1
|
Wang F, Wang J, Cao T, Ji X, Yan J, Ding S, Chen N. Seasonal hypoxia enhances sediment iron-bound phosphorus release in a subtropical river reservoir. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 936:173261. [PMID: 38761934 DOI: 10.1016/j.scitotenv.2024.173261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 05/11/2024] [Accepted: 05/13/2024] [Indexed: 05/20/2024]
Abstract
Dams worldwide commonly accelerate the eutrophication of reservoirs. While the seasonal hypoxia in deep reservoirs is widely acknowledged, there is limited research on its impact on benthic phosphorus (P) cycling and P fraction release from the reservoir sediments. Here we show that seasonal hypoxia enhances sediment P release and P fluxes at the sediment-water interface (SWI) which might alter P dynamics in deep reservoirs. We conducted a detailed measurement of sediment P fractions through the SEDEX approach, combined with a labile P gradient analysis using the diffusive gradients in thin films (DGT) technique to understand P cycling patterns in sediments during the transition period from spring (oxic) to late summer (hypoxic) conditions. The sediment P pool was predominantly composed of iron-bound phosphorus (Fe-P, 76-80 %), primarily due to the widespread occurrence of lateritic red soil (rich in Fe2O3/MnO2) in subtropical areas. More organic-P was observed in summer compared to spring. A significant increase in labile P occurred at the depth of 0-4 cm and 0-1 cm in spring and summer, respectively, where sediment P release was primarily governed by the reduction of Fe-P and the generation of S2-. A higher apparent fluxes of phosphate across the SWI were observed in summer characterized by higher temperature and lower oxygen levels. The current results suggest that seasonal hypoxia was a crucial factor affecting P cycling and diffusion in deep reservoirs. These findings present important implications for the ecology and management of the watershed-coast ecosystem.
Collapse
Affiliation(s)
- Fenfang Wang
- Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China
| | - Jie Wang
- Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
| | - Taotao Cao
- Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
| | - Xiuwen Ji
- Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
| | - Jing Yan
- Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China
| | - Shiming Ding
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Nengwang Chen
- Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China.
| |
Collapse
|
2
|
Liu H, Zhang C, Yang W, Ru Z, Ding J, Jing Y, Li C. Assessing spatial heterogeneity of nutrient loads in a large shallow lake using a lattice Boltzmann water quality model. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 366:121587. [PMID: 38981272 DOI: 10.1016/j.jenvman.2024.121587] [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: 03/13/2024] [Revised: 06/04/2024] [Accepted: 06/23/2024] [Indexed: 07/11/2024]
Abstract
Nutrient loads in lakes are spatially heterogeneous, but current spatial analysis method are mainly zonal, making them subjective and uncertain. This study proposes a high-resolution model for assessing spatial differences in nutrient loads based on the lattice Boltzmann method. The model was applied to Dongping Lake in China. Firstly, the contribution rates of four influencing factors, including water transfer, inflow, wind, and internal load, were calculated at different locations in the lake. Then, their proportionate contributions during different intervals to the whole lake area were calculated. Finally, the cumulative load could be calculated for any location within the lake. The validation showed that the model simulated hydrodynamics and water quality well, with relative errors between the simulated and measured water quality data smaller than 0.45. Wind increased the nutrient loads in most parts of the lake. The loads tended to accumulate in the east central area where high-frequency circulation patterns were present. Overall, the proposed water quality model based on the lattice Boltzmann method was able to simulate seven indexes. Therefore, this model represents a useful tool for thoroughly assessing nutrient load distributions in large shallow lakes and could help refine lake restoration management.
Collapse
Affiliation(s)
- Haifei Liu
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Chuqi Zhang
- School of Environment, Beijing Normal University, Beijing 100875, China.
| | - Wei Yang
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Zhiming Ru
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Jiewei Ding
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Yuetong Jing
- School of Economics and Management, Harbin Normal University, Harbin 150500, China
| | - Cheng Li
- Qingdao 63 Middle School, Shandong Province 266199, China
| |
Collapse
|
3
|
Wang L, Shao H, Guo Y, Bi H, Lei X, Dai S, Mao X, Xiao K, Liao X, Xue H. Ecological restoration for eutrophication mitigation in urban interconnected water bodies: Evaluation, variability and strategy. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 365:121475. [PMID: 38905792 DOI: 10.1016/j.jenvman.2024.121475] [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: 03/27/2024] [Revised: 06/05/2024] [Accepted: 06/10/2024] [Indexed: 06/23/2024]
Abstract
Many urban water bodies grapple with low flow flux and weak hydrodynamics. To address these issues, projects have been implemented to form integrated urban water bodies via interconnecting artificial lake or ponds with rivers, but causing pollution accumulation downstream and eutrophication. Despite it is crucial to assess eutrophication, research on this topic in urban interconnected water bodies is limited, particularly regarding variability and feasible strategies for remediation. This study focused on the Loucun river in Shenzhen, comprising an pond, river and artificial lake, evaluating water quality changes pre-(post-)ecological remediation and establishing a new method for evaluating the water quality index (WQI). The underwater forest project, involving basement improvement, vegetation restoration, and aquatic augmentation, in the artificial lake significantly reduced total nitrogen (by 43.58%), total phosphorus (by 79.17%) and algae density (by 36.90%) compared to pre-remediation, effectively controlling algal bloom. Rainfall, acting as a variable factor, exacerbated downstream nutrient accumulation, increasing total phosphorus by 4.56 times and ammonia nitrogen by 1.30 times compared to the dry season, and leading to algal blooms in the non-restoration pond. The improved WQI method effectively assesses water quality status. The interconnected water body exhibits obvious nutrient accumulation in downstream regions. A combined strategy that reducing nutrient and augmenting flux was verified to alleviate accumulation of nutrients downstream. This study provides valuable insights into pollution management strategies for interconnected pond-river-lake water bodies, offering significant reference for nutrient mitigation in such urban water bodies.
