Several studies have shown that removing these top predators can be devastating, affecting the entire food chain "the ecosystem as we knew it dies without sharks," Hueter says. As top predators, sharks control the density and behavior of their prey, indirectly affecting the abundance of species farther down the food chain—a trophic cascade. For example, too few sharks can result in too many large reef fish preying on smaller species that keep coral reef algae in check. As a result, the reef can become overwhelmed by algae, killing the coral.
The economy suffers as well. A study published in the May edition of Oryx noted the value of global shark catches is now $630 million and declining whereas shark ecotourism, which currently generates more than $314 million a year worldwide, is on the rise and will likely reach $780 million within 20 years. The authors concluded that protecting sharks would benefit a wide economic spectrum and help several species recover.
Last March the Convention on International Trade in Endangered Species added whitetip, scalloped, great, and smooth hammerhead sharks and porbeagle sharks to its Appendix II, effective September 14, 2013. International trade in products from these species after that date must be accompanied by CITES permits confirming the sharks are harvested sustainably and legally.
That could ease global pressure on these sharks.
Meanwhile in Cuba one of the trinational research initiative's goals is establishing a science-based sustainable shark fishery. Given the insufficient data, managing the fishery through prohibitions is difficult, according to Rader, who advocates instead programs that carefully track unintended shark mortality and create incentives for avoidance as well as better handling of animals to reduce such mortality.
One potential tool for sustainable fishing is "catch shares," which give every participating worker the right to take a percentage of a total allowable catch. Shareholders may fish for their percentage whenever they choose. A red snapper catch-share program in U.S. Gulf of Mexico waters cut the waste of nontargeted fish by 50 percent since 2006 whereas catch shares reduced wasted fish on the U.S. Pacific coast by 78 percent in one year and in New England by 77 percent, according to the EDF. The scientists acknowledge that any tool used will need to be compatible with Cuba's socialist system and its priority on of food security and jobs in this struggling economy.
One technique for protecting sharks has already taken hold in Cuba: the designation of marine protected areas (MPAs) and sanctuaries. The country has more than 100 MPAs proposed or in existence, the largest network in the Caribbean. Location and size of any new areas will be based on findings from current research initiatives.
Of course, MPAs only protect specific, limited locations. Some species of sharks are highly migratory, moving among feeding grounds based on season. Whitetips travel throughout the Gulf of Mexico, along the U.S. East Coast, into the Caribbean, and out into the Atlantic. Sharks tagged in MPAs have been found far outside the boundaries of those parks.
"The big-picture goal of this work is to develop a multinational, coordinated approach to managing fisheries for highly migratory species, including sharks," Hueter says. "You can't manage a species that moves around by developing procedures for sustainability in one part of its range, while it is subjected to unsustainable pressures in another part."