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Huang J, Zhang Y, Bing H, Peng J, Dong F, Gao J, Arhonditsis GB. Characterizing the river water quality in China: Recent progress and on-going challenges. WATER RESEARCH 2021; 201:117309. [PMID: 34116294 DOI: 10.1016/j.watres.2021.117309] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 04/11/2021] [Accepted: 05/25/2021] [Indexed: 05/25/2023]
Abstract
Food production systems, urbanization, and other anthropogenic activities dramatically alter natural hydrological and nutrient cycles, and are primarily responsible for water quality impairments in China's rivers. This study compiled a 16-year (2003-2018) dataset of river water quality (161,337 records from 2424 sites), watershed/landscape features, and meteorological conditions to investigate the spatial water quality patterns and underlying drivers of river impairment (defined as water quality worse than Class V according to China's Environmental Quality Standards for Surface Waters, GB3838-2002) at a national scale. Our analysis provided evidence of a distinct water quality improvement with a gradual decrease in the frequency of prevalence of anoxic conditions, an alleviation of the severity of heavy metal pollution, whereas the cultural eutrophication has only been moderately mitigated between 2003 and 2018. We also identified significant spatial variation with relatively poorer water quality in eastern China, where 17.2% of the sampling sites registered poor water quality conditions, compared with only 4.6% in western China. Total phosphorus (TP) and ammonia-nitrogen (NH3-N) are collectively responsible for >85% of the identified incidences of impaired conditions. Bayesian modelling was used to delineate the most significant covariates of TP/NH3-N riverine levels in six large river basins (Liao, Hai, Yellow, Yangtze, Huai, and Pearl). Water quality impairments are predominantly shaped by anthropogenic drivers (82.5% for TP, 79.5% for NH3-N), whereas natural factors appear to play a secondary role (20.5% for TP, 17.5% for NH3-N). Two indicator variables of urbanization (urban areal extent and nighttime light intensity) and farmland areal extent were the strongest predictors of riverine TP/NH3-N levels and collectively accounted for most of the ambient nutrient variability. We concluded that there is still a long way to go in order to eradicate eutrophication and realize acceptable ecological conditions. The design of the remedial measures must be tailored to the site-specific landscape characteristics, meteorological conditions, and should also consider the increasing importance of non-point source pollution and internal nutrient loading.
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Affiliation(s)
- Jiacong Huang
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China.
| | - Yinjun Zhang
- China National Environmental Monitoring Centre, 8(B) Dayangfang Beiyuan Road, Chaoyang District, Beijing, 100012, China
| | - Haijian Bing
- Key Laboratory of Mountain Surface Process and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, 9, Block 4, Renminnanlu Road, Chengdu, 610041, China
| | - Jian Peng
- Department of Remote Sensing, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, 04318, Leipzig, Germany; Remote Sensing Centre for Earth System Research, Leipzig University, 04103, Leipzig, Germany
| | - Feifei Dong
- Institute of Groundwater and Earth Sciences, Jinan University, 601 Huangpu Avenue, Guangzhou, 510630, China
| | - Junfeng Gao
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China
| | - George B Arhonditsis
- Ecological Modelling Laboratory, Department of Physical & Environmental Sciences, University of Toronto, Toronto, ON, M1C 1A4, Canada.
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Mishra DR, Kumar A, Muduli PR, Acharyya T, Acharya P, Singh S, Rastogi G. Landfall season is critical to the impact of a cyclone on a monsoon-regulated tropical coastal lagoon. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 770:145235. [PMID: 33513491 DOI: 10.1016/j.scitotenv.2021.145235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/29/2020] [Accepted: 01/05/2021] [Indexed: 06/12/2023]
Abstract
Cyclones can produce a wide variety of short-term and long-term ecological impacts on coastal lagoons depending on cyclone's physical-meteorological characteristics and the lagoon's geographic, geomorphic, and bathymetric characteristics. Here, we theorized that in monsoon regulated tropical coastal lagoons, another important factor that could determine the impact of a cyclone is the landfall season or time of the year with reference to the monsoon season. We analyzed the impact of two cyclones which made landfall near Chilika, Asia's largest brackish water lagoon in different seasons, Cyclone Fani and Titli before and after the monsoon season. We compared field measured and satellite-derived water quality parameters including nutrient, salinity, water temperature, transparency, Chlorophyll-a (Chl-a), total suspended matter (TSM), and colored dissolved organic matter (CDOM) before and after the cyclones. We found that although both the cyclones were of similar intensities, after their land interaction, their impact on the lagoon's water quality was contrasting. The post-monsoon cyclone produced a substantial increase in total nitrogen (TN) and total phosphorous (TP), a large drop in salinity, CDOM, and Chl-a. In contrast, after the pre-monsoon cyclone, TN and TP did not show any such hike, no substantial change in salinity and CDOM either, and only a slight increase in Chl-a was observed. We found that the controlling factor in determining the impact of a cyclone is the rate and duration of freshwater discharge to the lagoon, which is normally a strong pulse for pre-monsoon and a continued high flow for post-monsoon cyclones. We conclude that the antecedent conditions of the lagoon and the watershed at the time of a cyclone's landfall is a key criterion in determining the impact. The combined use of satellite data and field data was proved critical to capture the overall impact of cyclones on the hydrological characteristics of the monsoon-regulated coastal lagoon.
