scholarly journals Threshold values and management options for nutrients in a catchment of a temperate estuary with poor ecological status

2012 ◽  
Vol 9 (2) ◽  
pp. 2157-2211
Author(s):  
K. Hinsby ◽  
S. Markager ◽  
B. Kronvang ◽  
J. Windolf ◽  
T. O. Sonnenborg ◽  
...  
Keyword(s):  
Algal Blooms ◽  
Climate Models ◽  
Ecological Status ◽  
Water Clarity ◽  
Nutrient Loads ◽  
Threshold Values ◽  
Management Options ◽  
Total N ◽  
Good Ecological Status ◽  
Total P

Abstract. Intensive farming has severe impacts on the chemical status of groundwater and streams and consequently on the ecological status of dependent ecosystems. Eutrophication is a widespread problem in lakes and marine waters. Common problems are hypoxia, algal blooms and fish kills, and loss of water clarity, underwater vegetation, biodiversity, and recreational value. In this paper we evaluate the nitrogen (N) and phosphorus (P) chemistry of groundwater and surface water in a coastal catchment, the loadings and sources of N and P and their effect on the ecological status of an estuary. We calculate the necessary reductions in N and P loadings to the estuary for obtaining a good ecological status, which we define based on the number of days with N and P limitation, and the equivalent stream and groundwater threshold values assuming two different management options. The calculations are performed by the combined use of empirical models and a physically based 3-D integrated hydrological model of the whole catchment. The assessment of the ecological status indicates that the N and P loads to the investigated estuary should be reduced by a factor of 0.52 and 0.56, respectively, to restore good ecological status. Model estimates show that threshold total N concentrations should be in the range of 2.9 to 3.1 mg l−1 in inlet freshwater to Horsens Estuary and 6.0 to 9.3 mg l−1 in shallow aerobic groundwater (∼27–41 mg l−1 of nitrate), depending on the management measures implemented in the catchment. The situation for total P is more complex but data indicate that groundwater threshold values are not needed. The inlet freshwater threshold value for total P to Horsens Estuary for the selected management options is 0.084 mg l−1. Regional climate models project increasing winter precipitation and runoff in the investigated region resulting in increasing runoff and nutrient loads to coastal waters if present land use and farming practices continue. Hence, lower threshold values are required in the future to ensure good status of all water bodies and ecosystems.

scholarly journals Threshold values and management options for nutrients in a catchment of a temperate estuary with poor ecological status

2012 ◽  
Vol 16 (8) ◽  
pp. 2663-2683 ◽  
Author(s):  
K. Hinsby ◽  
S. Markager ◽  
B. Kronvang ◽  
J. Windolf ◽  
T. O. Sonnenborg ◽  
...  
Keyword(s):  
Algal Blooms ◽  
Climate Models ◽  
Regional Climate ◽  
Ecological Status ◽  
Water Clarity ◽  
Nutrient Loads ◽  
Threshold Values ◽  
Management Options ◽  
Total N ◽  
Good Ecological Status

Abstract. Intensive farming has severe impacts on the chemical status of groundwater and streams and consequently on the ecological status of dependent ecosystems. Eutrophication is a widespread problem in lakes and marine waters. Common problems are hypoxia, algal blooms, fish kills, and loss of water clarity, underwater vegetation, biodiversity and recreational value. In this paper we evaluate the nitrogen (N) and phosphorus (P) concentrations of groundwater and surface water in a coastal catchment, the loadings and sources of N and P, and their effect on the ecological status of an estuary. We calculate the necessary reductions in N and P loadings to the estuary for obtaining a good ecological status, which we define based on the number of days with N and P limitation, and the corresponding stream and groundwater threshold values assuming two different management options. The calculations are performed by the combined use of empirical models and a physically based 3-D integrated hydrological model of the whole catchment. The assessment of the ecological status indicates that the N and P loads to the investigated estuary should be reduced to levels corresponding to 52 and 56% of the current loads, respectively, to restore good ecological status. Model estimates show that threshold total N (TN) concentrations should be in the range of 2.9 to 3.1 mg l−1 in inlet freshwater (streams) to Horsens estuary and 6.0 to 9.3 mg l−1 in shallow aerobic groundwater (∼ 27–41 mg l−1 of nitrate), depending on the management measures implemented in the catchment. The situation for total P (TP) is more complex, but data indicate that groundwater threshold values are not needed. The stream threshold value for TP to Horsens estuary for the selected management options is 0.084 mg l−1. Regional climate models project increasing winter precipitation and runoff in the investigated region resulting in increasing runoff and nutrient loads to the Horsens estuary and many other coastal waters if present land use and farming practices continue. Hence, lower threshold values are required in many coastal catchments in the future to ensure good status of water bodies and ecosystems.

