Pub Date : 2022-01-28DOI: 10.1080/20442041.2022.2031813
Upendra Bhele, Burak Öğlü, T. Feldmann, P. Bernotas, H. Agasild, P. Zingel, P. Nõges, T. Nõges, F. Cremona
ABSTRACT Ecosystem models that measure the impact of quantitative interactions between trophic levels are widely used tools in ecosystem studies and fishery management. We constructed a mass-balance trophic model using an Ecopath with Ecosim (EwE) modelling suite for large shallow Lake Võrtsjärv, Estonia. The model was calibrated for 36 years (1983–2018) and included 23 functional groups. We examined trophic relationships, functional group interactions, energy fluxes, and keystone groups having a high impact on the ecosystem relative to their biomass. We tested 6 hypothetical scenarios based on future biomass changes for the major functional groups (phytoplankton, zooplankton, macrozoobenthos, piscivorous fish, and bream) for 20 years. The output of the predictive scenarios showed that the biomass changes of planktonic groups would affect the whole food web. Among consumers, macrozoobenthos was crucial for the food web balance because a reduction of their biomass would also reduce the biomass of the fish community. Changes in fish catches would cause minimal biomass difference in other groups. While increased fishing pressure on large piscivores would have a marked effect on the rest of the food web, the reduction of nonpiscivorous fish like bream would have little effect. The results suggested a positive relationship between the biomass of small phytoplankton and fish, alluding to the prevalence of bottom-up trophic processes. These outcomes could be helpful for assessing trophic dynamics in shallow lakes and important aspects for fisheries and ecosystem management.
衡量营养水平之间定量相互作用影响的生态系统模型是生态系统研究和渔业管理中广泛使用的工具。我们使用Ecopath with Ecosim (EwE)建模套件为爱沙尼亚Võrtsjärv的大型浅湖构建了一个质量平衡营养模型。该模型经过36年(1983-2018)的校准，包括23个官能团。我们研究了营养关系、功能群相互作用、能量通量和相对于生物量对生态系统有高影响的关键群。我们基于浮游植物、浮游动物、大型底栖动物、食鱼鱼类和鲷鱼等主要功能类群未来20年的生物量变化，测试了6种假设情景。预测情景的结果表明，浮游生物群落生物量的变化会影响整个食物网。在消费者中，大型底栖动物对食物网平衡至关重要，因为它们的生物量减少也会减少鱼类群落的生物量。渔获量的变化对其他种群的生物量差异影响很小。虽然对大型鱼食性动物的捕捞压力增加会对食物网的其他部分产生显著影响，但像鲷鱼这样的非鱼食性鱼类的减少几乎没有影响。结果表明，小型浮游植物的生物量与鱼类之间存在正相关关系，暗示自下而上的营养过程普遍存在。这些结果有助于评估浅湖的营养动态，并对渔业和生态系统管理具有重要意义。
{"title":"Modelling how bottom-up and top-down processes control the major functional groups of biota in a large temperate shallow lake","authors":"Upendra Bhele, Burak Öğlü, T. Feldmann, P. Bernotas, H. Agasild, P. Zingel, P. Nõges, T. Nõges, F. Cremona","doi":"10.1080/20442041.2022.2031813","DOIUrl":"https://doi.org/10.1080/20442041.2022.2031813","url":null,"abstract":"ABSTRACT Ecosystem models that measure the impact of quantitative interactions between trophic levels are widely used tools in ecosystem studies and fishery management. We constructed a mass-balance trophic model using an Ecopath with Ecosim (EwE) modelling suite for large shallow Lake Võrtsjärv, Estonia. The model was calibrated for 36 years (1983–2018) and included 23 functional groups. We examined trophic relationships, functional group interactions, energy fluxes, and keystone groups having a high impact on the ecosystem relative to their biomass. We tested 6 hypothetical scenarios based on future biomass changes for the major functional groups (phytoplankton, zooplankton, macrozoobenthos, piscivorous fish, and bream) for 20 years. The output of the predictive scenarios showed that the biomass changes of planktonic groups would affect the whole food web. Among consumers, macrozoobenthos was crucial for the food web balance because a reduction of their biomass would also reduce the biomass of the fish community. Changes in fish catches would cause minimal biomass difference in other groups. While increased fishing pressure on large piscivores would have a marked effect on the rest of the food web, the reduction of nonpiscivorous fish like bream would have little effect. The results suggested a positive relationship between the biomass of small phytoplankton and fish, alluding to the prevalence of bottom-up trophic processes. These outcomes could be helpful for assessing trophic dynamics in shallow lakes and important aspects for fisheries and ecosystem management.","PeriodicalId":49061,"journal":{"name":"Inland Waters","volume":"12 1","pages":"368 - 382"},"PeriodicalIF":3.1,"publicationDate":"2022-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47912749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-14DOI: 10.1080/20442041.2021.1991754
G. Boros