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Affiliation(s)
- Deepak R Mishra
- Department of Geography, University of Georgia, Athens, GA, USA.
| | - Abhishek Kumar
- Department of Geography, University of Georgia, Athens, GA, USA
| | - Pradipta R Muduli
- Wetland Research and Training Centre, Chilika Development Authority, Balugaon, Odisha, India
| | - Tamoghna Acharyya
- School of Sustainability, Xavier University, Bhubaneswar, Odisha, India
| | - Prasannajit Acharya
- Wetland Research and Training Centre, Chilika Development Authority, Balugaon, Odisha, India
| | - Sambit Singh
- School of Sustainability, Xavier University, Bhubaneswar, Odisha, India
| | - Gurdeep Rastogi
- Wetland Research and Training Centre, Chilika Development Authority, Balugaon, Odisha, India
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53
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Lorrain-Soligon L, Robin F, Rousseau P, Jankovic M, Brischoux F. Slight variations in coastal topography mitigate the consequence of storm-induced marine submersion on amphibian communities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 770:145382. [PMID: 33736409 DOI: 10.1016/j.scitotenv.2021.145382] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/19/2021] [Accepted: 01/19/2021] [Indexed: 06/12/2023]
Abstract
The rise in sea-level and the increase in frequency and intensity of extreme weather events (i.e., storms and associated surges) are expected to strongly impact coastal areas. The gradual impacts of sea-level rise may allow species to display adaptive responses to overcome environmental changes. In contrast, the abruptness of marine submersions during extreme weather events can induce changes that may exceed the ability of species to respond to brutally changing environments. Yet, site-specific topographical features may buffer the expected detrimental effects of marine submersions on wildlife. In order to test such topographical effects, we examined the long-term consequences of a major marine submersion (storm Xynthia) on the amphibian communities of two French Atlantic coastal wetlands that slightly differ in their topography and, thus, their susceptibility to marine submersion. Amphibians were monitored on 64 ponds for up to 13 years, using acoustic and visual methods, in conjunction with environmental parameters (e.g., pond topology, vegetation, salinity). We found that the amphibian communities at the two neighboring sites displayed different responses to the marine submersion linked to storm Xynthia. As predicted, slight differences in local topography induced strong differences in local magnitude of the landward marine surge, influencing salinization dynamics and associated consequences on wildlife (amphibians). The different species responses show that amphibian richness can recover to that of pre-storm conditions, but with significant changes in the composition of the community. Our results suggest that amphibian presence post-submersion in coastal wetlands results from an interaction between species traits (e.g., tolerance to elevated salinity), site-specific topography, and environmental parameters. Finally, our study emphasizes that relatively modest landscaping management may be critical to allow wildlife to successfully recover after a marine submersion.
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Affiliation(s)
- Léa Lorrain-Soligon
- Centre d'Etudes Biologiques de Chizé, CEBC UMR 7372 CNRS - La Rochelle Université, 79360 Villiers en Bois, France.
| | - Frédéric Robin
- LPO France, Fonderies Royales, 17300 Rochefort, France; Réserve naturelle de Moëze-Oléron, LPO, Plaisance, 17780 Saint-Froult, France; Réserve naturelle du marais d'Yves LPO, Ferme de la belle espérance, 17340 Yves, France.
| | - Pierre Rousseau
- Réserve naturelle de Moëze-Oléron, LPO, Plaisance, 17780 Saint-Froult, France.
| | - Marko Jankovic
- Réserve naturelle du marais d'Yves LPO, Ferme de la belle espérance, 17340 Yves, France.
| | - François Brischoux
- Centre d'Etudes Biologiques de Chizé, CEBC UMR 7372 CNRS - La Rochelle Université, 79360 Villiers en Bois, France.
