Balancing Human and Sea Turtle Safety: Evaluating Long-Wavelength Streetlights as a Coastal Roadway Management Tool

Abstract

Coastal roadways with tall, full-spectrum streetlights along sea turtle nesting beaches present a challenge for managers seeking to balance protection of sea turtles with public safety. Many communities extinguish these lights during nesting season to avoid impacting nesting and hatchling sea turtles. Long-wavelength light emitting diodes (LEDs) offer an alternative for managers in these communities, but additional information on sea turtle response to these lights is warranted prior to installation. We conducted arena assays on Florida’s west coast to evaluate hatchling orientation when exposed to a shielded, long-wavelength (624 nm) prototype lamp compared to an adjacent beach with the streetlights turned off. We compared orientation in test and control arenas simultaneously over two consecutive nights, recording crawl direction and timing for individual hatchlings. Hatchlings in test and control arenas oriented correctly toward the ocean in all trials, with no differences in hatchling dispersion or circling. Thus, the fully shielded, long-wavelength LED streetlight fixture tested provides an appropriate option to minimize impacts to sea turtles along coastal roadways throughout the Unites States and elsewhere. As such, this alternative solution to extinguishing necessary streetlights can aid coastal managers in concurrently protecting nesting habitat and providing light for public safety.