Do embedded roadway lights protect sea turtles?

  • Published source details Bertolotti L. & Salmon M. (2005) Do embedded roadway lights protect sea turtles?. Environmental Management, 36, 702-710.


This study is summarised as evidence for the following.

Action Category

Use low intensity lighting

Action Link
Reptile Conservation
  1. Use low intensity lighting

    A replicated, site comparison study in 2001 on a sandy beach in Florida, USA (Bertolotti & Salmon 2005) found that when street lighting was embedded in the road, loggerhead turtle Caretta caretta hatchling orientation was more often seawards compared to when overhead lighting was used, though results depended on whether there was a full moon or new moon. Hatchling orientation was similar between embedded and overhead lighting conditions (seawards) in both unshaded and shaded sites during full moons. During the new moon, hatchlings moved seawards at all three sites when embedded lights were used, whereas with overhead lighting, the direction of movement was seaward in shaded areas, but more mixed in unshaded areas. With embedded lights and cloud cover, fewer turtles oriented directly eastwards compared to when there was no cloud cover. The nesting beach was parallel to a road with streetlights. In July–September 2001, loggerhead turtle hatchling orientation was compared between embedded lighting (LED lights in road studs at 9 m intervals) and overhead lighting (150W high-pressure sodium vapour angled away from the beach, 7.5–9 m high on wooden poles at 60–100 m intervals) in two unshaded sites and one site shaded by shrubs. Newly emerged hatchlings were placed in a 4 m diameter arena and exit direction from the arena was recorded. Trials were carried out 2–3 times for each site, lighting condition and moon phase (24 hatchlings from two or more nests/trial, sourced from 76 total nests).

    (Summarised by: Maggie Watson, Katie Sainsbury)

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