The potential of Earth Observation in modelling nutrient loading and water quality in lakes of southern Québec, Canada

2017 ◽  
Vol 80 (1) ◽  
Author(s):  
Eirini Politi ◽  
Yves T. Prairie
Keyword(s):  
Water Quality ◽  
Nutrient Loading ◽  
Earth Observation

scholarly journals Effects of Different Fish Diets on the Water Quality in Semi-Intensive Common Carp (Cyprinus carpio) Farming

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1215
Author(s):  
László Berzi-Nagy ◽  
Attila Mozsár ◽  
Flórián Tóth ◽  
Dénes Gál ◽  
Zoltán Nagy ◽  
...  
Keyword(s):  
Water Quality ◽  
Common Carp ◽  
Cyprinus Carpio ◽  
Nutrient Loading ◽  
Fish Meal ◽  
Pond Water ◽  
Long Term Effects ◽  
Plant Oil ◽  
Common Carp Cyprinus Carpio ◽  
Carp Cyprinus Carpio

Semi-intensive common carp (Cyprinus carpio) farm technology uses several feed types affecting the growth performance; however, we know less about their long-term effects on water quality. Herein, we evaluated the effects of three commonly used feeds—moderate levels of fish meal and fish oil feed (FF), plant meal and plant oil feed (PF), and cereal feed (CF) on the nutrient (total nitrogen (TN), total phosphorus (TP) and organic matter (OM)) content of the pond water. The experiment was carried out over three consecutive years from juveniles to market-sized fish. The type of feed affected the net yields, but generally, it did not affect the water quality. The year of sampling, however, was a significant factor affecting TN, TP, and OM, whose concentrations decreased during the three years. Our findings highlight that the age of the stocked fish on water quality has a more pronounced effect than the nutrient profile of the supplementary feed. Additionally, the plant-based feed could provide comparable net yields as the fish meal-based feed without additional nutrient loading in the water column, reinforcing the sustainability of alternative feeds in semi-intensive carp farming.

Suggestions for a Modified Approach Towards Implementation and Assessment of Ganga Action Plan and Other Similar River Action Plans in India

2003 ◽  
Vol 38 (4) ◽  
pp. 607-626 ◽  
Author(s):  
Vinod Tare ◽  
Purnendu Bose ◽  
Santosh K. Gupta
Keyword(s):  
Water Quality ◽  
River Water ◽  
Public Perception ◽  
Nutrient Loading ◽  
Action Plan ◽  
Public Support ◽  
Uttar Pradesh ◽  
River Water Quality ◽  
Point Sources ◽  
Action Plans

Abstract In India, the implementation of river-cleaning operations through River Action Plans (RAPs) conventionally focuses on a reduction in concentrated or point sources of organic loading to the river, and is assessed by monitoring the consequent improvement in river water quality. However, in the case of Indian rivers or river stretches having substantial background pollution due to distributed or non-point loading of organic matter and nutrients, elimination of point sources of pollution may not substantially impact or improve river water quality. It is suggested that implementation of River Action Plans in India under such circumstances must be conducted using a multi-tier approach. The initial emphasis in such cases should be on the selection of priority stretches of the river, where pollution control will have maximum beneficial impact on the citizens, and interception and diversion of all concentrated or point loads of pollution from these stretches. In addition, measures to minimize non-point pollution and visible pollution to the river and initiation of riverfront restoration and development projects are necessary in these priority stretches. Such measures would result in aesthetic improvements, increase the beneficial uses of the river and its surroundings, and generate favorable public perception towards RAPs, though they may not be sufficient to enhance the river water quality to the desired levels. However, as a result of the above actions, public support for funding more expensive and longer-term river cleaning schemes, resulting in comprehensive reduction in organic and nutrient loading to the river from point and non-point sources all along its length, may be generated. The need for this alternative methodology for implementation and assessment of RAPs in India has been illustrated by taking the example of the Ganga Action Plan (GAP) and assessment of its implementation near the city of Kanpur in the state of Uttar Pradesh, India, as a test case.

scholarly journals Reduction of nutrient loading, planktivore removal and piscivore stocking as tools in water quality management: The feldberger haussee biomanipulation project

Limnologica ◽  
2003 ◽  
Vol 33 (3) ◽  
pp. 190-204 ◽  
Author(s):  
Peter Kasprzak ◽  
Rainer Koschel ◽  
Lothar Krienitz ◽  
Thomas Gonsiorczyk ◽  
Karl Anwand ◽  
...  
Keyword(s):  
Water Quality ◽  
Quality Management ◽  
Nutrient Loading ◽  
Water Quality Management

Unified, high resolution water quality retrievals from Earth Observation satellites

