Decadal and shorter period variability of surf zone water quality at Huntington Beach, California
Decadal and shorter period variability of surf zone water quality at Huntington Beach, California
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DOI：
10.1021/es020524u
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发表时间：
2002-09-15
影响因子：
11.4
通讯作者：
Wellman, DE
中科院分区：
文献类型：
--
作者：
Boehm, AB;Grant, SB;Wellman, DE
加利福尼亚州亨廷顿海滩冲浪区的粪便指示细菌浓度随着时间尺度的变化而变化，时间跨度至少有7个数量级，从几分钟到几十年。这种变异性的来源包括废水和干旱天气径流处理和处置的历史变化、厄尔尼诺事件、降雨量的季节变化、春季-小潮周期、阳光导致的细菌死亡以及近岸混合。平均而言，过去43年来，总大肠菌群浓度有所下降，尽管海岸线污染的点源(暴雨排水沟、河流排水口和海底排污口)继续导致水质暂时变差。这些瞬变点源通常持续5-8年，并受月相的影响，反映了潮汐对沿海海洋污染物来源和传输的影响，指示细菌对阳光非常敏感；因此，一天中采集样本的时间可能会影响水质测试的结果。这些结果表明，沿海水质是由当地和外部过程的复杂组合造成的，并对现有海洋洗浴水监测和报告方案的有效性提出了质疑。
The concentration of fecal indicator bacteria in the surf zone at Huntington Beach, CA, varies over time scales that span at least 7 orders of magnitude, from minutes to decades. Sources of this variability include historical changes in the treatment and disposal of wastewater and dry weather runoff, El Nino events, seasonal variations in rainfall, spring-neap tidal cycles, sunlight-induced mortality of bacteria, and nearshore mixing. On average, total coliform concentrations have decreased over the past 43 years, although point sources of shoreline contamination (storm drains, river outlets, and submarine outfalls) continue to cause transiently poor water quality. These transient point sources typically persist for 5-8 yr and are modulated by the phase of the moon, reflecting the influence of tides on the sourcing and transport of pollutants in the coastal ocean, Indicator bacteria are very sensitive to sunlight; therefore, the time of day when samples are collected can influence the outcome of water quality testing. These results demonstrate that coastal water quality is forced by a complex combination of local and external processes and raise questions about the efficacy of existing marine bathing water monitoring and reporting programs.