Impacts on dugongs - The Great Barrier Reef: An Environmental History - page 111

context. Heinsohn et al. (1978) indicated that a resident population of at least
300 dugongs remained in Moreton Bay in 1978; those authors also suggested
that significant migrations of dugongs between feeding areas occur, although that
suggestion had not been scientifically verified at that time. A more recent study,
by Chilvers et al. (2005), described the existence of large populations of marine
mammals, including dugongs, in Moreton Bay, adjacent to highly-developed
coastal environments, and despite the historical exploitation of the animals.
Those studies suggest that caution is required in reconstructing the impacts of the
commercial dugong fisheries, since the effects of over-exploitation may have been
confounded by those of large scale movements of the animals. That confounding
would account for the scarcity of dugongs reported in the historical literature
at some locations, in some years, and the biologically-impossible apparent rapid
recovery of the population. In particular, the fluctuations in dugong numbers
observed in Moreton Bay may be attributed to dugongs moving in response to
changes in their food supplies, as Marsh et al. (2004, 2005) suggested, as well as
a response to exploitation. Reconstructions of historical marine wildlife species
populations are problematic, as Marsh et al. (2005) have shown, and the response
of marine animals - such as dugongs - to anthropogenic and natural pressures
may be complex; therefore, further scientific research and monitoring is required
to understand changes in dugong abundance.
Notes
1 Sydney Morning Herald , 25 January 1847, p2.
2 Brisbane Courier , 4 September 1862, p2; Brisbane Courier , 31 July 1863; Pugh's
Almanac , 1861, p48.
3 These statistics were compiled from SCQ (for the years 1870-1900) and SSQ (for the
years 1901-02).
4 See the statistics published in SSQ , 1902, p199.
5 OHC 34, 12 October 2003.
6 OHC 34, 12 October 2003.
7 OHC 34, 12 October 2003.
8 See the annual report by J. K. Bleakley, Director of the Queensland Department of
Native Affairs (QDNA, for 1929, published in QVP .
9 Superintendent, Woorabinda Aboriginal Settlement to Director of Native Affairs,
Brisbane, 30 December 1940, SRS505/1 Box 662 Item 4493, Correspondence Files
(Alphanumeric), Woorabinda - Medical - Supplies, Dugong Oil, QSA; C. G.
Brown, Superintendent, Yarrabah Mission, Cairns to Director of Native Affairs,
Brisbane, 21 February 1941, SRS505/1 Box 1028 Item 7033, Correspondence
Files (Alphanumeric), Administration - Yarrabah - Supplies, Dugong Oil, QSA;
Deputy Director of Native Affairs to Acting Superintendent, Cherbourg Aboriginal
Settlement, 12 March 1941, SRS505/1 Box 585 Item 4027, Correspondence Files
(Alphanumeric), Cherbourg - Medical - Supplies, Dugong Oil, QSA; Matron Peatry,
Woorabinda Hospital, 13 September 1941, SRS505/1 Box 662 Item 4493, QSA.
10 Acting Superintendent, Palm Island Aboriginal Settlement, 9 January 1941, 'State of
Receipts, Expenditure and Earnings of “Wanderlust” Turtle Fishing Crew for month
ended 31/12/40 including Trip ended 22/11/40', SRS505/1 Box 520 Item 3625,
Correspondence Files (Alphanumeric), Palm Island - Industrial - Fishing Industry