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54
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Stefanidis K, Varlas G, Vourka A, Papadopoulos A, Dimitriou E. Delineating the relative contribution of climate related variables to chlorophyll-a and phytoplankton biomass in lakes using the ERA5-Land climate reanalysis data. WATER RESEARCH 2021; 196:117053. [PMID: 33774349 DOI: 10.1016/j.watres.2021.117053] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 03/09/2021] [Accepted: 03/12/2021] [Indexed: 06/12/2023]
Abstract
Understanding the climatic drivers of eutrophication is critical for lake management under the prism of the global change. Yet the complex interplay between climatic variables and lake processes makes prediction of phytoplankton biomass a rather difficult task. Quantifying the relative influence of climate-related variables on the regulation of phytoplankton biomass requires modelling approaches that use extensive field measurements paired with accurate meteorological observations. In this study we used climate and lake related variables obtained from the ERA5-Land reanalysis dataset combined with a large dataset of in-situ measurements of chlorophyll-a and phytoplankton biomass from 50 water bodies to develop models of phytoplankton related responses as functions of the climate reanalysis data. We used chlorophyll-a and phytoplankton biomass as response metrics of phytoplankton growth and we employed two different modelling techniques, boosted regression trees (BRT) and generalized additive models for location scale and shape (GAMLSS). According to our results, the fitted models had a relatively high explanatory power and predictive performance. Boosted regression trees had a high pseudo R2 with the type of the lake, the total layer temperature, and the mix-layer depth being the three predictors with the higher relative influence. The best GAMLSS model retained mix-layer depth, mix-layer temperature, total layer temperature, total runoff and 10-m wind speed as significant predictors (p<0.001). Regarding the phytoplankton biomass both modelling approaches had less explanatory power than those for chlorophyll-a. Concerning the predictive performance of the models both the BRT and GAMLSS models for chlorophyll-a outperformed those for phytoplankton biomass. Overall, we consider these findings promising for future limnological studies as they bring forth new perspectives in modelling ecosystem responses to a wide range of climate and lake variables. As a concluding remark, climate reanalysis can be an extremely useful asset for lake research and management.
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Affiliation(s)
- Konstantinos Stefanidis
- Hellenic Centre for Marine Research, Institute of Marine Biological Resources and Inland Waters, 46.7 km of Athens-Sounio Ave., 19013 Anavyssos, Attica, Greece.
| | - George Varlas
- Hellenic Centre for Marine Research, Institute of Marine Biological Resources and Inland Waters, 46.7 km of Athens-Sounio Ave., 19013 Anavyssos, Attica, Greece
| | - Aikaterini Vourka
- Hellenic Centre for Marine Research, Institute of Marine Biological Resources and Inland Waters, 46.7 km of Athens-Sounio Ave., 19013 Anavyssos, Attica, Greece
| | - Anastasios Papadopoulos
- Hellenic Centre for Marine Research, Institute of Marine Biological Resources and Inland Waters, 46.7 km of Athens-Sounio Ave., 19013 Anavyssos, Attica, Greece
| | - Elias Dimitriou
- Hellenic Centre for Marine Research, Institute of Marine Biological Resources and Inland Waters, 46.7 km of Athens-Sounio Ave., 19013 Anavyssos, Attica, Greece
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55
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Liu X, Chen L, Zhang G, Zhang J, Wu Y, Ju H. Spatiotemporal dynamics of succession and growth limitation of phytoplankton for nutrients and light in a large shallow lake. WATER RESEARCH 2021; 194:116910. [PMID: 33601234 DOI: 10.1016/j.watres.2021.116910] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 02/04/2021] [Accepted: 02/05/2021] [Indexed: 06/12/2023]
Abstract
Understanding the limiting factors of phytoplankton growth and competition is crucial for the restoration of aquatic ecosystems. However, the role and synergistic effect of co-varying environmental conditions, such as nutrients and light on the succession of phytoplankton community remains unclear. In this study, a hydrodynamic-ecological modeling approach was developed to explore phytoplankton growth and succession under co-varying environmental conditions (nutrients, total suspended solids (TSS) and variable N:P ratios) in a large shallow lake called Lake Chagan, in Northeast China. A phytoplankton bloom model was nested in the ecological modeling approach. In contrast to the traditonal ecological modeling, competition between phytoplankton species in our study was modeled at both the species/functional group and phenotype levels. Six phytoplankton functional groups, namely diatoms, green algae, Anabaena, Microcystis, Aphanizomenon and Oscillatoria and each of them with three