Management Research Needs 



Research Needed for Management of the Beach 

 Habitat (Jeanne A. Mortimer) 



Introduction 



The reproductive success of adult turtles and the survival 

 of their offspring are often diminished by adverse environmental 

 conditions at the nesting beach. Some of these environmental 

 factors occur naturally, but many are induced by human activity. 

 The following is a discussion of some of the most important 

 problems encountered by turtles in their nesting habitat along 

 with suggestions about what sort of research is needed to provide 

 a more complete understanding of these problems so that 

 mitigating steps may be taken. 



Disruption Caused bv Artificial Lighting 



One of the most obvious forms of disturbance at the nesting 

 beach is that caused by the presence of unnatural light sources, 

 either onshore or offshore. It is a problem that is increasing 

 in scope and magnitude as building and road construction 

 proliferate, and as electricity is introduced to remote areas. 

 The village of Tortuguero, Costa Rica, for example, which is 

 situated immediately adjacent to the nesting beach of the largest 

 green turtle breeding colony in the west Atlantic region, will 

 have electricity installed before the start of the 1988 green 

 turtle nesting season. 



Artificial light at the nesting beach can affect both 

 nesting females and hatchling turtles. There is evidence that 

 adult turtles may be discouraged from nesting in brightly lit 

 areas (literature reviewed by Raymond 1984a) . Hatchling turtles 

 of all species easily become disoriented or misoriented by bright 

 lights (literature reviewed by Raymond 1984a) , and then suffer 

 high rates of mortality due to a variety of causes. 

 Unfortunately, even distant sources of illumination — such as the 

 lights of a city located miles from the coast — can produce a 

 disorienting glow, especially on moonless nights. 



When hatchlings are distracted by bright lights located 

 directly behind the nesting beach, they may head inland rather 

 than towards the sea. If the light source is located farther 

 down the beach, hatchlings may walk long distances parallel to 

 the shoreline in that direction. Often disoriented hatchlings 

 will circle aimlessly, or wander onto nearby roads and be crushed 

 by traffic. Bright light is apparently so irresistible to 

 hatchlings as to prompt them to run directly into the flames of 

 burning fires. I found the charred carcasses of several hundred 



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