2021 ◽  
Author(s):  
James Harding
Keyword(s):  
Water Quality ◽  
Water Resource Management ◽  
State Of The Art ◽  
Earth Observation ◽  
Water Quality Parameter ◽  
Landsat 8 ◽  
Optical Parameters ◽  
Atmospheric Conditions ◽  
Mixture Density ◽  
Wide Range

<p>Earth Observation (EO) satellites are drawing considerable attention in areas of water resource management, given their potential to provide unprecedented information on the condition of aquatic ecosystems. Despite ocean colours long history; water quality parameter retrievals from shallow and inland waters remains a complex undertaking. Consistent, cross-mission retrievals of the primary optical parameters using state-of-the-art algorithms are limited by the added optical complexity of these waters. Less work has acknowledged their non- or weakly optical parameter counterparts. These can be more informative than their vivid counterparts, their potential covariance would be regionally specific. Here, we introduce a multi-input, multi-output Mixture Density Network (MDN), that largely outperforms existing algorithms when applied across different bio-optical regimes in shallow and inland water bodies. The model is trained and validated using a sizeable historical database in excess of 1,000,000 samples across 38 optical and non-optical parameters, spanning 20 years across 500 surface waters in Scotland. The single network learns to predict concurrently Chlorophyll-a, Colour, Turbidity, pH, Calcium, Total Phosphorous, Total Organic Carbon, Temperature, Dissolved Oxygen and Suspended Solids from real Landsat 7, Landsat 8, and Sentinel 2 spectra. The MDN is found to fully preserve the covariances of the optical and non-optical parameters, while known one-to-many mappings within the non-optical parameters are retained. Initial performance evaluations suggest significant improvements in Chl-a retrievals from existing state-of-the-art algorithms. MDNs characteristically provide a means of quantifying the noise variance around a prediction for a given input, now pertaining to real data under a wide range of atmospheric conditions. We find this to be informative for example in detecting outlier pixels such as clouds, and may similarly be used to guide or inform future work in academic or industrial contexts. </p>

scholarly journals Influence of EU policy on agricultural nutrient losses and the state of receiving surface waters in Finland

2008 ◽  
Vol 16 (4) ◽  
pp. 282 ◽  
Author(s):  
P. EKHOLM ◽  
K. GRANLUND ◽  
P. KAUPPILA
Keyword(s):  
Water Quality ◽  
Large Scale ◽  
Nutrient Loading ◽  
Nutrient Losses ◽  
Agricultural Catchments ◽  
Receiving Waters ◽  
Environmental Measures ◽  
Current Loading ◽  
Regional Specialisation

In Finland, the first large-scale efforts to control nutrient loading from agriculture got under way with the introduction of the EU Agri-Environmental Program in 1995. We examined whether these efforts have decreased agricultural nutrient losses and improved the quality of receiving waters. To do so we used monitoring data on fluxes of nutrients and total suspended solids in agricultural catchments in 1990–2004 and on the water quality of agriculturally loaded rivers, lakes and estuaries in 1990–2005. No clear reduction in loading or improvement in water quality was detected. Hydrological fluctuations do not seem to have eclipsed the effects of the measures taken, since there was no systematic pattern in runoff in the period studied. The apparent inefficiency of the measures taken may be due to the large nutrient reserves of the soil, which slowed down nutrient reductions within the period studied. Simultaneous changes in agricultural production (e.g. regional specialisation) and in climate may also have counteracted the effects of agri-environmental measures. The actions to reduce agricultural loading might have been more successful had they focused specifically on the areas and actions that contribute most to the current loading.;

Predicting change in biogeochemical potential of subsurface systems with changing hydrogeological conditions

2021 ◽  
Author(s):  
Swamini Khurana ◽  
Falk Heße ◽  
Martin Thullner
Keyword(s):  
Water Quality ◽  
Preferential Flow ◽  
Nutrient Loading ◽  
Temporal Dynamics ◽  
Reaction Network ◽  
Climate Scenario ◽  
Ecosystem Functions ◽  
External Forcing ◽  
Spatio Temporal ◽  
The Impact

