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Xiao W, Zhang Y, Chen X, Sha A, Xiong Z, Luo Y, Peng L, Zou L, Zhao C, Li Q. The Easily Overlooked Effect of Global Warming: Diffusion of Heavy Metals. TOXICS 2024; 12:400. [PMID: 38922080 PMCID: PMC11209588 DOI: 10.3390/toxics12060400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 05/24/2024] [Accepted: 05/27/2024] [Indexed: 06/27/2024]
Abstract
Since industrialization, global temperatures have continued to rise. Human activities have resulted in heavy metals being freed from their original, fixed locations. Because of global warming, glaciers are melting, carbon dioxide concentrations are increasing, weather patterns are shifting, and various environmental forces are at play, resulting in the movement of heavy metals and alteration of their forms. In this general context, the impact of heavy metals on ecosystems and organisms has changed accordingly. For most ecosystems, the levels of heavy metals are on the rise, and this rise can have a negative impact on the ecosystem as a whole. Numerous studies have been conducted to analyze the combined impacts of climate change and heavy metals. However, the summary of the current studies is not perfect. Therefore, this review discusses how heavy metals affect ecosystems during the process of climate change from multiple perspectives, providing some references for addressing the impact of climate warming on environmental heavy metals.
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Affiliation(s)
- Wenqi Xiao
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering & Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China; (W.X.); (Y.Z.); (X.C.); (A.S.); (Z.X.); (Y.L.); (L.P.); (L.Z.)
| | - Yunfeng Zhang
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering & Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China; (W.X.); (Y.Z.); (X.C.); (A.S.); (Z.X.); (Y.L.); (L.P.); (L.Z.)
| | - Xiaodie Chen
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering & Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China; (W.X.); (Y.Z.); (X.C.); (A.S.); (Z.X.); (Y.L.); (L.P.); (L.Z.)
| | - Ajia Sha
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering & Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China; (W.X.); (Y.Z.); (X.C.); (A.S.); (Z.X.); (Y.L.); (L.P.); (L.Z.)
| | - Zhuang Xiong
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering & Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China; (W.X.); (Y.Z.); (X.C.); (A.S.); (Z.X.); (Y.L.); (L.P.); (L.Z.)
| | - Yingyong Luo
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering & Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China; (W.X.); (Y.Z.); (X.C.); (A.S.); (Z.X.); (Y.L.); (L.P.); (L.Z.)
| | - Lianxin Peng
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering & Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China; (W.X.); (Y.Z.); (X.C.); (A.S.); (Z.X.); (Y.L.); (L.P.); (L.Z.)
| | - Liang Zou
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering & Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China; (W.X.); (Y.Z.); (X.C.); (A.S.); (Z.X.); (Y.L.); (L.P.); (L.Z.)
| | - Changsong Zhao
- School of Public Health, Chengdu Medical College, Chengdu 610500, China
| | - Qiang Li
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering & Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China; (W.X.); (Y.Z.); (X.C.); (A.S.); (Z.X.); (Y.L.); (L.P.); (L.Z.)
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Yang M, Yang Z. Pollutant transport model with large time-scale and estimation of land-use export coefficients at a watershed level. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2024; 96:e11031. [PMID: 38685725 DOI: 10.1002/wer.11031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 03/29/2024] [Accepted: 04/03/2024] [Indexed: 05/02/2024]
Abstract
The pollutant transport equilibrium in a watershed can be analyzed on a large time scale, and land-use export coefficients can be calculated directly under certain hydrologic and transport conditions, by ignoring hydrologic and transport processes at small space and time scales on hydrologic response units. In this study, the water environment system of a watershed was deconstructed into three parts (source, source-sink, and runoff transport) to construct a pollutant transportation equilibrium model on a large time scale. A watershed with an annual source-sink accumulation of zero was defined as a completely transported watershed; therefore, we derived a completely transported equilibrium equation. The problem of seeking the land export coefficient was converted into a problem of seeking the optimal solution of linear programming, which can be estimated according to the variation in pollutant output processes. The feasibility of the solution can be analyzed using multi-year stochastic rainfall processes. The model was used to analyze the transport equilibrium of chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) upstream of the monitored cross-sections in a watershed, which covered 3145.66 km2. The land export coefficients were calculated according to the model. The model calculations indicated that the watershed was completely transported during perennial years. The calculated export coefficients of COD, TN, and TP for farmland, primary vegetation, and urban land were within the range of general empirical values. The calculated maximum accumulations of COD, TN, and TP were 0.19 × 107, 0.063 × 107, and 0.049 × 106 kg, respectively, for perennial rainfall. PRACTITIONER POINTS: A completely transported watershed was defined, and a model of pollutant transportation equilibrium with large time-scale was constructed. A problem of seeking the optimal solution of a linear programming was designed to estimate the land export coefficient of COD, TN, and TP. The runoff transport and accumulation processes of COD, TN, and TP in a watershed was analyzed.
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Affiliation(s)
- Min Yang
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China
| | - Zemin Yang
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China
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Xu S, Kaldy JE, Zhang X, Yue S, Suonan Z, Zhou Y. Comparison of metals in eelgrass (Zostera marina L.) and the environment across the North Pacific Ocean: Environmental processes drive source delivery. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 343:123096. [PMID: 38070647 PMCID: PMC11025321 DOI: 10.1016/j.envpol.2023.123096] [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: 10/18/2023] [Revised: 11/30/2023] [Accepted: 12/02/2023] [Indexed: 12/26/2023]
Abstract
Seagrass beds play a critical role in biodiversity maintenance, serving as nursery habitats for fisheries, and aiding in carbon and sediment sequestration in the ecosystem. These habitats receive dissolved and particulate material inputs, like nutrients and heavy metals, affecting both plant health and the ecosystem. Eelgrass (Zostera marina L.), sediments, and water were randomly collected at twenty sites along the temperate North Pacific coasts of Asia and North America to assess heavy metals concentrations (Cr, Cu, Zn, Cd, and Pb). This aimed to understand heavy metal distribution and accumulation patterns in eelgrass tissues, revealing crucial factors influencing metal accumulation. The sampling included various areas, from pristine marine reserves to human-influenced zones, covering industrial, agricultural, and aquaculture regions, enabling a thorough analysis. This study's uniqueness lies in comparing heavy metal distributions in eelgrass tissues with sediments, uncovering unique accumulation patterns. Aboveground eelgrass tissues mainly accumulated Cd, Zn, and Cu, while belowground tissues stored Cr and Pb. Aboveground eelgrass tissues proved reliable in indicating Cd and Pb concentrations in sediments. However, the correlation between Cu, Zn, and Cr in eelgrass tissues and environmental concentrations seemed less direct, requiring further investigation into factors affecting metal accumulation in seagrass. Human activities are probable major contributors to heavy metal presence in Asian marine environments, whereas oceanographic processes serve as primary metal sources in North American Pacific estuaries. Critical discoveries emphasize the necessity for ongoing research on phytotoxic thresholds and in-depth studies on the complex connections between seagrass physiology and environmental metal concentrations. Understanding these dynamics is crucial for evaluating the broader impact of heavy metal pollution on coastal ecosystems and developing effective conservation measures.
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Affiliation(s)
- Shaochun Xu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China; CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Shandong Province Key Laboratory of Experimental Marine Biology, Qingdao, 266071, China
| | - James E Kaldy
- Pacific Ecological Systems Division, US EPA, 2111 SE Marine Science Center Dr., Newport, OR, 97365, USA
| | - Xiaomei Zhang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China; CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Shandong Province Key Laboratory of Experimental Marine Biology, Qingdao, 266071, China
| | - Shidong Yue
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China; CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Shandong Province Key Laboratory of Experimental Marine Biology, Qingdao, 266071, China
| | - Zhaxi Suonan
- Department of Biological Sciences, Pusan National University, Buson, 46241, Republic of Korea
| | - Yi Zhou
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China; CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Shandong Province Key Laboratory of Experimental Marine Biology, Qingdao, 266071, China.
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Lin J, Compton JE, Sabo RD, Herlihy AT, Hill RA, Weber MH, Brooks JR, Paulsen SG, Stoddard JL. The changing nitrogen landscape of United States streams: Declining deposition and increasing organic nitrogen. PNAS NEXUS 2024; 3:pgad362. [PMID: 38213613 PMCID: PMC10783649 DOI: 10.1093/pnasnexus/pgad362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 10/14/2023] [Accepted: 10/26/2023] [Indexed: 01/13/2024]
Abstract
Air quality regulations have led to decreased nitrogen (N) and sulfur deposition across the conterminous United States (CONUS) during the last several decades, particularly in the eastern parts. But it is unclear if declining deposition has altered stream N at large scales. We compared watershed N inputs with N chemistry from over 2,000 CONUS streams where deposition was the largest N input to the watershed. Weighted change analysis showed that deposition declined across most watersheds, especially in the Eastern CONUS. Nationally, declining N deposition was not associated with significant large-scale declines in stream nitrate concentration. Instead, significant increases in stream dissolved organic carbon (DOC) and total organic N (TON) were widespread across regions. Possible mechanisms behind these increases include declines in acidity and/or ionic strength drivers, changes in carbon availability, and/or climate variables. Our results also reveal a declining trend of DOC/TON ratio over the entire study period, primarily influenced by the trend in the Eastern region, suggesting the rate of increase in stream TON exceeded the rate of increase in DOC concentration during this period. Our results illustrate the complexity of nutrient cycling that links long-term atmospheric deposition to water quality. More research is needed to understand how increased dissolved organic N could affect aquatic ecosystems and downstream riverine nutrient export.
