Fiji\'s largest marine reserve has more sharks than surrounding areas that allow fishing, evidence protected areas are good for sharks, conservationists say. Researchers from the Wildlife Conservation Society and the University of Western Australia, studying the no-take reserve\'s shark populations, said they found the number of sharks in Namena Reserve -- located on the southern coast of Fiji\'s Vanua Levu Island --is two to four times greater than in adjacent areas where fishing is permitted. Namena is a 23-square-mile reserve established in 1997 and managed by local communities. The researchers used 60-minute video segments that captured images of five different species of reef shark to provide the data on shark abundance. \"The study not only provides evidence that Fiji\'s largest marine reserve benefits reef sharks, but achieves this in a non-destructive manner using novel stereo video technology,\" study leader Jordan Goetze said in a WCS release Monday. The most likely reason for higher shark densities within the reserve is a significantly higher availability of prey fish within the reserve boundaries compared with adjacent areas, the researchers said. \"The news from Fiji gives us solid proof that marine reserves can have positive effects on reef shark populations,\" said Caleb McClennen, director of the WCS Marine Program. \"Shark populations are declining worldwide due to the demand for shark products, particularly fins for the Asian markets. \"We need to establish management strategies that will protect these ancient predators and the ecosystems they inhabit.\"