An international team of scientists has proposed that bans on fishing gear, such as spear guns, fish traps, and beach seine nets, could aid in the recovery of reefs and fish populations hard hit by coral bleaching events.
Research carried out in Kenya and Papua New Guinea has shown that certain types of gear are more damaging to corals, to coral-dependent fish and to the key species of fish that are needed to help reefs recover from bleaching or storm damage.
Around the world corals have been dying at alarming rates, due to unusually warm water events resulting from global warming. “From an ecological perspective, the best response to bleaching is to close reefs to fishing entirely. But that is not feasible everywhere and is a particularly hard sell among the impoverished fishers in developing countries” says co-author Dr. Tim McClanahan of the Wildlife Conservation Society.
In those areas, where fishing cannot be avoided, restricting the use of certain types of fishing gear could mean a compromise, helping reefs and its fish recover and still provide fishers with some options for their livelihood. Fishers typically use several types of gear so they can still earn a living despite some sort of gear banning and will therefore be more likely to comply than to total closures.
The scientist have found in their research that spear guns, the fishing tool most used by the poorest fishers because they are cheap to make and the yield can be high, were the most damaging of all, to corals themselves – when a hit fish hides in the reef and fishermen break the coral to get it, to susceptible fish species and to the fish needed to help reefs recover by keeping seaweeds and urchins in check while the coral re-grows.
They further assessed fish traps also targeted both the most susceptible reef fish and the ones most involved in reef recovery. Beach seine nets didn’t target as many key fish species as gill nets, traps, or spear guns, but were damaging both to corals directly and took large amounts of juvenile fish.
“Where people really depend on reef resources, it may not be possible to permanently ban all of these types of gear. By creating temporary bans for specific types of gear following a coral bleaching event, reef managers could ease pressure on the reef and its fish population for a time when corals ecosystems are most sensitive without causing undue hardship to the human populations that depend on it.” said Dr. Cinner from the ARC Centre of Excellence for Coral Reef Studies and co-author of the study.
The study was conducted by the ARC Centre of Excellence for Coral Reef Studies at James Cook University, the Wildlife Conservation Society and other groups and the article “Gear-based fisheries management as a potential adaptive response to climate change and coral mortality,” by Cinner J. et al. appears in the latest issue of the Journal of Applied Ecology and provides managers with some ideas about the trade-offs involved in banning certain gear, which can be applied by coral reef management anywhere in the world.
Copyright © 2009 by Marine Science Today, a publication of OceanLines LLC