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Affiliation(s)
- Jiajia Lin
- Pacific Ecological Systems Division, Office of Research and Development, US Environmental Protection Agency, Corvallis, OR 97333, USA
- Oak Ridge Institute for Science and Education, Corvallis, OR 97333, USA
- Oregon Department of Environmental Quality, Water Quality Division, Portland, OR 97232, USA
| | - Jana E Compton
- Pacific Ecological Systems Division, Office of Research and Development, US Environmental Protection Agency, Corvallis, OR 97333, USA
| | - Robert D Sabo
- Center for Public Health and Environmental Assessment, Health and Environmental Effects Division, Office of Research and Development, US Environmental Protection Agency, Washington, DC 20004, USA
| | - Alan T Herlihy
- Pacific Ecological Systems Division, Office of Research and Development, US Environmental Protection Agency, Corvallis, OR 97333, USA
- Department of Fisheries, Wildlife, and Conservation Sciences, Oregon State University, Corvallis, OR 97331, USA
| | - Ryan A Hill
- Pacific Ecological Systems Division, Office of Research and Development, US Environmental Protection Agency, Corvallis, OR 97333, USA
| | - Marc H Weber
- Pacific Ecological Systems Division, Office of Research and Development, US Environmental Protection Agency, Corvallis, OR 97333, USA
| | - J Renée Brooks
- Pacific Ecological Systems Division, Office of Research and Development, US Environmental Protection Agency, Corvallis, OR 97333, USA
| | - Steve G Paulsen
- Pacific Ecological Systems Division, Office of Research and Development, US Environmental Protection Agency, Corvallis, OR 97333, USA
| | - John L Stoddard
- Pacific Ecological Systems Division, Office of Research and Development, US Environmental Protection Agency, Corvallis, OR 97333, USA
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Schramm MP. Linking watershed nutrient loading to estuary water quality with generalized additive models. PeerJ 2023; 11:e16073. [PMID: 37780377 PMCID: PMC10540774 DOI: 10.7717/peerj.16073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 08/20/2023] [Indexed: 10/03/2023] Open
Abstract
Evaluating estuary water quality responses to reductions (or increases) in nutrient loading attributed to on the ground management actions can be challenging due to the strong influence of environmental drivers on nutrient loads and non-linear relationships. This study applied generalized additive models to calculate watershed nutrient loads and assess responses in estuary water quality to seasonally-adjusted freshwater inflow and flow-adjusted nutrient loads in Lavaca Bay, Texas. Lavaca Bay is a secondary embayment on the Texas coast displaying early potential for eutrophication and water quality degradation. Use of flow-adjusted nutrient loads allowed the study to evaluate the response in water quality to changes in nutrient loads driven by anthropogenic sources. Cross-validation indicated that, despite data constraints, semiparametric models performed well at nutrient load prediction. Based on these models, delivered annual nutrient loads varied substantially from year to year. In contrast, minimal changes in flow-normalized loads indicate that nutrient loadings were driven by natural variation in precipitation and runoff as opposed to changes in management of nonpoint sources. Models indicated no evidence of long-term changes in dissolved oxygen or chlorophyll-a within Lavaca Bay. However, site specific long-term increases in both organic and inorganic nitrogen are concerning for their potential to fuel eutrophication. Further analysis found freshwater inflow had strong influences on nutrient and chlorophyll-a concentrations but there was no evidence that changes in watershed nutrient loading explained additional variation in dissolved oxygen and limited evidence that watershed nutrient loadings explained chlorophyll-a concentrations. In addition to providing a baseline assessment of watershed nutrient loading and water quality responses in the Lavaca Bay watershed, this study provides methodological support for the use of semiparametric models in load regression models and estuary assessments.
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Affiliation(s)
- Michael P. Schramm
- Texas A&M AgriLife Research, Texas Water Resources Institute, Texas A&M University, College Station, TX, United States of America
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Ridall A, Ingels J. Nematode community structures in the presence of wastewater treatment plant discharge. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 195:991. [PMID: 37491643 DOI: 10.1007/s10661-023-11555-5] [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: 03/08/2023] [Accepted: 06/24/2023] [Indexed: 07/27/2023]
Abstract
Wastewater treatment plants (WWTPs) represent major point sources of pollution in coastal systems, affecting benthic ecosystems. In the present study, we assessed the potential role that WWTPs have in shaping nematode communities and established baseline knowledge of free-living nematode community structures in St. Andrew Bay, Florida. Sediment samples were collected from four sites representing areas of WWTP outflow and areas with no apparent outflow, during the winter and summer. Nematode communities across sites were significantly different, and the differences were strongly associated with the distance to the nearest WWTP. While the communities were not different along transects at each site, nor across seasons, community dissimilarity across sites was high, implying strong contrasts throughout the bay system. Dominance of tolerant, opportunistic genera and Ecological Quality Status assessments suggest that the system is stressed by organic enrichment, possibly linked to the WWTPs. Our results suggest that knowledge on the life-history of dominant genera is imperative to assess the ecological quality of a benthic system, in addition to taxonomic and functional metrics. Considering the value of marine nematodes as bioindicators, more work should be done to monitor temporal variability in nematode communities in this system as future infrastructure changes alter its dynamics.
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Affiliation(s)
- Aaron Ridall
- Department of Biological Science, Florida State University, 319 Stadium Dr, Tallahassee, FL, 32306, USA.
- Florida State University Coastal and Marine Laboratory, 3618 Coastal Highway 98, St. Teresa, FL, 32358, USA.
| | - Jeroen Ingels
- Florida State University Coastal and Marine Laboratory, 3618 Coastal Highway 98, St. Teresa, FL, 32358, USA
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Ibáñez C, Caiola N, Barquín J, Belmar O, Benito‐Granell X, Casals F, Fennessy S, Hughes J, Palmer M, Peñuelas J, Romero E, Sardans J, Williams M. Ecosystem-level effects of re-oligotrophication and N:P imbalances in rivers and estuaries on a global scale. GLOBAL CHANGE BIOLOGY 2023; 29:1248-1266. [PMID: 36366939 PMCID: PMC10107953 DOI: 10.1111/gcb.16520] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 10/28/2022] [Accepted: 10/29/2022] [Indexed: 05/26/2023]
Abstract
Trends and ecological consequences of phosphorus (P) decline and increasing nitrogen (N) to phosphorus (N:P) ratios in rivers and estuaries are reviewed and discussed. Results suggest that re-oligotrophication is a dominant trend in rivers and estuaries of high-income countries in the last two-three decades, while in low-income countries widespread eutrophication occurs. The decline in P is well documented in hundreds of rivers of United States and the European Union, but the biotic response of rivers and estuaries besides phytoplankton decline such as trends in phytoplankton composition, changes in primary production, ecosystem shifts, cascading effects, changes in ecosystem metabolism, etc., have not been sufficiently monitored and investigated, neither the effects of N:P imbalance. N:P imbalance has significant ecological effects that need to be further investigated. There is a growing number of cases in which phytoplankton biomass have been shown to decrease due to re-oligotrophication, but the potential regime shift from phytoplankton to macrophyte dominance described in shallow lakes has been documented only in a few rivers and estuaries yet. The main reasons why regime shifts are rarely described in rivers and estuaries are, from one hand the scarcity of data on macrophyte cover trends, and from the other hand physical factors such as peak flows or high turbidity that could prevent a general spread of submerged macrophytes as observed in shallow lakes. Moreover, re-oligotrophication effects on rivers may be different compared to lakes (e.g., lower dominance of macrophytes) or estuaries (e.g., limitation of primary production by N instead of P) or may be dependent on river/estuary type. We conclude that river and estuary re-oligotrophication effects are complex, diverse and still little known, and in some cases are equivalent to those described in shallow lakes, but the regime shift is more likely to occur in mid to high-order rivers and shallow estuaries.
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Affiliation(s)
- Carles Ibáñez
- Department of Climate Change, Area of SustainabilityEURECAT, Technological Centre of CataloniaAmpostaSpain
- National Socio‐Environmental Synthesis Center (SESYNC)University of MarylandAnnapolisMarylandUSA
| | - Nuno Caiola
- Department of Climate Change, Area of SustainabilityEURECAT, Technological Centre of CataloniaAmpostaSpain
| | - José Barquín
- IHCantabria, Instituto de Hidráulica AmbientalUniversidad de CantabriaSantanderSpain
| | - Oscar Belmar
- IRTA, Program of Marine & Continental WatersLa RàpitaSpain
| | - Xavier Benito‐Granell
- National Socio‐Environmental Synthesis Center (SESYNC)University of MarylandAnnapolisMarylandUSA
- IRTA, Program of Marine & Continental WatersLa RàpitaSpain
| | - Frederic Casals
- Department of Animal ScienceUniversity of LleidaLleidaSpain
- Landscape Dynamics and Biodiversity ProgramCTFC—Forest Science and Technology Centre of CataloniaSolsonaSpain
| | - Siobhan Fennessy
- National Socio‐Environmental Synthesis Center (SESYNC)University of MarylandAnnapolisMarylandUSA
- Biology DepartmentKenyon CollegeGambierOhioUSA
| | - Jocelyne Hughes
- School of Geography and the EnvironmentUniversity of OxfordOxfordUK
| | - Margaret Palmer
- National Socio‐Environmental Synthesis Center (SESYNC)University of MarylandAnnapolisMarylandUSA
| | - Josep Peñuelas
- Global Ecology Unit, CREAF‐CSIC‐UABUniversitat Autònoma de BarcelonaBellaterraSpain
| | - Estela Romero
- Global Ecology Unit, CREAF‐CSIC‐UABUniversitat Autònoma de BarcelonaBellaterraSpain
| | - Jordi Sardans
- Global Ecology Unit, CREAF‐CSIC‐UABUniversitat Autònoma de BarcelonaBellaterraSpain
| | - Michael Williams
- Chesapeake Biological LaboratoryUniversity of Maryland Center for Environmental ScienceSolomonsMarylandUSA
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Nalley EM, Tuttle LJ, Conklin EE, Barkman AL, Wulstein DM, Schmidbauer MC, Donahue MJ. A systematic review and meta-analysis of the direct effects of nutrients on corals. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 856:159093. [PMID: 36183766 DOI: 10.1016/j.scitotenv.2022.159093] [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: 03/31/2022] [Revised: 09/14/2022] [Accepted: 09/24/2022] [Indexed: 06/16/2023]
Abstract
Chronic exposure of coral reefs to elevated nutrient conditions can modify the performance of the coral holobiont and shift the competitive interactions of reef organisms. Many studies have now quantified the links between nutrients and coral performance, but few have translated these studies to directly address coastal water quality standards. To address this management need, we conducted a systematic review of peer-reviewed studies, public reports, and gray literature that examined the impacts of dissolved inorganic nitrogen (DIN: nitrate, nitrite, and ammonium) and dissolved inorganic phosphorus (DIP: phosphate) on scleractinian corals. The systematic review resulted in 47 studies with comparable data on coral holobiont responses to nutrients: symbiont density, chlorophyll a (chl-a) concentration, photosynthesis, photosynthetic efficiency, growth, calcification, adult survival, juvenile survival, and fertilization. Mixed-effects meta-regression meta-analyses were used to determine the magnitude of the positive or negative effects of DIN and DIP on coral responses. Zooxanthellae density (DIN & DIP), chl-a concentration (DIN), photosynthetic rate (DIN), and growth (DIP) all exhibited positive responses to nutrient addition; maximum quantum yield (DIP), growth (DIN), larval survival (DIN), and fertilization (DIN) exhibited negative responses. In lieu of developing specific thresholds for the management of nutrients as a stressor on coral reefs, we highlight important inflection points in the magnitude and direction of the effects of inorganic nutrients and identify trends among coral responses. The responses of corals to nutrients are complex, warranting conservative guidelines for elevated nutrient concentrations on coral reefs.
