A team of scientists, led by the Institute for Ocean Conservation Science at Stony¹ Brook² University, used video cameras to count Caribbean reef sharks (Carcharhinus perezi) inside and outside marine³ reserves on the Mesoamerican Barrier Reef in the Caribbean Sea. Using survey data collected from 200 baited（诱饵） remote underwater video (BRUV) cameras, nicknamed "chum cams," the scientists compared the relative abundance of these reef sharks in two marine reserves with those in two areas where fishing is allowed, and demonstrated that the sharks were more abundant in the reserves. The research findings appear in the paper, "Reef sharks exhibit site-fidelity⁴ and higher relative abundance in marine reserves on the Mesoamerican Barrier Reef," published online March 8 in the journal PLoS ONE. The purpose of the study, conducted from 2005 through 2010, was to test the hypothesis that carcharhinid shark species, which include requiem⁵（安魂曲） and whaler sharks, are more abundant inside no-take marine reserves where fishing for sharks and their prey⁶ is prohibited. The authors tested the hypothesis by using BRUV surveys to determine the reef sharks' numbers, and combined these results with acoustic⁷ monitoring to measure their site fidelity (remaining within the same local area) in Glover's Reef Marine Reserve, Caye Caulker⁸ Marine Reserve, and two reefs where fishing is allowed, all located in Belize.

"Although we know that relatively⁹ sedentary（久坐的） reef fish and lobsters¹⁰ benefit from marine reserves, this study now presents visual proof that large, active sharks are also dramatically more abundant inside these protected areas too," said Mark Bond, lead author and doctoral student at Stony Brook University. "Nearly four times as many chum cam deployments in the marine reserves recorded reef sharks than on similar fished reefs. These areas provide the sharks and other coral reef species a respite¹¹ from fishing, which means decreased fishing mortality for the sharks and more prey for them to eat."