Low-pressure Sodium Lighting and Sea Turtles

These disclaimers apply to all information on this server.

Christian B. Luginbuhl
U.S. Naval Observatory Flagstaff Station
PO Box 1149
Flagstaff AZ 86002
cluginbuhl@nofs.navy.mil

Version 1.2
28 April 2004

Hatchling sea turtles emerging at night from their subterranean nests travel toward the brightest, most open horizon. Under natural nighttime conditions, this will lead them toward the sea. If artificial lighting is visible, the turtles may head instead toward the light, leading to increased mortality from a variety of causes. Research has shown that light rich in blue and green wavelengths has the strongest effect in this regard, while light of yellow or red wavelengths, particularly low-pressure sodium, has little or no effect. The links below lead to literature documenting these effects.

U.S. Fish and Wildlife Service's letter concerning lighting at Cape Canaveral Air Force Station and Patrick Air Force Base (2000). Excerpt (HTML, 3 KB); Letter (PDF, 1 MB).
Witherington, B.E. and R.E. Martin, "Understanding, Assessing, and Resolving Light Pollution Problems on Sea Turtle Nesting Beaches," Florida Marine Research Institute, Technical Report TR-2, 1996. Excerpt (HTML, 3 KB); Report (PDF, 2.2MB).
Recent Results on Hatchling Orientation Responses to Light Wavelengths and Intensities (1989), Dickerson, D.D. and D.A. Nelson, Proceedings of the Ninth Annual Workshop on Sea Turtle Conservation and Biology, NOAA Technical Memorandum NMFS-SEFC-232, page 41. Abstract (HTML, 4 KB); Proceedings (PDF, 20 MB).

C. Luginbuhl's Home Page