Climate-driven changes in ocean currents have facilitated the range extension of the long-spined sea urchin (Centrostephanus rodgersii) from Australia’s mainland to eastern Tasmania over recent decades. Since its arrival, the destructive grazing of the urchin has led to widespread formation of sea urchin ‘barrens’. The loss of habitat, biodiversity and productivity for important commercial reef species in conjunction with the development of an urchin fishery has led to conflicting objectives among some stakeholders that pose complex challenges for regional management. Stakeholders representatives and managers were engaged via a participatory workshop and subsequent one-on-one surveys to trial a structured decision making process to identify effective ecosystem-based management strategies. We directly and indirectly elicited each preferences for nine alternative management strategies by presenting them with the 10-year consequences of each strategy estimated from an ecosystem model of Tasmanian reef communities. These preferences were included in cost-effectiveness scores that were averaged (across stakeholders) to enable strategy ranking from most to least cost-effective. Rankings revealed strategies that included sea urchin removal or translocation of predatory lobsters were the most cost-effective. However, assessment of stakeholders’ individual cost-effectiveness scores showed some disparity among preferences in high ranking strategies. Additionally, inconsistencies in strategy preferences using alternative (direct or indirect) ranking scores reveal conflicting objectives as the most plausible explanation. Our study illustrates how structured decision making can effectively facilitate ecosystem-based management by engaging stakeholders step-by-step towards management strategy implementation and promoting collective learning.

由气候驱动的洋流变化促进了长旋海胆（Centrostephanus rodgersii）从澳大利亚大陆到塔斯马尼亚州的东部地区，近几十年来。自到达以来，海胆的破坏性放牧导致海胆“贫瘠”的广泛形成。重要商业珊瑚礁物种的栖息地，生物多样性和生产力的丧失，加上海胆渔业的发展，导致一些利益攸关方的目标相互矛盾，给区域管理带来了复杂的挑战。利益攸关方代表和管理人员通过参与性讲习班和随后的一对一调查参与，以试用结构化的决策过程，以确定有效的基于生态系统的管理策略。通过将根据塔斯马尼亚珊瑚礁群落生态系统模型估算出的每种策略的10年后果呈现给我们，我们直接或间接地引起了对9种替代管理策略的每种偏好。这些偏好包括在成本效益得分中，该得分被平均（在各个利益相关者之间），以使策略从最高成本效益到最低成本效益排名。排名显示，包括去除海胆或转移捕食性龙虾的策略最具成本效益。然而，对利益相关者个人成本效益得分的评估显示，在高排名策略中，偏好之间存在一些差异。此外，使用替代（直接或间接）排名分数的策略偏好不一致显示了相冲突的目标，这是最合理的解释。