Wan Alex H L, Wilkes Robert J, Heesch Svenja, Bermejo Ricardo, Johnson Mark P, Morrison Liam
Irish Seaweed Research Group, Ryan Institute and School of Natural Sciences, National University of Ireland, Galway, Co. Galway, Ireland.
Environmental Protection Agency, Castlebar, Co. Mayo, Ireland.
PLoS One. 2017 Jan 3;12(1):e0169049. doi: 10.1371/journal.pone.0169049. eCollection 2017.
Enrichment of nutrients and metals in seawater associated with anthropogenic activities can threaten aquatic ecosystems. Consequently, nutrient and metal concentrations are parameters used to define water quality. The European Union's Water Framework Directive (WFD) goes further than a contaminant-based approach and utilises indices to assess the Ecological Status (ES) of transitional water bodies (e.g. estuaries and lagoons). One assessment is based upon the abundance of opportunistic Ulva species, as an indication of eutrophication. The objective of this study was to characterise Ireland's Ulva blooms through the use of WFD assessment, metal concentrations and taxonomic identity. Furthermore, the study assessed whether the ecological assessment is related to the metal composition in the Ulva. WFD algal bloom assessment revealed that the largest surveyed blooms had an estimated biomass of 2164 metric tonnes (w/w). DNA sequences identified biomass from all locations as Ulva rigida, with the exception of New Quay, which was Ulva rotundata. Some blooms contained significant amounts of As, Cu, Cr, Pb and Sn. The results showed that all metal concentrations had a negative relationship (except Se) with the Ecological Quality Ratio (EQR). However, only in the case of Mn were these differences significant (p = 0.038). Overall, the metal composition and concentrations found in Ulva were site dependent, and not clearly related to the ES. Nevertheless, sites with a moderate or poor ES had a higher variability in the metals levels than in estuaries with a high ES.
与人为活动相关的海水中营养物质和金属的富集可能会威胁水生生态系统。因此，营养物质和金属浓度是用于定义水质的参数。欧盟的《水框架指令》（WFD）超越了基于污染物的方法，利用指标来评估过渡水体（如河口和泻湖）的生态状况（ES）。一种评估是基于机会性石莼属物种的丰度，作为富营养化的指标。本研究的目的是通过使用WFD评估、金属浓度和分类身份来表征爱尔兰的石莼藻华。此外，该研究评估了生态评估是否与石莼中的金属组成有关。WFD藻华评估显示，调查的最大藻华估计生物量为2164公吨（湿重）。DNA序列确定所有地点的生物量均为刚性石莼，新码头除外，其为圆石莼。一些藻华含有大量的砷、铜、铬、铅和锡。结果表明，除硒外，所有金属浓度与生态质量比（EQR）均呈负相关。然而，只有锰的这些差异具有显著性（p = 0.038）。总体而言，石莼中发现的金属组成和浓度因地点而异，与生态状况没有明显关系。尽管如此，生态状况中等或较差的地点的金属水平变化比生态状况良好的河口更大。