ABSTRACT Fish biomass can serve as a large temporary sink of limiting nutrients, and thus fishing may represent an important anthropogenic nutrient efflux from aquatic ecosystems. However, the significance of this type of nutrient removal has rarely been evaluated for freshwater lakes. The aim of this study was to reveal how fishing contributed to the nutrient output from Lake Balaton (Hungary), the largest lake in Central Europe. The results show that net fish removal (the difference between the removed and stocked fish biomass) returned to land on average (standard deviation) 3.1 (0.3) tonnes of phosphorus (P) and 10.2 (1.1) tonnes of nitrogen (N) per year from Lake Balaton between 2017 and 2019, which is equivalent to a removal rate of 0.05 (0) kg ha−1 yr−1 P and 0.17 (0.02) kg ha−1 yr−1 N. These rates corresponded to 7.5% (1.5%) of the annual external P and 1.4% (0.6%) of the annual N loads from the inflowing watercourses. These findings suggest that fish harvest was moderately effective at offsetting external loading during the observed period. To mitigate the ongoing within-lake nutrient accumulation, more intensive selective fishing should be promoted in Lake Balaton, along with reconsideration of regulations on fishing practices.
{"title":"Nitrogen and phosphorus removal by fishing in a large freshwater lake (Lake Balaton, Hungary)","authors":"G. Boros","doi":"10.1080/20442041.2021.1991754","DOIUrl":"https://doi.org/10.1080/20442041.2021.1991754","url":null,"abstract":"ABSTRACT Fish biomass can serve as a large temporary sink of limiting nutrients, and thus fishing may represent an important anthropogenic nutrient efflux from aquatic ecosystems. However, the significance of this type of nutrient removal has rarely been evaluated for freshwater lakes. The aim of this study was to reveal how fishing contributed to the nutrient output from Lake Balaton (Hungary), the largest lake in Central Europe. The results show that net fish removal (the difference between the removed and stocked fish biomass) returned to land on average (standard deviation) 3.1 (0.3) tonnes of phosphorus (P) and 10.2 (1.1) tonnes of nitrogen (N) per year from Lake Balaton between 2017 and 2019, which is equivalent to a removal rate of 0.05 (0) kg ha−1 yr−1 P and 0.17 (0.02) kg ha−1 yr−1 N. These rates corresponded to 7.5% (1.5%) of the annual external P and 1.4% (0.6%) of the annual N loads from the inflowing watercourses. These findings suggest that fish harvest was moderately effective at offsetting external loading during the observed period. To mitigate the ongoing within-lake nutrient accumulation, more intensive selective fishing should be promoted in Lake Balaton, along with reconsideration of regulations on fishing practices.","PeriodicalId":49061,"journal":{"name":"Inland Waters","volume":"12 1","pages":"277 - 282"},"PeriodicalIF":3.1,"publicationDate":"2022-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48691772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-14DOI: 10.1080/20442041.2021.2006553
Jemma Stachelek, Patrick J. Hanly, P. Soranno
ABSTRACT Lake and reservoir (waterbody) depth is a critical characteristic that influences many important ecological processes. Unfortunately, depth measurements are labor-intensive to gather and are only available for a small fraction of waterbodies globally. Therefore, scientists have tried to predict depth from characteristics easily obtained for all waterbodies, such as surface area or the slope of the surrounding land. One approach for predicting waterbody depth simulates basins using a geometric cone model where the nearshore land slope and distance to the center of the waterbody are assumed to be representative proxies for in-lake slope and distance to the deepest point respectively. We tested these assumptions using bathymetry data from ∼5000 lakes and reservoirs to examine whether differences in waterbody type or shape influenced depth prediction error. We found that nearshore land slope was not representative of in-lake slope, and using it for prediction increases error substantially relative to models using true in-lake slope for all waterbody types and shapes. Predictions were biased toward overprediction in concave waterbodies (i.e., bowl-shaped; up to 18% of the study population) and reservoir waterbodies (up to 30% of the study population). Despite this systematic overprediction, model errors were fewer (in absolute and relative terms, irrespective of any specific slope covariate) for concave than convex waterbodies, suggesting the geometric cone model is an adequate representation of depth for these waterbodies. But because convex waterbodies are far more common (>72% of our study population), minimizing overall depth prediction error remains a challenge.
