Characteristics of phytoplankton assemblages and their relationship with environmental factors in the Qiongzhou Strait, China

• Published in: Marine pollution bulletin Vol. 205; p. 116560
• Main Authors: Geng, Xinzhuo, Jiang, Wenxian, Zhang, Mingwei, Liu, Wei, Liu, Xiaoshou
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2024
• Subjects: Assemblage structure; Diversity; Environmental factors; Phytoplankton; Qiongzhou Strait; Assemblage structure; Phytoplankton; Environmental factors; Diversity; Qiongzhou Strait
• ISSN: 0025-326X; 1879-3363; 1879-3363
• DOI: 10.1016/j.marpolbul.2024.116560

The characteristics and influencing factors of phytoplankton assemblages were analyzed in July (rainy season) and November (dry season) 2022 in the Qiongzhou Strait, China. A total of 68 species of phytoplankton belonging to 33 genera and 3 phyla were recorded. Diatom was the most dominant group. The broad-temperature widespread species were the most abundant. The dominant species in the rainy season were Skeletonema costatum, S. tropicum, Chaetoceros preseudocurvisetus and Thalassionema nitzschioides while those in the dry season were T. frauenfeldii, T. nitzschioides and Coscinodiscus granii. Phytoplankton cell abundance was significantly positively correlated with nitrite and total nitrogen concentrations, and negatively correlated with temperature and pH. Red tide algae occurred with high frequency. All sites were at eutrophic level except for 3 sites in the rainy season, which were at mesotrophic level. Therefore, there is a potential risk of red tides in the Qiongzhou Strait, which requires long-term monitoring and precautions. •Nutrient Quality Index was higher in the nearshore that that in the offshore.•Red tides species were dominant in both rainy and dry seasons.•Most of the sites of the Qiongzhou Strait were at eutrophication level.•The Qiongzhou Strait has a potential risk of red tides and requires precautions.