Mitigating Microbial Hazards - Eliminating HABs risks in salmon farms

人类面临的最大全球挑战之一是在应对气候问题的同时确保可靠的蛋白质生产。人们认识到，许多蛋白质来源导致了不可持续的农业做法，因此正在为全球蛋白质转型做出相当大的努力，然而，水产养殖的蛋白质生产可以具有较低的碳足迹。此外，本文所述的工作计划旨在为联合国的多个可持续发展目标做出贡献，即联合国秘书长第2号“消除饥饿，实现粮食安全和改善营养，促进可持续农业”和联合国秘书长第12号：“保护和可持续利用海洋和海洋资源，促进可持续发展”。曾经被认为是一种奢侈食品，今天，英国每天消耗100万份鲑鱼餐，该行业从50年前的几个农场发展到现在的200个左右。鲑鱼是英国最大的食品出口之一，据说每年对经济的贡献接近10亿英镑。苏格兰是世界第三大养殖大西洋鲑鱼生产国，2020年产量超过20万吨。该部门拥有超过11，000个工作岗位，并希望到2030年将其翻一番。可能阻碍这一目标的因素之一是有害藻类水华（HAB）的发生，这可能导致大量鱼类死亡，原因是鳃受损、毒素的存在以及高生物量导致的氧气耗尽。这个雄心勃勃的项目将加速保护系统的创新，在藻类对鲑鱼造成伤害和重大经济损失之前消除藻类。多年来，我们开发了光催化系统，首先破坏了藻类和蓝藻毒素，并在饮用水处理中有潜在的应用。最近，我们将这项技术用于消除有害的蓝藻和藻类。光催化是一种采用催化剂的治疗方法，该催化剂被光激活，从而释放出强大的羟基自由基。这种类型的处理的一个显著好处是，它不需要添加化学品，并且反应性自由基的寿命非常短（纳秒），因此预计对非目标物种的负面影响最小。虽然我们已经证明了光催化剂作为一种新的处理策略对水中一系列微生物的潜力，但这项研究真正冒险的方面将是使用非常有选择性的波长来解开有害海藻趋光性的新知识。随着LED技术的不断进步，可以获得非常精确的波长（c. 15 nm），具有容易变化的光强度。我们将设计一种生物测定方法来筛选已知的有害藻类，以确定是否可以使用特定的LED将有害藻类引诱到光催化处理系统，该系统将采用可以部署以保护鲑鱼笼的窗帘的形式。保护幕的开发将通过与国际海洋工程专家OTAQ的合作进行，这将加快设计到部署适合恶劣海洋环境的工程系统，同时还直接连接到他们目前在鲑鱼养殖场工作的许多测试地点。该项目小组还包括来自苏格兰海洋科学协会的专家，他们一直在与鲑鱼养殖场周围的有害生物预警系统行业合作。我们提出的光催化幕的成功部署需要对潜在危险的藻华事件进行准确的警报。从一开始就与SAMS合作将确保这两项新技术结合在一起，以保护鲑鱼养殖场，支持这一重要行业的未来扩张。

One of the greatest global challenges facing human-kind is ensuring reliable protein production while addressing climate issues. Considerable effort is being committed to the global protein transition in recognition that many sources of protein contribute to unsustainable agricultural practices, however, protein production from aquaculture can have a lower carbon footprint. Furthermore, the programme of work described here aims to contribute several UN sustainability goals, namely, UNSG 2 "End hunger, achieve food security and improved nutrition and promote sustainable agriculture" and UNSG 12: Life Below Water "Conserve and sustainably use the oceans, seas and marine resources for sustainable development".Once thought of as a luxury food item, today 1 million salmon meals are consumed in the UK each day with the industry growing from a couple of farms 50 years ago to around 200 now. Salmon is one of the UK's biggest food exports and said to be worth close to £1bn a year to the economy. Scotland is the world's third largest producer of farmed Atlantic salmon, producing >200,000 tonnes in 2020. The sector employs >11,000 jobs with the aspiration to double this by 2030. One of the factors that may hamper this goal is the occurrence of Harmful Algal Blooms (HABs) which can cause mass fish mortalities due to damage to gills, the presence of toxins and also oxygen depletion due to high biomass. This ambitious Project will accelerate the innovation of a protective system to eliminate algae before they can cause injury to salmon and significant financial loss.Over a number of years we have developed photocatalytic systems which, in the first instance destroyed algal and cyanobacteria toxins with potential applications in drinking water treatment. More recently we have advanced this technology to the elimination of harmful cyanobacteria and algae. Photocatalysis is a treatment that employs a catalyst that is activated by light bringing about the release of powerful hydroxyl radicals. One of the significant benefits of this type of treatment is that it does not require the addition of chemicals and the reactive radicals are very short lived (nano seconds) hence are predicted to have minimum negative impact on non-target species. While we have demonstrated the potential of photocatalysis as a novel treatment strategy for a range of microbes in water, the truly adventurous aspect of this investigation will be to unlock new knowledge of the phototaxis of harmful marine algae using very selective wavelengths. With continuing advancements in LED technologies very precise wavelengths can be obtained (c. 15 nm) throughout the visible light spectrum with readily variable light intensity. We will design a bioassay approach to screen known harmful algae to determine if specific LEDs can be used to lure the harmful algae towards the photocatalytic treatment system which will take the form of a curtain that can be deployed to protect salmon cages. The development of the protective curtain will be carried out through collaboration with international marine engineering experts OTAQ which will expedite design through to deployment of an engineered system suitable for harsh marine environment while also linking directly to the many test sites they are currently working with on salmon farms. The project team also includes experts from Scottish Association for Marine Sciences (SAMS) who have been working with the industry on early warning systems for HABs around salmon farms. The successful deployment of our proposed photocatalytic curtain requires accurate alerts of potentially hazardous algal bloom events. Working with SAMS from the outset will ensure the two novel technologies come together to protect salmon farms supporting future expansion of this important industry.