{"title":"Imperfect slope measurements drive overestimation in a geometric cone model of lake and reservoir depth","authors":"Jemma Stachelek, Patrick J. Hanly, P. Soranno","doi":"10.1080/20442041.2021.2006553","DOIUrl":"https://doi.org/10.1080/20442041.2021.2006553","url":null,"abstract":"ABSTRACT Lake and reservoir (waterbody) depth is a critical characteristic that influences many important ecological processes. Unfortunately, depth measurements are labor-intensive to gather and are only available for a small fraction of waterbodies globally. Therefore, scientists have tried to predict depth from characteristics easily obtained for all waterbodies, such as surface area or the slope of the surrounding land. One approach for predicting waterbody depth simulates basins using a geometric cone model where the nearshore land slope and distance to the center of the waterbody are assumed to be representative proxies for in-lake slope and distance to the deepest point respectively. We tested these assumptions using bathymetry data from ∼5000 lakes and reservoirs to examine whether differences in waterbody type or shape influenced depth prediction error. We found that nearshore land slope was not representative of in-lake slope, and using it for prediction increases error substantially relative to models using true in-lake slope for all waterbody types and shapes. Predictions were biased toward overprediction in concave waterbodies (i.e., bowl-shaped; up to 18% of the study population) and reservoir waterbodies (up to 30% of the study population). Despite this systematic overprediction, model errors were fewer (in absolute and relative terms, irrespective of any specific slope covariate) for concave than convex waterbodies, suggesting the geometric cone model is an adequate representation of depth for these waterbodies. But because convex waterbodies are far more common (>72% of our study population), minimizing overall depth prediction error remains a challenge.","PeriodicalId":49061,"journal":{"name":"Inland Waters","volume":"12 1","pages":"283 - 293"},"PeriodicalIF":3.1,"publicationDate":"2022-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43685529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-02DOI: 10.1080/20442041.2021.2022433
B. Spears, M. Lürling, D. Hamilton
Mustering the troops toward preventative management in lakes Bryan M. Spears , Miquel Lürling , and David P. Hamilton a,d UK Centre for Ecology & Hydrology, Penicuik, UK; School of GeoSciences, University of Edinburgh, Edinburgh, UK; Aquatic Ecology & Water Quality Management Group, Wageningen University, Wageningen, the Netherlands; Australian Rivers Institute, Griffith University, Nathan, Australia
Bryan M. Spears, Miquel lrling和David P. Hamilton，英国佩尼库克英国生态与水文中心;英国爱丁堡大学地球科学学院，英国爱丁堡;荷兰瓦赫宁根大学水生生态与水质管理小组，瓦赫宁根;澳大利亚河流研究所，格里菲斯大学，内森，澳大利亚
{"title":"Mustering the troops toward preventative management in lakes","authors":"B. Spears, M. Lürling, D. Hamilton","doi":"10.1080/20442041.2021.2022433","DOIUrl":"https://doi.org/10.1080/20442041.2021.2022433","url":null,"abstract":"Mustering the troops toward preventative management in lakes Bryan M. Spears , Miquel Lürling , and David P. Hamilton a,d UK Centre for Ecology & Hydrology, Penicuik, UK; School of GeoSciences, University of Edinburgh, Edinburgh, UK; Aquatic Ecology & Water Quality Management Group, Wageningen University, Wageningen, the Netherlands; Australian Rivers Institute, Griffith University, Nathan, Australia","PeriodicalId":49061,"journal":{"name":"Inland Waters","volume":"12 1","pages":"1 - 7"},"PeriodicalIF":3.1,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43326292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-13DOI: 10.1080/20442041.2021.1969189
Frank van Oosterhout, Said Yasseri, N. Noyma, V. Huszar, Marcelo Manzi Marinho, M. Mucci, G. Waajen, M. Lürling