Collapse
Affiliation(s)
- Linlin Wang
- College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China
| | - Huaihao Shao
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Yuehua Guo
- China Communications First Harbor Bureau Ecological Engineering Co., LTD, Shenzhen, 518055, China
| | - Hongsheng Bi
- University of Maryland Center for Environmental Science, Chesapeake Bay Laboratory, Solomons, MD, 20688, USA
| | - Xiaoyu Lei
- Department of Research Affairs, Shenzhen MSU-BIT University, Shenzhen, 518055, China
| | - Shuangliang Dai
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Xianzhong Mao
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Kai Xiao
- State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Xiaomei Liao
- College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China.
| | - Hao Xue
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
| |
Collapse
|
4
|
Theis S, Chreston A, Wallace A, Graham B, Coey B, Little D, Cartwright L, Poesch M, Portiss R, Ruppert J. Nearshore fish community changes along the Toronto waterfront in accordance with management and restoration goals: Insights from two decades of monitoring. PLoS One 2024; 19:e0298333. [PMID: 38408042 PMCID: PMC10896508 DOI: 10.1371/journal.pone.0298333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 01/22/2024] [Indexed: 02/28/2024] Open
Abstract
Aquatic habitat in the Greater Toronto Area has been subject to anthropogenic stressors. The subsequent aquatic habitat degradation that followed led to the Toronto and Region waterfront being listed as an Area of Concern in 1987. Thus, extensive shoreline and riparian habitat restoration have been implemented as part of the Toronto and Region Remedial Action Plan in conjunction with local stakeholders, ministries, and NGOs in an overall effort to increase fish, bird, and wildlife habitat. A key aspect of current fish habitat restoration efforts, monitored by Toronto and Region Conservation Authority, is to account for long-term community changes within the target ecosystem to better understand overall changes at a larger spatial scale. Here we use electrofishing data from the past 20 years with over 100,000 records and across 72km of coastline to show how declines and fluctuations in fish biomass and catch along the waterfront are driven by a few individual species across three main ecotypes, such as coastal wetlands, embayments, and open coast sites, with the remaining species showing a high level of stability. Using community traits and composition for resident species we demonstrate native warmwater species have become more dominant along the waterfront in recent years, suggesting that restoration efforts are functioning as intended. Additionally, piscivore and specialist species have increased in their relative biomass contribution, approaching existing restoration targets. Altogether this waterfront-wide evaluation allows us to detect overall changes along the waterfront and can be beneficial to understand community changes at an ecosystem level when implementing and monitoring restoration projects.
Collapse
Affiliation(s)
- Sebastian Theis
- Fisheries and Aquatic Conservation Lab, Faculty of Agricultural, Life and Environmental Sciences, University of Alberta, Edmonton, Alberta, Canada
- Toronto and Region Conservation Authority, Watershed Planning and Ecosystem Science, North York, Ontario, Canada
| | - Andrea Chreston
- Toronto and Region Conservation Authority, Watershed Planning and Ecosystem Science, North York, Ontario, Canada
| | - Angela Wallace
- Toronto and Region Conservation Authority, Watershed Planning and Ecosystem Science, North York, Ontario, Canada
| | - Brian Graham
- Toronto and Region Conservation Authority, Watershed Planning and Ecosystem Science, North York, Ontario, Canada
| | - Brynn Coey
- Toronto and Region Conservation Authority, Watershed Planning and Ecosystem Science, North York, Ontario, Canada
| | - Don Little
- Toronto and Region Conservation Authority, Watershed Planning and Ecosystem Science, North York, Ontario, Canada
| | - Lyndsay Cartwright
- Toronto and Region Conservation Authority, Watershed Planning and Ecosystem Science, North York, Ontario, Canada
| | - Mark Poesch
- Fisheries and Aquatic Conservation Lab, Faculty of Agricultural, Life and Environmental Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Rick Portiss
- Toronto and Region Conservation Authority, Watershed Planning and Ecosystem Science, North York, Ontario, Canada
| | - Jonathan Ruppert
- Toronto and Region Conservation Authority, Watershed Planning and Ecosystem Science, North York, Ontario, Canada
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
5
|
Theis S, Poesch M. Mitigation bank applications for freshwater systems: Control mechanisms, project complexity, and caveats. PLoS One 2024; 19:e0292702. [PMID: 38319907 PMCID: PMC10846733 DOI: 10.1371/journal.pone.0292702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 09/26/2023] [Indexed: 02/08/2024] Open
Abstract
Biodiversity and mitigation banking has become a popular alternative offsetting mechanism, especially for freshwater species and systems. Central to this increase in popularity is the need for sound control mechanisms to ensure offset functionality. Two commonly used mechanisms are monitoring requirements and staggered release of bank credits over time. We used data from 47 banks in the United States, targeting freshwater systems and species. Based on the 47 banks meeting our criteria we showed that control mechanisms generally scale with increased project complexity and that banks release most of their total credit amount within the first 3 years. We further showed that advance credits are common and can increase the potential for credit release without providing tangible ecological benefits. Physical and biological assessment criteria commonly used by banks let us identify three main bank types focusing on connectivity, physical aspects, and habitat and species and their application possibilities and caveats to provide different ecosystem benefits for freshwater species and systems affected by anthropogenic development.
Collapse
Affiliation(s)
- Sebastian Theis
- Fisheries and Aquatic Conservation Lab, Faculty of Agricultural, Life and Environmental Sciences, University of Alberta, Edmonton, Canada
| | - Mark Poesch
- Fisheries and Aquatic Conservation Lab, Faculty of Agricultural, Life and Environmental Sciences, University of Alberta, Edmonton, Canada
| |
Collapse
|
6
|
van Wijk D, Chang M, Janssen ABG, Teurlincx S, Mooij WM. Regime shifts in shallow lakes explained by critical turbidity. WATER RESEARCH 2023; 242:119950. [PMID: 37348422 DOI: 10.1016/j.watres.2023.119950] [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: 06/29/2022] [Revised: 03/13/2023] [Accepted: 04/06/2023] [Indexed: 06/24/2023]
Abstract
Worldwide, water quality managers target a clear, macrophyte-dominated state over a turbid, phytoplankton-dominated state in shallow lakes. The competition mechanisms underlying these ecological states were explored in the 1990s, but the concept of critical turbidity seems neglected in contemporary water quality models. In particular, a simple mechanistic model of alternative stable states in shallow lakes accounting for resource competition mechanisms and critical turbidity is lacking. To this end, we combined Scheffer's theory on critical turbidity with insights from nutrient and light competition theory founded by Tilman, Huisman and Weissing. This resulted in a novel graphical and mathematical model, GPLake-M, that is relatively simple and mechanistically understandable and yet captures the essential mechanisms leading to alternative stable states in shallow lakes. The process-based PCLake model was used to parameterize the model parameters and to test GPLake-M using a pattern-oriented strategy. GPLake-M's application range and position in the model spectrum are discussed. We believe that our results support the fundamental understanding of regime shifts in shallow lakes and provide a starting point for further mechanistic and management-focused explorations and model development. Furthermore, the concept of critical turbidity and the relation between light-limited submerged macrophytes and nutrient-limited phytoplankton might provide a new focus for empirical aquatic ecological research and water quality monitoring programs.
