Vision-mediated influence of low oxygen on the physiology and ecology of marine larvae

由于海洋变暖和陆地营养物质的输入，全世界的海洋正在失去氧气。视力需要大量的氧气，当氧气短缺时，视力可能不太有效或需要更多的光线。对于眼睛和视觉能力复杂的活跃海洋动物尤其如此，包括活跃的节肢动物(螃蟹)、头足类动物(鱿鱼)和鱼。随着水深的增加，加州沿海水域的氧气和光照急剧下降。本项目研究幼年(幼体)高度视觉海洋动物的视觉生理学和生态学对缺氧的反应，重点是主要渔业和水产养殖物种。实验和观察将检验这一假设，即氧气应激将改变这些生物体有效观看所需的光线，影响它们能够生存和生存的水深。该项目将为学生和一位早期的职业科学家提供跨学科的体验，并向公众(通过在斯克里普斯海洋研究所的桦树水族馆进行宣传)和政策制定者了解海洋中氧气减少的影响。人们已经描述了氧气丢失对人类和其他陆地生物视力的负面影响，但从未在海洋环境中描述过，尽管海洋中的氧气可能会随着深度和时间的推移发生巨大变化，而且视觉系统的新陈代谢需求很高。本项目将通过3种眼睛设计和光传导机制的组合来测试低氧对视力的影响：复眼与横纹光感受器(节肢动物)、单眼与横纹光感受器(头足类)和单眼与睫状光感受器(FISH)。将在每一组具有代表性的分类群上进行一系列氧气和光控制的实验室实验，包括金枪鱼蟹，平足平足金枪鱼，市场鱿鱼，Doryteuthis opalescens，和白色海鱼，Atratoscion nobilis。在体内，电生理学和行为趋光性实验将确定视觉生理和功能的新氧气指标，并将与呼吸实验中确定的代谢阈值进行比较。位于南加州海湾的CalCOFI计划收集了30多年的水文数据，将根据视觉和新陈代谢限制进行评估，以确定氧气变化对每个物种的临界发光环境(目标物种的视觉生理和功能所需的氧气和光照条件的范围)边界的影响。这三个基于视觉的功能小组的研究结果可能会测试限氧视觉反应是否为低氧条件下高度视觉的远洋类群之间的物种分布浅滩提供了额外的解释，并将有助于集中未来的研究努力，更好地了解导致栖息地压缩和海洋中不断扩大的氧气损失的压力源。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Oxygen is being lost in the ocean worldwide as a result of ocean warming and the input of nutrients from land. Vision requires a large amount of oxygen, and may be less effective or require more light when oxygen is in short supply. This is especially true for active marine animals with complex eyes and visual capabilities, including active arthropods (crabs), cephalopods (squid), and fish. The California coastal waters exhibit a sharp drop in oxygen and light with increasing water depth. This project examines how visual physiology and ecology in young (larval) highly visual marine animals respond to oxygen loss, with a focus on key fisheries and aquaculture species. Experiments and observations will test the hypothesis that oxygen stress will change the light required for these organisms to see effectively, influencing the water depths where they can live and survive. The project will provide interdisciplinary experiences to students and an early career scientist and inform both the public (through outreach at the Birch Aquarium at Scripps Institution of Oceanography) and policy makers about the effects of oxygen decline in the ocean.Negative effects of oxygen loss on vision have been described for humans and other terrestrial organisms, but never in the marine environment, despite the large changes in oxygen that can occur with depth and over time in the ocean, and the high metabolic demand of visual systems. This project will test the effects of low oxygen on vision in 3 combinations of eye design and photo-transduction mechanisms: compound eye with rhabdomeric photoreceptors (arthropods), simple eye with rhabdomeric photoreceptors (cephalopods), and simple eye with ciliary photoreceptors (fish). A series of oxygen- and light-controlled laboratory experiments will be conducted on representative taxa of each group including the tuna crab, Pleuroncodes planipes; the market squid, Doryteuthis opalescens, and the white sea bass, Atractoscion nobilis. In vivo electrophysiology and behavioral phototaxis experiments will identify new oxygen metrics for visual physiology and function, and will be compared to metabolic thresholds determined in respiration experiments. Hydrographic data collected over 3 decades by the CalCOFI program in the Southern California Bight will be evaluated with respect to visual and metabolic limits to determine the consequences of oxygen variation on the critical luminoxyscape (range of oxygen and light conditions required for visual physiology and function in target species) boundary in each species. Findings for the three vision-based functional groups may test whether oxygen-limited visual responses offer an additional explanation for the shoaling of species distributions among highly visual pelagic taxa in low oxygen, and will help to focus future research efforts and better understand the stressors contributing to habitat compression with expanding oxygen loss in the ocean.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.