Water Quality Trends in Hamilton Harbour: 1987 to 1995

1996 ◽  
Vol 31 (3) ◽  
pp. 473-484 ◽  
Author(s):  
Murray N. Charlton ◽  
Robin Le Sage
Keyword(s):  
Algal Blooms ◽  
Action Plan ◽  
Secchi Depth ◽  
Water Clarity ◽  
Nutrient Loads ◽  
Hamilton Harbour ◽  
Near Shore ◽  
The Media ◽  
Park Area ◽  
Water Quality Trends

Abstract A series of water samples and Secchi depth measurements were conducted in Hamilton Harbour between 1987 and 1995. The data indicate little recent improvement in the harbour generally. Detection of real improvements may require high frequency sampling and a more extensive sample grid once a cause for improvement is in place. Some measures, such as chlorophyll and Secchi depth, approach RAP initial goals sometimes during recent years, but algal blooms still occur, which prevent attainment of satisfactory average conditions. The cause of aesthetic improvements in water clarity reported in the media was investigated with sampling along an inshore-offshore transect and intense Secchi measurements in the LaSalle Park area. The data are consistent with a transient clarifying effect of zebra mussels on structures near shore. The need to reduce nutrient loads as recommended in the Remedial Action Plan continues.

Hurdles for implementation of constructed wetlands as Nature-based Solutions in Sweden

2021 ◽  
Author(s):  
Julián Andrés García Murcia ◽  
Fernando Jaramillo ◽  
Sofia Wikström
Keyword(s):  
Water Framework Directive ◽  
Constructed Wetlands ◽  
Ecological Status ◽  
Nutrient Loads ◽  
Structured Interviews ◽  
The Status ◽  
Natural Wetlands ◽  
The Baltic ◽  
Good Ecological Status ◽  
Background Context

<p>Eutrophication in the Baltic Sea has been one of the major environmental issues during the last century partly due to extensive land-use change, loss of natural retention systems, and insufficient management. European legislation such as the Water Framework Directive (WFD) attempts to guide the recovery of good ecological status from freshwater to the sea, and suggests wetlands as ecosystems that can potentially contribute to achieving this goal. Wetlands are considered remarkable Nature-based Solutions (NbS) for improving water quality by diminishing the nutrient loads. This study aims to set a background context of the WFD implementation in Sweden, determine the status of constructed wetlands, and evaluate the stakeholders’ perspectives to identify the main administrative hurdles of wetland implementation in Sweden. For this purpose, we conducted a narrative review, database analysis, and semi-structured interviews with members of the institutions involved in water management. Our results show that it is essential to find synergies among the WFD and other directives to expand cross-sectoral cooperation, implement adjustments on the funding scheme that includes restoration and maintenance of natural wetlands, and increase compensation periods and cost ceiling. Likewise, it is crucial to perform significant improvements in the monitoring system, including more frequent data collection, as well as exploring new strategies to capture landowners’ interest in the implementation of NbS, such as the Catchment Officers program. Finally, we suggest paludiculture as a promising farming practice to increase proprietors’ attention on novel market alternatives, and in turn, to provide benefits for climate, water, and biodiversity.</p><p><strong>Keywords </strong>Wetlands management · Water Framework Directive · Nature-based Solutions · Eutrophication · Semi-structured interviews · Sweden</p>

scholarly journals Nitrogen and Phosphorus Balances Vary at the Whole-Farm, Field, and Within-Field Scales

2021 ◽  
Vol 2 ◽  
Author(s):  
Jonathan M. Berlingeri ◽  
Joseph R. Lawrence ◽  
S. Sunoj ◽  
Karl J. Czymmek ◽  
Quirine M. Ketterings
Keyword(s):  
N Uptake ◽  
Nutrient Balance ◽  
Corn Silage ◽  
Nitrogen And Phosphorus ◽  
Management Options ◽  
Total N ◽  
Available N ◽  
N Removal ◽  
The Impact ◽  
Total P