limitation types (i.e., light-limitation, nitrogen-limitation and phosphorus-limitation) were included in the bloom model. Our results demonstrated that the average biomass proportion of the three limitation types (light-limitation, nitrogen-limitation and phosphorus-limitation) in the six phytoplankton function groups accounted for approximately 50%, 37% and 23% of the total phytoplankton biomass, respectively. TSS suppressed the growth of diatoms and green algae, but favored the dominance of cyanobacteria in Lake Chagan, especially in the turbid water phase (TSS ≥ 60 mg/L). In addition, it was reported that the potential of either N-fixing or non-N-fixing cyanobacterial blooming along the gradients of N:P ratios could exist under the influence of the co-environmental factors in the lake. The proportion of non-N-fixing cyanobacteria (i.e., Microcystis and Oscillatoria) exceeded the proportion of N-fixing cyanobacteria (i.e., Anabaena and Aphanizomenon) when the N:P ratios exceeded 20. Non-N-fixing cyanobacteria would become dominant at higher TSS concentrations and lower light intensities in the turbid water. N-fixing cyanobacteria favored lower N:P ratios and higher light intensities in the clearwater phase (where TSS ≤ 60 mg/L). To sustain a good ecological status in the lake, our results suggest that nutrient and TSS levels in the lake should be maintained at or below the thresholds (TN ≤ 1.5 mg/L; TP ≤ 0.1 mg/L; N:P ratios between 15 and 20; and TSS ≤ 60 mg/L). These findings can help improve water quality management practices to restore aquatic ecosystems.
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Affiliation(s)
- Xuemei Liu
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences. Changchun 130102, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Liwen Chen
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences. Changchun 130102, China
| | - Guangxin Zhang
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences. Changchun 130102, China.
| | - Jingjie Zhang
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences. Changchun 130102, China; Environmental Research Institute, National University of Singapore, Kent Ridge 117576, Singapore; Shenzhen Municipal Engineering Lab of Environmental IoT Technologies, Southern University of Science and Technology, Shenzhen, 518055, China.
| | - Yao Wu
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences. Changchun 130102, China
| | - Hanyu Ju
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences. Changchun 130102, China; University of the Chinese Academy of Sciences, Beijing 100049, China
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56
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Seasonal Variations of Dissolved Organic Matter by Fluorescent Analysis in a Typical River Catchment in Northern China. WATER 2021. [DOI: 10.3390/w13040494] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Fluorescence (excitation-emission matrices, EEMs) spectroscopy coupled with PARAFAC (parallel factor) modelling and UV-Vis (ultraviolet visible) spectra were used to ascertain the sources, distribution and biogeochemical transformation of dissolved organic matter (DOM) in the Duliujian River catchment. Dissolved organic carbon (DOC), chromophoric dissolved organic matter (a335) (CDOM), and hydrophobic components (a260) were higher in summer than in other seasons with 53.3 m−1, while aromaticity (SUVA254) was higher in spring. Four fluorescent components, namely terrestrial humic acid (HA)-like (A/C), terrestrial fulvic acid (FA)-like (A/M), autochthonous fulvic acid (FA)-like (A/M), and protein-like substances (Tuv/T), were identified using EEM-PARAFAC modelling in this river catchment. The results demonstrated that terrestrial HA-like substances enhance its contents in summer ARE compared with BRE, whilst terrestrial FA-like substances were newly input in summer ARE, which was entirely absent upstream and downstream, suggesting that rain events could significantly input the terrestrial soil-derived DOM in the ambient downward catchments. Autochthonous FA-like substances in summer BRE could derive from phytoplankton in the downstream waters. The results also showed that DOM from wetland exhibited lower fluorescent intensity of humic-like peak A/C and fulvic-like peak A/M, molecular weight (SR) and humification index (HIX) during the low-flow season. Built-up land, cropland, and unused land displayed higher a335 (CDOM). A higher proportion of forest and industrial land in the SCs showed higher SUVA254 values. Humic-like moiety, molecular weight and aromaticity were more responsive to land use during stormflow in summer. Rainfall could increase the export of soil DOM from cropland and unused land, which influences the spatial variation of HIX. The results in this study highlighted that terrestrial DOM has a significant influence on the biogeochemical alterations of DOM compositions and thus water quality in the downward watershed catchments, which might significantly vary according to the land-use types and their alterations by human activities.
