Lighting is an important aspect to consider in sea turtle conservation as it pertains to the nesting females and the hatchlings. Instinctual by nature, sea turtles use lighting cues to orient themselves on the beach, whether it is a female looking for a suitable nesting site or finding her way back to the ocean after nesting, or a hatchling, first emerged from the safety of it’s egg chamber who must find the ocean before a predator finds it!

Research has proven that certain lights, wavelengths and lumens can negatively impact sea turtles causing them to become mis-oriented (definition: maintaining constant directional movement in any direction other than toward the ocean) or even worse, dis-oriented (definition: being unable to maintain a constant directional movement, including frequent changes in direction or circling). However, there are steps that can be taken to reduce harmful lighting without compromising human safety and security.
Research has been conducted on what types (bulbs, colors, wavelengths, lumens, wattage, etc.) of lights effect various species of sea turtle hatchlings in relation to their orientation to the ocean. From this graph you can see that lights with wavelengths longer than 580nm (nanometers) attract all 4 species of sea turtles. Loggerheads reach aversion to light around 580nm or longer. The attraction does increase for the other 3 species with wavelengths of 600nm or longer but never quite reach complete aversion. So while loggerheads are sensitive to lighting, the other 3 species are even more sensitive.

By changing your bulb choice, you can not only become ‘turtle-friendly’, but actually DECREASE the amount of energy you are using (helping the planet) and save money on your electric bill (helping yourself)! This graph shows a variety of bulb types and their energy output. As you can see, the best, most turtle-friendly light (next to no lights of course) is low pressure sodium. Low pressure sodium lights are monochromatic and have actually been shown to REPEL sea turtle hatchlings (Salmon and Witherington, 1995)! Don’t forget that bulbs should never be visible! Always have fixtures that allow the bulb to be recessed inside the fixture.

If you’re still confused about lights/bulbs and wavelengths, take a look at the adjacent photo. This photo shows the light spectrums for 5 different types of bulbs. Again, for turtle-friendliness, we want to stay on the long end of the spectrum, where your reds, oranges and yellows are. See the differences? This is another viewpoint that still shows the low pressure sodium bulb as being the most turtle-friendly!
What else can you do to ensure sea turtle-friendliness lighting? Add shields ! This photo describes how shields help in directing light in the appropriate direction. Shields should always cover 180° on the east side of the fixture.
There is a huge misunderstanding among the general population of just how lights work, what they do, and which ones provide safety. The biggest and/or brightest light does not necessarily mean ‘safety’. Your eyes have to, and take time to, adjust to the variations in available light too, it is in that transition period that misfortune can occur. By using proper bulbs, fixtures, shields, and re-direction you can actually INCREASE the amount of light you desire where you desire it! Still not convinced? Take a look at this photo (right). On the right is a decorative, highly aesthetic posted-light fixture. The bulb is way too bright and allows the light to be emitted in all directions. You can see how most of the light is being lost to the atmosphere, with very little reaching the ground where it is desired. On the left is a post light with a recessed bulb of a lower wattage. Because it is recessed, it is automatically directed straight down and therefore showers a significantly increased amount of light on the walkway.
By changing your way of thinking about lights, you can not only help out sea turtles and other nocturnal wildlife, but help conserve energy and even save a few dollars! Jekyll Island does have an approved and enforced Beach Lighting Ordinance that has recently been amended and adopted as of August 11, 2008 to include the latest research in regards to lights and sea turtles. To access this ordinance, click here.

*All photos and graphs courtesy of FWCC
Test your knowledge of sea turtles and lights by taking this fun FACT OR FICTION quiz!

Check out these links to vendors with approved ‘Turtle-Friendly Lights’!

Starry Night Lights:  http://www.starrynightlights.com/

Turtle Safe Lighting: http://www.turtlesafelighting.com/