Hydrological isolation accelerates algal blooms in floodplain lakes: biomarker evidence from Dongting Lake, China and its satellite lake

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL Water Research Pub Date : 2025-03-03 DOI:10.1016/j.watres.2025.123430

Linghan Zeng, Virginia N. Panizzo, Zekun Wang, Xianyu Huang, Xu Chen, Suzanne McGowan

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引用次数: 0

Abstract

Hydrological disconnection from main channels (either via natural siltation or due to construction of hydrological infrastructures) is modifying biogeochemical cycling in river-floodplain systems. Knowledge on how this process influences phytoplankton composition and harmful algal blooms (HABs) in floodplain lakes is quite scant due to the lack of long-term water quality monitoring and the concurrent influence of multiple drivers of change. Here, chlorophyll and carotenoid pigment biomarkers from dated sediment cores were analyzed from Dongting Lake (China's second largest freshwater lake) and one of its satellite lakes (Donghu) in the Yangtze floodplain, to evaluate the long-term influence of hydrological isolation on algal community composition and HABs. The results showed that pigment concentrations and the ratio of canthaxanthin/diatoxanthin (which reflects the relative abundance of cyanobacteria to diatoms) increased after the 1910s in Donghu Lake, when it was separated from Dongting Lake due to siltation. In contrast, significant increases in pigments started from the 1980s in Dongting Lake. Variance partitioning analysis revealed that the combined influence of hydrology, temperature and anthropogenic pollutants explained the largest proportion of variance (33.4%) in the pigment assemblages in Donghu Lake, followed by the joint effects of anthropogeny pollutants and hydrology (23.6%) and the sole effects of anthropogenic pollutants (14.9%) and hydrology (11.2%). In Dongting Lake, anthropogenic pollutants explained 24.5% of the variance in pigment assemblages solely, followed by the additive effects of anthropogenic pollutants and temperature (17.8%). These long-term analyses therefore demonstrate that, in combination with anthropogenic pollutants and warming, hydrological isolation from the main channel may stimulate algal production and the prevalence of cyanobacteria, whereas free hydrological connection with the Yangtze main channel seems to alleviate such HABs in these Yangtze floodplain lakes.

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来源期刊

Water Research 环境科学-工程：环境

CiteScore

20.80

自引率

9.40%

发文量

1307

审稿时长

38 days

期刊介绍： Water Research, along with its open access companion journal Water Research X, serves as a platform for publishing original research papers covering various aspects of the science and technology related to the anthropogenic water cycle, water quality, and its management worldwide. The audience targeted by the journal comprises biologists, chemical engineers, chemists, civil engineers, environmental engineers, limnologists, and microbiologists. The scope of the journal include: •Treatment processes for water and wastewaters (municipal, agricultural, industrial, and on-site treatment), including resource recovery and residuals management; •Urban hydrology including sewer systems, stormwater management, and green infrastructure; •Drinking water treatment and distribution; •Potable and non-potable water reuse; •Sanitation, public health, and risk assessment; •Anaerobic digestion, solid and hazardous waste management, including source characterization and the effects and control of leachates and gaseous emissions; •Contaminants (chemical, microbial, anthropogenic particles such as nanoparticles or microplastics) and related water quality sensing, monitoring, fate, and assessment; •Anthropogenic impacts on inland, tidal, coastal and urban waters, focusing on surface and ground waters, and point and non-point sources of pollution; •Environmental restoration, linked to surface water, groundwater and groundwater remediation; •Analysis of the interfaces between sediments and water, and between water and atmosphere, focusing specifically on anthropogenic impacts; •Mathematical modelling, systems analysis, machine learning, and beneficial use of big data related to the anthropogenic water cycle; •Socio-economic, policy, and regulations studies.