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57
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Urrutia-Cordero P, Langenheder S, Striebel M, Eklöv P, Angeler DG, Bertilsson S, Csitári B, Hansson LA, Kelpsiene E, Laudon H, Lundgren M, Osman OA, Parkefelt L, Hillebrand H. Functionally reversible impacts of disturbances on lake food webs linked to spatial and seasonal dependencies. Ecology 2021; 102:e03283. [PMID: 33428769 DOI: 10.1002/ecy.3283] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 09/17/2020] [Accepted: 10/26/2020] [Indexed: 11/09/2022]
Abstract
Increasing human impact on the environment is causing drastic changes in disturbance regimes and how they prevail over time. Of increasing relevance is to further our understanding on biological responses to pulse disturbances (short duration) and how they interact with other ongoing press disturbances (constantly present). Because the temporal and spatial contexts of single experiments often limit our ability to generalize results across space and time, we conducted a modularized mesocosm experiment replicated in space (five lakes along a latitudinal gradient in Scandinavia) and time (two seasons, spring and summer) to generate general predictions on how the functioning and composition of multitrophic plankton communities (zoo-, phyto- and bacterioplankton) respond to pulse disturbances acting either in isolation or combined with press disturbances. As pulse disturbance, we used short-term changes in fish presence, and as press disturbance, we addressed the ongoing reduction in light availability caused by increased cloudiness and lake browning in many boreal and subarctic lakes. First, our results show that the top-down pulse disturbance had the strongest effects on both functioning and composition of the three trophic levels across sites and seasons, with signs for interactive impacts with the bottom-up press disturbance on phytoplankton communities. Second, community composition responses to disturbances were highly divergent between lakes and seasons: temporal accumulated community turnover of the same trophic level either increased (destabilization) or decreased (stabilization) in response to the disturbances compared to control conditions. Third, we found functional recovery from the pulse disturbances to be frequent at the end of most experiments. In a broader context, these results demonstrate that top-down, pulse disturbances, either alone or with additional constant stress upon primary producers caused by bottom-up disturbances, can induce profound but often functionally reversible changes across multiple trophic levels, which are strongly linked to spatial and temporal context dependencies. Furthermore, the identified dichotomy of disturbance effects on the turnover in community composition demonstrates the potential of disturbances to either stabilize or destabilize biodiversity patterns over time across a wide range of environmental conditions.
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Affiliation(s)
- Pablo Urrutia-Cordero
- Limnology, Department of Ecology and Genetics, Evolutionary Biology Center, Uppsala University, Norbyvägen 18D, Uppsala, Sweden.,Helmholtz Institute for Functional Marine Biodiversity (HIFMB), Ammerländer Heerstrasse 231, Oldenburg, 26129, Germany.,Institute for Chemistry and Biology of Marine Environments (ICBM), Carl-von-Ossietzky University Oldenburg, Schleusenstrasse 1, Wilhelmshaven, 26382, Germany
| | - Silke Langenheder
- Limnology, Department of Ecology and Genetics, Evolutionary Biology Center, Uppsala University, Norbyvägen 18D, Uppsala, Sweden
| | - Maren Striebel
- Institute for Chemistry and Biology of Marine Environments (ICBM), Carl-von-Ossietzky University Oldenburg, Schleusenstrasse 1, Wilhelmshaven, 26382, Germany
| | - Peter Eklöv
- Limnology, Department of Ecology and Genetics, Evolutionary Biology Center, Uppsala University, Norbyvägen 18D, Uppsala, Sweden
| | - David G Angeler
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, Uppsala, 750 07, Sweden
| | - Stefan Bertilsson