Collapse
Affiliation(s)
- Dianneke van Wijk
- Water Systems and Global Change Group, Wageningen University & Research, Wageningen, the Netherlands; Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, the Netherlands; Aquatic Ecology and Water Quality Management Group, Wageningen University & Research, Wageningen, the Netherlands.
| | - Manqi Chang
- Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, the Netherlands; Yangtze Eco-Environment Engineering Research Center, China Three Gorges Corporation, 100038, Beijing, China
| | - Annette B G Janssen
- Water Systems and Global Change Group, Wageningen University & Research, Wageningen, the Netherlands
| | - Sven Teurlincx
- Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, the Netherlands
| | - Wolf M Mooij
- Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, the Netherlands; Aquatic Ecology and Water Quality Management Group, Wageningen University & Research, Wageningen, the Netherlands
| |
Collapse
|
7
|
Mitwally H, Rashidy HE, Montagna P. Linkages between pelagic and benthic biota in a deteriorated coastal lake after restoration, Maruit, Egypt. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 195:919. [PMID: 37405573 PMCID: PMC10322792 DOI: 10.1007/s10661-023-11525-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 06/17/2023] [Indexed: 07/06/2023]
Abstract
Until the 1960s, Lake Maruit was one of Egypt's most productive coastal brackish lakes. Continuous polluted discharge from Alexandria city resulted in long-term deterioration. The Egyptian government started a lake restoration program in 2010. Biological linkages between pelagic and benthic communities were assessed in November 2012 using parasitism and predation. This study examined ectoparasites infesting tilapia fish from 300 samples. The platyhelminth ectoparasite, Monogenea, and parasitic-copepod Ergasilus lizae were detected. Platyhelminthes parasitized Oreochromis niloticus and Oreochromis aureus, whereas the crustacean parasitized Coptodon zillii. The parasitic prevalence was low for Cichlidogyrus sp. and Ergasilus lizae. Benthic biotas were similar across basins. Fish abundance does not respond directly to benthic biotic components. Phytoplankton and benthic microalgae were not the main fish diet. Data on Halacaridae and fish clustered, indicating that either Halacaridae responds to their environment like fish or fish prey upon them because of their size. Linear correlations between pelagic, benthic biota, and parasite-infected fish indicate parasites may control their hosts. Some bioindicators indicate that stressed ecosystems differ from unstressed ecosystems. Fish species and biota abundances were low. Inconsistency in the food web and an absence of direct interactions between prey and predators are bioindicators of disturbed ecosystems. The low prevalence of ectoparasites and lack of heterogenous distribution of the various examined biota are bioindicators of habitat rehabilitation. Ongoing biomonitoring to better understand habitat rehabilitation is suggested.
Collapse
Affiliation(s)
- Hanan Mitwally
- Oceanography Department, Faculty of Science, Alexandria University, Alexandria, Egypt.
| | - Hoda El Rashidy
- Oceanography Department, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Paul Montagna
- Harte Research Institute, Texas A&M University-Corpus Christi, Corpus Christi, TX, USA
| |
Collapse
|
8
|
Deng J, Shan K, Shi K, Qian SS, Zhang Y, Qin B, Zhu G. Nutrient reduction mitigated the expansion of cyanobacterial blooms caused by climate change in Lake Taihu according to Bayesian network models. WATER RESEARCH 2023; 236:119946. [PMID: 37084577 DOI: 10.1016/j.watres.2023.119946] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 04/04/2023] [Accepted: 04/05/2023] [Indexed: 05/03/2023]
Abstract
Although nutrient reduction has been used for lake eutrophication mitigation worldwide, the use of this practice alone has been shown to be less effective in combatting cyanobacterial blooms, primarily because of climate change. In addition, quantifying the climate change contribution to cyanobacterial blooms is difficult, further complicating efforts to set nutrient reduction goals for mitigating blooms in freshwater lakes. This study employed a continuous variable Bayesian modeling framework to develop a model to predict spring cyanobacterial bloom areas and frequencies (the responses) using nutrient levels and climatic factors as predictors. Our results suggested that both spring climatic factors (e.g., increasing temperature and decreasing wind speed) and nutrients (e.g., total phosphorus) played vital roles in spring blooms in Lake Taihu, with climatic factors being the primary drivers for both bloom areas and frequencies. Climate change in spring had a 90% probability of increasing the bloom area from 35 km2 to 180 km2 during our study period, while nutrient reduction limited the bloom area to 170 km2, which helped mitigate expansion of cyanobacterial blooms. For lake management, to ensure a 90% probability of the mean spring bloom areas remaining under 154 km2 (the 75th percentile of the bloom areas in spring), the total phosphorus should be maintained below 0.073 mg·L-1 under current climatic conditions, which is a 46.3% reduction from the current level. Our modeling approach is an effective method for deriving dynamic nutrient thresholds for lake management under different climatic scenarios and management goals.