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Affiliation(s)
- Eileen M Nalley
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, 46-007 Lilipuna Road, Kāne'ohe, HI 96744, USA.
| | - Lillian J Tuttle
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, 46-007 Lilipuna Road, Kāne'ohe, HI 96744, USA; U.S. Geological Survey, Hawai'i Cooperative Fishery Unit, University of Hawai'i at Hilo, Hilo, HI 96720, USA
| | - Emily E Conklin
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, 46-007 Lilipuna Road, Kāne'ohe, HI 96744, USA
| | - Alexandria L Barkman
- Kewalo Marine Laboratory, Pacific Biosciences Research Center, University of Hawai'i at Mānoa, 41 Ahui Street, Honolulu, HI 96813, USA
| | - Devynn M Wulstein
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, 46-007 Lilipuna Road, Kāne'ohe, HI 96744, USA
| | - Madeline C Schmidbauer
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, 46-007 Lilipuna Road, Kāne'ohe, HI 96744, USA
| | - Megan J Donahue
- Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, 46-007 Lilipuna Road, Kāne'ohe, HI 96744, USA
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Pelletier MC, Charpentier M. Assessing the relative importance of stressors to the benthic index, M-AMBI: An example from U.S. estuaries. MARINE POLLUTION BULLETIN 2023; 186:114456. [PMID: 36502776 PMCID: PMC9813808 DOI: 10.1016/j.marpolbul.2022.114456] [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: 09/12/2022] [Revised: 10/25/2022] [Accepted: 11/28/2022] [Indexed: 06/17/2023]
Abstract
M-AMBI, a multivariate benthic index, has been used by European and American (U.S.) authorities to assess estuarine and coastal health and has been used in scientific studies throughout the world. It has been shown to be related to multiple pressures and stressors, but the relative importance of individual stressors within a multiple stressor context has not generally been assessed. In this study, we assembled data collected between 1999 and 2015 by the U.S. Environmental Protection Agency using consistent methods. These data included sediment and water quality measures and benthic invertebrate data which were used to calculate M-AMBI. We further assembled watersheds for all US estuaries with benthic data and calculated land use metrics. Random forest (RF) was used to identify those variables most strongly related to M-AMBI. Because RF is a compilation of multiple, nonlinear models, we then assessed which of these variables had a direct relationship with M-AMBI. The resulting variables were then assessed using RF to identify the subsets of variables that produced an effective and parsimonious model. This process was conducted at the national and ecoregional scale and the variables identified as being most important to predict M-AMBI were compared with literature reports of ecological patterns in a given area. At the national scale, better condition was correlated with clearer waters, lower amounts of agriculture in the watershed, and lower carbon and metal concentrations in estuarine sediments. Other stressors were identified as being important at the ecoregional scale, although sediment metal concentrations and watershed agriculture were identified as being important in most ecoregions. Our results suggest that this technique is useful to identify the most important variables impacting M-AMBI at broad spatial scales, even when the percentage of sites in Bad or Poor condition is low. This technique also provides an initial identification of important stressors that can be used to target more intensive local studies.
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Affiliation(s)
- Marguerite C Pelletier
- Atlantic Coastal Environmental Sciences Division, US EPA, ORD, CEMM, Narragansett, RI, USA.
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10
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Danylchuk AJ, Griffin LP, Ahrens R, Allen MS, Boucek RE, Brownscombe JW, Casselberry GA, Danylchuk SC, Filous A, Goldberg TL, Perez AU, Rehage JS, Santos RO, Shenker J, Wilson JK, Adams AJ, Cooke SJ. Cascading effects of climate change on recreational marine flats fishes and fisheries. ENVIRONMENTAL BIOLOGY OF FISHES 2022; 106:381-416. [PMID: 36118617 PMCID: PMC9465673 DOI: 10.1007/s10641-022-01333-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 08/27/2022] [Indexed: 06/15/2023]
Abstract
Tropical and subtropical coastal flats are shallow regions of the marine environment at the intersection of land and sea. These regions provide myriad ecological goods and services, including recreational fisheries focused on flats-inhabiting fishes such as bonefish, tarpon, and permit. The cascading effects of climate change have the potential to negatively impact coastal flats around the globe and to reduce their ecological and economic value. In this paper, we consider how the combined effects of climate change, including extremes in temperature and precipitation regimes, sea level rise, and changes in nutrient dynamics, are causing rapid and potentially permanent changes to the structure and function of tropical and subtropical flats ecosystems. We then apply the available science on recreationally targeted fishes to reveal how these changes can cascade through layers of biological organization-from individuals, to populations, to communities-and ultimately impact the coastal systems that depend on them. We identify critical gaps in knowledge related to the extent and severity of these effects, and how such gaps influence the effectiveness of conservation, management, policy, and grassroots stewardship efforts.
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Affiliation(s)
- Andy J. Danylchuk
- Department of Environmental Conservation, University of Massachusetts Amherst, 160 Holdsworth Way, Amherst, MA 01003 USA
| | - Lucas P. Griffin
- Department of Environmental Conservation, University of Massachusetts Amherst, 160 Holdsworth Way, Amherst, MA 01003 USA
| | - Robert Ahrens
- Fisheries Research and Monitoring Division, NOAA Pacific Islands Fisheries Science Center, 1845 Wasp Blvd., Bldg 176, Honolulu, HI 96818 USA
| | - Micheal S. Allen
- Nature Coast Biological Station, School of Forest, Fisheries and Geomatics Sciences, The University of Florida, 552 First Street, Cedar Key, FL 32625 USA
| | - Ross E. Boucek
- Bonefish & Tarpon Trust, 2937 SW 27th Ave, Suite 203, Miami, FL 33133 USA
- Earth and Environment Department, Florida International University, Miami, FL 33199 USA
| | - Jacob W. Brownscombe
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6 Canada
| | - Grace A. Casselberry
- Department of Environmental Conservation, University of Massachusetts Amherst, 160 Holdsworth Way, Amherst, MA 01003 USA
| | - Sascha Clark Danylchuk
- Department of Environmental Conservation, University of Massachusetts Amherst, 160 Holdsworth Way, Amherst, MA 01003 USA
- Keep Fish Wet, 11 Kingman Road, Amherst, MA 01002 USA
| | - Alex Filous
- Department of Environmental Conservation, University of Massachusetts Amherst, 160 Holdsworth Way, Amherst, MA 01003 USA
| | - Tony L. Goldberg
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, 1656 Linden Drive, Madison, WI 53706 USA
| | - Addiel U. Perez
- Bonefish & Tarpon Trust, 2937 SW 27th Ave, Suite 203, Miami, FL 33133 USA
| | - Jennifer S. Rehage
- Earth and Environment Department, Florida International University, Miami, FL 33199 USA
| | - Rolando O. Santos
- Department of Biological Sciences, Florida International University, Miami, FL 33181 USA
| | - Jonathan Shenker
- Department of Ocean Engineering and Marine Sciences, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL 32904 USA
| | - JoEllen K. Wilson
- Bonefish & Tarpon Trust, 2937 SW 27th Ave, Suite 203, Miami, FL 33133 USA
| | - Aaron J. Adams
- Bonefish & Tarpon Trust, 2937 SW 27th Ave, Suite 203, Miami, FL 33133 USA
- Florida Atlantic University Harbor Branch Oceanographic Institute, 5600 US 1 North, Fort Pierce, FL 34946 USA
| | - Steven J. Cooke
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6 Canada
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11
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Geostatistical Analysis of Mangrove Ecosystem Health: Mapping and Modelling of Sampling Uncertainty Using Kriging. FORESTS 2022. [DOI: 10.3390/f13081185] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This study assessed the health of the mangrove ecosystem and mapped the spatial variation in selected variables sampled across the Matang Mangrove Forest Reserve (MMFR) by using a geostatistical technique. A total of 556 samples were collected from 56 sampling points representing mangrove biotic and abiotic variables. All variables were used to generate the semivariogram model. The predicted variables over the entire MMFR have an overall prediction accuracy of 85.16% (AGB), 90.78% (crab abundance), 97.3% (soil C), 99.91% (soil N), 89.23% (number of phytoplankton species), 95.62% (number of diatom species), 99.36% (DO), and 87.33% (turbidity). Via linear weight combination, the prediction map shows that mangrove ecosystem health in Kuala Trong throughout the Sungai Kerang is excellent (5: MQI > 1.5). Some landward areas of Kuala Trong were predicted to have moderate health (3: −0.5 ≤ MQI ≤ 0.5), while Kuala Sepetang was predicted to have the bad ecosystem health (2: -1.5 ≤ MQI ≤ −0.5), with active timber harvesting operations and anthropogenic activities in the landward areas. The results of this method can be utilised to carry out the preferred restoration, through appropriate management and facilities distribution, for improving the ecosystem health of mangroves.
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12
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Zhang Q, Bostic JT, Sabo RD. Regional patterns and drivers of total nitrogen trends in the Chesapeake Bay watershed: Insights from machine learning approaches and management implications. WATER RESEARCH 2022; 218:118443. [PMID: 35461100 PMCID: PMC9743807 DOI: 10.1016/j.watres.2022.118443] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 03/11/2022] [Accepted: 04/08/2022] [Indexed: 06/14/2023]
Abstract
Anthropogenic nutrient inputs have led to nutrient enrichment in many waterbodies worldwide, including Chesapeake Bay (USA). River water quality integrates the spatial and temporal changes of watersheds and forms the foundation for disentangling the effects of anthropogenic inputs. We demonstrate with the Chesapeake Bay Non-Tidal Monitoring Network that machine learning approaches - i.e., hierarchical clustering and random forest (RF) classification - can be combined to better understand the regional patterns and drivers of total nitrogen (TN) trends in large monitoring networks, resulting in information useful for watershed management. Cluster analysis revealed regional patterns of short-term TN trends (2007-2018) and categorized the stations into three distinct trend clusters, namely, V-shape (n = 23), monotonic decline (n = 35), and monotonic increase (n = 26). RF models identified regional drivers of TN trend clusters by quantifying the effects of watershed characteristics (land use, geology, physiography) and major N sources on the trend clusters. Results provide encouraging evidence that improved agricultural nutrient management has resulted in declines in agricultural nonpoint sources, which in turn contributed to water-quality improvement in our period of analysis. Moreover, water-quality improvements are more likely in watersheds underlain by carbonate rocks, reflecting the relatively quick groundwater transport of this terrain. By contrast, water-quality improvements are less likely in Coastal Plain watersheds, reflecting the effect of legacy N in groundwater. Notably, results show degrading trends in forested watersheds, suggesting new and/or remobilized sources that may compromise management efforts. Finally, the developed RF models were used to predict TN trend clusters for the entire Chesapeake Bay watershed at the fine scale of river segments (n = 979), providing fine spatial information that can facilitate targeted watershed management, including unmonitored areas. More broadly, this combined use of clustering and classification approaches can be applied to other regional monitoring networks to address similar water-quality questions.
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Affiliation(s)
- Qian Zhang
- University of Maryland Center for Environmental Science, Chesapeake Bay Program Office, Annapolis, MD 21403, USA.
| | - Joel T Bostic
- University of Maryland Center for Environmental Science, Appalachian Laboratory, Frostburg, MD 21532, USA
| | - Robert D Sabo
- U.S. Environmental Protection Agency, Washington D.C. 20004, USA
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13
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Ross ER, Randhir TO. Effects of climate and land use changes on water quantity and quality of coastal watersheds of Narragansett Bay. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 807:151082. [PMID: 34710414 DOI: 10.1016/j.scitotenv.2021.151082] [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: 03/03/2021] [Revised: 10/09/2021] [Accepted: 10/15/2021] [Indexed: 06/13/2023]
Abstract
Land use is rapidly changing in coastal watersheds, with implications on eutrophication of coastal watersheds. The long-term consequences of climate change on these impacts are critical to watershed management. With coastal watersheds facing frequent hypoxic events and cultural eutrophication, the coupled influence of land use and climate change can lead to policies under nonstationarity assumptions. This study aims to model a regional coastal watershed system using a dynamic simulation with future land use and climate stressors for watershed sustainability. The efficacy of current nutrient management efforts may be limited or undone if future changes in climate or land use increase nutrient and sediment loads to the Narragansett Bay. The baseline model was calibrated and validated to accurately reflect watershed processes to simulate water quantity and quality under the independent and combined influence of future climate and land scenarios. Results show significant effects of climate change and land-use change on the watershed, with demonstrated impacts on sediment loading, organic N, organic P, and nitrates. Climate impacts were much more significant than land-use effects, but land-use impacts displayed greater regional variation. The results from combined simulations indicate that future climate and land-use change will likely negatively impact the coastal system and need restoration efforts that consider nonstationarity. However, the results also highlight the potential to utilize land use to mitigate and adapt to climate change impacts.