- Limnology, Department of Ecology and Genetics, Evolutionary Biology Center, Uppsala University, Norbyvägen 18D, Uppsala, Sweden.,Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, Uppsala, 750 07, Sweden
| | - Bianka Csitári
- Limnology, Department of Ecology and Genetics, Evolutionary Biology Center, Uppsala University, Norbyvägen 18D, Uppsala, Sweden.,Department of Microbiology, ELTE Eötvös Loránd University, Pázmány Péter stny. 1/c., Budapest, H-1117, Hungary
| | - Lars-Anders Hansson
- Department of Biology/Aquatic Ecology, Lund University, Ecology Building, Lund, SE-223 62, Sweden
| | - Egle Kelpsiene
- Department of Biochemistry and Structural Biology, Lund University, Lund, SE-221 00, Sweden
| | - Hjalmar Laudon
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, 90183, Sweden
| | - Maria Lundgren
- Swedish University of Agricultural Sciences, Unit for Field-based Forest Research, Asa Research Station, Lammhult, SE-363 94, Sweden.,Department of Biology and Environmental Science, Linnaeus University, Kalmar, SE-391 82, Sweden
| | - Omneya Ahmed Osman
- Limnology, Department of Ecology and Genetics, Evolutionary Biology Center, Uppsala University, Norbyvägen 18D, Uppsala, Sweden
| | | | - Helmut Hillebrand
- Helmholtz Institute for Functional Marine Biodiversity (HIFMB), Ammerländer Heerstrasse 231, Oldenburg, 26129, Germany.,Institute for Chemistry and Biology of Marine Environments (ICBM), Carl-von-Ossietzky University Oldenburg, Schleusenstrasse 1, Wilhelmshaven, 26382, Germany.,Aldfred-Wegener Institute, Helmholtz Center for Polar and Marine Research, Am Handelshafen 12, Bremerhaven, Germany
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58
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Woolway RI, Jennings E, Shatwell T, Golub M, Pierson DC, Maberly SC. Lake heatwaves under climate change. Nature 2021; 589:402-407. [PMID: 33473224 DOI: 10.1038/s41586-020-03119-1] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 10/21/2020] [Indexed: 01/30/2023]
Abstract
Lake ecosystems, and the organisms that live within them, are vulnerable to temperature change1-5, including the increased occurrence of thermal extremes6. However, very little is known about lake heatwaves-periods of extreme warm lake surface water temperature-and how they may change under global warming. Here we use satellite observations and a numerical model to investigate changes in lake heatwaves for hundreds of lakes worldwide from 1901 to 2099. We show that lake heatwaves will become hotter and longer by the end of the twenty-first century. For the high-greenhouse-gas-emission scenario (Representative Concentration Pathway (RCP) 8.5), the average intensity of lake heatwaves, defined relative to the historical period (1970 to 1999), will increase from 3.7 ± 0.1 to 5.4 ± 0.8 degrees Celsius and their average duration will increase dramatically from 7.7 ± 0.4 to 95.5 ± 35.3 days. In the low-greenhouse-gas-emission RCP 2.6 scenario, heatwave intensity and duration will increase to 4.0 ± 0.2 degrees Celsius and 27.0 ± 7.6 days, respectively. Surface heatwaves are longer-lasting but less intense in deeper lakes (up to 60 metres deep) than in shallower lakes during both historic and future periods. As lakes warm during the twenty-first century7,8, their heatwaves will begin to extend across multiple seasons, with some lakes reaching a permanent heatwave state. Lake heatwaves are likely to exacerbate the adverse effects of long-term warming in lakes and exert widespread influence on their physical structure and chemical properties. Lake heatwaves could alter species composition by pushing aquatic species and ecosystems to the limits of their resilience. This in turn could threaten lake biodiversity9 and the key ecological and economic benefits that lakes provide to society.
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Affiliation(s)
- R Iestyn Woolway
- Centre for Freshwater and Environmental Studies, Dundalk Institute of Technology, Dundalk, Ireland. .,European Space Agency Climate Office, ECSAT, Didcot, UK.
