This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
More dugongs (Dugong dugon) have died in Australia this year than in all of 2010. At least 90 of the marine mammals, close relatives of manatees, have starved to death off the coast of Queensland after floods destroyed the area's sea grass, the dugong's main source of food. Another six were killed by boats or fishing nets. Only 79 dugongs were found dead in that region in 2010.
Sea grass suffers when it is overwhelmed by freshwater. Massive floods in December and January followed by a cyclone in February dumped a lot of river water into the ocean off Queensland. The runoff also brought pesticides and sediment, providing what Queensland Minister for Environment Vicky Darling called a "triple whammy" to the vegetation.
The sea grass problem has also hurt sea turtles in the region. Several hundred dead turtles washed up along the state's northern coast late last month. Experts fear many other bodies drifted away or sank to the bottom and were never observed or counted.
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Darling said the sea grass is not likely to recover this year, although it is expected to eventually bounce back. She said the dugongs, aka sea cows, are also expected to recover in time.
Meanwhile, the Great Barrier Reef Marine Park Authority (GBRMPA) has warned the opposite: that dugong and sea turtle deaths in the area are only going to increase. "We're going to see more dugongs and green turtles straying from their regular foraging areas in search of food," GBRMPA chairman Russell Reichelt said in a prepared statement last month. "This makes them more vulnerable to disease and injury or death from other threats that may exist in these unfamiliar territories."
The GBRMPA has put out a series of posters asking boaters to "go slow—look out below" and is asking visitors to report animals observed in unusual locations.
A few of the dead dugongs and turtles (as well as three dolphins) were found in Gladstone Harbor, off the Great Barrier Reef. Two companies—Van Oord and Dredging International—are currently operating a joint venture to dredge the port to enhance operations for the area's liquid natural gas exports. Several conservation groups have opposed, and continue to challenge the project, saying it could cause an ecological disaster for the region's marine life. "Even if the work in this harbor is not directly killing marine animals, it is at least helping to create a situation where they are slowly being forced out of their traditional habitat to die of starvation," Friends of the Earth spokesman Drew Hutton told Australia's 9News.
Dugongs, which can be found throughout coastal Asian and East African waters, are listed as vulnerable to extinction by the International Union for Conservation of Nature and are protected under the Convention on International Trade in Endangered Species.
Previously in Extinction Countdown:
Photo by Julien Willem via Wikipedia. Used under Creative Commons license
