Dugong deaths stir more controversy
By John Mikkelsen
ENVIRONMENTALISTS are fuming over a claim by a government scientist that dugong deaths in the Gladstone region are at normal levels after it was recently named as one of Queensland’s two dugong death “hot spots”.
The reference to the high number of deaths and declining dugong populations at Gladstone and Townsville was made in a study by James Cook University Professor Helene Marsh on Marine Wildlife Management in the Great Barrier Reef World Heritage Area.
Professor Marsh said dugong mortalities recorded by StrandNet (the Queensland Marine Wildlife Mortality Database) in 2011 were the highest ever recorded.
“The data indicates that Townsville and Gladstone were the dugong mortality ‘hotspots’. In both these places seagrass was in poor condition,” Prof Marsh said.
Another Gladstone newspaper (The Observer) recently reported that her findings did not blame dredging or industry, but her report includes the following comments:
“We appreciate that the issues associated with the recent increased port development along the GBR coast are complex. However, ports pose significant threats to dugongs through the increased risk of mortality from vessel strike, the loss of seagrass habitat through dredging and the fragmentation of the coastal environment. We consider that several well-managed mega-ports would pose substantially fewer risks to dugongs than a larger number of smaller ports”.
The recent increased risk to dugongs from port development needed to be addressed as a matter of urgency, she said.
No dugong calves were seen in the southern Great Barrier Reef in the survey last year, and numbers were the lowest since the mid 1980s, indicating a dramatic decline in the endangered mammal’s population in the region.
“The recent survey report, estimates a total number of about 3000 dugongs in south-east Queensland’s Moreton and Hervey Bays, similar to the previous aerial survey figure in 2005.
“However it was a different story in the southern Great Barrier Reef region where the estimated size of the dugong population – about 500 to 600 – was the lowest since surveys began in 1986,” she said.
The population in Moreton and Hervey Bays was estimated at 3000.
“Similarly, while the proportion of dugong calves in Hervey and Moreton Bays was within the range expected for normal conditions, no calves were seen in the southern Great Barrier Reef during the 2011 survey, indicating a reduction in fertility in response to the extreme weather in 2011 which exacerbated a decline in their seagrass feeding grounds over several years….
However, according to Environment and Heritage Protection chief scientist, threatened species, Dr Col Limpus, the number of dugong deaths officially recorded in the Gladstone region recently was “as normal”.
Dr Limpus said two dugong deaths were reported in July and three in August.
“None of these dugongs had obvious signs of injuries or other possible causes of death and all were in an advanced stage of decomposition, unsuitable for necropsy or tissue sampling,” Dr Limpus said.
“There is therefore no way of knowing whether there is a pattern occurring but the number of strandings is within the ranges previously recorded for these months,” he said.
But according to the latest figures from the DEHP marine strandings site for the Gladstone region, which covers the area from Rodds Bay Peninsula to Sandy Point north of Yeppoon, 363 marine turtle strandings, 17 dugong strandings and nine dolphin deaths were recorded between 1 January 2011 and 31 August 2012.
Of the 17 dugong strandings: one mortality was suspected to be the result of a vessel strike; one was released alive; two died of disease.
The cause of death had not been identified in the remaining 13 cases, nor in the nine dolphin deaths.
“ Queensland Parks and Wildlife Service (QPWS) is negotiating with the Gladstone Ports Corporation and the three liquefied natural gas companies on Curtis Island to mitigate further vessel strikes on marine animals,” the department said.
According to the Coordinator of Australians for Animals Inc, Sue Arnold, the Federal and State Governments were not fulfilling their responsibilities under the Environment Protection and Biodiversity Conservation Act.
“It is simply outrageous that the dugong has become a football between the Federal and Queensland Governments with neither government willing to lift a finger to ensure the protection of these gentle sea cows,” she said.
“What is clear is that GPC has not informed the Federal government of the extent of dugong mortality and the Federal government has disregarded the major spike in dugong deaths in Gladstone since dredging began,” she said.
Environmental medicine specialist Dr Andrew Jeremijenko, who is an expert in health effects of heavy metals, told the Telegraph: “The dugongs, like the turtles with high arsenic in their blood, may have been poisoned by eating seagrass with heavy metals such as arsenic in it and on it.
“It is possible this may be contributing to the mortality hot spot and the lack of dugong calves seen in the survey”.
Gladstone Ports Corporation was invited to comment but declined.