bluefin Tuna Fishery Stock Assessment Group. Australian Fisheries Management Authority, Canberra. 14pp.

Fishery Assessment Report on Dugong in the Torres Strait 1999. Compiled by H. Marsh and edited by the Torres Strait Fisheries Assessment Group, for AFMA: Marsh, H. (1999) Torres Strait Dugong 1998, Fisheries Assessment Report, edited by the Torres Strait Fisheries Assessment Group. Australian Fisheries Management Authority, Canberra.

The referenced report is presented in two sections. The first section reports on the results of a third survey of dugong distribution and abundance in Torres Strait conducted over four days in November 1996. The second section estimates the size of a sustainable dugong catch in Torres Strait using the Potential Biological Removal Method (PBR). The sustainability of the dugong fishery is then evaluated by comparing aerial survey estimates of the size of the dugong population in 1987, 1991 and 1996, and catch statistics from the Torres Strait Protected Zone (TSPZ) since 1991 in the context of current knowledge of dugong life history parameters.

This dataset shows a raster spatial model of the distribution and relative density of dugongs (Dugong dugong) in the Torres Strait region based on an aggregate of 24 years (1987 - 2011) of systematic aerial surveys. Aerial surveys were conducted using the strip transect method described by Marsh and Sinclair (1989). The survey region was divided into blocks containing systematic transects of varying length, which were typically perpendicular to the coast across the depth gradient. Tandem teams with two observers on each side of the aircraft independently recorded sightings of dugongs, including information on group size and calf numbers. Transects were 200 m wide at the water’s surface on either side of the aircraft. The spatial data from all the aerial surveys in the region (1987, 1991, 1996, 2001, 2005, 2006, and 2011) were corrected for differences in sampling intensity and area sampled between surveys. The corrected data was then interpolated using universal kridging over the spatial extent of the aerial surveys. The modelled abundance and distribution show the relative density of dugongs (areas where there are more or less dugongs) and NOT the absolute dugong density as corrections for perception bias (animals that are available to, but missed by, observers) and availability bias (animals that are unavailable to observers because of water turbidity) can only be applied at the spatial scale of entire surveys (thousands of square kilometres), making them inappropriate for the spatial scale for this dataset. Nonetheless, the relative densities among regions should be approximately comparable (H. Marsh, personal communication). Planning units were classified as low (1), medium (2), high (3) and very high (4) dugong density on the basis of the relative density of dugongs estimated from the models and a frequency analysis. Low density areas: 0 dugongs per square km; medium density areas 0.0015 - 0.25 dugongs dugongs per square km; high density areas 0.25 - 0.5 dugongs per square km; very high density areas > 0.5 dugongs per square km. The spatial model is 134x118 pixels with a pixel size of 2kmx2km and a spatial reference of WGS84 UTM Zone 54S. The original dataset is stored in ESRI GRID format (60 KB), which was converted to a GeoTiff for use in the eAtlas (26 kB). Both datasets are available under a creative commons attribution license.

The knowledge of dugong (Dugong dugon) distribution as well as basic abundance estimates throughout the Kimberley are currently limited. This dataset brings together information collected through a series of aerial strip transects surveys during 1985, as well as anecdotal observations of dugong distribution collected from regular patrols conducted by Australian Customs. Data collection techniques were not rigorous enough to calculate abundance estimates, however the strip transect surveys do provide the first snapshot of dugong distribution through the West Kimberley. This dataset also forms a useful template for the conduct of more rigorous surveys.

This dataset shows the extent of the dugong sanctuary in the Torres Strait which prohibits the taking of dugong (area, gear and method restrictions). The dugong sanctuary is a legislative boundary which is outlined in the Torres Strait Fisheries Management Notice No. 65 http://www.comlaw.gov.au/Details/F2007B00345 . This dataset is for research purposes and is not authoritative. Refer to the legislation for the authoritative definition of the sanctuary.

Research article and relation data on the Australian dugong.

To examine of the location of Dugong in relation to environmental variables and DEC Marine Reserves.