Collapse
Affiliation(s)
- Jianming Deng
- Taihu Laboratory for Lake Ecosystem Research, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Kun Shan
- Chongqing Key Laboratory of Big Data and Intelligent Computing, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
| | - Kun Shi
- Taihu Laboratory for Lake Ecosystem Research, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Song S Qian
- Department of Environmental Sciences, University of Toledo, Toledo, Ohio OH 43606, USA
| | - Yunlin Zhang
- Taihu Laboratory for Lake Ecosystem Research, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Boqiang Qin
- Taihu Laboratory for Lake Ecosystem Research, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
| | - Guangwei Zhu
- Taihu Laboratory for Lake Ecosystem Research, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| |
Collapse
|
9
|
Tan L, Wang Z, Bai Y, Huang X. Short-term responses of nutrients and algal biomass in a eutrophic shallow lake to different scales of water transfer. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 880:163321. [PMID: 37030389 DOI: 10.1016/j.scitotenv.2023.163321] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 04/02/2023] [Accepted: 04/02/2023] [Indexed: 04/15/2023]
Abstract
With the expansion of water transfer projects worldwide, the original hydrological and physicochemical states of the systems receiving the transferred water have experienced dynamic temporal and spatial changes, especially shallow lakes with that are more vulnerable to these changes. Understanding the short-term response of lakes to human-managed water transfer events can provide specific information on the seasonal regularity and long-term evolution pattern of lakes. The present study selected an annual water transfer event that is uniform and relatively independent. Then, field monitoring was conducted, and a hydrodynamic-eutrophication model was established to investigate the effects of the water transfer scales and regulation on TN, TP and algal biomass in Lake Nansi, a main regulating lake on the eastern route of the South-to-North Water Transfer Project (SNWDP-ER), China. The results showed that the timing of the water transfer event had an important effect on the enrichment of algal biomass. When the water transfer occurred in the spring, algal growth increased, but the reverse occurred in the summer. Under a high P concentration and the current management regulations (TP 0.05 mg/L), an algal bloom resulted in 21 % and 22 % increases in Chl-a and TP in the receiving system. When the inflow rate increased to the maximum level (100 m3/s), the algal biomass in the first mixing zone was briefly diluted, but the subsequent deterioration in water quality in the first mixing zone was more significant. Sixty days after the water transfer event began, the proportion of middle eutrophication (26 ≤ Chl-a < 160 μg/L) increased from 84 % to 92 %. The results emphasize the importance of water transfer scales on water quality in shallow lakes and provide a reference for determining the long-term stability and maintenance of specific ecosystems and optimization of water transfer practices.
Collapse
Affiliation(s)
- Lang Tan
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210029, China; College of Water Resource & Hydropower, Sichuan University, Chengdu 610065, China
| | - Zongzhi Wang
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210029, China.
| | - Ying Bai
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210029, China
| | - Xiaorong Huang
- College of Water Resource & Hydropower, Sichuan University, Chengdu 610065, China
| |
Collapse
|
10
|
Costa RA, Ferragut C. Epipelon biomass responses to different restoration techniques in a eutrophic environment. ENVIRONMENTAL MANAGEMENT 2023:10.1007/s00267-023-01811-2. [PMID: 36964450 DOI: 10.1007/s00267-023-01811-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 03/13/2023] [Indexed: 06/18/2023]
Abstract
Eutrophication is a worldwide problem. In eutrophic lakes, phosphorus release from stored sediment hinders restoration processes. The epipelon is a community that grows attached to the sediment surface and has the potential to help phosphorus retention by autotrophic organisms. This study evaluated epipelon responses to four lake restoration techniques. The responses of abiotic variables and phytoplankton biomass were also evaluated. Four simultaneous mesocosm experiments were performed in a shallow eutrophic lake. The applied techniques were aeration, flocculant, floating macrophytes, and periphyton bioreactor. Water and epipelon samples were taken on days 3, 10, 17, 27, and 60. The aeration treatment and macrophytes decreased light availability in the epipelon, which had a predominance of heterotrophic components. Flocculant and periphyton bioreactor treatments favored epipelon growth with a higher contribution of autotrophic components. Therefore, some techniques may favor the epipelon growth, while others may harm the community, resulting in less efficient restoration processes. For the complete restoration of a lacustrine ecosystem, the choice of techniques to be applied must consider the restoration and maintenance of the benthic environment.
Collapse
Affiliation(s)
- Renata Aparecida Costa
- Programa de Pós-graduação em Biodiversidade Vegetal e Meio Ambiente, Instituto de Pesquisas Ambientais, Av. Miguel Stéfano, 3687, Água Funda, CEP 04301-902, São Paulo, SP, Brasil.
| | - Carla Ferragut
- Programa de Pós-graduação em Biodiversidade Vegetal e Meio Ambiente, Instituto de Pesquisas Ambientais, Av. Miguel Stéfano, 3687, Água Funda, CEP 04301-902, São Paulo, SP, Brasil
- Instituto de Pesquisas Ambientais, Núcleo de Conservação da Biodiversidade, Av. Miguel Stéfano, 3687, Água Funda, CEP 04301-902, São Paulo, SP, Brasil
| |
Collapse
|
11
|
Zanor GA, Lecomte KL, Jesús Puy Y Alquiza M, Saldaña-Robles A, Manjarrez-Rangel CS, Rubio-Jiménez CA, Pussetto N. A 16th century artificial reservoir under human pressure: water quality variability assessment in Laguna de Yuriria, central Mexico. ENVIRONMENTAL MONITORING AND ASSESSMENT 2022; 195:182. [PMID: 36481823 DOI: 10.1007/s10661-022-10782-6] [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: 09/04/2022] [Accepted: 11/25/2022] [Indexed: 06/17/2023]
Abstract
This study assesses the variability of physicochemical and biochemical parameters, identifies principal pollutant sources, and characterizes water quality in Yuriria reservoir using water quality indexes in combination with multivariate statistical techniques. In situ parameters were measured in 55 reservoir sites including surface and deep points and in 7 associated channels. Moreover, major compounds and biochemical data were determined. Yuriria reservoir had alkaline, bicarbonate-mixed waters, with total dissolved solids (TDS) of 393.83 ± 3.43 mg L-1. Water quality index (WQI) indicated a good class for agricultural irrigation but very poor and poor classes for preservation of aquatic life. The nutrient inputs and the internal nitrogen recycling triggered a hypereutrophic status in the reservoir. The decomposition of residual biomass from aquatic macrophytes contributed to reduce dissolved oxygen (DO) in the hypolimnetic waters (mean DO = 3.86 mg L-1). Statistical analysis revealed that the study area is highly exposed to anthropogenic stress and in a lesser extent to natural processes. Urban and agriculture runoff enhanced the salinization and the generation of solid particles which deteriorated water quality. Chemical oxygen demand (COD), biochemical oxygen demand (BOD), and NO3--N presented a common anthropogenic origin by external (point and diffuse) and internal pollution sources, while a diffuse source (agricultural activities) was reveled for phosphorus. This study is important to be used in systematic monitoring and sustainable co-management programs and for formulating the necessary strategies to remediate the Yuriria reservoir water quality and extrapolate to other reservoirs worldwide.
