About This Project

Our goal is to measure the effect of coastal light pollution on hatchling loggerhead ability to find the ocean. We hypothesize that there will be a threshold intensity above which hatchlings become disoriented and less efficient at "sea finding".

Artificial light is a pollutant which is increasing in U.S. urban environments at a rate of 6% per year. Determining hatchling response to various light levels will be important to the long term conservation strategies for endangered sea turtle species.

Ask the Scientists

What is the context of this research?

In coastal marine settings, it has been well established that light sources have the ability to alter the path of both nesting female and hatchling sea turtles. Hatchling sea turtles respond strongly to light stimuli upon immediate departure from their nest, and show sensitivity to wavelength, intensity, and directionality characteristics of that source (Lutz and Musick, 1993, Salmon 2003). Nesting females prefer dark for nesting and will often nest in front of shade casting "tall objects" in well developed coastlines (Salmon et al., 1995, salmon 2003). The potential for future threats from light disorientation were well expressed by Cinzano et al., (2001), who found that coastal light intensity "urban glow" associated with US coastlines were increasing at a rate of 6% per year.

What is the significance of this project?

Intense interest in artificial light source impacts have developed in nesting areas along the eastern Florida coast with heavy beachfront development, after observations of increasing large scale hatchling disorientation. The urban pollution levels in these regions of the state may be increasing within the near future in the Myrtle Beach region of our state. Documenting the contemporary influence of light, especially with regard to thresholds and current ranges could be useful to the state regarding conservation planning for Loggerheads. Importantly, because turtles have temperature-dependent sex determination, loggerhead hatchlings in South Carolina represent a significant proportion of the male turtles supporting the entire Southeastern US population.

What are the goals of the project?

Knowledge of light levels obtained from point source light measurements and satellite imagery data collected over the last two years will be used to study hatchling movements. Our goal is measure hatchling track characteristics from low, moderate, high, and very high light intensity areas within our study boundaries. Data will be collected from 20 nests, with individual hatchling tracks characterized by; direction (bearing), speed, and path variability (sinuosity). This data will be collected during the emergence from nests using a motion activated (non-luminated) IR video camera system. Frame by frame hatchling track information will be quantified using GIS ARC info software.