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，鲑鱼水产养殖每年价值 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，尽管联合国指令指出到 2050 年需要将产量翻一番，但公众的负面看法阻碍了增长。通常鲑科鱼水产养殖将陆上淡水孵化场与海围栏养殖系统结合起来。虽然需要较低的维护成本，但海围栏的使用增加了养殖鱼类患病的风险，并且与寄生虫溢出到野生鲑鱼种群中有关，导致本地种群数量严重下降。因此，需要缩短海洋养殖阶段的持续时间，或完全过渡到陆地养殖系统（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，迄今为止，RAS 养殖场的发展受到限制，因为与围栏相比，RAS 的生长减少，而且 RAS 的规模需要维持鱼类达到收获尺寸。生长减缓和不良健康结果很大程度上归因于与水化学相关的各种问题（例如二氧化碳、盐度、pH 等）。理查兹教授和布劳纳教授实验室之前的研究确定了 RAS 内生长银鲑鱼的最佳盐度。研究发现，与在淡水到全强度海水等其他盐度下生长的鱼类相比，在与血液大致等渗的盐度下生长的鲑鱼具有最快的生长速度和最低的食物转化率。这被假设为渗透调节的能量消耗减少。然而，该研究是在相对较低的 pH 值下进行的，表明水中存在呼吸性二氧化碳的积累，这是 RAS 中广泛描述的问题。由于鱼类的渗透调节和酸碱平衡之间的联系，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消耗而有利于鱼类的健康和生长，因此与在高二氧化碳下生长的鱼类相比，可以增加生长。在这里，我们计划让鱼适应淡水 (1 ppt) 或等渗水 (10 ppt)，然后将其暴露于大气中的二氧化碳水平或养鱼场内发现的高水平二氧化碳环境中。然后我们希望测量各种生理参数，例如生长、酸碱平衡和免疫功能。然后，该信息将用于确定最佳水化学条件，以最大限度地提高水产养殖中鲑鱼的生长。