The responses of physical, chemical, and microbiology components on the water quality of Cirebon's estuaries during pre and post-COVID-19 pandemic.

The COVID-19 pandemic has led to significant societal disruptions, prompting the Indonesian government to implement various measures, including partial lockdowns or Community Activities Restrictions Enforcement (CARE), to curb the virus's spread. This research aims to assess the impact of various environmental parameters on Cirebon's estuaries, focusing on physical components (such as temperature, total solids [TS], and turbidity), chemical components (including pH, biochemical oxygen demand (BOD), dissolved oxygen (DO), nitrate, and phosphate), and microbiology components (specifically total coliforms). These comprehensive components have notably impacted environmental parameters during pre-, during, and post-COVID-19 pandemic based on the Water Quality Index (WQI) assessment in Cirebon's estuaries. In the port city of Cirebon, located on Java Island's northern coast, the water quality of three river estuaries Kesenden, Sukalila, and Kalijaga was analyzed before and after the CARE implementation. Water samples collected in 2019, 2020, 2022, and 2023 were evaluated against Class II water quality standards per Indonesian Government Regulation No. 22 of 2021. The assessment of WQI was determined using the National Sanitation Foundation Water Quality Index (NSF-WQI) technique revealing significant fluctuations and trends across various stations over the 2019-2023. In 2019, the water quality at Kesenden, Sukalila, and Kalijaga stations was recorded at 52.21, 56.40, and 53.36, respectively. By 2020, began of COVID 19, there was a noticeable decreasing of WQI, Sukalila sustained a "Moderate" classification with a WQI of 54.59, whereas Kesenden and Kalijaga witnessed declines with values recorded at 49.5 and 49.7, respectively. However, the peak-implementation of the CARE program in 2022 saw a drastic decline in water quality, with values dropping below the threshold in all observed stations, 23.97 in Kesenden, 23.10 in Sukalila, and 35.36 in Kalijaga. Meanwhile, the water quality in 2023 experienced increasing (remained in the poor category) with index values of 44.31, 35.14, and 42.0 at Kesenden, Sukalila, and Kalijaga, respectively. The findings underscore the complex interplay between human activities and environmental health, highlighting the need for sustainable practices and robust water management policies to mitigate the adverse effects of such disruptions. The results from the monitoring of ocean health pre- and post-the CARE implementation in the pandemic era have provided a unique opportunity to reflect on human behavior and its impact on the environment, emphasizing the importance of adopting pro-environmental behaviors to support sustainable development in the post-pandemic era. PRACTITIONER POINTS: The onset of the COVID-19 pandemic led to an improvement in water quality due to the reduction in industrial and human activities resulting CARE. The significant reduction in anthropogenic activities such as industry and transportation, which lead the improvement in DO, pH, and coliform because decreasing the phosphate, nitrate, turbidity, total solid, and BOD. The CARE program in 2022 and 2023, there was a marked decline in the water quality index across all monitoring stations in Cirebon. CARE period of reduced anthropogenic pressure offers valuable insights for policymakers to develop sustainable water management strategies to maintain and further improve water quality post-pandemic.