Turtle deaths are from natural causes

By AAP and AG staff October 4, 2011
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A spike in turtle deaths in north Queensland is the result of natural causes, says a marine expert.

TURTLE DEATHS IN QUEENSLAND coast are nothing to be concerned about, a leading ecologist says.

In the past nine months, a spike in turtle deaths – 1000 mostly green turtles – have died, compared with 555 in 2010, 625 in 2009 and 552 in 2008, figures from the Department of Environment and Resource Management show.

They are mostly dying from natural causes and are often found emaciated, with just mango seeds or algae in their stomachs.

Turtles dying from lack of food

Sea grasses, turtles’ main food source, have died off in record amounts after millions of tonnes of sediment flowed into coastal areas during the summer’s floods.

James Cook University marine turtle ecologist Dr Mark Hamann says the turtle population is resilient and the scale of deaths have been taken out of context.

“Green turtles live all throughout the Great Barrier Reef, in the coral atolls, the lagoons and in the deeper water, from Moreton Bay all the way up to the Torres Strait, and it is only the coastal strip that has been impacted by this extreme weather,” he says.

“There are a lot of turtles out there that haven’t been impacted at all. To have 1000 die in a year is alarming, but it is not going to lead to any depletions. We don’t need to panic.”

Dredging could be to blame

The last survey of green turtles in coral areas, not including coastal areas, counted 800,000, and was increasing by three per cent a year, Mark says.

Concerns have been raised that a mass dredging project in the Port of Gladstone is contributing to the turtle die-off.

The state government is yet to decide whether a three-week ban on fishing in the port – which was implemented after diseased fish were caught – will be lifted when it expires on Friday.

About 46 million cubic tonnes of seabed is being dredged to make way for two liquefied natural gas plants and export hubs at Curtis Island, as well as the expansion of the Gladstone port. Local fishermen and the Australian Greens want dredging to be suspended until it can be confirmed that it’s not linked to marine life dying off.

Of the 1000 turtles that have become stranded this year, 188 were found in the Gladstone area, where six dolphins and eight dugongs have also died.

One of four dredgers working on the project had stopped work on Friday because turbidity was above set levels. Spoil (excess material) that is dredged is being dumped into Fisherman’s Landing on the harbour, a reclamation area that will create a land reserve used to service new port facilities.

Turtles not affected by dredging, company says

The Gladstone Ports Corporation says that water was leaking out of the Landing at extreme low tides at such a force it stirred up sediment on the outside of the bund wall.

Chief executive Leo Zussino says that no spoil has leaked out from the bund wall as a membrane liner is designed to stop its movement. However, he said the GPC and DERM were looking at options to completely seal the bund wall. He said monitoring checks by DERM show there are no toxic substances in the spoil.

The GPC also says there is no scientific evidence to suggest the project to date has had any effect that would contribute to the loss of marine life or disease in fish.