The COVID-19 lockdown significantly improved the global environmental quality by restricted anthropogenic activities. We aimed to understand the response of Indian coastal environmental quality and an estuarine (Zuari estuary, central west coast of India) water quality to the lockdown using satellite-derived data sets and in-situ measurements, respectively. The in-situ study was carried out for two weeks (during August and September 2020) to measure chlorophyll-a and macro-nutrients. Recent 5-years (2015–2019; March–August) data sets of aerosol optical depth (AOD), rainfall, air temperature, sea surface temperature (SST), chlorophyll-a, particulate inorganic carbon (PIC) and particulate organic carbon (POC) were compared with lockdown period (2020). The AOD was decreased during the lockdown period (23 ± 11%) as compared with recent 5-years shows the significant impact of lockdown on industrial, transport and urbanization activities. The water quality parameters and chlorophyll-a biomass have remained similar to the past data sets, indicating the insignificant effect of lockdown on these parameters. The results of the case study were compared with the previous reports, which showed a decrease in the concentration of nitrate, phosphate and silicate and comparable concentration of chlorophyll-a. Recent studies show significant impacts of lockdown on the atmospheric parameters and water quality parameters, however the present study did not observe any significant variations in the in-situ and satellite derived data sets of water quality and chlorophyll-a. We have discussed the possible reasons underlying in the less/undetectable response of the chlorophyll-a and water quality of the Indian coastal waters and estuaries during the lockdown.

COVID-19 封锁通过限制人为活动显着改善了全球环境质量。我们旨在分别使用卫星衍生数据集和原位测量来了解印度沿海环境质量和河口（Zuari 河口，印度中西海岸）水质对封锁的响应。原位研究进行了两周（2020 年 8 月和 9 月），以测量叶绿素a和常量营养素。最近5年（2015至2019年;三月月）气溶胶光学厚度的数据集（AOD），降雨，空气温度，海面温度（SST），叶绿素一个、颗粒无机碳 (PIC) 和颗粒有机碳 (POC) 与锁定期（2020 年）进行了比较。与最近 5 年相比，封锁期间的 AOD 下降 (23 ± 11%)，表明封锁对工业、交通和城市化活动的重大影响。水质量参数和叶绿素一个生物质仍然类似于过去的数据集，指示锁定对这些参数的影响不大。案例研究的结果与之前的报告进行了比较，之前的报告显示硝酸盐、磷酸盐和硅酸盐的浓度下降，而叶绿素a 的浓度相当. 最近的研究表明锁定对大气参数和水质参数显著的影响，但目前的研究并没有在-观察任何显著的变化原地和卫星获得的数据集水质和受叶绿素一个。我们已经讨论了在封锁期间叶绿素a和印度沿海水域和河口水质的反应较少/无法检测的潜在原因。