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Affiliation(s)
- Evan R Ross
- College of Natural Sciences, University of Massachusetts, Amherst, MA 01003, United States of America.
| | - Timothy O Randhir
- Department of Environmental Conservation, 160 Holdsworth Way, University of Massachusetts, Amherst, MA 01003, United States of America.
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14
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Murphy RR, Keisman J, Harcum J, Karrh RR, Lane M, Perry ES, Zhang Q. Nutrient Improvements in Chesapeake Bay: Direct Effect of Load Reductions and Implications for Coastal Management. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:260-270. [PMID: 34931816 DOI: 10.1021/acs.est.1c05388] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In Chesapeake Bay in the United States, decades of management efforts have resulted in modest reductions of nutrient loads from the watershed, but the corresponding improvements in estuarine water quality have not consistently followed. Generalized additive models were used to directly link river flows and nutrient loads from the watershed to nutrient trends in the estuary on a station-by-station basis, which allowed for identification of exactly when and where responses are happening. Results show that Chesapeake Bay's total nitrogen and total phosphorus conditions are mostly improving after accounting for variation in freshwater flow. Almost all of these improving nutrient concentrations in the estuary can be explained by reductions in watershed loads entering through 16 rivers and 145 nearby point sources, with the nearby point source reductions being slightly more effective at explaining estuarine nutrient trends. Overall, these two major types of loads from multiple locations across the watershed are together necessary and responsible for the improving estuarine nutrient conditions, a finding that is highly relevant to managing valuable estuarine resources worldwide.
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Affiliation(s)
- Rebecca R Murphy
- University of Maryland Center for Environmental Science, Chesapeake Bay Program Office, 1750 Forest Dr., Suite 130, Annapolis, Maryland 21401, United States
| | - Jennifer Keisman
- U.S. Geological Survey, 5522 Research Park Drive, Catonsville, Maryland 21228, United States
| | - Jon Harcum
- Tetra Tech, Inc., 10306 Eaton Place, Suite 340, Fairfax, Virginia 22030, United States
| | - Renee R Karrh
- Maryland Department of Natural Resources, 580 Taylor Ave-D2, Annapolis, Maryland 21401, United States
| | - Mike Lane
- Department of Biological Sciences, Old Dominion University, Norfolk, Virginia 23529-0050, United States
| | - Elgin S Perry
- Statistics Consultant, 377 Resolutions Rd., Colonial Beach, Virginia 22443, United States
| | - Qian Zhang
- University of Maryland Center for Environmental Science, Chesapeake Bay Program Office, 1750 Forest Dr., Suite 130, Annapolis, Maryland 21401, United States
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15
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Fox RJ, Fisher TR, Gustafson AB, Koontz EL, Lepori-Bui M, Kvalnes KL, Bunnell-Young DE, Gardner JR, Lewis J, Winsten JR, Fisher KA, Silaphone K. An evaluation of the Chesapeake Bay management strategy to improve water quality in small agricultural watersheds. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 299:113478. [PMID: 34488113 DOI: 10.1016/j.jenvman.2021.113478] [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: 07/13/2020] [Revised: 07/28/2021] [Accepted: 08/02/2021] [Indexed: 06/13/2023]
Abstract
Chesapeake Bay water quality has been a concern since 1970. In rural areas, agriculture is the dominant N and P source, and the voluntary application of best management practices (BMPs) is the primary management tool. Here we test the hypothesis that the current management approach of primarily voluntary, untargeted BMP implementation is insufficient to create detectable, widespread reductions in N, P, and total suspended solid (TSS) concentrations in agricultural watersheds of the Choptank basin, a tributary of Chesapeake Bay. To test this hypothesis, we assessed BMP implementation and sampled water quality on participating farms, at intermediate streams within each watershed, and at watershed outlets of four watersheds from 2013 to 2014. We also present water quality data from 2003 to 2014 at the outlets of 12 additional agricultural and one forested watershed and survey-directed interviews of farmers. By the end of 2014, large numbers of BMPs, both structural and cultural, had been implemented. Of the 16 agricultural watersheds, 50% showed significant decreases in baseflow N, 37.5% showed no changes, and 12.5% showed increasing TN. Baseflow P significantly decreased at just one watershed, increased at one, and remained stable at 14. Stormflow N was similar to baseflow, but stormflow P was 5 times higher than baseflow. These data partially support our hypothesis. Surveys suggested farmers considered themselves responsible for the quality of water leaving their farms, but out-of-pocket cost was the major impediment to further BMP adoption. We suggest that greater outreach and more financial support for farmers to implement BMPs is required to increase the types and densities of BMPs needed to achieve regional water quality goals.
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Affiliation(s)
- R J Fox
- Department of Environmental Science and Studies, Washington College, 300 Washington Ave., Chestertown, MD, 21620, USA; Horn Point Laboratory, Center for Environmental Science, University of Maryland, Cambridge, MD, 21613, USA.
| | - T R Fisher
- Horn Point Laboratory, Center for Environmental Science, University of Maryland, Cambridge, MD, 21613, USA
| | - A B Gustafson
- Horn Point Laboratory, Center for Environmental Science, University of Maryland, Cambridge, MD, 21613, USA
| | - E L Koontz
- Horn Point Laboratory, Center for Environmental Science, University of Maryland, Cambridge, MD, 21613, USA
| | - M Lepori-Bui
- Horn Point Laboratory, Center for Environmental Science, University of Maryland, Cambridge, MD, 21613, USA
| | - K L Kvalnes
- Horn Point Laboratory, Center for Environmental Science, University of Maryland, Cambridge, MD, 21613, USA
| | - D E Bunnell-Young
- Horn Point Laboratory, Center for Environmental Science, University of Maryland, Cambridge, MD, 21613, USA
| | - J R Gardner
- Horn Point Laboratory, Center for Environmental Science, University of Maryland, Cambridge, MD, 21613, USA
| | - J Lewis
- University of Maryland Extension, Denton, MD, 21629, USA
| | - J R Winsten
- Winrock International, Arlington, VA, 22202, USA
| | - K A Fisher
- Winrock International, Arlington, VA, 22202, USA
| | - K Silaphone
- Horn Point Laboratory, Center for Environmental Science, University of Maryland, Cambridge, MD, 21613, USA; Department of Geography and Geosciences, Salisbury University, Salisbury, MD, 21801, USA
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16
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Frei RJ, Lawson GM, Norris AJ, Cano G, Vargas MC, Kujanpää E, Hopkins A, Brown B, Sabo R, Brahney J, Abbott BW. Limited progress in nutrient pollution in the U.S. caused by spatially persistent nutrient sources. PLoS One 2021; 16:e0258952. [PMID: 34843503 PMCID: PMC8629290 DOI: 10.1371/journal.pone.0258952] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 10/10/2021] [Indexed: 01/01/2023] Open
Abstract
Human agriculture, wastewater, and use of fossil fuels have saturated ecosystems with nitrogen and phosphorus, threatening biodiversity and human water security at a global scale. Despite efforts to reduce nutrient pollution, carbon and nutrient concentrations have increased or remained high in many regions. Here, we applied a new ecohydrological framework to ~12,000 water samples collected by the U.S. Environmental Protection Agency from streams and lakes across the contiguous U.S. to identify spatial and temporal patterns in nutrient concentrations and leverage (an indicator of flux). For the contiguous U.S. and within ecoregions, we quantified trends for sites sampled repeatedly from 2000 to 2019, the persistence of spatial patterns over that period, and the patch size of nutrient sources and sinks. While we observed various temporal trends across ecoregions, the spatial patterns of nutrient and carbon concentrations in streams were persistent across and within ecoregions, potentially because of historical nutrient legacies, consistent nutrient sources, and inherent differences in nutrient removal capacity for various ecosystems. Watersheds showed strong critical source area dynamics in that 2-8% of the land area accounted for 75% of the estimated flux. Variability in nutrient contribution was greatest in catchments smaller than 250 km2 for most parameters. An ensemble of four machine learning models confirmed previously observed relationships between nutrient concentrations and a combination of land use and land cover, demonstrating how human activity and inherent nutrient removal capacity interactively determine nutrient balance. These findings suggest that targeted nutrient interventions in a small portion of the landscape could substantially improve water quality at continental scales. We recommend a dual approach of first prioritizing the reduction of nutrient inputs in catchments that exert disproportionate influence on downstream water chemistry, and second, enhancing nutrient removal capacity by restoring hydrological connectivity both laterally and vertically in stream networks.
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Affiliation(s)
- Rebecca J. Frei
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, Utah, United States of America
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Gabriella M. Lawson
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, Utah, United States of America
| | - Adam J. Norris
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, Utah, United States of America
| | - Gabriel Cano
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, Utah, United States of America
| | - Maria Camila Vargas
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, Utah, United States of America
| | - Elizabeth Kujanpää
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, Utah, United States of America
| | - Austin Hopkins
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, Utah, United States of America
| | - Brian Brown
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, Utah, United States of America
| | - Robert Sabo
- United States Environmental Protection Agency, Washington, D. C., United States of America
| | - Janice Brahney
- Department of Watershed Sciences and Ecology Center, Utah State University, Logan, Utah, United States of America
| | - Benjamin W. Abbott
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, Utah, United States of America
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17
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Carleton JN, Washington BJ. Assessing Evidence of Phosphorus Concentration Trends in North American Fresh Waters. JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION 2021; 57:956-971. [PMID: 36960312 PMCID: PMC10031499 DOI: 10.1111/1752-1688.12970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 10/13/2021] [Indexed: 06/18/2023]
Abstract
The U.S. EPA's National Aquatic Resource Surveys (NARS) documented evidence of widespread, unexplained total phosphorus (TP) concentration increases in lakes and streams across the United States during the 2000 - 2012 time period. To examine the robustness of evidence for this trend, we used additional monitoring datasets to calculate rates of TP change in thousands of individual waterbodies across the U.S. during the same time frame, and compared them against TP change rates calculated in the same manner for waterbodies that were resurveyed under NARS in different years. For the additional datasets, median rates of TP change were substantially lower than median rates calculated using NARS data. To further examine differences between NARS and non-NARS results in specific waterbodies, we assembled composite datasets for 52 predominantly northern lakes that by chance had been sampled under both NARS and other sampling programs during the same time frame. Using only NARS data, the median calculated TP change rate for this set of lakes was positive, and similar to that for the larger set of 401 resurveyed NARS lakes. However, when additional sample data were included, the median calculated TP change rate for these lakes was much lower. Results suggest that increasing TP concentrations in waterbodies may not have been as ubiquitous as suggested. They also illustrate a need to supplement randomized continental-scale monitoring with detailed, site-focused investigations.
