between Cape 

 Lookout and 

 Topsail Island 

 and at 



Southport and 

 Long Beach. 

 All but one 

 were logger- 

 heads, the other, 

 a green turtle. 

 The animals 

 bore sores and 

 lesions on their 

 skin and shells 

 and carried 

 extremely high 

 numbers of 

 barnacles, an 

 indication of 

 poor health. 

 Some of the 

 animals were so 

 underweight 

 that their 

 undershells 

 were concave, a sign to Boettcher that 

 they were sick for a very long time. 



The turtles from both strandings 

 were sent to the North Carolina State 

 University College of Veterinary Medi- 

 cine for analysis. Andy Stamper, a 

 resident in zoological medicine, says 

 the evidence doesn't support a human- 

 related cause of death, but he also 

 doesn't dismiss the possibility of toxic 

 poisoning. Testing for pesticides or 

 other pollutants in a turtle's body is 

 complex and time-consuming, he says, 

 and the levels that would be lethal for a 

 sea turtle have not yet been fixed. 



One effect that toxins could have 

 on turtles is to compromise their im- 

 mune systems, leaving them vulnerable 

 to parasites they normally fend off. 

 Also, a toxin may depress the immune 

 system, thereby allowing bacteria to 

 invade, Stamper says, and cause the 

 kinds of symptoms found on the ne- 

 crotic turtles. Finally, the animals 

 could have traveled through areas af- 

 fected by red tide or a similar phenom- 

 enon elsewhere and then, because their 

 bodies incorporate toxins very slowly, 

 suffered the effects when they came to 



North Carolina waters. 



"A lot of research needs to be 

 done to determine the interactions of 

 the environment and pollutants in the 

 environment with the turtles," Stamper 

 says. "It's very frustrating because 

 everyone is concerned about the human 

 interactions with sea turtles, and we 

 haven't even determined all the natural 

 causes of mortalities." 



Another of those possible natural 

 causes is a parasitic fluke. The turtles 

 in both natural mortality events last 

 year had flukes in their blood vessels, 

 but it's unclear to Stamper whether that 

 caused or contributed to the turtles' 

 deaths. 



Human Impacts 



Though natural causes can often 

 be cryptic, human-related turtle mor- 

 talities — those in which an interaction 

 between human and turtle has occurred 

 — are more obvious. Humans dump 

 their trash in the seas, trash such as 

 plastic bags that a turtle will eat and 

 that will clog its digestive tract. Deep 

 wounds caused by propeller strikes as 

 well as collisions with boats often re- 



sult in death. 

 Other activities 

 that can kill 

 turtles include 

 dredging, min- 

 ing, drilling and 

 setting up un- 

 derwater struc- 

 tures. Occasion- 

 ally, turtles are 

 killed in power 

 plant water- 

 intake systems. 



And, for 

 whatever incon- 

 ceivable reason, 

 people some- 

 times mutilate 

 living turtles. 



Of the ways 

 people and 

 turtles collide, 

 those that in- 

 volve recre- 

 ational and 

 commercial fisheries are most contro- 

 versial. Nets used by commercial fisher- 

 ies can ensnare turtles, forcing the ani- 

 mals to stay underwater and drown. The 

 animals can ingest hooks or become 

 entangled in monofilament line dis- 

 carded in inshore and offshore waters. 

 Though researchers know that fisheries 

 have an impact on turtle populations, 

 Boettcher says the degree of the impact 

 is still unclear. 



Recent scientific studies indicate 

 that turtle excluder devices (TEDs), 

 escape routes for turtles built into trawl 

 nets, reduce mortalities from shrimp 

 trawling if they are used properly and 

 consistently. The compliance rate for 

 TEDs in North Carolina is high, says 

 Boettcher. Because a TED must be able 

 to exclude at least 97 percent of turtles 

 to be certified, mortalities from the 

 shrimping industry are considerably 

 lower than in pre-TED days. 



But North Carolina is home to fish- 

 ery activities other than shrimp trawling, 

 and that fact makes it difficult to deter- 

 mine the impact of fisheries as a whole 

 in this state, says Boettcher. The scien- 



Continued 



COASTWATCH 19 



