Andreu-Cazenave Miguel, Subida Maria Dulce, Fernandez Miriam
Núcleo Milenio - Centro de Conservación Marina CCM, Estación Costera de Investigaciones Marinas, Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
PLoS One. 2017 Jun 30;12(6):e0180012. doi: 10.1371/journal.pone.0180012. eCollection 2017.
There is an urgent need to quantify the impacts of artisanal fisheries and define management practices that allow for the recovery and conservation of exploited stocks. The extent of illegal catch is particularly critical as a driver of overexploitation in artisanal fisheries. However, the lack of data at proper spatial scales limits the evaluation of illegal fishing and effectiveness of management practices. We used a catch curve analysis to estimate total instantaneous mortality as a proxy of fishing pressure in the artisanal benthic fishery in central Chile. We compared the patterns of total mortality in fishing grounds under the well-studied territorial use rights for fisheries system (TURF) immersed in a landscape of open access areas (OAA; no access restriction), and from these patterns determined the extent of illegal fishing in open access areas focusing on the two most frequently extracted resources: locos (Concholepas concholepas) and keyhole limpets (Fissurella spp.). The beauty of this seascape is the presence of the no-take (NT) area of Las Cruces as control (no fishing), allowing us to estimate natural mortality. Loco exploitation is banned in OAAs. However, loco mortality in OAAs was 92% higher than in the NT, and 42% higher than in TURFs. Keyhole limpet mortality was similar between TURFs and the NT, but doubled in OAAs. We also found strong differences in mortality among fishing grounds with the same level of protection (i.e. TURFs), and over time. Our results highlight (a) the high level of illegal fishing that may occur in artisanal fisheries under traditional management regimes, and (b) that TURFs can be effective to reduce fishing mortality. However, large variability among TURFs suggests the need for a deeper understanding of the drivers of success of TURFs.
迫切需要量化个体渔业的影响，并确定能够促进被开发种群恢复和保护的管理措施。非法捕捞的程度作为个体渔业过度开发的一个驱动因素，尤为关键。然而，缺乏适当空间尺度的数据限制了对非法捕捞以及管理措施有效性的评估。我们采用渔获曲线分析来估计总瞬时死亡率，以此作为智利中部个体底栖渔业捕捞压力的一个指标。我们比较了在深入研究的渔业领地使用权制度（TURF）下的渔场与开放获取区域（OAA；无进入限制）的总死亡率模式，并从这些模式中确定开放获取区域的非法捕捞程度，重点关注两种最常捕捞的资源：海螺（Concholepas concholepas）和钥匙孔帽贝（Fissurella spp.）。这片海景的美妙之处在于存在拉斯克鲁塞斯禁捕（NT）区域作为对照（无捕捞），这使我们能够估计自然死亡率。在开放获取区域，海螺捕捞是被禁止的。然而，开放获取区域的海螺死亡率比禁捕区域高92%，比渔业领地使用权制度区域高42%。钥匙孔帽贝在渔业领地使用权制度区域和禁捕区域的死亡率相似，但在开放获取区域增加了一倍。我们还发现在具有相同保护水平（即渔业领地使用权制度区域）的渔场之间以及不同时间，死亡率存在显著差异。我们的结果突出表明：（a）在传统管理制度下个体渔业可能存在的高水平非法捕捞；（b）渔业领地使用权制度对于降低捕捞死亡率是有效的。然而，渔业领地使用权制度区域之间的巨大差异表明需要更深入地了解渔业领地使用权制度成功的驱动因素。
