Australia: More bad news for dugongs

The Observer 14 Sep 12;

THE bad news just keeps coming for Gladstone's dugongs.

A survey in 2011 found no dugong calves in the southern Great Barrier Reef area, which includes Gladstone.

James Cook University Professor Helene Marsh said the results show a reduction in fertility in response to the floods and cyclone of early 2011.

Professor Marsh painted a dire picture for the endangered mammals, especially in Gladstone. She said dugong deaths recorded in Queensland by StrandNet in 2011 were the highest ever recorded.

"The data indicates that Townsville and Gladstone were the dugong mortality 'hotspots'," she said. "In both these places seagrass was in poor condition."

The survey said the extreme weather had exasperated a decline in seagrass over several years.

The number of dugongs spotted in the southern Great Barrier Reef were the lowest since the mid-1980s, which indicates a dramatic decline in the endangered mammal's population in the region.

"The latest aerial survey by researchers from JCU of dugong distribution and abundance indicates a significant decline in the dugong population of the southern Great Barrier Reef," Prof Marsh said.

"Although aerial survey estimates of dugong are underestimates, they track trends in the population.

"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.

"Similarly, while the proportion of dugong calves in Hervey and Morton 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."

Proposals for 'mega-ports'

Whether or not the survey is intended to become part of a controversy, it is sure to play a part in arguments over the impact of dredging in Gladstone Harbour. Some people remain convinced the dredging has caused dugong deaths, but Prof Marsh did not blame industrial activity for the spate of deaths. While the survey does not blame industry.
However, she did say management of port development would need to be carefully managed to protect the dugongs. She called on Governments to develop policies that favour the establishment of several well managed "mega-ports" along the Great barrier Reef coast, which she said would pose fewer risks to dugongs and their habitats than a larger number of smaller ports.