Evaluation of environmental impact of red tide around Pearl River Estuary, Guangdong, China.

This paper presents a case study of red tide hazards around the Pearl River Estuary (PRE). Red tide hazards, meteorological data, and seawater monitoring data were collected from 1996 to 2020 at different locations around the PRE to investigate the internal and external factors influencing the occurrence of red tides. The enhancement of the assessment of estuarine trophic status (ASSETS) method enables us to evaluate the effects of meteorological factors and seawater eutrophication status on the red tide risk level. Using ASSETS, we established a framework for red tide risk assessment of the Pearl River Estuary. We analysed the external and internal factors causing the red tide based on meteorological data and seawater monitoring data in the PRE. The results show that the temperature was higher than the annual monthly average temperature of 1.265 °C, and east and north winds at velocities of 3–4 m/s could result in the formation of red tides. However, precipitation inhibits the formation of the red tide in PRE. [Display omitted] • We analysed the interior factors and external factors effect on red tide occurrence. • The meteorological conditions suitable for algae growth in PRE area were proposed. • Forming mechanism of meteorological factors affecting red tide is described. • Relationship between nutrient concentration and red tide in PRE area was analysed. • ASSETS method was adopted to evaluate the red tide risk level. [ABSTRACT FROM AUTHOR]