ABSTRACT Lake Rauwbraken was impacted by eutrophication caused by diffuse external phosphorus (P) loads (total 1.21 mg m−2 d−1, estimated in 2008). Over 40 years, this load built up a legacy pool in the sediments, resulting in 6.82 mg m−2 d−1 PO4-P internal load (estimated in 2008), causing cyanobacterial blooms and swimming bans. To address the internal load in this lake, a low dose treatment of flocculant (polyaluminium chloride) combined with a solid phase phosphate fixative (lanthanum-modified bentonite) was applied in 2008. We examined the chemical and ecological responses to this treatment to demonstrate the efficacy of controlling internal loading without reducing external loading. Based on 2 years pre- and 10 years post-treatment monitoring, the mean Secchi disk depth (3.5–4.0 m) and the hypolimnetic oxygen concentration (0.86–4.55 mg L−1) increased while decreases occurred in turbidity (5.4 to 2.2 NTU), chlorophyll a (16.5 to 5.5 µg L−1), contribution of cyanobacteria (64% to 17% of chlorophyll a), total phosphorus (134 to 14 µg L−1), and total nitrogen (0.96 to 0.50 mg L−1). The treatment reduced the PO4-P release from sediment under anoxic conditions from 15.1 to 1.7 mg m−2 d−1 post-treatment in 2008, 2.3 mg m−2 d−1 in 2011, and 4.7 mg m−2 d−1 in 2013. Post-treatment, submerged macrophytes reached high coverage in 2008 and 2009. Longer term, post-treatment macrophyte cover was reduced. The lake is returning to a eutrophic state as a result of ongoing external P loads 10 years following the control of internal loading.
{"title":"Assessing the long-term efficacy of internal loading management to control eutrophication in Lake Rauwbraken","authors":"Frank van Oosterhout, Said Yasseri, N. Noyma, V. Huszar, Marcelo Manzi Marinho, M. Mucci, G. Waajen, M. Lürling","doi":"10.1080/20442041.2021.1969189","DOIUrl":"https://doi.org/10.1080/20442041.2021.1969189","url":null,"abstract":"ABSTRACT Lake Rauwbraken was impacted by eutrophication caused by diffuse external phosphorus (P) loads (total 1.21 mg m−2 d−1, estimated in 2008). Over 40 years, this load built up a legacy pool in the sediments, resulting in 6.82 mg m−2 d−1 PO4-P internal load (estimated in 2008), causing cyanobacterial blooms and swimming bans. To address the internal load in this lake, a low dose treatment of flocculant (polyaluminium chloride) combined with a solid phase phosphate fixative (lanthanum-modified bentonite) was applied in 2008. We examined the chemical and ecological responses to this treatment to demonstrate the efficacy of controlling internal loading without reducing external loading. Based on 2 years pre- and 10 years post-treatment monitoring, the mean Secchi disk depth (3.5–4.0 m) and the hypolimnetic oxygen concentration (0.86–4.55 mg L−1) increased while decreases occurred in turbidity (5.4 to 2.2 NTU), chlorophyll a (16.5 to 5.5 µg L−1), contribution of cyanobacteria (64% to 17% of chlorophyll a), total phosphorus (134 to 14 µg L−1), and total nitrogen (0.96 to 0.50 mg L−1). The treatment reduced the PO4-P release from sediment under anoxic conditions from 15.1 to 1.7 mg m−2 d−1 post-treatment in 2008, 2.3 mg m−2 d−1 in 2011, and 4.7 mg m−2 d−1 in 2013. Post-treatment, submerged macrophytes reached high coverage in 2008 and 2009. Longer term, post-treatment macrophyte cover was reduced. The lake is returning to a eutrophic state as a result of ongoing external P loads 10 years following the control of internal loading.","PeriodicalId":49061,"journal":{"name":"Inland Waters","volume":"12 1","pages":"61 - 77"},"PeriodicalIF":3.1,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46081633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-13DOI: 10.1080/20442041.2021.1965444
L. May, A. Dobel, C. Ongore
ABSTRACT Over the last century, water hyacinth, Eichhornia crassipes (Mart.) Solms, has invaded freshwater systems in more than 50 countries, causing changes in biodiversity and widespread ecological damage. It also disrupts fisheries, navigation routes, power generation, and water supply. Although water hyacinth has invaded all tropical and subtropical countries and some parts of the Mediterranean basin, recent climate change models suggest that its distribution may soon expand into higher latitudes as temperatures rise within Europe, unless effective preventative management measures are put in place. In this paper, we explore the potential ecological and socioeconomic impacts of water hyacinth invasion using well-documented case studies from Lake Victoria. We also consider the relative effectiveness of biological, chemical, and mechanical control measures on established