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Affiliation(s)
- James N. Carleton
- Office of Research and Development, Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency (Mail Code 8623R), 1200 Pennsylvania Ave NW, Washington, DC
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18
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Modelling the effects of urbanization on nutrients pollution for prospective management of a tropical watershed: A case study of Skudai River watershed. Ecol Modell 2021. [DOI: 10.1016/j.ecolmodel.2021.109721] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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19
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Reyes AGB, Vergara MCS, Blanco AC, Salmo SG. Seagrass biomass and sediment carbon in conserved and disturbed seascape. Ecol Res 2021. [DOI: 10.1111/1440-1703.12272] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
| | | | - Ariel C. Blanco
- Department of Geodetic Engineering, College of Engineering University of the Philippines Diliman Quezon City Philippines
| | - Severino G. Salmo
- Department of Environmental Science Ateneo de Manila University Quezon City Philippines
- Institute of Biology, College of Science, University of the Philippines Diliman Quezon City Philippines
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20
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Suárez-Castro AF, Beyer HL, Kuempel CD, Linke S, Borrelli P, Hoegh-Guldberg O. Global forest restoration opportunities to foster coral reef conservation. GLOBAL CHANGE BIOLOGY 2021; 27:5238-5252. [PMID: 34350684 DOI: 10.1111/gcb.15811] [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: 03/30/2021] [Revised: 06/24/2021] [Accepted: 06/27/2021] [Indexed: 06/13/2023]
Abstract
Sediment runoff from disturbed coastal catchments is a major threat to marine ecosystems. Understanding where sediments are produced and where they are delivered enables managers to design more effective strategies for improving water quality. A management strategy is targeted restoration of degraded terrestrial areas, as it provides opportunities to reduce land-based runoff from coastal areas and consequently foster coral reef conservation. To do this strategically, a systematic approach is needed to identify watersheds where restoration actions will provide the highest conservation benefits for coral reefs. Here, we develop a systematic approach for identifying global forest restoration opportunities that would also result in large decreases in the flux of sediments to coral reefs. We estimate how land-use change affects sediment runoff globally using high-resolution spatial data and determine the subsequent risk of sediment exposure on coral reefs using a diffusion-based ocean transport model. Our results reveal that sediment export is a major issue affecting 41% of coral reefs globally. The main coastal watersheds with the highest sediment export are predominantly located in Southeast Asian countries, with Indonesia and the Philippines accounting for 52% of the sediment export in coastal areas near coral reefs. We show how restoring forest across multiple watersheds could help to reduce sediment export to 63,000 km2 of coral reefs. Although reforestation opportunities in areas that discharge onto coral reefs are relatively small across watersheds, it is possible to achieve large sediment reduction benefits by strategically targeting watersheds located in regions with a high density of corals near to the coast. Thus, reforestation benefits on coral reefs do not necessarily come from the watersheds that produce the highest sediment export. These analyses are key for generating informed action to support both international conservation policy and national restoration activities.
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Affiliation(s)
- Andrés F Suárez-Castro
- School of Biological Sciences, The University of Queensland, St Lucia, Qld, Australia
- Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, Bogotá, Colombia
| | - Hawthorne L Beyer
- School of Biological Sciences, The University of Queensland, St Lucia, Qld, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, The University of Queensland, St Lucia, Qld, Australia
| | - Caitlin D Kuempel
- School of Biological Sciences, The University of Queensland, St Lucia, Qld, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, The University of Queensland, St Lucia, Qld, Australia
| | - Simon Linke
- Australian Rivers Institute - Coast and Estuaries, School of Environment and Science, Griffith University, Gold Coast, Qld, Australia
| | - Pasquale Borrelli
- Department of Earth and Environmental Sciences, University of Pavia, Pavia, Italy
- Department of Biological Environment, Kangwon National University, Chuncheon, Republic of Korea
| | - Ove Hoegh-Guldberg
- School of Biological Sciences, The University of Queensland, St Lucia, Qld, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, The University of Queensland, St Lucia, Qld, Australia
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21
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Kim D, Lim JH, Chun Y, Nayna OK, Begum MS, Park JH. Phytoplankton nutrient use and CO 2 dynamics responding to long-term changes in riverine N and P availability. WATER RESEARCH 2021; 203:117510. [PMID: 34375930 DOI: 10.1016/j.watres.2021.117510] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 06/21/2021] [Accepted: 07/27/2021] [Indexed: 06/13/2023]
Abstract
Long-term trends in riverine nutrient availability have rarely been linked to both phytoplankton composition and functioning. To explore how the changing availability of N and P affects not only phytoplankton abundance and composition but also the resource use efficiency of N, P, and CO2, a 25-year time series of water quality in the lower Han River, Korea, was combined with additional measurements of riverine dissolved organic carbon (DOC) and CO2. Despite persistent eutrophication, recent decreases in P relative to N have been steep in the lowest reach, increasing the annual mean mass ratio of N to P (N/P) from 24 (1994-2015) to 65 (2016-2018). While Chl a and cyanobacterial abundance exhibited overall positive and inverse relationships with P concentrations and N/P, respectively, severe harmful algal blooms (HABs) concurred with short-term increases in P and temperature. Microcystis often dominated HABs at low N/P that usually favors N-fixing cyanobacteria such as Anabaena. In the middle and lower reaches, phytoplanktonic P use efficiency was typically lower at low N/P. V-shaped relationships between N/P and CO2 concentrations, together with longitudinal upward shifts in the inverse relationship between Chl a and CO2, implied that eutrophication-enhanced phytoplankton biomass could turn into a significant source of CO2. after passing a threshold. The combined results suggest that cyanobacterial dominance co-limited by P availability and temperature can lower planktonic P use efficiency, while enhancing riverine CO2 emissions at low N/P ratios.
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Affiliation(s)
- Dohee Kim
- Department of Environmental Science and Engineering, Ewha Womans University, Seoul 03760, South Korea
| | - Ju-Hee Lim
- Department of Environmental Science and Engineering, Ewha Womans University, Seoul 03760, South Korea
| | - Yewon Chun
- Department of Environmental Science and Engineering, Ewha Womans University, Seoul 03760, South Korea
| | - Omme Kulsum Nayna
- Department of Environmental Science and Engineering, Ewha Womans University, Seoul 03760, South Korea
| | - Most Shirina Begum
- Department of Environmental Science and Engineering, Ewha Womans University, Seoul 03760, South Korea
| | - Ji-Hyung Park
- Department of Environmental Science and Engineering, Ewha Womans University, Seoul 03760, South Korea.
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22
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Hansen AT, Campbell T, Cho SJ, Czuba JA, Dalzell BJ, Dolph CL, Hawthorne PL, Rabotyagov S, Lang Z, Kumarasamy K, Belmont P, Finlay JC, Foufoula-Georgiou E, Gran KB, Kling CL, Wilcock P. Integrated assessment modeling reveals near-channel management as cost-effective to improve water quality in agricultural watersheds. Proc Natl Acad Sci U S A 2021; 118:e2024912118. [PMID: 34260382 PMCID: PMC8285912 DOI: 10.1073/pnas.2024912118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 05/28/2021] [Indexed: 11/18/2022] Open
Abstract
Despite decades of policy that strives to reduce nutrient and sediment export from agricultural fields, surface water quality in intensively managed agricultural landscapes remains highly degraded. Recent analyses show that current conservation efforts are not sufficient to reverse widespread water degradation in Midwestern agricultural systems. Intensifying row crop agriculture and increasing climate pressure require a more integrated approach to water quality management that addresses diverse sources of nutrients and sediment and off-field mitigation actions. We used multiobjective optimization analysis and integrated three biophysical models to evaluate the cost-effectiveness of alternative portfolios of watershed management practices at achieving nitrate and suspended sediment reduction goals in an agricultural basin of the Upper Midwestern United States. Integrating watershed-scale models enabled the inclusion of near-channel management alongside more typical field management and thus directly the comparison of cost-effectiveness across portfolios. The optimization analysis revealed that fluvial wetlands (i.e., wide, slow-flowing, vegetated water bodies within the riverine corridor) are the single-most cost-effective management action to reduce both nitrate and sediment loads and will be essential for meeting moderate to aggressive water quality targets. Although highly cost-effective, wetland construction was costly compared to other practices, and it was not selected in portfolios at low investment levels. Wetland performance was sensitive to placement, emphasizing the importance of watershed scale planning to realize potential benefits of wetland restorations. We conclude that extensive interagency cooperation and coordination at a watershed scale is required to achieve substantial, economically viable improvements in water quality under intensive row crop agricultural production.
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Affiliation(s)
- Amy T Hansen
- St. Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN 55455;
- Civil, Environmental, and Architectural Engineering Department, University of Kansas, Lawrence, KS 66045
| | - Todd Campbell
- Center for Agricultural and Rural Development, Iowa State University, Ames, IA 50011
| | - Se Jong Cho
- St. Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN 55455
- Hydrodynamic Branch, US Geological Survey, Reston, VA 20192
| | - Jonathan A Czuba
- St. Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN 55455
- Department of Biological Systems Engineering, Virginia Tech, Blacksburg, VA 24061
| | - Brent J Dalzell
- Department of Soil, Water, and Climate, University of Minnesota, St. Paul, MN 55108
- Soil and Water Management Research Unit, US Department of Agriculture Agricultural Research Service, St. Paul, MN 55108
| | - Christine L Dolph
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN 55108
- Dyson School of Applied Economics and Management, Cornell University, Ithaca, NY 14853
| | - Peter L Hawthorne
- Institute on the Environment, University of Minnesota, St. Paul, MN 55108
| | - Sergey Rabotyagov
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA 98195
| | - Zhengxin Lang
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA 98195
| | - Karthik Kumarasamy
- Department of Watershed Sciences, Utah State University, Logan, UT 84322
| | - Patrick Belmont
- Department of Watershed Sciences, Utah State University, Logan, UT 84322
| | - Jacques C Finlay
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN 55108
| | - Efi Foufoula-Georgiou
- St. Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN 55455
- Department of Civil and Environmental Engineering, University of California, Irvine, CA 92697
- Department of Earth System Science, University of California, Irvine, CA 92697
| | - Karen B Gran
- Department of Earth and Environmental Sciences, University of Minnesota, Duluth, MN 55812
| | - Catherine L Kling
- Center for Agricultural and Rural Development, Iowa State University, Ames, IA 50011
- Dyson School of Applied Economics and Management, Cornell University, Ithaca, NY 14853
| | - Peter Wilcock
- Department of Watershed Sciences, Utah State University, Logan, UT 84322
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23
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Long CA, Chabot RM, El‐Khazen MN, Kelley JR, Mollet‐Saint Benoît C, Mansfield KL. Incongruent long‐term trends of a marine consumer and primary producers in a habitat affected by nutrient pollution. Ecosphere 2021. [DOI: 10.1002/ecs2.3553] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
| | - Ryan M. Chabot
- University of Central Florida Orlando Florida32816USA
- Inwater Research Group, Inc. Jensen Beach Florida34957USA
| | | | | | - Céline Mollet‐Saint Benoît
- University of Central Florida Orlando Florida32816USA
- Metropolitan North Georgia Water Planning District Atlanta Regional Commission Atlanta Georgia30303USA
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24
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Abstract
Increasing evidence suggests that coral reefs exposed to elevated turbidity may be more resilient to climate change impacts and serve as an important conservation hotspot. However, logistical difficulties in studying turbid environments have led to poor representation of these reef types within the scientific literature, with studies using different methods and definitions to characterize turbid reefs. Here we review the geological origins and growth histories of turbid reefs from the Holocene (past), their current ecological and environmental states (present), and their potential responses and resilience to increasing local and global pressures (future). We classify turbid reefs using new descriptors based on their turbidity regime (persistent, fluctuating, transitional) and sources of sediment input (natural versus anthropogenic). Further, by comparing the composition, function and resilience of two of the most studied turbid reefs, Paluma Shoals Reef Complex, Australia (natural turbidity) and Singapore reefs (anthropogenic turbidity), we found them to be two distinct types of turbid reefs with different conservation status. As the geographic range of turbid reefs is expected to increase due to local and global stressors, improving our understanding of their responses to environmental change will be central to global coral reef conservation efforts.