A field nutrient balance (supplied minus harvested) can be an effective, end-of-season management evaluation tool. However, development of guidance for balance-based management requires knowledge of variability in balance inputs. To contribute to development of such guidelines, we evaluated the impact of corn silage hybrid selection, nutrient management, and growing conditions on field nitrogen (N) balances and documented variability in N and phosphorus (P) balances at the whole-farm, field, within-field levels. Variability in N removal among hybrids was evaluated using hybrid trials (5 locations, 4 years each). Variability in farm and field balances (4 farms, 2 years each) and within-field balances (2 farms, 2 years each) was assessed as well. Nitrogen supply comprised soil N (soil type-specific book values), rotation N, past manure N, and current year N (fertilizer and/or manure). Total N balances included all current year manure N while available N balances considered only plant-available N from manure. Phosphorus balances were derived as total P applied minus P harvested. Yield explained 81% of the variability in N uptake across hybrids. Nitrogen uptake intensity (NUI; N uptake per unit of yield) varied across locations and years, averaging 4.3 ± 0.1 kg N/Mg for short-season hybrids [≤95 days-to-maturity (DTM)] vs. 4.1 ± 0.1 kg N Mg−1 for longer-season hybrids. Whole-farm N balances ranged from 139 to 251 kg N ha−1 for total N and 43 to 106 kg N ha−1 for available N. Phosphorus balances ranged from 28 to 154 kg P ha−1. Balances per field ranged from −8 to 453, −66 to 250 kg N ha−1, and −30 to 315 kg P ha−1 for total N, available N, and total P, respectively, while within-field balances showed even larger ranges. We conclude that (1) variability in corn silage N and P balances at field and within-field scales and across year is large, emphasizing the need for field and within-field (where feasible) evaluation tools and management options, and (2) feasible limits for N balances should include both total and available N.

scholarly journals Changes of the nutrient loads of the Odra River during the last century - their causes and consequences

2008 ◽  
Vol 12 (1) ◽  
pp. 127-144 ◽  
Author(s):  
Horst Behrendt ◽  
Dieter Opitz ◽  
Agnieszka Kolanek ◽  
Rafalina Korol ◽  
Marzenna Strońska
Keyword(s):  
Point Source ◽  
Total Phosphorus ◽  
Inorganic Nitrogen ◽  
Nutrient Loads ◽  
Dissolved Inorganic Nitrogen ◽  
Total N ◽  
Odra River ◽  
Time Periods ◽  
Total P ◽  
Point Source Discharges

Changes of the nutrient loads of the Odra River during the last century - their causes and consequencesNutrient emissions by point and diffuse sources and their loads were estimated for the Odra catchment over the time period of the last 50 years by means of the model MONERIS. For nitrogen a change of the total emissions from 38 kt·a−1N in the mid of 1950s a maximum of 105 kt·a−1N in the early 1980s and a recent value of about 84 kt·a−1N were estimated for the total Odra Basin. The share of the point source discharges on the total N emissions varied between 24% (1955) and 35% (1995). The emissions from groundwater and tile drained areas represent the dominant pathway (37-56% of total N emissions) during all investigated time periods. Emissions from tile drained areas increased from the mid of 1950s to end of 1980s by a factor of 20 and reached in this period the same amount as emissions by groundwater. For phosphorus the emissions changed from 4 kt·a−1P in 1955 to 14 kt·a−1P in 1990 and a recent level of 7 kt·a−1P. Point source discharges caused between 36 to 66% of total P emissions and represent the dominant pathway for all investigated time periods. Erosion and discharges from paved urban areas and sewer systems was the dominant diffuse pathway of the total P emissions into the river system. The comparison of calculated and observed nutrient loads for the main monitoring stations along the Odra River shows that the average deviation is 12% for total phosphorus (1980-2000) and 15% for dissolved inorganic nitrogen (1960-2000). From the analysis it can be concluded that the present load of dissolved inorganic nitrogen (DIN) and total nitrogen (TN) of the Odra into the Baltic Sea is about 2.3 times higher than in the mid of 1960s. The maximum DIN load (1980s) was more than 3 times higher than in the 1960s. The change of the total phosphorus (TP) load is characterized by an increase from the 1955s to 1980 from 2 to 7 kt·a−1P (factor 2.6). Around 2000 the TP load was 4 kt·a−1which is only the double of the level of the 1955s.

scholarly journals The ecological status of Puhatu cutover peatland

2009 ◽  
Vol 51 (1) ◽  
pp. 28-39
Author(s):  
Katri Ots ◽  
Karin Kikamägi ◽  
Tatjana Kuznetsova
Keyword(s):  
Ecological Status ◽  
Height Growth ◽  
Pine Needles ◽  
Optimum Level ◽  
Total N ◽  
Total P

Puhatu ammendatud jääksoo ökoloogilisest seisundistThe aim of the present study was estimation of the ecological status of Puhatu cutover peatland in Norteast Estonia. Results of the samples showed that the pH of peat in Puhatu cutover peatland was in the range 5.1-5.5. The nutrients concentrations of peat (%) varied as follows: total N 2.1-2.9, total P 0.016-0.032, K 0.004-0.02, Ca 1.2-3.5 and Mg 0.08-0.2. The height of pines was 3.0 ± 0.6 m and height growth in current year was up to 73 cm. Comparison of our results with the scale presented by Ingestad suggests that the content of P, K and Mg in pine needles and birch leaves is lower and Ca content significantly higher than the optimum level.