populations. We conclude that water hyacinth is almost impossible to remove once established, and that controlling its spread into new areas is probably the most cost-effective way of reducing its impact. We propose a framework for the preventative management of this weed by combining the use of environmental DNA as an early warning system with heightened biosecurity to prevent accidental introductions and the physical removal of invasive plants before they become established. We also recommend that nutrient concentrations be lowered in waterbodies to reduce their susceptibility to water hyacinth invasion and reduce its growth rate if introduced accidentally.
{"title":"Controlling water hyacinth (Eichhornia crassipes (Mart.) Solms): a proposed framework for preventative management","authors":"L. May, A. Dobel, C. Ongore","doi":"10.1080/20442041.2021.1965444","DOIUrl":"https://doi.org/10.1080/20442041.2021.1965444","url":null,"abstract":"ABSTRACT Over the last century, water hyacinth, Eichhornia crassipes (Mart.) Solms, has invaded freshwater systems in more than 50 countries, causing changes in biodiversity and widespread ecological damage. It also disrupts fisheries, navigation routes, power generation, and water supply. Although water hyacinth has invaded all tropical and subtropical countries and some parts of the Mediterranean basin, recent climate change models suggest that its distribution may soon expand into higher latitudes as temperatures rise within Europe, unless effective preventative management measures are put in place. In this paper, we explore the potential ecological and socioeconomic impacts of water hyacinth invasion using well-documented case studies from Lake Victoria. We also consider the relative effectiveness of biological, chemical, and mechanical control measures on established populations. We conclude that water hyacinth is almost impossible to remove once established, and that controlling its spread into new areas is probably the most cost-effective way of reducing its impact. We propose a framework for the preventative management of this weed by combining the use of environmental DNA as an early warning system with heightened biosecurity to prevent accidental introductions and the physical removal of invasive plants before they become established. We also recommend that nutrient concentrations be lowered in waterbodies to reduce their susceptibility to water hyacinth invasion and reduce its growth rate if introduced accidentally.","PeriodicalId":49061,"journal":{"name":"Inland Waters","volume":"12 1","pages":"163 - 172"},"PeriodicalIF":3.1,"publicationDate":"2021-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44398824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-08DOI: 10.1080/20442041.2021.1969190
Hadiseh Bolkhari, L. Boegman, Ralph E. H. Smith
ABSTRACT Lake Simcoe has undergone eutrophication and hypoxia since the 1960s. Climate change, leading to enhanced summer thermal stratification, has been identified as a key stressor. In this study, we modeled the impacts of climate change on hydrodynamics and biogeochemistry in Lake Simcoe by applying a 1-dimensional (vertical) model forced with A2 and B1 scenario outputs from a global climate model over 2000–2100. The model was calibrated in 2008 and validated in 2009, with maximum root mean square error (RMSE) of modelled temperature between 1.5 and 3.0 °C and dissolved oxygen RMSE between 0.5 and 2.5 mg L−1. Phytoplankton chlorophyll a was simulated with RMSE between 1.25 µg L−1 (large diatoms) and ∼0.5 µg L−1 (other groups). Interannual variability in spring water temperature and length of stratification were related to changes in the North Atlantic and Artic Oscillation indices, respectively. Under A2 and B1 forcing, the duration of stratification will increase by 45 and 38 days in summer between spring and fall turnover, respectively. The extended stratified period leads to a reduction in hypolimnetic dissolved oxygen from 3–7 to <3 mg L−1, thereby reducing the quality of cold-water fish habitat and increasing internal phosphorus loading from the benthos. These internal loads, combined with increased water temperatures, lead to increased cyanobacteria concentrations, beginning around 2070.