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25
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Lapointe BE, Brewton RA, Herren LW, Wang M, Hu C, McGillicuddy DJ, Lindell S, Hernandez FJ, Morton PL. Nutrient content and stoichiometry of pelagic Sargassum reflects increasing nitrogen availability in the Atlantic Basin. Nat Commun 2021; 12:3060. [PMID: 34031385 PMCID: PMC8144625 DOI: 10.1038/s41467-021-23135-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 04/09/2021] [Indexed: 11/25/2022] Open
Abstract
The pelagic brown macroalgae Sargassum spp. have grown for centuries in oligotrophic waters of the North Atlantic Ocean supported by natural nutrient sources, such as excretions from associated fishes and invertebrates, upwelling, and N2 fixation. Using a unique historical baseline, we show that since the 1980s the tissue %N of Sargassum spp. has increased by 35%, while %P has decreased by 44%, resulting in a 111% increase in the N:P ratio (13:1 to 28:1) and increased P limitation. The highest %N and δ15N values occurred in coastal waters influenced by N-rich terrestrial runoff, while lower C:N and C:P ratios occurred in winter and spring during peak river discharges. These findings suggest that increased N availability is supporting blooms of Sargassum and turning a critical nursery habitat into harmful algal blooms with catastrophic impacts on coastal ecosystems, economies, and human health.
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Affiliation(s)
- B E Lapointe
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, FL, USA.
| | - R A Brewton
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, FL, USA
| | - L W Herren
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, FL, USA
| | - M Wang
- College of Marine Science, University of South Florida, St. Petersburg, FL, USA
| | - C Hu
- College of Marine Science, University of South Florida, St. Petersburg, FL, USA
| | | | - S Lindell
- Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - F J Hernandez
- Division of Coastal Sciences, University of Southern Mississippi, Ocean Springs, MS, USA
| | - P L Morton
- Florida State University/National High Magnetic Field Lab, Tallahassee, FL, USA
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26
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Mosesso LR, Buda A, Collick A, Kennedy C, Folmar G, Shober A. Examining sources and pathways of phosphorus transfer in a ditch-drained field. JOURNAL OF ENVIRONMENTAL QUALITY 2021; 50:680-693. [PMID: 33843067 DOI: 10.1002/jeq2.20226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 03/31/2021] [Indexed: 06/12/2023]
Abstract
Understanding the processes that mobilize and transport dissolved phosphorus (P) during storms is critical to managing P in flat landscapes with open ditch drainage and legacy soil P. In this study, we used routine baseflow monitoring and intensive storm sampling at a ditch-drained site on Maryland's Lower Eastern Shore (July 2017-September 2018) to assess whether concentration-discharge (C-Q) relationships and chemical and isotopic hydrograph separation could provide insight into the processes that mobilize and transport dissolved P in ditch drainage. Using a segmented regression model, we determined that long-term C-Q relationships for dissolved P differed above and below a discharge threshold of 6.4 L s-1 . Intensive storm sampling revealed that small storms (n = 3) occurring at or below the discharge threshold generally exhibited complex hysteresis and dissolved P dilution patterns that were consistent with deeper (>122 cm) groundwater inputs with low dissolved P concentrations (0.04 mg L-1 ). In contrast, large storms occurring well above the discharge threshold (n = 4) induced rising water tables and preferential flow pathways that most likely tapped dissolved P-enriched shallow (<20 cm) soil waters (0.89 mg L-1 ), producing consistent clockwise hysteresis and dissolved P flushing patterns. Notably, chemical and isotope hydrograph separation during two of the largest storms revealed significant event water fractions (59-68%) that strongly suggested a role for the rapid delivery of dissolved P via preferential flow pathways. Findings highlight the need to mitigate vertical P stratification as a means for reducing dissolved P flushing from ditch-drained landscapes with legacy P.
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Affiliation(s)
- Lauren R Mosesso
- Dep. of Plant and Soil Sciences, Univ. of Delaware, 531 S. College Ave., Newark, DE, 19716, USA
| | - Anthony Buda
- USDA-ARS, Pasture Systems and Watershed Management Research Unit, Curtin Road, University Park, PA, 16802, USA
| | - Amy Collick
- Dep. of Agricultural Sciences, Morehead State Univ., 326 Reed Hall, Morehead, KY, 40351, USA
| | - Casey Kennedy
- USDA-ARS, Pasture Systems and Watershed Management Research Unit, East Wareham, MA, 02538, USA
| | - Gordon Folmar
- USDA-ARS, Pasture Systems and Watershed Management Research Unit, Curtin Road, University Park, PA, 16802, USA
| | - Amy Shober
- Dep. of Plant and Soil Sciences, Univ. of Delaware, 531 S. College Ave., Newark, DE, 19716, USA
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27
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Sabo RD, Clark CM, Gibbs DA, Metson GS, Todd MJ, LeDuc SD, Greiner D, Fry MM, Polinsky R, Yang Q, Tian H, Compton JE. Phosphorus Inventory for the Conterminous United States (2002-2012). JOURNAL OF GEOPHYSICAL RESEARCH. BIOGEOSCIENCES 2021; 126:1-21. [PMID: 37089664 PMCID: PMC10116864 DOI: 10.1029/2020jg005684] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Published reports suggest efforts designed to prevent the occurrence of harmful algal blooms and hypoxia by reducing non-point and point source phosphorus (P) pollution are not delivering water quality improvements in many areas. Part of the uncertainty in evaluating watershed responses to management practices is the lack of standardized estimates of phosphorus inputs and outputs. To assess P trends across the conterminous United States, we compiled an inventory using publicly available datasets of agricultural P fluxes, atmospheric P deposition, human P demand and waste, and point source discharges for 2002, 2007, and 2012 at the scale of the 8-digit Hydrologic Unit Code subbasin (~1,800 km2). Estimates of agricultural legacy P surplus accumulated from 1945 to 2001 were also developed. Fertilizer and manure inputs were found to exceed crop removal rates by up to 50% in many agricultural regions. This excess in inputs has led to the continued accumulation of legacy P in agricultural lands. Atmospheric P deposition increased throughout the Rockies, potentially contributing to reported increases in surface water P concentrations in undisturbed watersheds. In some urban areas, P fluxes associated with human waste and non-farm fertilizer use has declined despite population growth, likely due, in part, to various sales bans on P-containing detergents and fertilizers. Although regions and individual subbasins have different contemporary and legacy P sources, a standardized method of accounting for large and small fluxes and ready to use inventory numbers provide essential infromation to coordinate targeted interventions to reduce P concentrations in the nation's waters.
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Affiliation(s)
- Robert D Sabo
- Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Office of Research and Development, U.S. EPA, Washington, DC, USA
| | - Christopher M Clark
- Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Office of Research and Development, U.S. EPA, Washington, DC, USA
| | | | - Geneviève S Metson
- Department of Physics, Chemistry, and Biology, Linköping University, Linköping, Sweden
| | - M Jason Todd
- U.S. Environmental Protection Agency, Office of Chemical Safety and Pollution, U.S. EPA, Washington, DC, USA
| | - Stephen D LeDuc
- Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Office of Research and Development, U.S. EPA, Research Triangle Park, NC, USA
| | - Diana Greiner
- U.S. Environmental Protection Agency, U.S. EPA, Dallas, TX, USA
| | - Meridith M Fry
- Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Office of Research and Development, U.S. EPA, Washington, DC, USA
| | - Robyn Polinsky
- U.S. Environmental Protection Agency, U.S. EPA, Atlanta, GA, USA
| | - Qichun Yang
- Pacific Northwest National Lab, Richland, WA, USA
| | - Hanqin Tian
- International Center for Climate and Global Change Research, School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL, USA
| | - Jana E Compton
- Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Office of Research and Development, U.S. EPA, Corvallis, OR, USA
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28
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Langholtz M, Davison BH, Jager HI, Eaton L, Baskaran LM, Davis M, Brandt CC. Increased nitrogen use efficiency in crop production can provide economic and environmental benefits. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 758:143602. [PMID: 33234272 DOI: 10.1016/j.scitotenv.2020.143602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 10/26/2020] [Accepted: 10/30/2020] [Indexed: 05/22/2023]
Abstract
Potential economic and environmental benefits of increasing nitrogen-use efficiency (NUE) are widely recognized but scarcely quantified. This study quantifies the effects of increased NUE on 1) the national agricultural economy using a simulation model of US agriculture and 2) regional water quality effects using a biogeochemical model for the Arkansas-White-Red river basin. National economic effects are reported for NUE improvement scenarios of 10%, 20%, 50%, and 100%, whereas regional water quality effects are estimated for a 20% NUE improvement scenario in the Arkansas-White-Red river basin. Simulating a 20% increase in NUE in row crops is shown to reduce N requirements by 1.4 million tonnes y-1 and increase farmer net profits by 1.6% ($743 million) per year by 2026 over the baseline simulation for the same period. For each 10% increase in NUE, annual farm revenues for commodity crops increased over the baseline by approximately $350 million per year by 2026. Changes in crop prices and land-use relative to the baseline were less than 2%. This suggests a net benefit even though fertilizer cost savings can result in increased cultivation of land, i.e., 'Jevon's paradox'. Results from the biogeochemical model of the Arkansas-White-Red river basin suggest that a 20% increase in NUE corresponds to a 5.72% reduction in nitrate loadings to freshwaters, with higher reductions in agricultural watersheds. The value of these reductions was estimated as $43 ha-1, for a total of $15.3 to 136.7 million yr-1 in avoided water treatment costs. After estimating the social value of increased NUE, we conclude with a discussion of potential strategies to increase efficiency and the research needed to achieve this goal. These include perennialization of the agricultural landscape, genetic crop improvement, targeted fertilizer application, and manipulation of the plant-root microbiome.
