Temporal and Spatial Patterns of Harmful Algae Affecting Scottish Shellfish Aquaculture
Temporal and Spatial Patterns of Harmful Algae Affecting Scottish Shellfish Aquaculture
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DOI：
10.3389/fmars.2021.785174
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发表时间：
2021-12-22
影响因子：
3.7
通讯作者：
Davidson, Keith
中科院分区：
文献类型：
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作者：
Gianella, Fatima;Burrows, Michael T.;Davidson, Keith
有害藻华（HAB）事件的一致模式在科学文献中并不明显，这表明局部或区域的变化可能对调节任何总体趋势都很重要。本研究总结了苏格兰范围内蓝贻贝（Mytilus edulis）中有害藻华和贝类生物毒素发生率的15年高时间频率时间序列（2006-2020年）的时空格局，这些数据是苏格兰食品标准（FSS）监管监测计划的一部分。探讨了全国年度赤潮事件和生物毒素与环境变量的关系。时间模式表现出年际变化，没有逐年增加，年际之间也没有相关性。夏季开花频率呈上升趋势，在7月达到高峰，在5 - 7月达到高峰。利用50 km网格单元逐月收集的监测数据，采用主成分分析（PCA）和聚类k -均值分析（聚类K-means）对其时空格局进行了多元统计分析。PCA分析表明，具有相似时间动态的区域之间存在相关性，季节性是影响赤潮变异的主要因素之一，其时空格局由第一主成分和第二主成分解释。利用k -均值聚类评价了开花时间和大小在区域间的相似模式。分析证实，有害藻华的最高风险通常发生在夏季，但表明以类似方式（高风险或低风险）作出反应的地区并不总是地理上接近。例如，最普遍的赤潮藻属Dinophysis spp.的发生情况在全国范围内是相似的，但在风险水平上存在区域趋势，“非常高”和“高”群集主要位于西南海岸、中部和北部西海岸岛屿以及设得兰群岛。“早”和“晚”开花也与某些地区和风险水平有关。总体而言，高风险区主要面向西南方向，低风险区主要面向南或东南方向。我们发现全国范围内环境变量与赤潮之间的关系相对较少，这证实了需要进行区域分析来支持赤潮预警。
Consistent patterns of Harmful Algal Bloom (HAB) events are not evident across the scientific literature, suggesting that local or regional variability is likely to be important in modulating any overall trend. This study summarizes Scotland-wide temporal and spatial patterns in a robust 15-year high temporal frequency time series (2006-2020) of the incidence of HABs and shellfish biotoxins in blue Mussels (Mytilus edulis), collected as part of the Food Standards Scotland (FSS) regulatory monitoring program. The relationship between the countrywide annual incidence of HAB events and biotoxins with environmental variables was also explored. Temporal patterns exhibited interannual variability, with no year-on-year increase, nor any correlation between annual occurrences. Within years, there was a summer increase in bloom frequency, peaking in July for Dinophysis spp. and Pseudo-nitzschia spp., and a plateau from May to July for Alexandrium spp. Temporal-spatial patterns were analyzed with multivariate statistics on data from monitoring sites aggregated monthly into 50-km grid cells, using Principal Component Analysis (PCA) and cluster K-means analysis. PCA analyses showed correlation between areas with similar temporal dynamics, identifying seasonality as one of the main elements of HAB variability with temporal-spatial patterns being explained by the first and second principal components. Similar patterns among regions in timing and magnitude of blooms were evaluated using K-means clusters. The analysis confirmed that the highest risk from HABs generally occurred during summer, but demonstrated that areas that respond in a similar manner (high or low risk) are not always geographically close. For example, the occurrence of the most prevalent HAB genus, Dinophysis spp., is similar countrywide, but there is a regional trend in risk level with "very-high" and "high" clusters located primarily on the southwest coast, the islands of the central and northern west coast and the Shetland Islands. "Early" and "late" blooms were also associated with certain areas and level of risk. Overall, high risk areas mainly face in a southwest direction, whilst low risk locations face a south or southeast direction. We found relatively few countrywide relationships between environmental variables and HABs, confirming the need for regional analysis to support HAB early warning.