Researchers in the Turks and Caicos Islands (TCI) have been successfully using “finger print files” stored in a newly developed database to match recently identified predators lurking around the Islands. These predators, however, are not human nor have they broken any laws. The subjects under surveillance are white spotted eagle rays (Aetobatus narinari), beautifully marked fish that glide effortlessly through the world’s tropical waters. Eagle rays, which are both predator and prey, are an important link in the tropic’s food chain. Marine researcher Jan Lupton, an intern at The School for Field Studies Center for Marine Resource Studies on South Caicos has devoted much of her time this past year using a special software tool that has allowed her to create “fingerprints” of each individual’s unique spot patterns in order to identify and understand the species. Lupton’s study is the first of its kind and will hopefully provide many answers to questions about the ecological role of this population and their impact on human livelihood.

The global population of spotted eagle rays is listed as “near threatened” by the International Union for the Conservation of Nature (IUCN), an organization that helps the world find pragmatic solutions to our most pressing environment and development challenges. Eagle rays are most threatened from overfishing in areas of the world where inshore and artisanal fisheries are most common or places where they are caught as by-catch in large trawler nets. The inshore waters of the TCI are one of very few places in the world where divers are able to frequently spot large schools, making them a valuable attraction to the tourism industry – an important player in the national economy.

In other areas of the globe it is thought that local populations are in fact increasing due to the intensive overfishing of large sharks, which prey on the rays. In the United State’s Chesapeake Bay, the removal of sharks such as the great hammerhead has led to its main prey, the cownose ray, to dramatically increase in size and decimate local shellfish fisheries. If eagle ray populations were to follow suit in the TCI, the Island’s fishing industry could collapse as the eagle ray’s main prey, the juvenile conch, is the most important commercial export in the economy.

Eagle ray population numbers are vulnerable to dramatic shifts in either direction making research on them essential to conservationists and economists alike. It is important to attempt to understand their foraging behavior, population dynamics, and life histories when they and their prey are such valuable tourist attractions and commodities, respectively. Eagle rays, however, are capable of traveling large distances at high speeds, making them difficult to keep track of: Consequently, very little has been known about their behavior.

With so many questions unanswered, Lupton decided to set up a study by collecting photographs of individuals and recording their behaviors, movements, and locations around the Island’s coral reefs. Using the software tool Interactive Individual Identification System (I³S) she has been able to match newly identified rays against the unique spot patterns of rays already in the database. Eagle ray spot patterns, which resemble hundreds of bright, white magnified cells covering their dark brown dorsal skin, are similar at first glance yet intricately unique much like human fingerprints. Eighty-eight individuals have been identified from as far back as June 2007.

Lupton, along with undergraduate students at the SFS Center for Marine Resource Studies, have already documented several interesting observations. In the summer of 2009 two students witnessed and caught on camera a male and female mating near the Center’s dock – a rare site that has only been documented before in aquariums. Lupton has also recorded rays swimming in the same location almost one year apart prompting the question, “Do rays reside in the same waters year round, traveling between locations, or do they venture further afield and are in the Islands only periodically?” While such questions are only the beginning to reaching a comprehensive understanding of this species, a pressing environmental and economic concern is being addressed.

In late October 2009, Lupton presented her research project to the Department of Environment and Coastal Resources in Provo, TCI’s capital, as well as the Sea and Learn educational symposium in Saba, Netherland Antilles. Her work is gaining considerable attention from her website www.spottedeaglerays.com and a feature article in TCI’s magazine Times of the Islands. Lupton’s monitoring project has already been extended to Provo with coordination by Big Blue Eco Tours.

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