The effect of on-shore light pollution on sea-turtle hatchlings commencing their off-shore swim

作者：Truscott Zoe; Booth David T^*; Limpus Colin J

来源：Wildlife Research, 2017, 44(2): 127-134.

DOI：10.1071/WR16143

• Chelonia mydas
• green turtle
• Heron Island
• misorientation
• recruitment
• swimming

Context. Off-shore recruitment impairment of sea-turtle hatchlings because of light pollution is a growing concern to conservation of sea-turtle population throughout the world. Studies have focussed on sea-turtle hatchling sea-finding behaviour, and ignored the possible effect that on-shore lighting might have on hatchlings after they have entered the sea.
Aims. We experimentally evaluated the effect that on-shore light pollution has on the swimming behaviour of green turtle hatchlings once they have entered the sea and begun swimming off-shore. We also estimated the decrease in off-shore recruitment of hatchlings as a result of light pollution disruption of the off-shore swim.
Methods. Hatchling misorientation rates were quantified by releasing marked hatchlings to the sea from different land-based locations adjacent to light-polluted beach areas under a variety of environmental conditions. The beach in light-polluted regions was then searched for marked hatchlings returning to shore from the sea.
Key results. Misorientation rates were highest in trials conducted during moonless nights (66.7% of trials had some hatchlings return to shore) and lowest during trials conducted during moonlit nights (no trials had hatchlings return to shore). Green turtle hatchling off-shore recruitment for the entire 2014-15 nesting season at Heron Island was estimated to decrease 1.0 - 2.4% as a result of on-shore lights disrupting hatchling off-shore swimming behaviour.
Conclusions. On moonless nights, sea-turtle hatchlings after having successfully completed their journey from nest to sea and entered the sea can be lured back to shore again by shore-based light pollution and, this will decrease their off-shore recruitment success.
Implications. To ensure maximum off-shore recruitment of sea-turtle hatchlings, on-shore light pollution adjacent to nesting beaches needs to be minimised so as to minimise misorientation and disorientation of hatchlings while on the beach and in near-shore waters.

• 出版日期2017-6