Optimising water chemistry for intensive production of rainbow trout in Recirculating Aquaculture Systems (RAS). (Ref: 4292)

陆基循环水产养殖系统(RAS)为水产养殖提供了许多优点，包括大大减少了淡水的提取，提高了生物安全性和对养鱼水生环境的控制，更容易管理污水，大大减少了污水水量。但是，RAS也创造了与自然环境截然不同的水化学条件，需要管理和技术解决方案，以避免对鱼类的不利健康和福利后果。特别是，二氧化碳总是高于大气平衡，作为RAS水化学管理战略的一部分，RAS管理者经常将pH、碱度、钙硬度和盐度提高到超过自然淡水环境中的水平。然而，还没有研究确定所有这些变量对包括虹鲑鱼在内的鱼类的交互影响，也没有提供关于最佳水平可能是什么的循证指导。人们已经对其中一些变量(例如，二氧化碳升高)和肾钙质沉着症(肾结石)等问题感到担忧。这将是第一次探索导致这一健康问题的所有潜在因素，包括水化学和饮食，以及它们在鱼类生长、健康和福利的更一般方面所起的作用。这一博士学位将与我们的项目合作伙伴(英国鲑鱼协会和各种鲑鱼养殖公司)密切合作，调查英国鲑鱼养殖场的水化学数据和养殖户的意见，了解什么对避免不利的健康后果和拥有最高效的生产最相关。根据这项调查，拟议的博士项目将使用生理学方法和体内实验工作的彩虹鲑鱼，以提供全面的探索水化学和饮食如何影响生长，健康和福利(例如免疫功能)。该项目提供了进一步的跨学科组成部分，解决了我们在水产养殖业中发现的另一个知识空白；缺乏实时传感器来持续监测RAS中的许多水化学变量(廉价、坚固和准确)，以帮助日常管理水化学及其对鱼类生长和健康的优化。在SWBio财团(GW4水安全联盟-“环境传感器”工作组，特别是巴斯大学的Pedro Estrela博士)旗下的埃克塞特(Alexis Perry博士)在化学和环境传感器方面的专业知识，将帮助开发针对这一问题的创新解决方案。

Land-based recirculating aquaculture systems (RAS) offer many advantages for aquaculture including greatly reduced freshwater abstraction, enhanced biosecurity and control over the aquatic environment for growing fish, easier management of effluent water and greatly reduced effluent water volume.However, RAS also creates water chemistry conditions that are quite different from the natural environment, and that require management and technological solutions to avoid adverse health and welfare outcomes for the fish. In particular CO2 is always elevated above atmospheric equilibrium, and RAS managers often increase pH, alkalinity, calcium hardness and salinity beyond levels in natural freshwater environments as part of the RAS water chemistry management strategy. However, no studies have yet established the interactive effects of all these variables on fish, including rainbow trout, or provided evidence-based guidance on what optimal levels might be. There is already concern about some of these variables (e.g., elevated CO2) and problems such as nephrocalcinosis (kidney stones). This will be the first study to explore all the potential contributors to this health problem, including water chemistry and diet, as well as their role in more general aspects of fish growth, health and welfare. This PhD will work closely with our project partners (the British Trout Association and various trout farming companies) to survey water chemistry data and farmer opinion from UK trout farms on what is most relevant to avoiding adverse health outcomes and having the most efficient production. Based on this survey, the proposed PhD project will use physiological approaches and in vivo experimental work with rainbow trout to provide a full exploration of how both water chemistry and diet affect growth, health and welfare (e.g. immune function). This project provides a further inter-disciplinary component, by addressing a further knowledge gap we have identified in the aquaculture industry; the lack of real-time sensors for continuously monitoring many water chemistry variables in RAS (that are cheap, robust and accurate) to aid day-to-day management of water chemistry and its optimisation for fish growth and health. Expertise in chemistry and environmental sensors at Exeter (Dr. Alexis Perry) within the SWBio consortium (GW4 Water Security Alliance - "Environmental Sensors" working group in particular Dr. Pedro Estrela at Bath University), will help develop innovative solutions to this problem.