Collapse
Affiliation(s)
- Gabriela A Zanor
- Departamento de Ciencias Ambientales, División de Ciencias de la Vida (DICIVA), Universidad de Guanajuato, Ex Hacienda El Copal, Km 9 Carretera Irapuato-Silao AP. 311, CP. 36500, Irapuato, Guanajuato, México.
- Posgrado en Biociencias, División de Ciencias de La Vida (DICIVA), Universidad de Guanajuato, Ex Hacienda El Copal, Km 9 Carretera Irapuato-Silao AP. 311, CP. 36500, Irapuato, Guanajuato, México.
| | - Karina L Lecomte
- Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Av. Vélez Sarsfield 1611 (X5016GCA), Córdoba, Argentina
- Centro de Investigaciones en Ciencias de La Tierra (CICTERRA), CONICET-UNC. Av. Vélez Sarsfield 1611 (X5016GCA), Córdoba, Argentina
| | - María Jesús Puy Y Alquiza
- Departamento de Ingeniería en Minas, División de Ingenierías, Universidad de Guanajuato, Metalurgia y Geología, Ex Hacienda de San Matías S/N, CP. 36020, Guanajuato, Guanajuato, México
| | - Adriana Saldaña-Robles
- Posgrado en Biociencias, División de Ciencias de La Vida (DICIVA), Universidad de Guanajuato, Ex Hacienda El Copal, Km 9 Carretera Irapuato-Silao AP. 311, CP. 36500, Irapuato, Guanajuato, México
- Departamento de Ingeniería Agrícola, División de Ciencias de la Vida (DICIVA), Universidad de Guanajuato, Ex Hacienda El Copal, Km 9 Carretera Irapuato-Silao AP. 311, CP. 36500, Irapuato, Guanajuato, México
| | - Cinthya Soledad Manjarrez-Rangel
- Posgrado en Biociencias, División de Ciencias de La Vida (DICIVA), Universidad de Guanajuato, Ex Hacienda El Copal, Km 9 Carretera Irapuato-Silao AP. 311, CP. 36500, Irapuato, Guanajuato, México
| | - Carlos Alberto Rubio-Jiménez
- Departamento de Ciencias Ambientales, División de Ciencias de la Vida (DICIVA), Universidad de Guanajuato, Ex Hacienda El Copal, Km 9 Carretera Irapuato-Silao AP. 311, CP. 36500, Irapuato, Guanajuato, México
| | - Nathalie Pussetto
- Instituto Nacional del Agua (INA) Subgerencia Centro de la Región Semiárida, Av. Ambrosio Olmos 1142, X5000JGT, Córdoba, Argentina
| |
Collapse
|
12
|
Lu H, Yang L, Fan Y, Qian X, Liu T. Novel simulation of aqueous total nitrogen and phosphorus concentrations in Taihu Lake with machine learning. ENVIRONMENTAL RESEARCH 2022; 204:111940. [PMID: 34599896 DOI: 10.1016/j.envres.2021.111940] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 06/17/2021] [Accepted: 08/20/2021] [Indexed: 06/13/2023]
Abstract
This study demonstrates the utility of internal nutrient loads as an additional parameter to improve the performance of machine learning models in predicting the temporal variations of aqueous TN and TP concentrations in Taihu Lake, a large shallow lake. Internal loads, as a potential input parameter for machine learning models, were estimated using a mass balance calculation. The results showed that between 2011 and 2018 the maximum monthly internal loads of nitrogen and phosphorus in Taihu Lake were 4200 t and 178 t, respectively. Monthly changes in the aqueous TN and TP concentrations of Taihu Lake did not correlate significantly with inflow loads whereas the correlations with estimated internal loads were positive and significant. Long short-term memory (LSTM), random forest (RF), and gradient boosting regression tree (GBRT) models were built, and for all of them the inclusion of internal loads in the input parameters improved their performance. LSTM model III, whose input parameters included both inflow loads and internal loads, had the best performance, based on a testing root mean square error of 0.11 mg TN/L and 0.017 mg TP/L. A 28 % decrease in the annual aqueous TP concentration in Taihu Lake in 2018 simulated by LSTM model III was achieved by lowering the average water level from 3.29 m to 2.99 m, suggesting a possible strategy to control the TP concentration in the lake. In summary, our study showed that aqueous TN and TP concentrations in shallow lakes can be simulated using machine learning, with LSTM models outperforming RF and GBRT models; in these models, internal loads should be included as an input parameter. Additionally, our study identified the water level as an important factor affecting the aqueous TP concentration in Taihu Lake.
Collapse
Affiliation(s)
- Hao Lu
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Liuyan Yang
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Yifan Fan
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Xin Qian
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
| | - Tong Liu
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
| |
Collapse
|
13
|
Guo Y, Dong Y, Chen Q, Wang S, Ni Z, Liu X. Water inflow and endogenous factors drove the changes in the buffering capacity of biogenic elements in Erhai Lake, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150343. [PMID: 34571238 DOI: 10.1016/j.scitotenv.2021.150343] [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: 06/26/2021] [Revised: 09/09/2021] [Accepted: 09/10/2021] [Indexed: 06/13/2023]
Abstract
Buffering capacity could provide a comprehensive view to recognize the response between external loads and water quality and help address the significant challenges associated with the reduction of lake pollution. However, quantification of the dynamic change in the holistic buffering capacity of biogenic elements in lakes and its driving mechanisms has not been fully understood. Taking Erhai Lake in China as an example, this study quantified the long-term (2000-2019) dynamic changes in buffering capacity and revealed key driving forces for the changes in buffering capacity. The results showed that nitrogen buffering capacity (NBC) and organic buffering capacity (CODBC) decreased during the past 20 years, while phosphorus buffering capacity (PBC) did not change significantly. Endogenous factors are the main controlling factors of buffering capacity. Specifically, algal biomass drove the change in NBC (interpretation rate of 62.2%); the adsorption and sedimentation effects of sediments maintained the relative stability of PBC (56.30%) while algal biomass indirectly impacted the PBC (1.69% only) by affecting the redox environment of the sediments; and algae-derived organic matter and refractory organic matter accumulation dominated the change in CODBC (61.4% and 32.8%, respectively). Water inflow is another controlling factor for NBC and CODBC due to dilution of lake water. This study indicated that the accumulation of endogenous loads and a decrease in water inflow drove the decrease in the lake's buffering capacity (mainly NBC and CODBC), which could help explain why the decrease in external loads in Erhai Lake has not yet reversed the trend of water quality decline. Our study highlights the importance of comprehensive buffering capacity improvement instead of simple external load control to optimize lake environmental management. In the future, attention should be given to controlling endogenous loads, especially preventing algal blooms, and to optimizing hydrodynamic conditions to cope with the decrease in water inflow.
