Raby Graham D, Donaldson Michael R, Nguyen Vivian M, Taylor Mark K, Sopinka Natalie M, Cook Katrina V, Patterson David A, Robichaud David, Hinch Scott G, Cooke Steven J
Ecol Appl. 2014;24(7):1803-19. doi: 10.1890/13-1885.1.
We used biotelemetry and human dimensions surveys to explore potential solutions to migration mortality of an endangered population of coho salmon caught as bycatch in an aboriginal beach seine fishery. From 2009 to 2011, 182 wild coho salmon caught as bycatch in the lower Fraser River (Canada) were radio-tagged and tracked as they attempted to complete their migrations to natal spawning areas over 300 km upstream. Failure to survive to reach terminal radio receiving stations averaged 39% over three years. This mortality estimate is low compared to those obtained from telemetry studies on other salmon fisheries in the Fraser River. However, this value is markedly higher than the mortality estimate currently used to manage the fishery's impact. It is also in contrast to the perceptions of the majority of aboriginal fishers, who did not think survival of coho salmon is affected by capture and release from their fishery. Increased probability of survival was associated with lower reflex impairment, which is consistent with previous findings. Reflex impairment was positively correlated with entanglement time, suggesting that greater efforts by the fishers to release bycatch from their nets quickly would minimize post-release mortality. Survey responses by aboriginal fishers also suggested that they are receptive to employing new bycatch handling methods if they are shown to increase post-release survival. However, attempts to facilitate revival of a subset of captured fish using cylindrical in-river recovery bags did not improve migration success. Fisheries managers could use the new information from this study to better quantify impacts and evaluate different harvest options. Since aboriginal fishers were receptive to using alternate handling methods, efforts to improve knowledge on minimizing reflex impairment through reductions in handling time could help increase bycatch survival. Such a direct integration of social science and applied ecology is a novel approach to understanding conservation issues that can better inform meaningful actions to promote species recovery.
我们运用生物遥测技术和人类维度调查，探索解决在原住民海滩围网渔业中作为兼捕渔获的濒危银大麻哈鱼洄游死亡问题的潜在解决方案。2009年至2011年期间，在加拿大弗雷泽河下游作为兼捕渔获的182条野生银大麻哈鱼被安装无线电标签，并在它们试图向上游300多公里外的出生地产卵区洄游时进行跟踪。在三年时间里，未能存活至到达终端无线电接收站的平均比例为39%。与弗雷泽河其他鲑鱼渔业的遥测研究所得出的死亡率相比，这个死亡率估计值较低。然而，该数值明显高于目前用于管理渔业影响的死亡率估计值。这也与大多数原住民渔民的认知相反，他们认为银大麻哈鱼的存活不受其渔业捕捞和放生的影响。生存概率的增加与较低的反射损伤相关，这与之前的研究结果一致。反射损伤与纠缠时间呈正相关，这表明渔民加大力度迅速将兼捕渔获物从网中放生，可将放后的死亡率降至最低。原住民渔民的调查反馈也表明，如果新的兼捕渔获物处理方法能提高放后的存活率，他们愿意采用。然而，使用圆柱形河中恢复袋来促进部分捕获鱼复苏的尝试，并未提高洄游成功率。渔业管理人员可利用本研究的新信息，更好地量化影响并评估不同的捕捞方案。由于原住民渔民愿意采用替代处理方法，努力通过减少处理时间来提高对最小化反射损伤的认识，有助于提高兼捕渔获物的存活率。这种将社会科学与应用生态学直接结合的方式，是理解保护问题的一种新颖方法，可为促进物种恢复的有意义行动提供更好的信息。
