Ecosystem-based management requires consideration of overlapping resource use between humans and other consumers. Pacific salmon are an important resource for both fisheries and populations of wildlife around the Pacific rim, including coastal brown bears (Ursus arctos); salmon consumption has been positively linked to bear density, body size, and reproductive rate. As a case study within the broader context of human-wildlife competition for food, we used 16-22 yr of empirical data in four different salmon-bearing systems in southwestern Alaska to explore the relationship between sockeye salmon (Oncorhynchus nerka) availability and consumption by bears. We found a negative relationship between the annual biomass of salmon available to bears and the fraction of biomass consumed per fish, and a saturating relationship between salmon availability and the total annual biomass of salmon consumed by bears. Under modeled scenarios, bear consumption of salmon was predicted to increase only with dramatic (on the order of 50-100%) increases in prey availability. Even such large increases in salmon abundance were estimated to produce relatively modest increases in per capita salmon consumption by bears (2.4-4.8 kg·bear-1 ·d-1 , 15-59% of the estimated daily maximum per capita intake), in part because bears did not consume salmon entirely, especially when salmon were most available. Thus, while bears catching salmon in small streams may be limited by salmon harvest in some years, current management of the systems we studied is sufficient for bear populations to reach maximum salmon consumption every 2-4 yr. Consequently, allocating more salmon for brown bear conservation would unlikely result in an ecologically significant response for bears in these systems, though other ecosystem components might benefit. Our results highlight the need for documenting empirical relationships between prey abundance and consumption, particularly in systems with partial consumption, when evaluating the ecological response of managing prey resources for wildlife populations.

中文翻译：

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为野生生物管理鲑鱼：渔业是否限制阿拉斯加小溪流中的熊食用鲑鱼？

基于生态系统的管理需要考虑人类与其他消费者之间重叠的资源使用。太平洋鲑鱼是太平洋沿岸渔业和野生动植物种群的重要资源，包括沿海棕熊（Ursus arctos）；鲑鱼的消费与熊的密度，体型和生殖率呈正相关。作为在人类与野生动物争夺食物的更广泛背景下的案例研究，我们在阿拉斯加西南部四个不同的鲑鱼养殖系统中使用了16-22年的经验数据，以探索红鲑（Oncorhynchus nerka）的可获得性与消费之间的关系。熊。我们发现熊的鲑鱼年度生物量与每条鱼消耗的生物量比例之间存在负相关关系，鲑鱼的可获得性与熊每年消耗的鲑鱼总生物量之间的饱和关系。在模拟的情况下，预计鲑鱼的熊食消耗只会随着猎物可利用性的急剧增加（大约50-100％）而增加。据估计，即使如此大量的鲑鱼丰度增加，熊的人均鲑鱼消费量也相对适度增加（2.4-4.8 kg·bear-1·d-1，估计为人均每日最大摄入量的15-59％）。部分原因是熊没有完全食用鲑鱼，特别是在鲑鱼最多的时候。因此，虽然熊类在小溪中捕捞鲑鱼可能会受到鲑鱼收获的限制，但我们研究的系统的当前管理足以使熊种群每2-4年达到最大鲑鱼消费量。所以，在这些系统中，分配更多的鲑鱼用于棕熊保护可能不会对熊产生生态学上的重大反应，尽管其他生态系统组件可能也会受益。我们的结果凸显了在评估管理野生动物种群猎物资源的生态响应时，需要记录猎物丰富度与消费之间的经验关系，尤其是在部分消费的系统中。