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Gao Y, Hao P, Wei Z, Li S, Song J, Yu C. Dynamic causes contribute to the increasing trend of red tides in the east China sea during 2020-2022. MARINE ENVIRONMENTAL RESEARCH 2024; 198:106521. [PMID: 38678753 DOI: 10.1016/j.marenvres.2024.106521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 03/30/2024] [Accepted: 04/16/2024] [Indexed: 05/01/2024]
Abstract
Red tide is a marine phenomenon caused by the excessive growth of microscopic algae in the ocean. This study aims to analyze the development trends of red tides in the past 20 years and the dynamic external causes that induce red tides based on existing satellite remote sensing and numerical simulation data. And the changes in dominant species of red tides in different seasons are analyzed. The results show significant temperature fluctuations within the week before the red tide occurs, with an average increase of 1.42 °C. In contrast, the change in salinity is relatively small. Meanwhile, ocean fronts are areas in the ocean where different water masses meet and form boundaries. The average strength of ocean fronts increased by 3.7%, indicating enhanced ocean mixing over a short period of time. Under the combined influence of these factors, the probability of a red tide outbreak in the East China Sea increases rapidly. Therefore, this study has important reference value for further research on the causes of red tides and their response to ocean dynamic changes.
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Affiliation(s)
- Yu Gao
- Ocean College, Zhejiang University, Zhoushan City, 316021, PR China
| | - Peng Hao
- Ocean College, Zhejiang University, Zhoushan City, 316021, PR China
| | - Zilu Wei
- Ocean College, Zhejiang University, Zhoushan City, 316021, PR China
| | - Shuang Li
- Ocean College, Zhejiang University, Zhoushan City, 316021, PR China.
| | - Jinbao Song
- Ocean College, Zhejiang University, Zhoushan City, 316021, PR China
| | - Chengcheng Yu
- Marine Science and Technology College, Zhejiang Ocean University, Zhoushan City, 316004, PR China
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Wang L, Lei X, Yuehua G, Zhou Y, Han JC, Huang Y, Li B, Mao XZ, Tang Z. A novel method of identifying estuary high-nutrient zones for water quality management. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169578. [PMID: 38154631 DOI: 10.1016/j.scitotenv.2023.169578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 11/13/2023] [Accepted: 12/19/2023] [Indexed: 12/30/2023]
Abstract
Coastal shallow waters are highly vulnerable to pollution, often leading to the development of intricate eutrophication zones. However, accurately determining these areas poses a significant challenge due to the complex interplay of estuarine hydrodynamics and nutrient transformation. To address such issue, a novel method was proposed to identify high-nutrient zones through calculating the continuous zonation of released tracers when their instantaneous concentrations declined to 1/e of their initial values. The method was well tested using idealized estuary models with varying shape parameters, water depths and river discharges. The results consistently revealed that the boundaries of high-nutrient zones fell within the mixed zone, characterized by salinity levels of 10- 20 psu. In Shenzhen Bay, a typical shallow bay, distinct differences were observed in the concentrations of dissolved inorganic nitrogen (DIN) and PO43-. Both the 20 psu isohaline and the proposed method effectively identified the partition boundary of high DIN and PO43- in 2001-2010, but only the newly proposed method demonstrated accuracy in delineating the actual high-nutrient zone during the continuous nutrient reduction period from 2010 to 2020. This study provides a practical and feasible approach that can serve as an auxiliary decision-making tool for managing estuarine water environments, and it has potential to facilitate the implementation of timely and effective measures for pollution control.
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Affiliation(s)
- Linlin Wang
- Water Science and Environmental Engineering Research Center, College of Chemical and Environmental Engineering, Shenzhen University, Shenzhen 518060, China; State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China
| | - Xiaoyu Lei
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Guo Yuehua
- CCCC First Navigation Bureau Ecological Engineering Co., Ltd., Shenzhen 518107, China
| | - Yang Zhou
- Water Science and Environmental Engineering Research Center, College of Chemical and Environmental Engineering, Shenzhen University, Shenzhen 518060, China
| | - Jing-Cheng Han
- Water Science and Environmental Engineering Research Center, College of Chemical and Environmental Engineering, Shenzhen University, Shenzhen 518060, China.
| | - Yuefei Huang
- State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China; Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining 810016, China
| | - Bing Li
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Xian-Zhong Mao
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Zhaozhao Tang
- Water Science and Environmental Engineering Research Center, College of Chemical and Environmental Engineering, Shenzhen University, Shenzhen 518060, China
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