Maravilla-Chávez M O, Hernández-Vázquez S, Zavala-González A, Ortega-Rubio A
Instituto Nacional de Ecología, Programa de Investigación de los Mamiferos Marinos, Ocampo 1045. Centro, C.P. 23000.
J Environ Biol. 2006 Oct;27(4):629-31.
Activities of fishermen in the Bay of La Paz, B. C. S. are focused to satisfy the local demand of fish and shellfish by using approximately 300 small outboard crafts equipped with gillnets. Sea lions in this Bay attack the fishes captured damaging both product and gear. We did experimental gillnet throws to determine the frequency and preferences of sea lions in fishing areas. 52 experimental gillnet throws with time averages of 2 hr were performed, rending an average of 30 kg of fish captured and less than 10% of damages to the net.. Traditional fishermen in this Bay usually left the net the whole night, (approximately 7.50 hr, obtaining an average of 50 kg of captured fish, but the damages to the nets is in average of 40%. The cost-benefit balance comparing our alternative fishing method, which includes the use of the gillnets during the afternoon, watching for sea lions and retiring the nets at their arrival, it is more sustainable and profitable than the traditional fishing method currently used by the local fishermen. This paper suggests how to minimize the harmful effects of the sea lions on the fishermen productivity and gear, maximizing the production and reducing the damage. Our alternative method is applicable to other regions where this harmful interaction is taking place. We conclude that the coexistence of sea lions-fisheries is feasible, by applying the simple measures that we propose.
下加利福尼亚州拉巴斯湾渔民的活动主要是通过约300艘配备刺网的小型舷外作业船来满足当地对鱼类和贝类的需求。该海湾的海狮会攻击捕获的鱼类，对产品和渔具都造成损害。我们进行了刺网投掷实验，以确定海狮在捕鱼区域的活动频率和偏好。共进行了52次实验性刺网投掷，每次平均时长2小时，平均捕获30千克鱼，刺网损坏率不到10%。该海湾的传统渔民通常会让网整夜放置（约7.5小时），平均捕获50千克鱼，但网的平均损坏率为40%。将我们的替代捕鱼方法（包括在下午使用刺网、监视海狮并在其到来时收起网）进行成本效益平衡分析，结果表明这种方法比当地渔民目前使用的传统捕鱼方法更具可持续性和盈利能力。本文提出了如何将海狮对渔民生产力和渔具的有害影响降至最低，同时实现产量最大化并减少损失。我们的替代方法适用于其他存在这种有害相互作用的地区。我们得出结论，通过采用我们提出的简单措施，海狮与渔业的共存是可行的。
