image: Fishers collectively harvesting from a tambu area, Ahus Island, Manus, Papua New Guinea. view more
Credit: Michael Marnane
By performing simultaneous studies of reef conservation and socioeconomic charateristics of a set of reef management systems, researchers have gained new insight into the factors that can contribute to effective marine conservation strategies. The researchers found evidence suggesting that when resources for conservation enforcement are lacking, management strategies designed to meet community goals can succeed in compliance and conservation to a greater degree than strategies that are based on different priorities. The findings are reported by Timothy McClanahan and Michael Marnane of the Wildlife Conservation Society and colleagues at James Cook University and Fagatele Bay National Marine Sanctuary in American Samoa. The work appears in the July 25th issue of Current Biology, published by Cell Press.
In their work, the researchers examined three different types of reef management systems in Indonesia and Papua New Guinea. The sites included four national parks, which encompassed large areas and were managed and enforced by the national government with the explicit goal of sustainable use and improvement of reef conditions; four "co-managed" reserves, which encompassed small areas and were managed and enforced by the community in partnership with non-governmental organizations, tourism operators, and universities, with a range of social and economic goals; and three traditionally managed areas, which also encompassed small areas but were instigated and maintained by the community with the goals of providing food for celebratory events or goals that in some other way provided a social benefit to the community.
The researchers performed underwater censuses of key reef features, and found that two--the average size and biomass of targeted fish species--were found to be different in managed areas compared to similar non-managed areas. A key finding was that three of the four sites that exhibited the greatest average size and biomass of fishes within the management areas were the self-governing, traditionally managed systems. The other site was one of the co-managed systems. The authors note that, contrary to the idea that permanent reef closures are the most effective ways to improve reef ecosystem health, none of the traditional management regimes involved permanent reef closures--instead, fishing was limited in other ways. The fourth, co-managed site did implement a permanent reef closure.
The authors also noted that the traditionally managed sites were implemented to meet community goals, rather than goals that explicitly reflect western concepts of ecological conservation. In addition, the fourth, co-managed site, was designed largely from a social perspective after community consultation, and was chosen because of its high visibility to the community. In their socioeconomic survey of the various sites under study, the authors found that the sites that were effective at conserving resources had higher compliance with conservation rules, were visible to the local community, and had been under management for a longer period of time than the less successful protected areas. The areas associated with the successful sites also tended to have less involvement in formal or professional economic activities, had lower populations, and less overall wealth. The authors' findings indicated that high compliance at the traditionally managed areas--despite a lack of formal enforcement patrols--was probably influenced by the locations of the areas near the village, the existence of traditional social barriers that limited use by outsiders, and understanding of the relationship between human-environment interactions and local benefits.
On the basis of their findings, the authors propose that while large, permanent marine-protected areas may provide the best protection for species that are at particular risk from overfishing, a combination of such large marine protected areas and traditionally managed systems may represent the best overall solution for meeting conservation and community goals and reversing the degradation of reef ecosystems.
The researchers include Timothy R. McClanahan, Michael J. Marnane of Wildlife Conservation Society, Marine Programs in Bronx, New York; Joshua E. Cinner of the Centre of Excellence for Coral Reef Studies, James Cook University in Townsville, Australia; William Kiene of Fagatele Bay National Marine Sanctuary in Pago Pago, American Samoa.
This work was funded by the David and Lucile Packard Foundation.
McClanahan et al.: "A Comparison of Marine Protected Areas and Alternative Approaches to Coral-Reef Management." Publishing in Current Biology 16, 1408–1413, July 25, 2006 DOI 10.1016/j.cub.2006.05.062 www.current-biology.com
Related Dispatch by Kareiva et al.: "Conservation Biology: Beyond Marine Protected Areas."
Journal
Current Biology