Collapse
Affiliation(s)
- Ying Guo
- Guangdong-Hong Kong Joint Laboratory for Water Security, Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai 519087, China; College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Ministry of Education on Groundwater Pollution Control and Remediation, Beijing 100875, China
| | - Yue Dong
- Guangdong-Hong Kong Joint Laboratory for Water Security, Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai 519087, China; Engineering Research Center of Ministry of Education on Groundwater Pollution Control and Remediation, Beijing 100875, China
| | - Qiuying Chen
- Guangdong-Hong Kong Joint Laboratory for Water Security, Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai 519087, China; College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Ministry of Education on Groundwater Pollution Control and Remediation, Beijing 100875, China
| | - Shengrui Wang
- Guangdong-Hong Kong Joint Laboratory for Water Security, Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai 519087, China; College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Ministry of Education on Groundwater Pollution Control and Remediation, Beijing 100875, China; Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake Watershed, Kunming, Yunnan Province 650034, China.
| | - Zhaokui Ni
- Guangdong-Hong Kong Joint Laboratory for Water Security, Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai 519087, China; College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Ministry of Education on Groundwater Pollution Control and Remediation, Beijing 100875, China
| | - Xiaofei Liu
- Guangdong-Hong Kong Joint Laboratory for Water Security, Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai 519087, China; College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Ministry of Education on Groundwater Pollution Control and Remediation, Beijing 100875, China
| |
Collapse
|
14
|
Ji N, Zou R, Jiang Q, Liang Z, Hu M, Liu Y, Yu Y, Wang Z, Wang H. Internal positive feedback promotes water quality improvement for a recovering hyper-eutrophic lake: A three-dimensional nutrient flux tracking model. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 772:145505. [PMID: 33581532 DOI: 10.1016/j.scitotenv.2021.145505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 01/24/2021] [Accepted: 01/25/2021] [Indexed: 06/12/2023]
Abstract
Nutrient dynamics in lakes are determined by the combined effects of external and internal nutrient fluxes. However, the feedback loop of nutrient fluxes and water quality changes is still an open question. An integrated three-dimensional flux tracking approach based on the Environmental Fluid Dynamics Code model was established to quantify the long-term dynamic changes in external and internal processes in Lake Dianchi (one of the three most hyper-eutrophic lakes in China), and to explore the potential causes of water quality improvement during 2012-2018. The long-term trends and relative influences of nutrient fluxes on water quality were identified. The results showed that the inflow flux was the largest input source and declined by 50% between 2003 and 2012, which was followed by a stable trend from 2012 to 2018. The second largest input source was benthic release, which exhibited a significant interannual reduction. Algae sedimentation was the largest removal process, and declined by 45% between 2012 and 2018. An integrated analysis demonstrated that, following an external loading reduction prior to 2012, the positive feedback of internal fluxes promoted water quality improvement during 2012-2018. Considering the long timescale of the nutrient-flux feedback mechanism, reducing external loading is still the top priority for a long-term virtuous cycle of water quality in the process of eutrophic lake restoration.
Collapse
Affiliation(s)
- Ningning Ji
- College of Environmental Sciences and Engineering, State Environmental Protection Key Laboratory of All Materials Flux in Rivers, Peking University, Beijing 100871, China
| | - Rui Zou
- Rays Computational Intelligence Lab, Beijing Inteliway Environmental Ltd., Beijing 100085, China
| | - Qingsong Jiang
- College of Environmental Sciences and Engineering, State Environmental Protection Key Laboratory of All Materials Flux in Rivers, Peking University, Beijing 100871, China
| | - Zhongyao Liang
- Pennsylvania Cooperative Fish and Wildlife Research Unit, Pennsylvania State University, 407 Forest Resources Building, University Park, PA 16802, USA
| | - Mengchen Hu
- College of Environmental Sciences and Engineering, State Environmental Protection Key Laboratory of All Materials Flux in Rivers, Peking University, Beijing 100871, China
| | - Yong Liu
- College of Environmental Sciences and Engineering, State Environmental Protection Key Laboratory of All Materials Flux in Rivers, Peking University, Beijing 100871, China; Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake-Watershed, Kunming 650034, China.
| | - Yanhong Yu
- Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake-Watershed, Kunming 650034, China
| | - Zhiyun Wang
- Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake-Watershed, Kunming 650034, China
| | - Hailing Wang
- Kunming Dianchi Investment Co., Ltd., Kunming 650100, China
| |
Collapse
|
15
|
Sediment Nutrient Flux Rates in a Shallow, Turbid Lake Are More Dependent on Water Quality Than Lake Depth. WATER 2021. [DOI: 10.3390/w13101344] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The bottom sediments of shallow lakes are an important nutrient sink; however, turbidity may alter the influence of water depth on sediment nutrient uptake by reducing light and associated oxic processes, or altering nutrient availability. This study assessed the relative influence of water quality vs. water depth on sediment nutrient uptake rates in a shallow agricultural lake during spring, when sediment and nutrient loading are highest. Nitrate and soluble reactive phosphorus (SRP) flux rates were measured from sediment cores collected across a depth and spatial gradient, and correlated to water quality. Overlying water depth and distance to shore did not influence rates. Both nitrate and SRP sediment uptake rates increased with greater Secchi depth and higher water temperature, and nitrate and SRP rates increased with lower water total N and total P, respectively. The importance of water temperature on N and P cycling was confirmed in an additional experiment; however, different patterns of nitrate reduction and denitrification suggest that alternative N2 production pathways may be important. These results suggest that water quality and temperature can be key drivers of sediment nutrient flux in a shallow, eutrophic, turbid lake, and water depth manipulation may be less important for maximizing spring runoff nutrient retention than altering water quality entering the lake.