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Affiliation(s)
- Matthew Langholtz
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
| | - Brian H Davison
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Henriette I Jager
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Laurence Eaton
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Latha M Baskaran
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Maggie Davis
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Craig C Brandt
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
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29
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Zhang Q, Webber JS, Moyer DL, Chanat JG. An approach for decomposing river water-quality trends into different flow classes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 755:143562. [PMID: 33199002 DOI: 10.1016/j.scitotenv.2020.143562] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 10/29/2020] [Accepted: 11/03/2020] [Indexed: 06/11/2023]
Abstract
A number of statistical approaches have been developed to quantify the overall trend in river water quality, but most approaches are not intended for reporting separate trends for different flow conditions. We propose an approach called FN2Q, which is an extension of the flow-normalization (FN) procedure of the well-established WRTDS ("Weighted Regressions on Time, Discharge, and Season") method. The FN2Q approach provides a daily time series of low-flow and high-flow FN flux estimates that represent the lower and upper half of daily riverflow observations that occurred on each calendar day across the period of record. These daily estimates can be summarized into any time period of interest (e.g., monthly, seasonal, or annual) for quantifying trends. The proposed approach is illustrated with an application to a record of total nitrogen concentration (632 samples) collected between 1985 and 2018 from the South Fork Shenandoah River at Front Royal, Virginia (USA). Results show that the overall FN flux of total nitrogen has declined in the period of 1985-2018, which is mainly attributable to FN flux decline in the low-flow class. Furthermore, the decline in the low-flow class was highly correlated with wastewater effluent loads, indicating that the upgrades of treatment technology at wastewater treatment facilities have likely led to water-quality improvement under low-flow conditions. The high-flow FN flux showed a spike around 2007, which was likely caused by increased delivery of particulate nitrogen associated with sediment transport. The case study demonstrates the utility of the FN2Q approach toward not only characterizing the changes in river water quality but also guiding the direction of additional analysis for capturing the underlying drivers. The FN2Q approach (and the published code) can easily be applied to widely available river monitoring records to quantify water-quality trends under different flow conditions to enhance understanding of river water-quality dynamics.
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Affiliation(s)
- Qian Zhang
- University of Maryland Center for Environmental Science, Chesapeake Bay Program Office, Annapolis, MD, USA.
| | - James S Webber
- U.S. Geological Survey, Virginia and West Virginia Water Science Center, Richmond, VA, USA
| | - Douglas L Moyer
- U.S. Geological Survey, Virginia and West Virginia Water Science Center, Richmond, VA, USA
| | - Jeffrey G Chanat
- U.S. Geological Survey, Virginia and West Virginia Water Science Center, Richmond, VA, USA
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30
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Waite SJ, Clark AR, Suresh V, Singhal N, Clarke RJ. Using flow simulation to inform the design and placement of remediation units in rivers. J R Soc N Z 2021. [DOI: 10.1080/03036758.2020.1868540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Stephen J. Waite
- Department of Engineering Science, University of Auckland, Auckland, New Zealand
| | - Alys R. Clark
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Vinod Suresh
- Department of Engineering Science, University of Auckland, Auckland, New Zealand
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Naresh Singhal
- Department of Civil and Environmental Engineering, University of Auckland, Auckland, New Zealand
| | - Richard J. Clarke
- Department of Engineering Science, University of Auckland, Auckland, New Zealand
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31
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Covert SA, Shoda ME, Stackpoole SM, Stone WW. Pesticide mixtures show potential toxicity to aquatic life in U.S. streams, water years 2013-2017. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 745:141285. [PMID: 32943215 DOI: 10.1016/j.scitotenv.2020.141285] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/24/2020] [Accepted: 07/25/2020] [Indexed: 05/24/2023]
Abstract
During water years (WY) 2013-2017, the U.S. Geological Survey, National Water-Quality Assessment (NAWQA) Project, sampled the National Water Quality Network - Rivers and Streams (NWQN) year-round and reported on 221 pesticides at 72 sites across the United States in agricultural, developed, and mixed land use watersheds. The Pesticide Toxicity Index (PTI) was used to estimate the potential chronic and acute toxicity to three taxonomic groups - fish, cladocerans, and benthic invertebrates. For invertebrates (either cladocerans, benthic invertebrates, or both), the maximum PTI score exceeded the predicted acute toxicity screening level at 18 of the 72 sites (25%) at some point during WY 2013-2017. The predicted toxicity of a single pesticide compound was found to overwhelm the toxicity of other pesticides in the mixtures after concentrations were toxicity weighted. For this study, about 71%, 72%, and 92% of the Fish-, Cladoceran-, and Benthic Invertebrate-PTI scores, respectively, had one pesticide compound primarily contributing to sample potential toxicity (>50%). There were 17 (13 insecticides, 2 herbicides, 1 fungicide, and 1 synergist) of the 221 pesticide compounds analyzed that were the primary drivers of potential toxicity in each water sample in which the PTI and TUmax (toxic unit score for the pesticide that makes the single largest contribution to the PTI) scores were above predicted chronic (>0.1) or acute (>1) toxicity levels for one of the three taxa. For cladocerans and benthic invertebrates, the drivers of predicted chronic (>0.1) and acute (>1) PTIs were mostly insecticides. For cladocerans, the pesticide compounds driving the PTI scores were bifenthrin, carbaryl, chlorpyrifos, diazinon, dichlorvos, dicrotophos, diflubenzuron, flubendiamide, and tebupirimfos. For benthic invertebrates, atrazine (an herbicide), as well as the insecticides - bifenthrin, carbaryl, carbofuran, chlorpyrifos, diazinon, dichlorvos, fipronil, imidacloprid, and methamidophos - were the drivers of predicted toxicity. For fish, there were three pesticide types that contributed the most to predicted chronic (>0.1) PTIs - acetochlor, an herbicide; carbendazim, a fungicide degradate; and piperonylbutoxide, a synergist.
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Affiliation(s)
- S Alex Covert
- U.S. Geological Survey, Ohio-Kentucky-Indiana Water Science Center, Columbus, OH, United States of America.
| | - Megan E Shoda
- U.S. Geological Survey, Ohio-Kentucky-Indiana Water Science Center, Indianapolis, IN, United States of America.
| | - Sarah M Stackpoole
- U.S. Geological Survey, Water Mission Area, Denver, CO 80225, United States of America.
| | - Wesley W Stone
- U.S. Geological Survey, Caribbean-Florida Water Science Center, Lutz, FL, United States of America.
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32
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Ator SW, Blomquist JD, Webber JS, Chanat JG. Factors driving nutrient trends in streams of the Chesapeake Bay watershed. JOURNAL OF ENVIRONMENTAL QUALITY 2020; 49:812-834. [PMID: 33016477 DOI: 10.1002/jeq2.20101] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 05/11/2020] [Indexed: 05/23/2023]
Abstract
Despite decades of effort toward reducing nitrogen and phosphorus flux to Chesapeake Bay, water-quality and ecological responses in surface waters have been mixed. Recent research, however, provides useful insight into multiple factors complicating the understanding of nutrient trends in bay tributaries, which we review in this paper, as we approach a 2025 total maximum daily load (TMDL) management deadline. Improvements in water quality in many streams are attributable to management actions that reduced point sources and atmospheric nitrogen deposition and to changes in climate. Nutrient reductions expected from management actions, however, have not been fully realized in watershed streams. Nitrogen from urban nonpoint sources has declined, although water-quality responses to urbanization in individual streams vary depending on predevelopment land use. Evolving agriculture, the largest watershed source of nutrients, has likely contributed to local nutrient trends but has not affected substantial changes in flux to the bay. Changing average nitrogen yields from farmland underlain by carbonate rocks, however, may suggest future trends in other areas under similar management, climatic, or other influences, although drivers of these changes remain unclear. Regardless of upstream trends, phosphorus flux to the bay from its largest tributary has increased due to sediment infill in the Conowingo Reservoir. In general, recent research emphasizes the utility of input reductions over attempts to manage nutrient fate and transport at limiting nutrients in surface waters. Ongoing research opportunities include evaluating effects of climate change and conservation practices over time and space and developing tools to disentangle and evaluate multiple influences on regional water quality.
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Affiliation(s)
- Scott W Ator
- USGS, 5522 Research Park Dr., Baltimore, MD, 21228, USA
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33
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Ruprecht JE, Glamore WC, Dafforn KA, Wemheuer F, Crane SL, van Dorst J, Johnston EL, Mitrovic SM, Turner IL, Ferrari BC, Birrer SC. A novel real-world ecotoxicological dataset of pelagic microbial community responses to wastewater. Sci Data 2020; 7:158. [PMID: 32461582 PMCID: PMC7253417 DOI: 10.1038/s41597-020-0496-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 04/20/2020] [Indexed: 11/08/2022] Open
Abstract
Real-world observational datasets that record and quantify pressure-stressor-response linkages between effluent discharges and natural aquatic systems are rare. With global wastewater volumes increasing at unprecedented rates, it is urgent that the present dataset is available to provide the necessary information about microbial community structure and functioning. Field studies were performed at two time-points in the Austral summer. Single-species and microbial community whole effluent toxicity (WET) testing was performed at a complete range of effluent concentrations and two salinities, with accompanying environmental data to provide new insights into nutrient and organic matter cycling, and to identify ecotoxicological tipping points. The two salinity regimes were chosen to investigate future scenarios based on a predicted salinity increase at the study site, typical of coastal regions with rising sea levels globally. Flow cytometry, amplicon sequencing of 16S and 18S rRNA genes and micro-fluidic quantitative polymerase-chain reactions (MFQPCR) were used to determine chlorophyll-a and total bacterial cell numbers and size, as well as taxonomic and functional diversity of pelagic microbial communities. This strong pilot dataset could be replicated in other regions globally and would be of high value to scientists and engineers to support the next advances in microbial ecotoxicology, environmental biomonitoring and estuarine water quality modelling.
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Affiliation(s)
- J E Ruprecht
- Water Research Laboratory, School of Civil & Environmental Engineering, UNSW Sydney, Sydney, NSW, 2052, Australia.
| | - W C Glamore
- Water Research Laboratory, School of Civil & Environmental Engineering, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - K A Dafforn
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
- Department of Earth and Environmental Sciences, Macquarie University, Macquarie Park, NSW, 2109, Australia
| | - F Wemheuer
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - S L Crane
- Ferrari Lab, School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - J van Dorst
- Ferrari Lab, School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - E L Johnston
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - S M Mitrovic
- Freshwater and Estuarine Research Group, School of Life Sciences, University of Technology Sydney, Ultimo, 2007, NSW, Australia
| | - I L Turner
- Water Research Laboratory, School of Civil & Environmental Engineering, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - B C Ferrari
- Ferrari Lab, School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - S C Birrer
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
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Yang G, Moyer DL. Estimation of nonlinear water-quality trends in high-frequency monitoring data. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 715:136686. [PMID: 32032984 DOI: 10.1016/j.scitotenv.2020.136686] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 01/12/2020] [Accepted: 01/12/2020] [Indexed: 06/10/2023]
Abstract
Recent advances in high-frequency water-quality sensors have enabled direct measurements of physical and chemical attributes in rivers and streams nearly continuously. Water-quality trends can be used to identify important watershed-scale changes driven by natural and anthropogenic influences. Statistical methods to estimate trends using high-frequency data are lacking. To address this gap, an evaluation of the generalized additive model (GAM) approach to test for trends in high-frequency data was conducted. Our proposed framework includes methods for handling serial correlation, trend estimation and slope-change detection, and trend interpretation at arithmetic scale for log-transformed variables. Water-temperature and turbidity data, representing two analytes with different temporal patterns, collected from the James River at Cartersville, Virginia, USA, were chosen for this analysis. Results indicated that the model, including flow, season, time covariates, and interaction between flow and season performed well for both analytes. The same model structure was applied to specific conductance data, collected from a small highly urbanized watershed, with satisfactory model performance. The water temperature GAM results indicated that the significant decreasing-then-increasing patterns after 2012 were mainly driven by air temperature changes. The turbidity trend was not significant over time. The specific conductance results showed a consistently upward trend over the last decade due to ever-increasing urbanization in the small watershed. This study suggests that the GAM method has great potential as a useful tool for trend analysis on high-frequency data, and for informing watershed managers of hydro-climatic and human influences on water quality by detecting crucial signal variation over time.
