PPG/Dept. of Ecology, Federal University of Rio Grande do Sul, CP 15007, 91501-970 Porto Alegre, RS, Brazil.
J Environ Manage. 2013 Oct 15;128:274-82. doi: 10.1016/j.jenvman.2013.05.037. Epub 2013 Jun 10.
Identifying the factors that influence the amount of fish caught, and thus the fishers' income, is important for proposing or improving management plans. Some of these factors influencing fishing rewards may be related to fishers' behavior, which is driven by economic motivations. Therefore, those management rules that have less of an impact on fishers' income could achieve better acceptance and compliance from fishers. We analyzed the relative influence of environmental and socioeconomic factors on fish catches (biomass) in fishing communities of a large tropical river. We then used the results from this analysis to propose alternative management scenarios in which we predicted potential fishers' compliance (high, moderate and low) based on the extent to which management proposals would affect fish catches and fishers' income. We used a General Linear Model (GLM) to analyze the influence of environmental (fishing community, season and habitat) and socioeconomic factors (number of fishers in the crew, time spent fishing, fishing gear used, type of canoe, distance traveled to fishing grounds) on fish catches (dependent variable) in 572 fishing trips by small-scale fishers in the Lower Tocantins River, Brazilian Amazon. According to the GLM, all factors together accounted for 43% of the variation in the biomass of the fish that were caught. The behaviors of fishers' that are linked to fishing effort, such as time spent fishing (42% of the total explained by GLM), distance traveled to the fishing ground (12%) and number of fishers (10%), were all positively related to the biomass of fish caught and could explain most of the variation on it. The environmental factor of the fishing habitat accounted for 10% of the variation in fish caught. These results, when applied to management scenarios, indicated that some combinations of the management measures, such as selected lakes as no-take areas, restrictions on the use of gillnets (especially during the high-water season) and individual quotas larger than fishers' usual catches, would most likely have less impact on fishers' income. The proposed scenarios help to identify feasible management options, which could promote the conservation of fish, potentially achieving higher fishers' compliance.
确定影响渔获量（进而影响渔民收入）的因素对于提出或改进管理计划至关重要。影响捕鱼收益的因素中，有些可能与渔民的经济动机驱动的行为有关。因此，那些对渔民收入影响较小的管理规则可能会得到渔民更好的接受和遵守。我们分析了环境和社会经济因素对大型热带河流渔业社区鱼类捕捞量（生物量）的相对影响。然后，我们利用该分析的结果，提出了替代管理方案，根据管理建议对鱼类捕捞量和渔民收入的影响程度，预测渔民的潜在遵守程度（高、中、低）。我们使用广义线性模型（GLM）分析了环境（渔业社区、季节和栖息地）和社会经济因素（渔船上的渔民人数、捕鱼时间、使用的渔具、独木舟类型、前往捕鱼地的距离）对小型渔民在巴西亚马逊地区托坎廷斯河下游的 572 次捕鱼活动中鱼类捕捞量（因变量）的影响。根据 GLM，所有因素共同解释了所捕获鱼类生物量变化的 43%。与捕鱼努力相关的渔民行为，如捕鱼时间（GLM 总解释量的 42%）、前往捕鱼地的距离（12%）和渔民人数（10%），均与所捕获鱼类的生物量呈正相关，并且可以解释大部分变化。捕鱼栖息地的环境因素解释了所捕获鱼类生物量变化的 10%。将这些结果应用于管理方案，表明一些管理措施的组合，例如选择湖泊作为禁渔区、限制使用刺网（特别是在高水位季节）以及比渔民通常捕捞量更大的个人配额，可能对渔民的收入影响较小。所提出的方案有助于确定可行的管理方案，从而促进鱼类保护，提高渔民的遵守率。