Collapse
|
16
|
Evaluation of the quality of lentic ecosystems in Romania by a GIS based WRASTIC model. Sci Rep 2021; 11:5361. [PMID: 33686107 PMCID: PMC7970884 DOI: 10.1038/s41598-021-84802-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 02/22/2021] [Indexed: 11/08/2022] Open
Abstract
Globally, ecosystems are constantly degrading as a result of pressures derived from human activities and climate change. For working towards the restoration of the natural balance, it is necessary to evaluate the deviations induced in the ecosystems, to identify where the changes took place, to know what is their amplitude and to decide where it is possible to get involved. Many aquatic ecosystems are depreciated and their restoration is often difficult. Development of appropriate assessment methodologies will improve the decision-making process in public policies for environmental protection and conservation of biodiversity. This study presents an assessment of the degradation level of lentic ecosystems in Romania, performed through a multi-criteria analysis. An extension of the WRASTIC index (Wastewater-Recreational-Agricultural-Size-Transportations-Indutrial-Cover) was generated, namely WRASTIC-HI. The new index was obtained by including values derived from the Potential Pollutant Load index. The analysis showed that 13% of the evaluated lakes are natural, 56.5% are semi-degraded and 30.5% are degraded. The proposed methodology allows to determine the spatial distribution of the degradation sources and to calculate the corresponding indicators. The results obtained provide a useful tool for diagnostic step that can be used as a cornerstone to further identification of environmental conflicts and proposals for improvement of the ecological status of the lentic ecosystems.
Collapse
|
17
|
Phosphorous Supply to a Eutrophic Artificial Lake: Sedimentary versus Groundwater Sources. WATER 2021. [DOI: 10.3390/w13040563] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The eutrophic Lake Eichbaumsee, a ~1 km long and 280 m wide (maximum water depth 16 m) dredging lake southeast of Hamburg (Germany), has been treated for water quality improvements using various techniques (i.e., aeration plants, removal of dissolved phosphorous by aluminum phosphorous precipitation, and by Bentophos® (Phoslock Environmental Technologies, Sydney, Australia), adsorption) during the past ~15 years. Despite these treatments, no long-term improvement of the water quality has been observed and the lake water phosphorous content has continued to increase by e.g., ~670 kg phosphorous between autumn 2014 and autumn 2019. As no creeks or rivers drain into the lake and hydrological groundwater models do not suggest any major groundwater discharge into the lake, sources of phosphorous (and other nutrients) are unknown. We investigated the phosphorous fluxes from sediment pore water and from groundwater in the water body of the lake. Sediment pore water was extracted from sediment cores recovered by divers in August 2018 and February 2019. Diffusive phosphorous fluxes from pore water were calculated based on phosphorus gradients. Stable water isotopes (δ2H, δ18O) were measured in the lake water, in interstitial waters in the banks surrounding the lake, in the Elbe River, and in three groundwater wells close to the lake. Stable isotope (δ2H, δ18O) water mass balance models were used to compute water inflow/outflow to/from the lake. Our results revealed pore-water borne phosphorous fluxes between 0.2 mg/m2/d and 1.9 mg/m2/d. Assuming that the measured phosphorous fluxes are temporarily and spatially representative for the whole lake, about 11 kg/a to 110 kg/a of phosphorous is released from sediments. This amount is lower than the observed lake water phosphorous increase of ~344 kg between April 2018 and November 2018. Water stable isotope (δ2H, δ18O) compositions indicate a water exchange between an aquifer and the lake water. Based on stable isotope mass balances we estimated an inflow of phosphorous from the aquifer to the lake of between ~150 kg/a and ~390 kg/a. This result suggests that groundwater-borne phosphorous is a significant phosphorous source for the Eichbaumsee and highlights the importance of groundwater for lake water phosphorous balances.
Collapse
|
18
|
DeAngelis DL, Franco D, Hastings A, Hilker FM, Lenhart S, Lutscher F, Petrovskaya N, Petrovskii S, Tyson RC. Towards Building a Sustainable Future: Positioning Ecological Modelling for Impact in Ecosystems Management. Bull Math Biol 2021; 83:107. [PMID: 34482488 PMCID: PMC8418459 DOI: 10.1007/s11538-021-00927-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 07/20/2021] [Indexed: 12/05/2022]
Abstract
As many ecosystems worldwide are in peril, efforts to manage them sustainably require scientific advice. While numerous researchers around the world use a great variety of models to understand ecological dynamics and their responses to disturbances, only a small fraction of these models are ever used to inform ecosystem management. There seems to be a perception that ecological models are not useful for management, even though mathematical models are indispensable in many other fields. We were curious about this mismatch, its roots, and potential ways to overcome it. We searched the literature on recommendations and best practices for how to make ecological models useful to the management of ecosystems and we searched for 'success stories' from the past. We selected and examined several cases where models were instrumental in ecosystem management. We documented their success and asked whether and to what extent they followed recommended best practices. We found that there is not a unique way to conduct a research project that is useful in management decisions. While research is more likely to have impact when conducted with many stakeholders involved and specific to a situation for which data are available, there are great examples of small groups or individuals conducting highly influential research even in the absence of detailed data. We put the question of modelling for ecosystem management into a socio-economic and national context and give our perspectives on how the discipline could move forward.
