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2nd
ASEAN Symposium and Workshop on
Sea Turtle Biology and Conservation
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SESSION
3: Beyond the Beach....
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ABSTRACTS
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THE INFLUENCE
OF GAS FLARES ON THE ORIENTATION OF GREEN TURTLE HATCHLINGS AT THEVENARD
ISLAND – WESTERN AUSTRALIA
Kellie Pendoley
Thevenard Island, situated 10 nm
off the coast of north western Australia, is a known nesting site for Green
turtles (Chelonia mydas). Thevenard Island also supports an oil
production facility. A condition of the government approval to develop
the facility was that the development be managed to minimize light impact
on sea turtles. Consequently the original gas flare was purpose built to
shield the flame from nearby nesting beaches. A second pit flare was installed
in the early 1990's for short term use while the primary shielded flare
was undergoing maintenance. Post commissioning surveys and routine inspections
indicated that both the flares and the facility lights were potential sources
of impact on the sea finding success of C. mydas hatchlings. In
September 1995 the spectral characteristics of the two flares were measured.
The results indicated the flares emitted light in a spectral range outside
of that visible to C. mydas (as reported in the literature). Arena
experiments were subsequently carried out to determine if the light sources
were misorienting or disorienting hatchlings emerging in the vicinity of
the flares and over what distance the influence might extend. The results
suggested that the flares caused misorientation of hatchlings during nights
of new moon however this impact was reduced with distance from the source
and as the lunar cycle progressed towards a full moon. |
