Prior research shows that it is not hard for a vessel to become a "ghost ship" by turning off, eliminating, or modifying its Automated Identification System (AIS) equipment meant to track and identify watercraft.
Douglas said he has since learned that ghost or pirate ships often venture out in pairs, with one sometimes meeting the other in remote parts of the ocean to allow for exchange of illegally taken catches, helping to further erase movements. He suspects that such activity in the Marshall Islands National Shark Sanctuary increases at around the end of October when trade-winds strengthen. Facilitated by the winds, some fishermen can then save up to 30 percent in fuel costs, he said.
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Tom Letessier of the Zoological Society of London leads a team that helps to monitor shark and wildlife populations in other marine sanctuaries, including the world's oldest in Palau, located in the western Pacific, and another in the Chagos Archipelago within the Indian Ocean. The Chagos Archipelago sanctuary is actually proving to be a success story, at least so far, because recent research found that it has higher than expected fish population.
Nevertheless, Letessier told Discovery News, "We find that some illegal fishing is still occurring inside the reserves, in part because these are attractive fishing grounds, but also because they are, by definition, large and remote and thus hard to enforce and patrol. In addition, places like Palau and the Marshall Islands may lack enforcement resources."
Letessier believes that new technologies may offer economic solutions to the problems. These may include remote surveillance using Synthetic Aperture Radar on satellites, as well as video and acoustic systems mounted on ocean gliders or fixed on land.
Bradley added that these and other possible solutions need to be supported in a global effort because "we cannot continue to place the burden of enforcement on small island nations that host most of the world's shark sanctuaries." Douglas, Cousteau and Gourse agree, and point out that the same or similar technologies can apply to monitoring endangered terrestrial species, such as rhinos and elephants.
Cousteau and Gorse remain hopeful, given the central Pacific site's difficult past.
They said, "As we saw in the Marshall Islands, even after man destroyed everything in its path with nuclear bombs, nature was able to bounce back. Nature is resilient and, if left alone, she will flourish. We, as humans, just have to ask ourselves if we will give her that chance."