Collapse
Affiliation(s)
- Donald L. DeAngelis
- U.S. Geological Survey, Fort Lauderdale, FL 33315 USA ,Department of Biology, University of Miami, Coral Gables, FL 33124 USA
| | - Daniel Franco
- Departamento de Matemática Aplicada, Universidad Nacional de Educación a Distancia (UNED), c/ Juan del Rosal 12, 28040 Madrid, Spain
| | - Alan Hastings
- Department of Environmental Science and Policy, University of California, Davis, CA 95616 USA ,Santa Fe Institute, Santa Fe, NM 87501 USA
| | - Frank M. Hilker
- Institute of Mathematics and Institute of Environmental Systems Research, Osnabrück University, 49069 Osnabrück, Germany
| | - Suzanne Lenhart
- Department of Mathematics, University of Tennessee, Knoxville, TN 37996 USA
| | - Frithjof Lutscher
- Department of Mathematics and Statistics, and Department of Biology, University of Ottawa, Ottawa, ON K1N6N5 Canada
| | - Natalia Petrovskaya
- School of Mathematics, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
| | - Sergei Petrovskii
- School of Mathematics and Actuarial Science, University of Leicester, Leicester, LE1 7RH UK ,Peoples Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya St, Moscow, Russian Federation 117198
| | - Rebecca C. Tyson
- Mathematics and Statistics, Unit 5, Irving K. Barber, School of Arts and Sciences, University of British Columbia-Okanagan, Kelowna, British Columbia, V1V 1V7 Canada
| |
Collapse
|
19
|
Kiani M, Tammeorg P, Niemistö J, Simojoki A, Tammeorg O. Internal phosphorus loading in a small shallow Lake: Response after sediment removal. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 725:138279. [PMID: 32305643 DOI: 10.1016/j.scitotenv.2020.138279] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 03/19/2020] [Accepted: 03/26/2020] [Indexed: 06/11/2023]
Abstract
Mankind is taking advantage of numerous services by small shallow lakes such as drinking water supply, irrigation, and recreational function; however, many of these lakes suffer from eutrophication. Given the key role of phosphorus (P) in eutrophication process, one of the effective restoration methods especially for small shallow lakes is removal of sediments enriched with nutrients. In our study, we used interannual, seasonal, and spatial data to examine the changes in sediment P mobility after removal of sediments in 2016 from a 1-ha highly eutrophic lake. We measured the sediment redox potential, analyzed soluble reactive P (SRP) in the pore water and P fractional composition of the surface sediments, and calculated the diffusive flux of P in three locations in two continuous years (2017 and 2018) after the excavation. Similar measurements were done before sediment removal at central site of the lake in 2015. Removing nutrient-rich sediment also removed 6400 kg of P, and thus the potential for release of P from sediments decreased on a long-term scale. However, a large pool of releasable P was rebuilt soon after the sediment removal due to high external P loading, resulting in extensive anoxia of sediment surface and associated internal P loading as high as 1450 mg m-2 summer-1. Moreover, the Fe-P and labile P fractions were the most important sources of P release, as evidenced by their considerable seasonal and interannual changes after the sediment removal. The sediment total Fe negatively correlated with diffusive flux of P, pore water SRP, and near-bottom water total P and SRP concentrations which indicated a strong linkage between sediment P dynamics and Fe after the restoration. Sediment removal could be a beneficial restoration approach, but the effects on lake water quality remain only short-term unless there is an adequate control on external loading to the lake.
Collapse
Affiliation(s)
- Mina Kiani
- Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland.
| | - Priit Tammeorg
- Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland
| | - Juha Niemistö
- Ecosystems and Environment Research Programme, University of Helsinki, Helsinki, Finland
| | - Asko Simojoki
- Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland
| | - Olga Tammeorg
- Ecosystems and Environment Research Programme, University of Helsinki, Helsinki, Finland; Centre for Limnology, Estonian University of Life Sciences, 61117 Rannu, Tartumaa, Estonia
| |
Collapse
|
20
|
Wang M, Xu X, Wu Z, Zhang X, Sun P, Wen Y, Wang Z, Lu X, Zhang W, Wang X, Tong Y. Seasonal Pattern of Nutrient Limitation in a Eutrophic Lake and Quantitative Analysis of the Impacts from Internal Nutrient Cycling. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:13675-13686. [PMID: 31599576 DOI: 10.1021/acs.est.9b04266] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Nutrient dynamics in lakes are determined by the external anthropogenic discharges and unobserved internal cycling processes. In this work, a decadal nutrient data set from the eutrophic Lake Taihu, China, revealed a strong seasonal pattern of nutrient concentration and limitation. A nutrient-driven dynamic eutrophication model based on a Bayesian hierarchical framework was established to quantify the relative contributions to temporal variations from external discharges and internal processes. Results showed that after years of efforts on nutrient reduction, external discharges were relatively small and fluctuated less between seasons compared to the internal processes. A quantitative relationship between monthly nutrient concentration and corresponding internal loading was observed. Lake sediment could transform from a source of phosphorus in overlying water in summer and autumn to a sink in winter and spring. Together with temporal variations in nitrification and denitrification, seasonal transformation from the limitation of phosphorus induced colimitation of nitrogen and phosphorus. Understanding the potential impact of internal nutrient cycling on a seasonal pattern of nutrient concentration and limitation, the growth of phytoplankton, and, possibly, phytoplankton community composition should be emphasized, given the change in the relative importance of external discharges and internal loading in the process of lake restoration.
Collapse
Affiliation(s)
- Mengzhu Wang
- School of Environmental Science and Engineering , Tianjin University , Tianjin 300072 , China
| | - Xiwen Xu
- School of Environmental Science and Engineering , Tianjin University , Tianjin 300072 , China
| | - Zhen Wu
- Department of Earth, Atmospheric and Planetary Sciences , Massachusetts Institute of Technology , Cambridge Massachusetts 02139 , United States
| | - Xiaoqian Zhang
- Center for Rural Environment Protection , Chinese Academy for Environmental Planning , Beijing 100012 , China
| | - Peizhe Sun
- School of Environmental Science and Engineering , Tianjin University , Tianjin 300072 , China
| | - Yingting Wen
- School of Environmental Science and Engineering , Tianjin University , Tianjin 300072 , China
| | - Zhen Wang
- Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences , Nanjing 210008 , China
| | - Xuebin Lu
- School of Science , Tibet University , Lhasa 850012 , China
| | - Wei Zhang
- School of Environment and Natural Resources , Renmin University of China , Beijing 100872 , China
| | - Xuejun Wang
- College of Urban and Environmental Sciences , Peking University , Beijing 100871 , China
| | - Yindong Tong
- School of Environmental Science and Engineering , Tianjin University , Tianjin 300072 , China
| |
Collapse
|