Zachry Department of Civil and Environmental Engineering, Texas A&M University, College Station, TX 77843, USA.
Zachry Department of Civil and Environmental Engineering, Texas A&M University, College Station, TX 77843, USA; Department of Environmental Engineering, National Cheng Kung University, Tainan 70101, Taiwan ROC.
J Hazard Mater. 2021 Jun 5;411:124953. doi: 10.1016/j.jhazmat.2020.124953. Epub 2020 Dec 26.
Unprecedented rainfall after Hurricane Harvey caused a catastrophic flood in the southern coast of Texas, and flushed significant floodwater and sediments into Galveston Bay, the largest estuary along the Texas Gulf Coast. This study investigated the immediate and long-term (6 months post-Harvey) fecal indicators, pathogenic bacteria, antibiotic resistance genes (ARGs), and ecotoxicity in the Galveston Bay. Dramatic decrease of salinity profile to zero, increased levels of fecal indicator bacteria and pathogenic bacteria, and detection of various ARGs were observed in the water and sediment samples collected 2 weeks post-Harvey. High levels of Bla and cytotoxicity measured by yeast bioluminescent assay (BLYR) were also observed especially near the river mouths. While Vibrio spp. was dominant in water, much higher abundance of fecal indicator bacteria and pathogen were detected in the sediments. A decreasing trend of Bla and cytotoxicity was observed in March 2018 samples, suggesting the Bay has returned to its pre-hurricane conditions 6 months post-Harvey. Interestingly, the abundance of fecal indicator bacteria and pathogens were shifted dramatically according to high-streamflow and low-streamflow seasons in the Bay. The data are useful to construct the model of risk assessment in coastal estuaries system and predict the effects of extreme flooding events in the future.
飓风哈维过后的强降雨，导致德克萨斯州南部海岸发生了灾难性洪灾，大量洪水和沉积物被冲入德克萨斯湾沿岸最大的河口加尔维斯顿湾。本研究调查了哈维飓风过后即刻及 6 个月（即时及长期）时加尔维斯顿湾的粪便指示物、致病菌、抗生素耐药基因（ARGs）和生态毒性。在哈维飓风过后 2 周采集的水样和沉积物样本中，观察到盐度剖面急剧降至零，粪便指示菌和致病菌水平升高，并且检测到各种 ARGs。通过酵母生物发光法（BLYR）测量，还观察到高 bla 和细胞毒性，尤其是在河口附近。虽然水中优势菌为弧菌属，但在沉积物中检测到更高丰度的粪便指示菌和致病菌。2018 年 3 月的样本中，bla 和细胞毒性呈下降趋势，表明海湾在哈维飓风过后 6 个月已恢复到飓风前的状况。有趣的是，海湾内高流量和低流量季节会导致粪便指示菌和致病菌的丰度发生显著变化。这些数据可用于构建沿海河口系统风险评估模型，并预测未来极端洪水事件的影响。