| | - Eleanor Jennings
- Centre for Freshwater and Environmental Studies, Dundalk Institute of Technology, Dundalk, Ireland
| | - Tom Shatwell
- Department of Lake Research, Helmholtz Centre for Environmental Research (UFZ), Magdeburg, Germany
| | - Malgorzata Golub
- Department of Ecology and Genetics/Limnology, Uppsala University, Uppsala, Sweden
| | - Don C Pierson
- Department of Ecology and Genetics/Limnology, Uppsala University, Uppsala, Sweden
| | - Stephen C Maberly
- UK Centre for Ecology and Hydrology, Lancaster Environment Centre, Lancaster, UK
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59
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Vizzo JI, Cabrerizo MJ, Helbling EW, Villafañe VE. Extreme and gradual rainfall effects on winter and summer estuarine phytoplankton communities from Patagonia (Argentina). MARINE ENVIRONMENTAL RESEARCH 2021; 163:105235. [PMID: 33338796 DOI: 10.1016/j.marenvres.2020.105235] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 11/30/2020] [Accepted: 12/04/2020] [Indexed: 06/12/2023]
Abstract
Rainfall events bring both, terrigenous materials (including DOM) and nutrients to the aquatic system (e.g., via riverine runoff) having potential effects on the structure and metabolism of the phytoplankton communities. As extreme rainfall events in Patagonia occurred more frequently in the last decade (2010-2019) as compared to the previous ones (1972-2009), we exposed winter and summer phytoplankton communities (using microcosms) to solar radiation, simulating two rainfall conditions - a single extreme vs. intermittent i.e., with gradual inputs, and we assessed their photosynthetic and growth rates responses and taxonomic changes. Rainfall scenarios significantly increased growth of both communities, mainly of small nanoplanktonic species, as compared to the control. Small nanoplanktonic centric diatoms increased and dominated in both rainfall scenarios, as compared to the control, during winter and summer, with significantly smaller cells during summer as compared to winter. Photosynthetic efficiency increased in both rainfall scenarios at the end of the experiment as compared to the control. Overall, the change towards small cells (associated to rainfall events) that can use more effectively solar radiation and nutrients (as compared to large cells) may have a significant impact on the trophic webs of the South West Atlantic Ocean by favoring grazing pressure by microzooplankton, especially during summer.
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Affiliation(s)
- Juan I Vizzo
- Estación de Fotobiología Playa Unión, Casilla de Correos 15, 9103, Rawson, Chubut, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
| | - Marco J Cabrerizo
- Centro de Investigación Mariña da Universidade de Vigo (CIM-UVigo), Illa de Toralla s/n, 36331, Vigo, Spain; Departamento de Ecología y Biología Animal, Universidade de Vigo, Facultad de Ciencias del Mar, Campus Lagoas Marcosende s/n, 36310, Vigo, Spain.
| | - E Walter Helbling
- Estación de Fotobiología Playa Unión, Casilla de Correos 15, 9103, Rawson, Chubut, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
| | - Virginia E Villafañe
- Estación de Fotobiología Playa Unión, Casilla de Correos 15, 9103, Rawson, Chubut, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
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Gao X, Chen H, Gu B, Jeppesen E, Xue Y, Yang J. Particulate organic matter as causative factor to eutrophication of subtropical deep freshwater: Role of typhoon (tropical cyclone) in the nutrient cycling. WATER RESEARCH 2021; 188:116470. [PMID: 33045638 DOI: 10.1016/j.watres.2020.116470] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 09/25/2020] [Accepted: 09/26/2020] [Indexed: 06/11/2023]
Abstract
Intense storms pose a serious threat to ecosystem functioning and services. However, the effects of typhoons (tropical cyclones) on the biogeochemical processes mediating risk of eutrophication in deep freshwater ecosystems remain unclear. Here, we conducted a three-year study to elucidate linkages between environmental change, stable isotopes and the stoichiometry of particulate organic matter (POM), and nutrient cycling (i.e., carbon, nitrogen and phosphorus) in a subtropical deep reservoir subjected to typhoon events. The typhoons significantly changed the nutrient levels in the deep waters as well as the thermocline position. Increased typhoon-driven organic matter input, algae sinking and heterotrophic decomposition interacted with each other to cause steep and prolonged increases of total nitrogen, ammonium nitrogen and total phosphorus in the bottom waters of the reservoir. Small-sized or pico-sized POM (i.e., 0.2-3 μm) showed a substantial increase in bottom waters, and it exhibited stronger response than large-sized POM (i.e., 3-20, 20-64, 64-200 μm) to the typhoons. Our results also indicated that typhoons boost the nutrient cycling in deep waters mainly through pico-sized POM.
