Variations of environmental parameters and zooplankton abundance in port dickson coastal waters over a decade of development

Environmental parameters and zooplankton abundance in Port Dickson coastal waters in 2010 were compared with those in 2020 to detect marine environmental changes over the 10-year period in this rapidly developing tourist destination. The first COVID-19 movement control order (MCO) began in March until June 2020, after which the MCO was relaxed to allow tourism. Turbidity, nutrients and chlorophyll-a were significantly higher in 2020 compared to those in 2010. Within the year 2020, nutrients and chlorophyll-a were relatively low immediately after the MCO, but steadily increased as human activities intensified in the area. Nutrient enrichments were highest in September 2020, approximately three months after the first MCO. With the increase of primary production, zooplankton density concomitantly increased from a mean density of 559.9 in.m-3 in 2010 to 2717.0 in.m-3 in 2020. In both years, copepods were the most dominant zooplankton group, contributing to 79.7% and 82.5% of the total zooplankton in 2010 and 2020, respectively. This study illustrated that Port Dickson coastal waters showed nutrient enrichment over the years. The temporary absence/decrease of human activities related to COVID-19 pandemic resulted in relatively low nutrients and chlorophyll-a, but rapidly increased again with the relaxation of the restrictive movement order. © 2023 Author(s).