December 22nd 2008
Another threat to turtles
It sounds like a typical Magnetic Island beach party. Some friends gather at a secluded spot at the mouth of a creek. They've brought some drinks and drag a log up and build a fire and set back to chill out for the evening. It's a laid back party but it is also likely that the drinkers are underage, by morning there's an unsightly mess of bottles and other rubbish, the fire has burned down the log but, 30 to 50cms down in the sand, a clutch of turtle eggs from a vulnerable species, the sort from which perhaps one in a thousand will survive to adulthood, have just been cooked.
This is the scenario, which might have occurred over the weekend before last, on the beach at the creek mouth near the former helipad at Nelly Bay. Even if it didn't cause the eggs to be lost the threat is real.
The Environment Protection Agency (EPA), Magnetic Island Rangers were alerted to a still-warm, burnt-out, log very close to the nest a turtle had, a few days previously, laid eggs into.
The location has for years been a popular spot for night-time teenage parties.
Rubbish is left around the site
Ranger in Charge, Patrick Centurino, cannot be sure at this stage whether this particular fire has had any impact on the eggs which hatch six or seven weeks later. But the sand, after the female has dug the nest, will be less compacted and more susceptible to activities on the surface. "It is possible the fire could affect them" he said, adding, "With a party where people are milling around on the sand there is a risk of increased pressure on the egg chamber," said Patrick.
Patrick added that at another of the nesting sites, this one on the beach in front of X-base backpackers, a turtle was seen digging a nest which was found to contain a broken bottle. Fortunately the turtle was not injured.
"Turtles are pretty tough but they may be put off nesting here," says Patrick. "Some say that only one in a thousand green or flat back turtles' (the species which nest on Magnetic) eggs survive to maturity. We are trying to reduce the risk to the environment here and some of these measures might look negligible but it is the, this-plus-this-plus-this, the cumulative impact, we are trying to reduce."
There are presently three nests on Nelly Bay Beach and, as many resident's also use the beach as an illegal dogs-off-leash area, the risks to turtles, at this time of year, is even greater. "People need to control their dogs especially if they start to dig a hole," said Patrick.
"Driving on beaches, removing vegetation from beaches, leaving rubbish and fires all reduce turtle resilience" says Patrick.
There are estimated to be between 10 and 20 nests around Magnetic Island with flat backs laying three to seven clutches fortnightly from November to February with about 50 eggs per clutch while green turtles can lay 100 eggs. Sea turtles grow slowly and often take between 30 - 50 years to reach sexual maturity.
"Living here and having turtles nesting here is incredible" says Patrick, "It is something we need to cherish. Maybe one day they wont be there."
A barrier has now been erected at the Nelly Bay site to protect the nest area.
For more information about sea turtles (click here)
Story: George Hirst
Photos: Courtesy Queensland EPA
To add your comment,
or read those of others, see below