Chirico Angelica A D, McClanahan Timothy R, Eklöf Johan S
Department of Ecology, Environment and Plant Sciences (DEEP), Stockholm University, Stockholm, Sweden.
Marine Programs, Wildlife Conservation Society, Bronx, New York, United States of America.
PLoS One. 2017 Aug 14;12(8):e0182342. doi: 10.1371/journal.pone.0182342. eCollection 2017.
Government-managed marine protected areas (MPAs) can restore small fish stocks, but have been heavily criticized for excluding resource users and creating conflicts. A promising but less studied alternative are community-managed MPAs, where resource users are more involved in MPA design, implementation and enforcement. Here we evaluated effects of government- and community-managed MPAs on the density, size and biomass of seagrass- and coral reef-associated fish, using field surveys in Kenyan coastal lagoons. We also assessed protection effects on the potential monetary value of fish; a variable that increases non-linearly with fish body mass and is particularly important from a fishery perspective. We found that two recently established community MPAs (< 1 km2 in size, ≤ 5 years of protection) harbored larger fish and greater total fish biomass than two fished (open access) areas, in both seagrass beds and coral reefs. As expected, protection effects were considerably stronger in the older and larger government MPAs. Importantly, across management and habitat types, the protection effect on the potential monetary value of the fish was much stronger than the effects on fish biomass and size (6.7 vs. 2.6 and 1.3 times higher value in community MPAs than in fished areas, respectively). This strong effect on potential value was partly explained by presence of larger (and therefore more valuable) individual fish, and partly by higher densities of high-value taxa (e.g. rabbitfish). In summary, we show that i) small and recently established community-managed MPAs can, just like larger and older government-managed MPAs, play an important role for local conservation of high-value fish, and that ii) these effects are equally strong in coral reefs as in seagrass beds; an important habitat too rarely included in formal management. Consequently, community-managed MPAs could benefit both coral reef and seagrass ecosystems and provide spillover of valuable fish to nearby fisheries.
政府管理的海洋保护区（MPA）能够恢复小型鱼类种群，但因排斥资源使用者并引发冲突而备受诟病。一种前景良好但研究较少的替代方案是社区管理的海洋保护区，在这种保护区中，资源使用者更多地参与到保护区的设计、实施和执法中。在此，我们利用对肯尼亚沿海泻湖的实地调查，评估了政府管理和社区管理的海洋保护区对与海草和珊瑚礁相关鱼类的密度、大小和生物量的影响。我们还评估了对鱼类潜在货币价值的保护效果；该变量随鱼体质量呈非线性增加，从渔业角度来看尤为重要。我们发现，在海草床和珊瑚礁中，两个最近设立的社区海洋保护区（面积小于1平方公里，保护年限小于等于5年）比两个捕捞（开放获取）区域拥有更大的鱼类和更高的鱼类总生物量。正如预期的那样，在规模更大、年代更久的政府海洋保护区中，保护效果要显著得多。重要的是，在不同管理方式和栖息地类型中，对鱼类潜在货币价值的保护效果比对鱼类生物量和大小的影响要强得多（在社区海洋保护区中，对潜在货币价值的保护效果分别比对鱼类生物量和大小的影响高6.7倍和2.6倍、1.3倍）。这种对潜在价值的强烈影响部分是由于存在更大（因而更有价值）的个体鱼类，部分是由于高价值分类群（如兔鱼）的密度更高。总之，我们表明：i）新近设立的小型社区管理海洋保护区与规模更大、年代更久的政府管理海洋保护区一样，能够在当地高价值鱼类保护中发挥重要作用；ii）这些影响在珊瑚礁和海草床中同样显著，而海草床这一重要栖息地很少被纳入正式管理。因此，社区管理的海洋保护区可能使珊瑚礁和海草生态系统都受益，并为附近渔业提供有价值鱼类的溢出效应。