{"title":"Simulated impacts of climate change on Lake Simcoe water quality","authors":"Hadiseh Bolkhari, L. Boegman, Ralph E. H. Smith","doi":"10.1080/20442041.2021.1969190","DOIUrl":"https://doi.org/10.1080/20442041.2021.1969190","url":null,"abstract":"ABSTRACT Lake Simcoe has undergone eutrophication and hypoxia since the 1960s. Climate change, leading to enhanced summer thermal stratification, has been identified as a key stressor. In this study, we modeled the impacts of climate change on hydrodynamics and biogeochemistry in Lake Simcoe by applying a 1-dimensional (vertical) model forced with A2 and B1 scenario outputs from a global climate model over 2000–2100. The model was calibrated in 2008 and validated in 2009, with maximum root mean square error (RMSE) of modelled temperature between 1.5 and 3.0 °C and dissolved oxygen RMSE between 0.5 and 2.5 mg L−1. Phytoplankton chlorophyll a was simulated with RMSE between 1.25 µg L−1 (large diatoms) and ∼0.5 µg L−1 (other groups). Interannual variability in spring water temperature and length of stratification were related to changes in the North Atlantic and Artic Oscillation indices, respectively. Under A2 and B1 forcing, the duration of stratification will increase by 45 and 38 days in summer between spring and fall turnover, respectively. The extended stratified period leads to a reduction in hypolimnetic dissolved oxygen from 3–7 to <3 mg L−1, thereby reducing the quality of cold-water fish habitat and increasing internal phosphorus loading from the benthos. These internal loads, combined with increased water temperatures, lead to increased cyanobacteria concentrations, beginning around 2070.","PeriodicalId":49061,"journal":{"name":"Inland Waters","volume":"12 1","pages":"215 - 231"},"PeriodicalIF":3.1,"publicationDate":"2021-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49357920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-07DOI: 10.1080/20442041.2021.1987796
Qing Zhan, X. Kong, K. Rinke
ABSTRACT Rising dissolved organic carbon (DOC) is interfering with drinking water production. While strategies for DOC removal during water treatment have been successfully implemented, the potential for DOC load reduction by optimized reservoir operation is not yet fully explored, mainly constrained by data paucity on real-time DOC dynamics. In this study, we utilized the emerging in situ high-frequency (HF) monitoring technique for DOC and developed a simulation–operation framework that promotes DOC mitigation in Germany’s largest drinking water reservoir. Rappbode Reservoir is embedded in a network of smaller upstream reservoirs from which Königshütte Reservoir delivers the most water but can also be operated as a bypass system. Using high-frequency monitoring of DOC concentrations and discharge at the inflows and outflows, we constructed a mass balance model that simulated the DOC dynamics in the reservoir, allowing us to explore alternative operation regimes that deliver the same amount of water but a lower DOC load. Our results show that, through rapid decision-making that enables bypassing of water with high DOC concentrations around the drinking water reservoir, the optimized operation regime is able to reduce DOC load of the drinking water reservoir by 25 ± 3%. Therefore, our proposed operational strategy to minimize DOC loading to reservoirs is promising.
