Impact of CO2 and salinity in aquaculture on physiology, growth and health of coho salmon

水产养殖中二氧化碳和盐度对银大麻哈鱼生理、生长和健康的影响

• 批准号: NE/T01458X/1
• 负责人: Rod Wilson
• 金额: $ 0.84万
• 依托单位: UNIVERSITY OF EXETER
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FT01458X%2F1
• 关键词: Impact; CO2; salinity; aquaculture; physiology

BBSRC : William Davison : BB/M009122/1 (1921484)As of 2017 salmonid aquaculture was worth $22 billion USD per year with the UK contributing $1.4 billion USD and Canada responsible for $988 million USD. However, despite UN directives stating a need to double production by 2050, growth is hampered by negative public perception. Typically salmonid aquaculture combines land-based freshwater hatcheries with sea-pen rearing systems. While requiring lower maintenance costs the use of sea-pens increases risk of disease in farmed fish and has been linked with parasite overspill into wild populations of salmon causing serious declines in native populations. As such there is a demand to reduce the duration of the marine grow out phase, or transition entirely to land based farm systems (referred to as recirculating aquaculture systems - RAS) which largely avoid many of these problems. However, thus far development of RAS farms has been limited due to reduced growth observed in RAS compared to pens, and the scale of RAS required to maintain fish up to harvest size. Reduced growth and adverse health outcomes have largely been attributed to various issues relating to water chemistry (e.g. CO2, salinity, pH etc.). Previous research from Prof. Richards and Prof Brauner's labs identified an optimal salinity for growing Coho salmon within RAS. Salmon grown at a salinity approximately isosmotic to blood were found to have the fastest growth rate and lowest food conversion ratio compare to fish grown at other salinities ranging from freshwater to full strength seawater. This has been hypothesised to be reduced energy expenditure for osmoregulation. However, that study was conducted at relatively low pHs indicative of a build-up of respiratory CO2 in the water, a problem that has been characterised extensively in RAS. Due to the link between osmoregulation and acid-base balance in fish, any reduction in environmental CO2 may therefore benefit fish health and growth by reducing energy expenditure on acid-base balance and therefore allow increased growth compared to fish grown at high CO2.Here we plan to acclimate fish to either freshwater (1 ppt) or isosmotic water (10 ppt) and then expose them to either atmospheric levels of CO2 or to the elevated levels of CO2 found within fish farms. We then hope to measure a variety of physiological parameters such as growth, acid-base balance and immune function. This information will then be used to determine optimal water chemistry conditions to maximise growth of salmon in aquaculture.

BBSRC：William Davison：BB/M009122/1(1921484)截至2017年，鲑鱼养殖每年价值220亿美元，其中英国贡献14亿美元，加拿大贡献9.88亿美元。然而，尽管联合国指示需要在2050年之前将产量翻一番，但公众的负面看法阻碍了增长。典型的鲑鱼水产养殖结合了陆上淡水孵化场和海水围栏养殖系统。虽然需要较低的维护成本，但使用海栏增加了养殖鱼类的疾病风险，并与寄生虫过度进入野生鲑鱼种群有关，导致当地种群严重下降。因此，需要缩短海洋养殖阶段的持续时间，或完全过渡到陆上养殖场系统(称为循环水产养殖系统--RAS)，这在很大程度上避免了许多此类问题。然而，到目前为止，RAS养殖场的发展受到限制，因为与围栏相比，RAS中观察到的生长减少，以及维持鱼类达到捕捞规模所需的RAS规模。生长减慢和不利的健康后果在很大程度上归因于与水化学有关的各种问题(例如二氧化碳、盐度、酸碱度等)。理查兹教授和布劳纳教授的实验室之前的研究确定了在RAS中种植Coho鲑鱼的最佳盐度。在接近血液等渗的盐度下生长的三文鱼生长速度最快，食物转化率最低，而在淡水到全海水等盐度的其他盐度下生长的三文鱼生长速度最快，食物转化率最低。这被假设为降低了渗透调节的能量消耗。然而，这项研究是在相对较低的PHS下进行的，表明水中呼吸性二氧化碳的积累，这一问题在RAS中得到了广泛的表征。由于渗透调节和鱼的酸碱平衡之间的联系，因此，环境二氧化碳的任何减少都可能通过减少酸碱平衡的能量支出而有利于鱼类的健康和生长，因此与在高二氧化碳条件下生长的鱼相比，可以促进生长。我们计划使鱼适应淡水(1ppt)或等渗水(10ppt)，然后将它们暴露在大气二氧化碳水平或养鱼场中二氧化碳水平升高的环境中。然后，我们希望测量各种生理参数，如生长、酸碱平衡和免疫功能。这些信息将被用来确定最佳的水化学条件，以最大限度地促进水产养殖中鲑鱼的生长。