SEA 



SCIENCE 



The idea was to conduct 



what scientists call a 



mark-recapture" study. 



Instead of tagging dolphins 



with physical markers, 



researchers "marked" 



them photographically 



and "recaptured" them 



on film a week or so later. 



L 



Counting 

 Dolphins 



By Cynthia Henderson 



iike the most diligent detective 

 who pores over countless mug shots, Kim 

 Urian is a pro at getting a make on 

 individuals from minute details in photo- 

 graphs. But hers aren't the usual suspects, 

 and she is a most unusual detective. 



Urian identifies bottlenose dolphins 

 from dorsal fin markings and maintains a 

 photographic record of individuals of the 

 species from New Jersey to Florida. 

 Officially, she is curator of the Mid- 

 Atlantic Bottlenose Dolphin Photo-ID 

 Catalog, established by the National Marine 

 Fisheries Service (NMFS) as part of its 

 program for stock structure assessments. 



Recently, Urian played a key role in a 

 study proposed by commercial fisher Bill 

 Foster of Hatteras and funded by the North 

 Carolina Fishery Resource Grant Program 

 (FRG). The project was a photographic 

 survey of bottlenose dolphins that inhabit 

 North Carolina sounds and estuaries in 

 northern, central and southern coastal 

 regions. 



The idea was to conduct what 

 scientists call a "mark-recapture" study. 

 Instead of tagging dolphins with physical 

 markers, researchers "marked" them 

 photographically and "recaptured" them on 

 film a week or so later. 



The technique is not new and drew on 

 the experience of other researchers such as 

 those in Nags Head Dolphin Watch, 

 featured in Coastwatch last year. But this 

 was the most comprehensive survey ever 

 done in the North Carolina. The results 

 were surprising: The number of bottlenose 

 dolphins identified in the state's inshore 



waters is nearly half of what has been 

 presumed to be the total population along 

 the entire eastern shore of the United States. 



In addition to Urian, a unique assem- 

 blage of experts came together for the 

 project. Andy Read, assistant professor of 

 marine conservation ecology at Duke 

 University Marine Lab in Beaufort (and 

 Urian' s husband), coordinated field surveys 

 and assisted with statistical analysis. 



Foster acted as general coordinator and 

 contributed his knowledge of waterways 

 accumulated in 29 years in commercial 

 fishing. He also holds a master's degree in 

 ecology from North Carolina State Univer- 

 sity. This was not his first project with 

 marine mammals. In a previous FRG grant 

 he established, along with Read, a whale 

 disentanglement network to rescue whales 

 caught in fishing gear. 



Ben Wilson of Scotland, internationally 

 recognized for his research with bottlenose 

 dolphins, helped with research design and 

 data interpretation. 



Commercial fishers, wildlife officers, 

 fishhouse workers and others who work on 

 the water played an invaluable role as 

 informants, providing "leads" on dolphin 

 sightings to Ann Pierce, in Sea Grant's 

 Manteo office. Pierce relayed the sightings 

 to researchers on the water. 



"I've never had a cell phone ring as 

 often out on a boat," Read says. 



And Pierce, described by Read as a 

 "dynamo," even took to the air one day for a 

 bird's eye view from a Cessna to help locate 

 schools of dolphins. 



Continued 



26 SUMMER 2001 



