January 27, 2011
Guest Post: Australia Floods Further Endanger Dugongs
Guest blogger Jon Bowermaster is a writer and filmmaker. His most recent documentary is “SoLa, Louisiana Water Stories” and his most recent book is OCEANS, The Threats to the Sea and What You Can Do To Turn the Tide.
The worst flooding in 130 years has turned eastern Australia into a giant wading pond, killing dozens of people, wiping out crops and livestock, destroying tens of thousands of homes and shutting down hundreds of towns and cities.
At risk at the edge of Queensland’s shores is the nearly extinct dugong – the prehistoric marine mammal that looks part sea lion, part bulldog – that feeds off the sea grass that line the coast. Unfortunately the floodwaters are inundating those feeding grounds with sediment, topsoil, rubbish and all sorts of debris on top of toxic industrial and agricultural run-off.
Environmental officials are concerned that the floods will similarly destroy wetlands, coral reefs and marine parks along Australia’s coast. Fresh water kills coral reefs, though it remains to be seen what the long-term effects will be from this particular flood.
To investigate the damage they’ve launched a robotic underwater glider shaped like a torpedo and armed with sensors to monitor the ecosystems off Brisbane.
Most concerning for the dugongs is that there simply aren’t that many left on the planet. Related to manatees, they have what are called “fusiform” bodies, meaning no dorsal fin or hind limbs. They maneuver with a dolphin-like tail and paddle with forelimbs, vacuuming food off the seafloor with downturned snouts. They can live more than 70 years; the biggest seen in recent years was off the coat of Tanzania, weighing more than 600 pounds.
Dugongs are threatened by natural predators including sharks, killer whales and crocodiles, and they also continue to be hunted by man even while listed by the IUCN as “vulnerable to extinction.” They are found around the world, from the Philippines to the Persian Gulf, and because they live off freshwater grasses they are susceptible to all kinds of offshore pollutions. For example, a sizable population of about 7,500 live off the coast of Iraq, where they are dangerously threatened there by constant oil spills. Around the world there are only a half-dozen living in captivity.
Thanks to its previous reputation for clean, clear shallows, Moreton Bay in Brisbane has long been the most popular research stop for dugong scientists. This past month of big rains and flooding may change that reputation forever.