Researchers Create More Complete Picture of Freshwater Toxic Algal Blooms
For Immediate Release
Using two different measurement methods, researchers from North Carolina State University conducted a two-year study of North Carolina’s Jordan Lake in which they monitored toxic algal blooms. The researchers found that multiple cyanotoxins from toxic algal blooms are present year-round, albeit in very low concentrations. Their findings could improve the ability to predict toxic blooms.
Freshwater algal blooms have increased due to nutrients from sources such as fertilizers and other agricultural runoff entering the water. While every algal bloom isn’t toxic – some algal species can produce both toxic and nontoxic blooms – toxic blooms can cause problems for swimmers and other recreational users in the form of rashes or allergic reactions.
“We’ve confirmed both that the toxins are there year-round and that multiple toxins are there simultaneously but in very low levels,” says Astrid Schnetzer, associate professor of marine, earth and atmospheric sciences at NC State and corresponding author of a paper describing the research. “First, let’s be clear that the presence of the toxins doesn’t affect drinking water – treatment plants scrub all of that out. Secondly, the amounts of toxins we did find are about an order of magnitude below safe levels, so that’s also good news.”
Schnetzer and former NC State graduate student Daniel Wiltsie wanted to know which cyanotoxins were present in Jordan Lake, a major drinking water reservoir in central North Carolina.
From 2014-16 Schnetzer and Wiltsie sampled the lake water in two ways: by taking discrete samples (in which water is collected in a container) and by using solid phase adsorption toxin tracking (SPATT) bags, which are left in the water for a period of days or weeks. SPATT bags contain an absorbent resin that captures dissolved toxins. “By using two methods we were better able to determine what the concentrations looked like over time,” Schnetzer says. “Algal blooms are ephemeral, so it’s possible to completely miss them if you only look at discrete sampling. SPATT bags give you data on how the toxins can accumulate and overlap.”
研究人员分析了五种不同毒素的样品，并发现了四种：微染色蛋白，Anatoxin-A，clindrospermopsin和β-N-甲基氨基 - L-丙氨酸（BMAA）。在86％的采样位点和44％的采样事件中检测到多种毒素。
Schnetzer说：“这项研究是第一个使用Spatt袋和抽样来评估水中毒素的研究。”“这是创建更好知识的方法的第一步，以真正了解这些花朵的频率和幅度。
“In the future, we want to have a better predictive capability regarding these blooms as well as the ability to identify new emerging toxins. The data may also help us determine risk from chronic low-level exposures, as well as tease out what risks derive from exposure to multiple toxins at once.”
该研究出现在Toxins并获得了城市水财团/水资源研究所（Grant 16-11-U）和北卡罗来纳州Sea Grant（5104348）的资金。Schnetzer是对应作家，Wiltsie是第一作者。这项研究是通过与北卡罗来纳州环境质量部水资源部的Jason Green，Mark Vander Borgh和Elizabeth Fensin建立合作伙伴关系的。
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Note to editors: An abstract of the paper follows
“Algal Blooms and Cyanotoxins in Jordan Lake, North Carolina”
Authors:Daniel Wiltsie, Astrid Schnetzer, North Carolina State University; Jason Green, Mark Vander Borgh, Elizabeth Fensin, North Carolina Department of Environmental Quality, Division of Water Resources
出版：毒素
Abstract：水道的富营养化导致全球蓝细菌有害藻类开花（蓝虫）的增长。湖泊中由于过量的藻类生物量而导致的水质恶化已得到充分证明（例如，水的清晰度，低氧条件），但在没有毒素信息的情况下，与氰毒素相关的健康风险仍然在很大程度上无法探索。这项研究是第一个记录在北卡罗来纳州的主要饮用水库的约旦湖中溶解的微囊蛋白蛋白，Anatoxin-A，cylindrospermopsin和β-N-甲基氨基-l-丙氨酸的存在。萨克西毒素的存在尚未得到证实。在2014年至2016年之间的44％的采样事件中检测到了86％的测试地点的多种毒素。尽管浓度很低，但生物体继续暴露于多种毒素引起了一些担忧。离散抽样和in-situtracking (Solid Phase Adsorption Toxin Tracking [SPATT]) revealed that microcystin and anatoxin were the most pervasive year-round. Between 2011 and 2016, summer and fall blooms were dominated by the same cyanobacterial genera, all of which are suggested producers of a single or multiple cyanotoxins. The study’s findings provide further evidence of the ubiquitous nature of cyanotoxins and discusses the challenges involved in linking CyanoHAB dynamics to specific environmental forcing factors.
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