Mitigating Microbial Hazards - Eliminating HABs risks in salmon farms

人类面临的最大全球挑战之一是在解决气候问题的同时确保可靠的蛋白质生产。由于认识到许多蛋白质来源会导致不可持续的农业做法，正在为全球蛋白质转型作出相当大的努力，然而，水产养殖生产的蛋白质可以产生较低的碳足迹。此外，这里所述的工作计划旨在促进若干联合国可持续发展目标，即联合国可持续发展目标2“消除饥饿，实现粮食安全和改善营养，促进可持续农业”和联合国可持续发展目标12：水下生命“保护和可持续利用海洋和海洋资源促进可持续发展”。三文鱼一度被认为是一种奢侈食品，如今英国每天消费100万份三文鱼餐，该行业从50年前的几个养殖场发展到现在的200个左右。三文鱼是英国最大的食品出口产品之一，据说每年对经济的价值接近10亿英镑。苏格兰是世界上第三大养殖大西洋鲑鱼生产国，到2020年将生产20万吨。该行业的就业人数为11000人，预计到2030年这一数字将翻一番。可能阻碍这一目标的因素之一是有害藻华（HABs）的发生，由于鳃受损、毒素的存在以及高生物量导致的氧气消耗，有害藻华可能导致大量鱼类死亡。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将其消灭。多年来，我们已经开发出光催化系统，在第一个实例中破坏藻类和蓝藻毒素，在饮用水处理中具有潜在的应用。最近，我们已经将这项技术先进到消除有害的蓝藻和藻类。光催化是一种使用一种催化剂的治疗方法，这种催化剂被光激活，释放出强大的羟基自由基。这种治疗的一个显著优点是它不需要添加化学物质，而且活性自由基的寿命很短（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作为一种治疗水中一系列微生物的新策略的潜力，但这项研究真正具有冒险精神的方面将是利用非常选择性的波长来解开有害海洋藻类的光敏性的新知识。随着LED技术的不断进步，可以在整个可见光光谱中获得非常精确的波长（约15纳米），并且可以随时改变光强度。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来引诱有害藻类进入光催化处理系统，该系统将采用窗帘的形式，可以展开来保护鲑鱼笼。保护罩的开发将通过与国际海洋工程专家OTAQ合作进行，这将加快设计到适合恶劣海洋环境的工程系统的部署，同时也直接连接到他们目前在鲑鱼养殖场工作的许多试验点。项目团队还包括来自苏格兰海洋科学协会（SAMS）的专家，他们一直在与该行业合作开发鲑鱼养殖场周围赤潮的预警系统。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，将确保这两种新技术结合起来，保护鲑鱼养殖场，支持这一重要产业的未来扩张。

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.