green turtle hatchlings in the ashes of a single bonfire behind a 

 nesting beach at Ascension Island, S.A.O. Disoriented hatchlings 

 may spend an entire night trying to crawl up a wall or some other 

 structure in an effort to reach a light source. Others travel so 

 far inland that they are unable to make it back to the sea on 

 their own. Although hatchlings are usually able to reorient 

 towards the sea once the sun rises, many simply become too 

 exhausted or desiccated to do so. Moreover, the longer a 

 hatchling is detained on shore, the more susceptible it becomes 

 to such terrestrial predators as crabs, or birds foraging at 

 dawn. Hatchlings returning to the sea after sunrise are probably 

 subject to higher rates of predation from fish than are those 

 entering the sea at night. 



Sometimes illumination from sources onshore remains visible 

 from the surf and may continue to disorient hatchlings even after 

 they enter the sea ( Wither ington 1986) . Under such circumstances 

 hatchlings could be delayed in the shallow waters of the surf- 

 zone, where high concentrations of predatory fish occur, and thus 

 suffer higher than normal levels of predation. 



Hatchlings are also thought to be attracted by artificial 

 light sources located offshore — such as lighted ships at anchor, 

 or oil rigs. In addition to attracting young turtles, such 

 lights may also concentrate the predatory fish that then feed 

 upon the disoriented hatchlings (Fletemeyer 1986, and pers. 

 comm. ) . 



More studies are needed to document how much mortality 

 occurs in the presence of varying levels of light pollution, and 

 to quantify exactly what light intensities and color saturations 

 cause the greatest and the least harm. Ways of minimizing the 

 impact must be developed through experimentation with different 

 types of light sources and different ways of shading lights. 

 Such investigations are now underway at the University of Florida 

 (by B. Witherington and K. Bjorndal) and at the University of 

 Illinois (by M. Salmon and J. Wyneken) . 



Through research we may be able to devise ways to reduce the 

 negative effects of artificial lights at the nesting beach; but 

 research alone will not solve the problem. The ideal nesting 

 beach is one that is completely free of unnatural lighting. To 

 tackle the problem posed by light pollution we must conduct 

 educational campaigns to create public awareness. Laws and 

 ordinances must also be passed that will restrict the placement 

 and proliferation of lights in the vicinity of nesting beaches. 

 Such laws have been passed in Florida and in Australia, and are 

 apparently effective. In Brevard County, Florida, Witherington 

 (1986) found a substantial reduction in hatchling disorientation 

 after enactment of a lighting ordinance there in 1985. 



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