{"title":"High-frequency monitoring enables operational opportunities to reduce the dissolved organic carbon (DOC) load in Germany’s largest drinking water reservoir","authors":"Qing Zhan, X. Kong, K. Rinke","doi":"10.1080/20442041.2021.1987796","DOIUrl":"https://doi.org/10.1080/20442041.2021.1987796","url":null,"abstract":"ABSTRACT Rising dissolved organic carbon (DOC) is interfering with drinking water production. While strategies for DOC removal during water treatment have been successfully implemented, the potential for DOC load reduction by optimized reservoir operation is not yet fully explored, mainly constrained by data paucity on real-time DOC dynamics. In this study, we utilized the emerging in situ high-frequency (HF) monitoring technique for DOC and developed a simulation–operation framework that promotes DOC mitigation in Germany’s largest drinking water reservoir. Rappbode Reservoir is embedded in a network of smaller upstream reservoirs from which Königshütte Reservoir delivers the most water but can also be operated as a bypass system. Using high-frequency monitoring of DOC concentrations and discharge at the inflows and outflows, we constructed a mass balance model that simulated the DOC dynamics in the reservoir, allowing us to explore alternative operation regimes that deliver the same amount of water but a lower DOC load. Our results show that, through rapid decision-making that enables bypassing of water with high DOC concentrations around the drinking water reservoir, the optimized operation regime is able to reduce DOC load of the drinking water reservoir by 25 ± 3%. Therefore, our proposed operational strategy to minimize DOC loading to reservoirs is promising.","PeriodicalId":49061,"journal":{"name":"Inland Waters","volume":"12 1","pages":"245 - 260"},"PeriodicalIF":3.1,"publicationDate":"2021-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46866405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-11DOI: 10.1080/20442041.2021.1970462
Z. Cao, J. Melack, Miao Liu, H. Duan, R. Ma
ABSTRACT Chlorophyll a (Chl-a) in lakes is an indicator of phytoplankton biomass and widely employed in lake management. Here, we used Chl-a data from 586 lakes ≥1 km2 in eastern China from 2013 to 2018 derived from the Operational Land Imager (OLI) onboard the Landsat-8 satellite to examine influences of climatic and anthropogenic factors on Chl-a variations among these lakes, partitioned into groups of different sizes. The results indicate that Chl-a values in small lakes (1–50 km2) were higher than those in large lakes (>50 km2), and the mean Chl-a in summer and autumn was higher than in spring and winter. Air temperature was positively correlated with the seasonal mean Chl-a in all sizes of lakes. Small lakes had a larger cropland proportion in their watersheds than large lakes, suggesting that the higher cropland proportion of the land cover contributed to the high Chl-a of these lakes. This research highlights the merit of high spatial resolution remote sensing for monitoring lakes in a regional context and indicates that the management of lakes could benefit from controlling agricultural activities in their watersheds.
{"title":"Spatial and seasonal variability of chlorophyll a in different-sized lakes across eastern China","authors":"Z. Cao, J. Melack, Miao Liu, H. Duan, R. Ma","doi":"10.1080/20442041.2021.1970462","DOIUrl":"https://doi.org/10.1080/20442041.2021.1970462","url":null,"abstract":"ABSTRACT Chlorophyll a (Chl-a) in lakes is an indicator of phytoplankton biomass and widely employed in lake management. Here, we used Chl-a data from 586 lakes ≥1 km2 in eastern China from 2013 to 2018 derived from the Operational Land Imager (OLI) onboard the Landsat-8 satellite to examine influences of climatic and anthropogenic factors on Chl-a variations among these lakes, partitioned into groups of different sizes. The results indicate that Chl-a values in small lakes (1–50 km2) were higher than those in large lakes (>50 km2), and the mean Chl-a in summer and autumn was higher than in spring and winter. Air temperature was positively correlated with the seasonal mean Chl-a in all sizes of lakes. Small lakes had a larger cropland proportion in their watersheds than large lakes, suggesting that the higher cropland proportion of the land cover contributed to the high Chl-a of these lakes. This research highlights the merit of high spatial resolution remote sensing for monitoring lakes in a regional context and indicates that the management of lakes could benefit from controlling agricultural activities in their watersheds.","PeriodicalId":49061,"journal":{"name":"Inland Waters","volume":"12 1","pages":"205 - 214"},"PeriodicalIF":3.1,"publicationDate":"2021-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47352457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：