The benefits of ecosystem restoration Human activities have fundamentally altered many ecosystems. Recent successful restoration efforts have led to healthier ecosystems, but this has led to a disruption in economies dependent on the altered state of the system. One of the best-known trophic cascades is the sea otter–kelp forest system, wherein recovery of once extirpated sea otters is bringing back biodiverse and healthy kelp forests but reducing the abundance of harvested shellfish. Gregr et al. looked at the costs and benefits of this shift and found that for key trade-offs, the value of kelp forest–associated features such as tourism, fin fish fisheries, and carbon capture outweighed the losses to economies (see the Perspective by Estes and Carswell). Thus, ecosystem recovery can benefit both ecosystems and economies. Science, this issue p. 1243; see also p. 1178 Modeling the effects of sea otters on shellfish fisheries reveals the economic benefit of a recovering trophic cascade. Predator recovery often leads to ecosystem change that can trigger conflicts with more recently established human activities. In the eastern North Pacific, recovering sea otters are transforming coastal systems by reducing populations of benthic invertebrates and releasing kelp forests from grazing pressure. These changes threaten established shellfish fisheries and modify a variety of other ecosystem services. The diverse social and economic consequences of this trophic cascade are unknown, particularly across large regions. We developed and applied a trophic model to predict these impacts on four ecosystem services. Results suggest that sea otter presence yields 37% more total ecosystem biomass annually, increasing the value of finfish [+9.4 million Canadian dollars (CA$)], carbon sequestration (+2.2 million CA$), and ecotourism (+42.0 million CA$). To the extent that these benefits are realized, they will exceed the annual loss to invertebrate fisheries (−$7.3 million CA$). Recovery of keystone predators thus not only restores ecosystems but can also affect a range of social, economic, and ecological benefits for associated communities.

中文翻译：

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由恢复的关键捕食者触发的级联社会生态成本和收益

生态系统恢复的好处 人类活动从根本上改变了许多生态系统。最近成功的恢复工作导致了更健康的生态系统，但这导致依赖于系统状态改变的经济中断。最著名的营养级联之一是海獭 - 海带森林系统，其中曾经灭绝的海獭的恢复正在带回生物多样性和健康的海带森林，但减少了收获的贝类的丰度。格雷格等人。研究了这种转变的成本和收益，发现对于关键的权衡，海带森林相关特征的价值，如旅游业、鳍鱼渔业和碳捕获，超过了对经济的损失（见埃斯蒂斯和卡斯韦尔的观点） ）。因此，生态系统恢复可以使生态系统和经济都受益。科学，这个问题 p。1243; 另见第 1178 模拟海獭对贝类渔业的影响揭示了恢复营养级联的经济效益。捕食者恢复通常会导致生态系统变化，从而引发与最近建立的人类活动的冲突。在北太平洋东部，海獭的恢复正在通过减少底栖无脊椎动物的数量和从放牧压力中释放海带森林来改变沿海系统。这些变化威胁到已建立的贝类渔业并改变了各种其他生态系统服务。这种营养级联的不同社会和经济后果是未知的，特别是在大区域。我们开发并应用了一个营养模型来预测这些对四种生态系统服务的影响。结果表明，海獭的存在每年产生的总生态系统生物量增加了 37%，增加有鳍鱼的价值 [+940 万加元 (CA$)]、碳封存（+220 万加元）和生态旅游（+4200 万加元）。如果实现这些收益，它们将超过无脊椎动物渔业的年度损失（-730 万加元）。因此，关键捕食者的恢复不仅可以恢复生态系统，还可以影响相关社区的一系列社会、经济和生态效益。