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Toxic algae and sea-loch sediments: A novel investigation to understand the influence of climate change on harmful algal blooms and aquaculture

有毒藻类和海湾沉积物：一项了解气候变化对有害藻华和水产养殖影响的新研究

基本信息

批准号：
BB/M026620/1
负责人：
William Edward Newns Austin
金额：
$ 28.24万
依托单位：
University of St Andrews
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2015
资助国家：
英国
起止时间：
2015 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=BB%2FM026620%2F1
关键词：
Toxic algae sea loch sediments

项目摘要

A worldwide threat to human health from shellfish aquaculture comes from harmful, and particularly biotoxin producing, marine phytoplankton (often termed harmful algal blooms, HABs). These biotoxins accumulate in the shellfish flesh and can reach harmful concentrations. Consumption of shellfish flesh contaminated with these toxins can pose a serious risk to human health.In Europe, human health is protected by the EU Shellfish Hygiene Directive which enforce a system of shellfish harvesting closures based on concentrations of shellfish toxins above a regulatory limit. Such closures have a marked negative impact on the economics of the industry and have been enforced in Scottish waters on an almost annual basis since routine monitoring began in 1991. The Scottish Government is currently promoting an expansion of the shellfish industry in Scottish, but there is currently no mechanism to assess the vulnerability of new sites to the impacts of HABs or climate change on their shellfish beds. Improved understanding of the processes that govern harmful phytoplankton dynamics and toxicity is therefore urgently required to allow better monitoring, assessment of risk and management of coastal waters to safeguard human health and promote the sustainability and expansion of the shellfish industry.A number of shellfish poisoning syndromes exist, of which, owing to the severity of the intoxication syndrome, paralytic shellfish poisoning (PSP) is one of the most important globally. This potentially fatal condition results from the ingestion of neurotoxins called saxitoxins. Dinoflagellates within the species complex Alexandrium tamarense are potent producers of PSP toxins worldwide including Scottish waters. Monitoring for the presence of PSP toxins in the UK began along the northeast coast of England in 1968 and was expanded along the Scottish coasts in 1990 in response to a major PSP event. In 1996 monitoring for the dinoflagellate genus Alexandrium in the water column was initiated revealing the occurrence of 'hot-spots' for both the detection of Alexandrium cells in the water column and PSP toxicity in shellfishRoutine monitoring has revealed considerable interannual variation both in the abundance of Alexandrium cells alongside a decreasing trend in the toxicity recorded in Scottish shellfish. The cause for this is currently unknown. The current challenge is to extend the Scottish record prior to 1990 to understand what happened in these environments over longer time-scales when good climate data are available to help understand potential forcing mechanisms.The dinoflagellate Alexandrium tamarense presents a unique opportunity to address this lack of data. As part of its sexual life cycle, at the end of its growing season, Alexandrium cells form zygotes which fuse to form a robust cyst. This cyst sinks to the seabed and overwinters on the sediment until the following year when it hatches and undergoes meiotic division to form vegetative cells and subsequent blooms. Not all of the cysts will hatch and cysts that remain in the sediment can act as a 'footprint' of the diversity of the Alexandrium bloom during preceding years. This sedimentary cyst record, particularly in the sheltered and restricted exchange environments of Scotland's sea-lochs where marine aquaculture is concentrated, holds the potential to inform our understanding of natural climate variability as well as preserving a record of the Alexandrium diversity.The project will therefore build a new capacity in HABs research and advice in relation to aquaculture and climate change. The project provides exciting new opportunities to link current understanding of HAB plankton dynamics available through monitoring programmes directly to the sedimentary record; thereby enabling the first systematic evaluation of the risks posed to aquaculture from viable HAB cysts in these sediments and how decadal variation may be influenced by climate change.

贝类水产养殖对全球人类健康的威胁来自有害的，特别是产生生物毒素的海洋浮游植物（通常称为有害藻华，HAB）。这些生物毒素积聚在贝类肉中，并可达到有害浓度。食用受这些毒素污染的贝类肉会对人类健康构成严重风险。在欧洲，人类健康受到欧盟贝类卫生指令的保护，该指令根据贝类毒素浓度超过监管限值强制执行贝类捕捞关闭制度。这种关闭对该行业的经济产生了明显的负面影响，自 1991 年开始例行监测以来，苏格兰水域几乎每年都会实施此类关闭。苏格兰政府目前正在推动苏格兰贝类产业的扩张，但目前没有机制来评估新地点对赤潮区或气候变化对其贝类床的影响的脆弱性。因此，迫切需要更好地了解控制有害浮游植物动态和毒性的过程，以便更好地监测、评估风险和管理沿海水域，以保障人类健康并促进贝类产业的可持续性和扩张。存在多种贝类中毒综合症，其中由于中毒综合症的严重性，麻痹性贝类中毒（PSP）是最重要的一种。全球。这种潜在的致命疾病是由于摄入了一种叫做石房蛤毒素的神经毒素造成的。塔玛亚历山大藻复合体中的甲藻是世界各地（包括苏格兰水域）PSP 毒素的有效产生者。英国于 1968 年开始在英格兰东北海岸对 PSP 毒素的存在进行监测，并于 1990 年扩大到苏格兰海岸，以应对重大的 PSP 事件。 1996 年，开始对水体中的亚历山大藻属进行监测，发现水体中的亚历山大藻细胞检测和贝类中的 PSP 毒性均出现“热点”。常规监测显示，亚历山大藻细胞的丰度存在显着的年际变化，而苏格兰贝类中记录的毒性呈下降趋势。目前尚不清楚其原因。当前的挑战是扩展 1990 年之前的苏格兰记录，以了解在更长的时间范围内这些环境中发生的情况，此时可以获得良好的气候数据，以帮助了解潜在的强迫机制。塔玛亚历山大藻为解决数据缺乏的问题提供了独特的机会。作为其性生命周期的一部分，在生长季节结束时，亚历山大细胞形成受精卵，这些受精卵融合形成坚固的囊肿。这种包囊沉入海底并在沉积物上越冬，直到第二年孵化并进行减数分裂形成营养细胞并随后开花。并非所有的包囊都会孵化，残留在沉积物中的包囊可以作为前几年亚历山大藻水华多样性的“足迹”。这种沉积包囊记录，特别是在海水养殖集中的苏格兰海湾的受庇护和受限交换环境中，有可能帮助我们了解自然气候变化以及保存亚历山大藻多样性的记录。因此，该项目将建立与水产养殖和气候变化有关的HAB研究和建议的新能力。该项目提供了令人兴奋的新机会，将当前通过监测计划获得的 HAB 浮游生物动态的理解直接与沉积记录联系起来；从而能够首次系统评估这些沉积物中的活 HAB 包囊对水产养殖造成的风险，以及气候变化如何影响年代际变化。