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Grief on the coral reef

POSTED 21 SEPTEMBER 2006

Reefs: Nothing but grief?
Virtually all reef biologists favor controlling global warming and reducing overfishing and overfertilization of the seas, but what else works to conserve reefs? In the face of all the problems we have seen, no question is more pressing.

One simple approach is to change fishing gear, says Wildlife Conservation Society biologist Tim McClanahan (see "Fisheries Management..." in the bibliography). Taking fish can affect a reef directly: Grazing fish, for example, remove light-blocking seaweed can otherwise can coat coral in vegetation. Full of color and light, fish swim through thriving coral communityBut fishing can also have indirect effects, McClanahan says. Fishing "can increase the amount of pest species like the crown-of-thorns starfish, which has negative effects on the coral. It is a complex system, and when you start toying with it," you should expect "unexpected consequences," he says.

Yes, that's a Spanish hogfish on this healthy reef. Photo: Florida Keys National Marine Sanctuary

Hunger is one cause of overfishing, which forces local people to fish with fine-meshed fishing nets, but these remove fish before they can reproduce. Most people in Kenya don't like that type of net, because it hauls in such tiny fish, McClanahan says. "They use it because they are desperate. It's the terminal stage of overfishing," he says.

McClanahan notes that a program in southern Kenya that introduced larger-mesh nets increased the catch per person two- or three-fold in five years. "It was surprising; the catch started going up in six months," he says. "Tropical fish can grow fairly fast" -- in just six months, a fish can add a few hundred few grams to its weight. "The net effect, over many fisherman, and many areas, is to increase the weight of the catch," he says.

Think globally, act locally?
One pressing conservation question is whether a local approach is superior to a national one. In a recent study, McClanahan compared reef conservation in Indonesia and Papua New Guinea.

Reflecting local conditions, most reefs that are protected in Indonesia are inside large marine protected areas, while Papua New Guinea favors community-based conservation. "Indonesia and Papua New Guinea have very different systems," McClanahan says. "Indonesia is top-down, government driven, while in Papua New Guinea ... most resource management is done at the local level. We have an interesting situation, a series of islands with two governments, two histories ... in a center for biodiversity in terms of fish, corals" and most other shallow-ocean organisms.

Brown and dreary, this dead reef is still home to a few fish
Dead corals and bare reef framework are slathered in harmful algae. This barren scene in Australia's Great Barrier Reef shows the effects of feeding by the crown-of-thorns starfish. Photo: Australian Institute of Marine Science

The Papua New Guinea conservation tradition rests on the requirement to stage funeral feasts and relies on taboos, where specific reefs are closed to fishing for several months or years. The motivation is "not directly for conservation, but indirectly. They are trying to get a store of fish for the feasts," McClanahan says.

During a three-year period, McClanahan and his colleagues studied reefs in the two countries and concluded that local management in Papua New Guinea worked better. 'You have to adapt the conservation system to the  local system.'The effect "was not enormous," McClanahan says, but the fish did seem larger in the community conservation areas. In Indonesia, the researchers did not see a "lot of evidence that the large national parks were functioning well. They claimed to be doing lot of management, but not much progress was evident," even after 20 or 30 years.

Getting the lesson
But is the Papuan system deliberate conservation, or a byproduct of cultural practices with other goals? Environmental scientists, McClanahan says, have debated the question: "Is this enlightened barefoot ecologists who manage the reef based on a lot of knowledge of how it works, or is it based on a metaphysical view of life that has no grounding in resource management?" The answer lay somewhere in between, he says. "You have Papuans in grass skirts at the feasts, giving what were really mechanical explanations. The taboos, they said, were really for the feasts," he says.

Although the study can be seen as evidence that local conservation works better than large marine protected areas, McClanahan warns that one study in one location does not prove the point. "But it does mean you have to adapt the conservation system to the local system," he says. "You have to integrate and accept, understand the management implications. Where people know the rules -- like in Papua New Guinea, everybody knows the taboo -- it's no mystery and they see the direct benefit."

Diver swims through shallow waters, encountering many different types of coral
Earthwatch volunteer Mark Keegan maps signs of coral bleaching on an Earthwatch project in the Bahamas. Photo: John Rollino, Earthwatch

Moreover, one local measure cannot overcome the multiple factors that are killing reefs, he adds. "This is not necessarily the one solution to the coral reef problem. These are small areas, on small islands, and the [community conservation] system is tending to decay over time, as these people get more integrated into national and global economy."

The study has another conservation implication, McClanahan adds: "Don't go back to the past, but we can recreate ... traditional ideas. Integrate people into the decisions, involve them in management, get their participation and combine that with national-level programs. This study clearly shows that communities with a direct stake in preserving healthy fisheries around reefs can often serve as the best managers and police to protect these areas from overfishing."

Heard any other bright ideas for conserving reefs?

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