<p>In a changing climate scenario, we expect weather event patterns to change, both in frequency and in intensity. The subsequent impacts of these changing patterns on ecosystem functions are of great interest. Water quality particularly is critical due to public health concerns. Already, seasonal variation of water quality has been attributed to varying microbial community assemblages and nutrient loading in the corresponding water body but the contribution of the variations in the quantity of groundwater recharge is a missing link. It is thus beneficial to establish links between external forcing such as changing infiltration rate or recharge on nutrient cycling in the subsurface. We undertake this study to investigate the impact of temporal variation in external forcing on the biogeochemical potential of spatially heterogeneous subsurface systems using a numerical modeling approach. We used geostatistical tools to generate spatial random fields by considering difference combinations of the variance in the log conductivity field and the anisotropy of the domain. Tuning these two parameters assists in effective representation of a wide variety of geologic materials with varying intensity of preferential flow paths in the heterogeneous domain. We ran simulations using OGS#BRNS that enables us to combine a flexibly defined microbial mediated reaction network with the mentioned spatially heterogeneous domains in transient conditions. We propose that a combination of estimated field indicators of Damköhler number, Peclet number (transformed Damköhler number: Da<sub>t</sub>), and projected temporal dynamics in surface conditions can assist us in predicting the change in biogeochemical potential of the subsurface system. Preliminary results indicate that we miss potentially critical variations in reactive species concentration if we neglect spatio-temporal heterogeneities for regimes where 1<Da<sub>t</sub><40. For regimes characterized by values outside this range, we propose that spatio-temporal heterogeneities due to subsurface structure and changing hydrological forcing may not be relevant.</p>

Cage aquaculture and water-quality changes in the LaCloche Channel, Lake Huron, Canada: a paleolimnological assessment

2004 ◽  
Vol 61 (9) ◽  
pp. 1691-1701 ◽  
Author(s):  
Saloni Clerk ◽  
Daniel T Selbie ◽  
John P Smol
Keyword(s):  
Water Quality ◽  
Nutrient Loading ◽  
Fish Farming ◽  
Lake Huron ◽  
Quality Changes ◽  
Low Oxygen ◽  
Hypolimnetic Oxygen ◽  
Cage Aquaculture ◽  
Relative Abundances ◽  
Area Of Concern

Lake eutrophication due to cage aquaculture is an area of concern in Ontario; however, without knowledge of pre-impact conditions, it is difficult to determine the extent and magnitude of environmental change. Paleolimnological techniques were used to estimate water-quality conditions prior to, during, and briefly following aquaculture operation in the LaCloche Channel, Lake Huron. Past oxygen and nutrient levels were inferred from assemblages of chironomids and diatoms, respectively, to determine whether recent low-oxygen and nutrient-rich conditions were related to cage aquaculture in operation from 1989 to 1998. Chironomid assemblages exhibited trends consistent with decreased hypolimnetic oxygen levels, with reductions in oxic-type profundal taxa and increased relative abundances of littoral communities. Diatom assemblages reflected a period of nutrient enrichment by increased relative abundances of meso-eutrophic taxa. Improvements in water quality are inferred from assemblages of diatoms in surface sediments, which may correspond to the cessation of fish-farming activities in 1998. In contrast, no sign of deep-water oxygen recovery is recorded by chironomids. These trends are consistent with eutrophication, and suggest that the LaCloche Channel was sensitive to nutrient loading from the cage-aquaculture operation. This study demonstrates the potential of using paleolimnological techniques to track water-quality changes associated with cage farming.

scholarly journals Exploring How Cyanobacterial Traits Affect Nutrient Loading Thresholds in Shallow Lakes: A Modelling Approach

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2467 ◽  
Author(s):  
Manqi Chang ◽  
Sven Teurlincx ◽  
Jan Janse ◽  
Hans Paerl ◽  
Wolf Mooij ◽  
...  
Keyword(s):  
Water Quality ◽  
Nitrogen Fixation ◽  
Shallow Lakes ◽  
Lake Restoration ◽  
Nutrient Loading ◽  
Ecosystem Model ◽  
Water Bodies ◽  
Cyanobacterial Blooms ◽  
Eutrophic Water ◽  
Modelling Approach

Globally, many shallow lakes have shifted from a clear macrophyte-dominated state to a turbid phytoplankton-dominated state due to eutrophication. Such shifts are often accompanied by toxic cyanobacterial blooms, with specialized traits including buoyancy regulation and nitrogen fixation. Previous work has focused on how these traits contribute to cyanobacterial competitiveness. Yet, little is known on how these traits affect the value of nutrient loading thresholds of shallow lakes. These thresholds are defined as the nutrient loading at which lakes shift water quality state. Here, we used a modelling approach to estimate the effects of traits on nutrient loading thresholds. We incorporated cyanobacterial traits in the process-based ecosystem model PCLake+, known for its ability to determine nutrient loading thresholds. Four scenarios were simulated, including cyanobacteria without traits, with buoyancy regulation, with nitrogen fixation, and with both traits. Nutrient loading thresholds were obtained under N-limited, P-limited, and colimited conditions. Results show that cyanobacterial traits can impede lake restoration actions aimed at removing cyanobacterial blooms via nutrient loading reduction. However, these traits hardly affect the nutrient loading thresholds for clear lakes experiencing eutrophication. Our results provide references for nutrient loading thresholds and draw attention to cyanobacterial traits during the remediation of eutrophic water bodies.

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