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Affiliation(s)
- Xiaofei Gao
- Aquatic EcoHealth Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huihuang Chen
- Aquatic EcoHealth Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Binhe Gu
- Soil and Water Science Department, University of Florida, 106 Newell Hall, Gainesville, FL 32611, United States
| | - Erik Jeppesen
- Department of Bioscience, Aarhus University, Vejlsøvej 25, 8600 Silkeborg, Denmark; Sino-Danish Centre for Education and Research, Beijing 100049, China; Limnology Laboratory, Department of Biological Sciences and Centre for Ecosystem Research and Implementation, Middle East Technical University, Ankara, Turkey; Institute of Marine Sciences, Middle East Technical University, Mersin, Turkey
| | - Yuanyuan Xue
- Aquatic EcoHealth Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Jun Yang
- Aquatic EcoHealth Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
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Multiple interacting environmental drivers reduce the impact of solar UVR on primary productivity in Mediterranean lakes. Sci Rep 2020; 10:19812. [PMID: 33188224 PMCID: PMC7666193 DOI: 10.1038/s41598-020-76237-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 10/23/2020] [Indexed: 11/25/2022] Open
Abstract
Increases in rainfall, continental runoff, and atmospheric dust deposition are reducing water transparency in lakes worldwide (i.e. higher attenuation Kd). Also, ongoing alterations in multiple environmental drivers due to global change are unpredictably impacting phytoplankton responses and lakes functioning. Although both issues demand urgent research, it remains untested how the interplay between Kd and multiple interacting drivers affect primary productivity (Pc). We manipulated four environmental drivers in an in situ experiment—quality of solar ultraviolet radiation (UVR), nutrient concentration (Nut), CO2 partial pressure (CO2), and light regime (Mix)—to determine how the Pc of nine freshwater phytoplankton communities, found along a Kd gradient in Mediterranean ecosystems, changed as the number of interacting drivers increased. Our findings indicated that UVR was the dominant driver, its effect being between 3–60 times stronger, on average, than that of any other driver tested. Also, UVR had the largest difference in driver magnitude of all the treatments tested. A future UVR × CO2 × Mix × Nut scenario exerted a more inhibitory effect on Pc as the water column became darker. However, the magnitude of this synergistic effect was 40–60% lower than that exerted by double and triple interactions and by UVR acting independently. These results illustrate that although future global-change conditions could reduce Pc in Mediterranean lakes, multiple interacting drivers can temper the impact of a severely detrimental driver (i.e. UVR), particularly as the water column darkens.
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Impacts of Extreme Weather Events on Bacterial Community Composition of a Temperate Humic Lake. WATER 2020. [DOI: 10.3390/w12102757] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Extreme weather events are projected to increase in frequency and intensity as climate change continues. Heterotrophic bacteria play a critical role in lake ecosystems, yet little research has been done to determine how they are affected by such extremes. The purpose of this study was to use high-throughput sequencing to explore the bacterial community composition of a humic oligotrophic lake on the North Atlantic Irish coast and to assess the impacts on composition dynamics related to extreme weather events. Samples for sequencing were collected from Lough Feeagh on a fortnightly basis from April to November 2018. Filtration was used to separate free-living and particle-associated bacterial communities and amplicon sequencing was performed for the 16S rRNA V4 region. Two named storms, six high discharge events, and one drought period occurred during the sampling period. These events had variable, context-dependent effects on bacterial communities in Lough Feeagh. The particle-associated community was found to be more likely to respond to physical changes, such as mixing, while the free-living population responded to changes in nutrient and carbon concentrations. Generally, however, the high stability of the bacterial community observed in Lough Feeagh suggests that the bacterial community is relatively resilient to extreme weather events.
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Effects of Consecutive Extreme Weather Events on a Temperate Dystrophic Lake: A Detailed Insight into Physical, Chemical and Biological Responses. WATER 2020. [DOI: 10.3390/w12051411] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Between May and July 2018, Ireland experienced an exceptional heat wave, which broke long-term temperature and drought records. These calm, stable conditions were abruptly interrupted by a second extreme weather event, Atlantic Storm Hector, in late June. Using high-frequency monitoring data, coupled with fortnightly biological sampling, we show that the storm directly affected the stratification pattern of Lough Feeagh, resulting in an intense mixing event. The lake restabilised quickly after the storm as the heatwave continued. During the storm there was a three-fold reduction in Schmidt stability, with a mixed layer deepening of 9.5 m coinciding with a two-fold reduction in chlorophyll a but a three-fold increase in total zooplankton biomass. Epilimnetic respiration increased and net ecosystem productivity decreased. The ratio of total nitrogen:total phosphorus from in-lake versus inflow rivers was decoupled, leading to a cascade effect on higher trophic levels. A step change in nitrogen:phosphorus imbalances suggested that the zooplankton community shifted from phosphorus to nitrogen nutrient constraints. Such characterisations of both lake thermal and ecological responses to extreme weather events are relatively rare but are crucial to our understanding of how lakes are changing as the impacts of global climate change accelerate.
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