Habitat Severity and Internal Ice in Antarctic Notothenioid Fishes

北极目鱼类生活在南极洲周围世界上最冷的海域，它们进化出了避免冰冻的策略。过去的研究表明，大多数南极类海豚会产生特殊的抗冻蛋白，以防止进入人体的冰晶生长。虽然这些蛋白质有助于防止个体被生长的冰晶杀死，但随着时间的推移，这些鱼如何避免这些小冰晶在它们的组织中积累还不清楚。该项目将观察冰晶积累如何与南极洲麦克默多海湾不同生境中鱼类栖息地的严酷程度和鱼类的行为有关。研究人员将在不同的野外地点收集鱼类和海洋观测数据，涵盖温度和寒冷程度方面的一系列栖息地严重程度。研究人员将在麦克默多站附近安装一个水下海洋观测站，其中将包括一个高清摄像机和水听器。天文台将允许持续监测海洋状况和鱼类行为，这将有助于解释有助于体内冰的获取和积累的条件和行为。来自天文台的声学和视频数据将向其他科学家和公众开放。该项目将促进人们对极端寒冷环境中生活面临的许多挑战的理解。这项工作延续了一系列调查结果，发现了潜在的医疗和食品保存应用。实验室中已经进行了数百项抗冻蛋白(AFP)的结构-功能研究，为AFP与冰的相互作用提供了基本的物理理解。然而，AFP如何在鱼类及其环境范围内发挥作用还远不清楚。这个项目将通过量化内部冰晶的获取、积累和损失来了解Nototheniid的冰冻避免机制和策略。具体地说，目标是确定栖息地的严重性(根据冰冻程度、海水温度和过冷水的盛行来定义)和鱼类行为是否以及如何影响其组织中冰晶的丰度。将对麦克默多海峡四个不同生境严重程度的地点进行采样，以了解海洋条件和鱼类组织中的冰晶数量。研究人员将使用一种新技术来计算脾冰晶的数量，对以前的方法进行扩展和简化。在项目期间，将在四个地点部署环境数据记录器，以提供环境条件的背景和实时评估。麦克默多站附近的一个海洋观测站将提供全年、实时和存档的海洋条件记录、锚冰生长和冰-生物相互作用的现场视频观测、水声记录，并作为扩大麦克默多海峡与过冷水监测和海洋信息有关的科学基础设施的概念验证。

Notothenioid fishes live in the world's coldest marine waters surrounding Antarctica and have evolved strategies to avoid freezing. Past studies have shown that most Antarctic notothenioids produce special antifreeze proteins that prevent the growth of ice crystals that enter the body. While these proteins help prevent individuals from being killed by growing ice crystals, it is unclear how these fish avoid the accumulation of these small ice crystals inside their tissues over time. This project will observe how ice crystal accumulation relates to the harshness of the fish's habitat and the fish's behavior within different habitats of McMurdo Sound, Antarctica. The researchers will collect fishes and ocean observations at different field sites that cover a range of habitat severity in terms of temperature and iciness. Researchers will install an underwater ocean observatory near McMurdo Station which will include a HD video camera and hydrophone. The observatory will allow continuous monitoring of ocean conditions and fish behavior that will help explain the conditions and behaviors that contribute to the acquisition and accrual of ice inside the body. Acoustic and video data from the observatory will be available to other scientists and to the public. The project will advance understanding of the many challenges life faces in extreme cold environments. This work continues a line of inquiry that has resulted in the discovery of potential medical and food preservation applications. Hundreds of antifreeze protein (AFP) structure-function studies have been conducted in the laboratory, providing a basic physical understanding of the AFP-ice interaction. How AFPs function within fishes and their range of environments, however, is far from clear. This project will provide an understanding of notothenioid's freezing avoidance mechanisms, and strategies by quantifying the acquisition, accumulation, and loss of internal ice crystals. Specifically, the goal is to determine if and how habitat severity (as defined by iciness, seawater temperature, and prevalence of supercooled water) and fish behavior influence the abundance of ice crystals in their tissues. Four locations in the McMurdo Sound with different levels of habitat severity will be sampled for oceanographic conditions and ice crystal count within fish tissues. Researchers will use a new technique to count the number of splenic ice crystals, expanding on and simplifying previous methods. Environmental data loggers will be deployed for the duration of the project at the four sites to provide context and real-time assessment of environmental conditions. An oceanographic observatory near McMurdo Station will provide year-round, real-time and archival records of oceanographic conditions, in situ video observations of anchor ice growth and ice-organism interactions, hydroacoustic recordings, and serve as proof-of concept for expanding scientific infrastructure in McMurdo Sound related to monitoring of supercooled waters and oceanographic information.