Aliens in the twilight zone: using robots to study and manage invasive lionfish on Caribbean mesophotic coral ecosystems

研究背景入侵狮子鱼（Pterois spp.）已经在西大西洋广泛传播，对本地海洋生物多样性构成重大威胁。狮子鱼不受限制地捕食本地鱼类种群，而这些鱼类种群与狮子鱼的本地印度洋-太平洋范围不同，没有进化的防御能力。目前的管理在很大程度上依赖于休闲潜水员的机会性淘汰，但这种方法只能提供当地的短期喘息。这是因为休闲潜水员倾向于停留在30米以上，但狮子鱼在这个深度以下的丰度很高，因此被错过了。此外，最近的证据表明，这些更深的狮子鱼-在中光珊瑚生态系统（MCE：30-150米）-更大，更肥沃的比那些发现在浅水区。MCE的研究很少，因为它们对于传统的SCUBA潜水来说太深了，但又不足以证明昂贵的研究潜水器是合理的。Wallacea行动与美国慈善机构Robots in Service of the Environment（RSE）进行了新的合作，该机构开发了一种小型，具有成本效益的机器人，能够访问MCE并捕获狮子鱼。在2019年的试点测试中，该机器人已成功在85米深度运行，设计深度超过200米。研究问题这些深种群的狮子鱼可能会大大有助于招聘浅礁，破坏管理工作，允许快速繁殖后，扑杀。这种潜力在多大程度上得以实现，以及它在多大程度上影响了管理工作，需要对MCE狮子鱼有更深入的生态学了解。我们的目标是利用这些机器人令人兴奋的新能力来（1）确定MCE狮子鱼在物种种群动态中的作用，（2）量化入侵狮子鱼对更广泛的MCE鱼类群落的影响，和（3）使用空间结构的人口模型，以制定最佳的管理实践，淘汰MCE lionfish种群。方法实地工作将主要是在行动Wallacea的长期海洋研究地点在洪都拉斯（自2005年以来活跃;自2016年以来有23篇同行评审的科学论文）。使用外部资助的、安装有摄像头的定制原型机器人，将收集狮子鱼及其栖息的生态系统的标准化数据，特别是关注MCE。具体来说，视频调查将用于调查狮子鱼在其整个深度范围内的分布，并确定猎物的可用性。这些机器人还将捕捉狮子鱼并将它们送回水面，以实现肠道内容物分析和整个深度的人口变化。利用这些数据，将开发一个空间结构的人口模型，以了解狮子鱼种群动态。有了这个模型，我们将探索不同的淘汰方案，并制定最佳策略的假设。这些策略将通过涉及机器人支持的深度剔除的现场实验进行测试。根据研究结果，种群模型将被改进，以应用于其他地点，并为全球狮子鱼管理提供信息。时间表第1年：强化培训/指导。文献综述。录像观察（洪都拉斯）。分析丰度分布、种群结构、捕食行为和更广泛的MCE鱼类群落。第2年：肠道内容物，繁殖力和身体状况分析。发展空间结构种群模型，为淘汰实验提供信息。第三年：通过田间实验确定最佳淘汰策略，并验证/完善模型。制定和实施入侵狮子鱼管理的最佳实践指南。

Research contextInvasive lionfish (Pterois spp.) have spread widely across the western Atlantic and are a substantial threat to native marine biodiversity. Lionfish predate unchecked on native fish populations which, unlike in the lionfish's native Indo-Pacific range, have no evolved defence. Current management relies largely on opportunistic culling by recreational SCUBA divers yet this method only provides local short-term respite. This is because recreational divers tend to stay above 30 m, yet lionfish are at high abundance below this depth and are consequently missed. Also, recent evidence shows these deeper lionfish - in mesophotic coral ecosystems (MCEs: 30-150 m) - are larger and more fecund than those found in the shallows. MCEs are poorly studied because they are too deep for conventional SCUBA diving but not deep enough to justify expensive research submersibles. Operation Wallacea has a new collaboration with US-based charity Robots in Service of the Environment (RSE), which has developed a small, cost-effective robot capable of accessing MCEs and capturing lionfish. The robot has successfully operated at 85m depth during 2019 pilot tests and is designed to reach beyond 200m. Research questionsThese deep populations of lionfish may contribute substantially to recruitment in shallow reefs, undermining management efforts by allowing rapid recolonisation after culls. How far this potential is realised, and thus how much it compromises management efforts, requires greater ecological understanding of MCE lionfish.We aim to exploit these robots exciting new capability to (1) determine the role of MCE lionfish in the species' population dynamics, (2) quantify the impacts of invasive lionfish on the wider MCE fish community, and (3) use spatially-structured demographic models to develop best management practice for culling MCE lionfish populations.MethodsFieldwork will primarily be at Operation Wallacea's long-term marine research sites in Honduras (active since 2005; 23 peer-reviewed scientific papers since 2016). Using externally funded, bespoke prototype robots mounted with cameras, standardised data will be collected on lionfish and the ecosystems they inhabit, particularly focusing on MCEs. Specifically, video surveys will be used to survey the distribution of lionfish at their full depth range and determine prey availability. The robots will also catch lionfish and return them to the surface to enable gut content analysis and demographic changes across depth. Using these data, a spatially-structured demographic model will be developed to understand lionfish population dynamics. With this model, we will explore different culling scenarios and develop hypotheses for optimal strategies. These strategies will be tested via field experiments involving robot-enabled deep culling. Based on the results, the population model will be refined for application to other locations, and to inform lionfish management globally.TimelineYear 1: intensive training/orientation. Literature review. Video observations (Honduras). Analysis of abundance distribution, population structure, predatory behaviour and wider MCE fish community. Year 2: Gut content, fecundity and body condition analyses. Develop spatially-structured population model to inform culling experiment.Year 3: Field experiments to determine optimal culling strategy and validate/refine model. Develop and implement best-practice guidelines for invasive lionfish management.