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Affiliation(s)
- Guoxiang Yang
- Natural Systems Analysts, Contractor to U.S. Geological Survey, 1730 East Parham Road, Richmond, VA 23228, United States of America.
| | - Douglas L Moyer
- U.S. Geological Survey, 1730 East Parham Road, Richmond, VA 23228, United States of America
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Stets EG, Sprague LA, Oelsner GP, Johnson HM, Murphy JC, Ryberg K, Vecchia AV, Zuellig RE, Falcone JA, Riskin ML. Landscape Drivers of Dynamic Change in Water Quality of U.S. Rivers. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:4336-4343. [PMID: 32216285 DOI: 10.1021/acs.est.9b05344] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Water security is a top concern for social well-being, and dramatic changes in the availability of freshwater have occurred as a result of human uses and landscape management. Elevated nutrient loading and perturbations to major ion composition have resulted from human activities and have degraded freshwater resources. This study addresses the emerging nature of streamwater quality in the 21st century through analysis of concentrations and trends in a wide variety of constituents in streams and rivers of the U.S. Concentrations of 15 water quality constituents including nutrients, major ions, sediment, and specific conductance were analyzed over the period 1982-2012 and a targeted trend analysis was performed from 1992 to 2012. Although environmental policy is geared toward addressing the long-standing problem of nutrient overenrichment, these efforts have had uneven success, with decreasing nutrient concentrations at urbanized sites and little to no change at agricultural sites. Additionally, freshwaters are being salinized rapidly in all human-dominated land use types. While efforts to control nutrients are ongoing, rapid salinity increases are ushering in a new set of poorly defined issues. Increasing salinity negatively affects biodiversity, mobilizes sediment-bound contaminants, and increases lead contamination of drinking water, but its effects are not well integrated into current paradigms of water management.
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Affiliation(s)
- Edward G Stets
- U.S. Geological Survey, Earth System Process Division, 3215 Marine St, Ste E-127, Boulder, Colorado 80303, United States
| | - Lori A Sprague
- U.S. Geological Survey, Earth System Process Division, W Sixth Ave Kipling St 415, Lakewood, Colorado 80225, United States
| | - Gretchen P Oelsner
- U.S. Geological Survey, New Mexico Water Science Center, 6700 Edith Blvd NE, Albuquerque, New Mexico 87113, United States
| | - Hank M Johnson
- U.S. Geological Survey, Oregon Water Science Center, 2130 SW Fifth Ave, Portland, Oregon 97201, United States
| | - Jennifer C Murphy
- U.S. Geological Survey, Lower Mississippi-Gulf Water Science Center, 640 Grassmere Park, Ste. 100, Nashville, Tennessee 37211, United States
| | - Karen Ryberg
- U.S. Geological Survey, Dakota Water Science Center, 821 East Interstate Ave, Bismarck, North Dakota 58503, United States
| | - Aldo V Vecchia
- U.S. Geological Survey, Dakota Water Science Center, 821 East Interstate Ave, Bismarck, North Dakota 58503, United States
| | - Robert E Zuellig
- U.S. Geological Survey, Colorado Water Science Center, Denver Federal Center, W Sixth Ave Kipling St 415, Lakewood, Colorado 80225, United States
| | - James A Falcone
- U.S. Geological Survey, Earth System Process Division, 12201 Sunrise Valley Dr 413 Reston, Virginia 20192, United States
| | - Melissa L Riskin
- U.S. Geological Survey, New Jersey Water Science Center, 3450 Princeton Pike Lawrenceville, New Jersey 08648, United States
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Räike A, Taskinen A, Knuuttila S. Nutrient export from Finnish rivers into the Baltic Sea has not decreased despite water protection measures. AMBIO 2020; 49:460-474. [PMID: 31278623 PMCID: PMC6965342 DOI: 10.1007/s13280-019-01217-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 03/29/2019] [Accepted: 06/24/2019] [Indexed: 05/16/2023]
Abstract
To tackle the symptoms of eutrophication in the open Baltic Sea and Finnish coastal waters, Finland has agreed to reduce both total nitrogen (TN) and total phosphorus (TP) inputs. Due to large investments in treatment of municipal and industrial wastewaters, TP loads started to decrease already in the mid-1970s and the respective TN loads in the mid-1990s. During the last two decades, much effort has been spent in decreasing the load originating from diffuse sources. Trend analyses in 1995-2016 showed that, despite various mitigation measures, riverine nutrient export has not substantially decreased, and especially the export from rivers draining agricultural lands remains high. In some areas TN concentrations and export were increasing and we found evidence that it was linked to ditching of peatlands. Several factors connected to climate/weather (e.g. temperature and precipitation) have counteracted the mitigation measures, and therefore Finland will not achieve the nutrient reduction targets by 2021.
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Affiliation(s)
- Antti Räike
- Finnish Environment Institute, Latokartanonkaari 11, 00790 Helsinki, Finland
| | - Antti Taskinen
- Finnish Environment Institute, Latokartanonkaari 11, 00790 Helsinki, Finland
| | - Seppo Knuuttila
- Finnish Environment Institute, Latokartanonkaari 11, 00790 Helsinki, Finland
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Casila JC, Ella V, Yokoyama K. Effect of neap-spring hydrodynamics on salt and suspended sediment transport in multi-branched urban estuaries. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 694:133653. [PMID: 31394329 DOI: 10.1016/j.scitotenv.2019.133653] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 07/26/2019] [Accepted: 07/27/2019] [Indexed: 06/10/2023]
Abstract
Unique neap and spring tide hydrodynamic features were studied in the estuarine areas of multi-branched urban rivers in Tokyo, Japan. Intensive measurements of salinity, turbidity, dissolved oxygen, velocity, particulate organic matter (POM), and nutrients were conducted for 13h in five stations simultaneously on July 3 and July 11, 2017. Water sampling, analysis and calculations of salt and sediment transport were performed. Results showed that the Arakawa and Sumida Rivers follow the typical natural estuary hydrodynamics while Shakujii River followed a typical artificial urban estuary. Shakujii River upstream estuary had lower flow velocity during spring tide (-0.05 to 0.04m/s) than neap tide (-0.09 to 0.16m/s) because of the channel slope that does not allow the transit of water to upstream even during high tide. Shakujii River downstream estuary had hypoxic (DO<2mg/L) bottom depths during neap and spring tide. Sumida River and Shakujii River are adjacent yet the nutrient and POM had different nature. Shakujii River is highly influenced by freshwater from combined sewer systems carrying POM, nutrients and sediments. The freshwater was 54% (14,650m3) and 100% (28,671.1m3) by volume during neap and spring tide, respectively. The POM and nutrients in Sumida River is influenced by tidal processes and tributary rivers. SS was transported from Sumida to Shakujii River during flood phase of spring tide. Freshwater from Arakawa River flows to Sumida River during ebb tide. Salt (-0.066kg/m/s) and SS (-0.16 to -2.435kg/m/s) were retained in the estuaries which may lead to river deterioration and occurrence of scum, hypoxia and odor. The results of the study, particularly on Shakujii River, are significant and could serve as basis for water quality management in similar urban estuaries.
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Affiliation(s)
- Joan Cecilia Casila
- Department of Civil and Environmental Engineering, Tokyo Metropolitan University, 1-1, Minami-Osawa, Hachioji, Tokyo 192-0397, Japan; Land and Water Resources Division, IAE, CEAT, University of the Philippines Los Baños, College, Laguna 4031, Philippines
| | - Victor Ella
- Land and Water Resources Division, IAE, CEAT, University of the Philippines Los Baños, College, Laguna 4031, Philippines
| | - Katsuhide Yokoyama
- Department of Civil and Environmental Engineering, Tokyo Metropolitan University, 1-1, Minami-Osawa, Hachioji, Tokyo 192-0397, Japan.
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Ballard TC, Sinha E, Michalak AM. Long-Term Changes in Precipitation and Temperature Have Already Impacted Nitrogen Loading. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:5080-5090. [PMID: 30979339 DOI: 10.1021/acs.est.8b06898] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Increases in nitrogen loading over the past several decades have led to widespread water quality impairments across the U.S. Elevated awareness of the influence of climate variability on nitrogen loading has led to several studies investigating future climate change impacts on water quality. However, it remains unclear whether long-term climate impacts can already be observed in the historical record. Here, we quantify long-term trends in total nitrogen loading over the period 1987-2012 across the contiguous U.S. and attribute these trends to long-term changes in nitrogen inputs and climatic variables. We find that annual precipitation, extreme springtime precipitation, and springtime temperature are key drivers of trends in historical loading in most regions. These decadal climate trends have either amplified or offset loading trends expected from nitrogen inputs alone. We also find that rising temperatures have been insufficient to offset precipitation-induced loading increases, suggesting that future increases in temperature under climate change may have limited potential to counteract loading increases expected as a result of anticipated changes in precipitation. This work demonstrates the important role of decadal climate variability in long-term nitrogen loading, emphasizing the need to consider climate change risks when designing and monitoring nutrient reduction programs.
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Affiliation(s)
- Tristan C Ballard
- Department of Earth System Science , Stanford University , Stanford , California 94305 United States
- Department of Global Ecology , Carnegie Institution for Science , Stanford , California 94305 United States
| | - Eva Sinha
- Department of Earth System Science , Stanford University , Stanford , California 94305 United States
- Department of Global Ecology , Carnegie Institution for Science , Stanford , California 94305 United States
| | - Anna M Michalak
- Department of Earth System Science , Stanford University , Stanford , California 94305 United States
- Department of Global Ecology , Carnegie Institution for Science , Stanford , California 94305 United States
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Stutter M, Kronvang B, Ó hUallacháin D, Rozemeijer J. Current Insights into the Effectiveness of Riparian Management, Attainment of Multiple Benefits, and Potential Technical Enhancements. JOURNAL OF ENVIRONMENTAL QUALITY 2019; 48:236-247. [PMID: 30951120 DOI: 10.2134/jeq2019.01.0020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Buffer strips between land and waters are widely applied measures in diffuse pollution management, with desired outcomes across other factors. There remains a need for evidence of pollution mitigation and wider habitat and societal benefits across scales. This paper synthesizes a collection of 16 new primary studies and review papers to provide the latest insights into riparian management. We focus on the following areas: (i) diffuse pollution removal efficiency of conventional and saturated buffer strips, (ii) enhancing biodiversity of buffers, (iii) edge-of-field technologies for improving nutrient retention, and (iv) potential reuse of nutrients and biomass from buffers. Although some topics represent emerging areas, for other well-studied topics (e.g., diffuse pollution), it remains that effectiveness of conventional vegetated buffer strips for water quality improvement varies. The collective findings highlight the merits of targeted, designed buffers that support multiple benefits, more efficiently interrupting surface and subsurface contaminant flows while enhancing diversity in surface topography, soil moisture and C, vegetation, and habitat. This synthesis also highlights that despite the significant number of studies on the functioning of riparian buffers, research gaps remain, particularly in relation to (i) the capture and retention of soluble P and N in subsurface flows through buffers, (ii) the utilization of captured nutrients, (iii) the impact of buffer design and management on terrestrial and aquatic habitats and species, and (iv) the effect of buffers (saturated) on greenhouse gas emissions and the potential for pollution swapping.
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