scholarly journals Possible effects of climate change on ecological functioning of shallow lakes, Lake Loenderveen as a case study

2007 ◽  
Vol 38 (1) ◽  
pp. 95-104 ◽  
Author(s):  
Sebastiaan Schep ◽  
Gerard Ter Heerdt ◽  
Jan Janse ◽  
Maarten Ouboter
Keyword(s):  
Climate Change ◽  
Shallow Lakes ◽  
Ecological Status ◽  
Nutrient Load ◽  
Nutrient Loads ◽  
Clear Water ◽  
Turbid State ◽  
Good Ecological Status ◽  
Ecological Functioning

Possible effects of climate change on ecological functioning of shallow lakes, Lake Loenderveen as a case study The European Water Framework Directive (WFD) requires all inland and coastal waters to reach "good ecological status" by 2015. The good ecological status of shallow lakes can be characterised by clear water dominated by submerged vegetation. The ecological response of shallow lakes on nutrients largely depends on morphological and hydrological features, such as water depth, retention time, water level fluctuations, bottom type, fetch etc. These features determine the "critical nutrient load" of a lake. When the actual nutrient load of a lake is higher than the critical nutrient load, the ecological quality of this lake will deteriorate, resulting in a turbid state dominated by algae. Climate change might lead to changes in both environmental factors and ecosystem response. This certainly will have an effect on the ecological status. As an illustration the results of a multidiscipline study of a shallow peaty lake (Loenderveen) are presented, including hydrology, geochemistry and ecology. Ground- and surface water flows, nutrient dynamics and ecosystem functioning have been studied culminating in an application of the ecological model of the lake (PCLake). Future scenarios were implemented through changing precipitation, evaporation and temperature. Climate change will lead to higher nutrient loads and lower critical nutrient loads. As a consequence lakes shift easier from clear water to a turbid state.

LAND USE TYPES AND SOIL CHARACTERISTICTS: A CASE STUDY IN HUONG VINH COMMUNE, HUONG TRA TOWN, THUA THIEN HUE PROVINCE

2017 ◽  
Vol 126 (4B) ◽  
Author(s):  
Trần Thanh Đức
Keyword(s):  
Land Use ◽  
Sweet Potato ◽  
Soil Analysis ◽  
Soil Characteristics ◽  
Low Ph ◽  
Clay Loam ◽  
Total N ◽  
Land Use Types ◽  
Total P

This research carried out in Huong Vinh commune, Huong Tra town, Thua Thien Hue province aimed to identify types of land use and soil characteristics. Results showed that five crops are found in Huong Vinh commune including rice, peanut, sweet potato, cassava and vegetable. There are two major soil orders with four soil suborders classified by FAO in Huong Vinh commune including Fluvisols (Dystric Fluvisols<em>, </em>Gleyic Fluvisols and Cambic Fluvisols) and Arenosols (Haplic Arenosols). The results from soil analysis showed that three soil suborders including Dystric Fluvisols<em>, </em>Gleyic Fluvisols and Cambic Fluvisols belonging to Fluvisols were clay loam in texture, low pH, low in OC, total N, total P<sub>2</sub>O<sub>5</sub> and total K<sub>2</sub>O. Meanwhile, the Haplic Arenosols was loamy sand in texture, poor capacity to hold OC, total N, total P<sub>2</sub>O<sub>5</sub> and total K<sub>2</sub>O

scholarly journals Influence of Anthropogenic Loads on Surface Water Status: A Case Study in Lithuania

2021 ◽  
Vol 13 (8) ◽  
pp. 4341
Author(s):  
Laima Česonienė ◽  
Daiva Šileikienė ◽  
Vitas Marozas ◽  
Laura Čiteikė
Keyword(s):  
Total Nitrogen ◽  
Water Status ◽  
Arable Land ◽  
Ecological Status ◽  
Water Bodies ◽  
Agricultural Pollution ◽  
Good Ecological Status ◽  
Water Catchment ◽  
Lake Basins

Twenty-six water bodies and 10 ponds were selected for this research. Anthropogenic loads were assessed according to pollution sources in individual water catchment basins. It was determined that 50% of the tested water bodies had Ntotal values that did not correspond to the good and very good ecological status classes, and 20% of the tested water bodies had Ptotal values that did not correspond to the good and very good ecological status classes. The lake basins and ponds received the largest amounts of pollution from agricultural sources with total nitrogen at 1554.13 t/year and phosphorus at 1.94 t/year, and from meadows and pastures with total nitrogen at 9.50 t/year and phosphorus at 0.20 t/year. The highest annual load of total nitrogen for lake basins on average per year was from agricultural pollution from arable land (98.85%), and the highest total phosphorus load was also from agricultural pollution from arable land (60%).

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