School of the Environment, Geography and Geosciences, University of Portsmouth, Burnaby Road, Portsmouth, PO1 3QL, UK.
Cefas Laboratory, Pakefield Road, Lowestoft, Suffolk, NR33 OHT, UK.
Environ Monit Assess. 2020 Feb 18;192(3):184. doi: 10.1007/s10661-020-8138-0.
Increased concentrations of phosphorus (P) in riverine systems lead to eutrophication and can contribute to other environmental effects. Chalk rivers are known to be particularly sensitive to elevated P levels. We used high-frequency (daily) automatic water sampling at five distinct locations in the upper River Itchen (Hampshire, UK) between May 2016 and June 2017 to identify the main P species (including filterable reactive phosphorus, total filterable phosphorus, total phosphorus and total particulate phosphorus) present and how these varied temporally. Our filterable reactive phosphorus (considered the biologically available fraction) data were compared with the available Environment Agency total reactive phosphorus (TRP) values over the same sampling period. Over the trial, the profiles of the P fractions were complex; the major fraction was total particulate phosphorus with the mean percentage value ranging between 69 and 82% of the total P present. Sources were likely to be attributable to wash off from agricultural activities. At all sites, the FRP and Environment Agency TRP mean concentrations over the study were comparable. However, there were a number of extended time periods (1 to 2 weeks) where the mean FRP concentration (e.g. 0.62 mg L) exceeded the existing regulatory values (giving a poor ecological status) for this type of river. Often, these exceedances were missed by the limited regulatory monitoring procedures undertaken by the Environment Agency. There is evidence that these spikes of elevated concentrations of P may have a biological impact on benthic invertebrate (e.g. blue-winged olive mayfly) communities that exist in these ecologically sensitive chalk streams. Further research is required to assess the ecological impact of P and how this might have implications for the development of future environmental regulations.
河流水体中磷（P）浓度的增加会导致富营养化，并可能对其他环境产生影响。白垩河流通常对高磷水平特别敏感。我们在 2016 年 5 月至 2017 年 6 月期间，在英国汉普郡的上伊钦河（River Itchen）的五个不同位置，使用高频（每日）自动水质采样，以确定存在的主要 P 物种（包括可过滤性反应性磷、总可过滤磷、总磷和总颗粒磷）以及它们如何随时间变化。在同一采样期间，我们将可过滤性反应性磷（被认为是生物可利用的部分）数据与可用的环境署总反应性磷（TRP）值进行了比较。在整个试验过程中，P 分数的分布很复杂；主要分数是总颗粒磷，其平均百分比值在总磷的 69%至 82%之间。来源可能归因于农业活动的冲刷。在所有站点，研究期间 FRP 和环境署 TRP 的平均浓度相当。然而，有许多延长的时间段（1 到 2 周），平均 FRP 浓度（例如 0.62 毫克/升）超过了此类河流的现有监管值（生态状况不佳）。通常，环境署进行的有限监管监测程序会错过这些超过值。有证据表明，这些 P 浓度升高的峰值可能对存在于这些生态敏感的白垩溪流中的底栖无脊椎动物（例如蓝翅橄榄飞蝇）群落产生生物影响。需要进一步研究来评估 P 的生态影响，以及这可能对未来环境法规的制定产生哪些影响。
