Trophic state evolution in a subtropical reservoir over 34 years in response to different management procedures

2011 ◽  
Vol 64 (12) ◽  
pp. 2338-2344 ◽  
Author(s):  
D. G. F. Cunha ◽  
D. Grull ◽  
M. Damato ◽  
J. R. C. Blum ◽  
J. E. I. Lutti ◽  
...  
Keyword(s):  
Flood Control ◽  
Trophic State ◽  
Phase 1 ◽  
Nutrient Inputs ◽  
Chl A ◽  
P Limitation ◽  
Tietê River ◽  
Management Procedures ◽  
Special Cases ◽  
Nitrogen Concentrations

Despite their importance for water management, long-term studies on trophic state are relatively scarce in subtropical reservoirs. We analyzed total phosphorus (TP), total nitrogen (TN) and chlorophyll a (Chl a) concentrations in the Billings Reservoir (Brazil) over time: Phase 1 (1977–1992, Tietê River water was pumped to Billings to increase energy generation, 100 m3 s−1); Phase 2 (1992–2007, Tietê water was conveyed to Billings only in special cases for flood avoidance, 8 m3 s−1); and Phase 3 (2007–2010, besides flood control, Billings received Tietê water treated by an in situ flotation system, 13 m3 s−1). We compared our results with data from 12 reservoirs to evaluate current (2005–2009) enrichment conditions. Phosphorus and nitrogen concentrations decreased (p < 0.05, MANOVA) from Phase 1 to 2 and were stable thereafter. TN/TP ratios increment (1977–2010) indicated shift from N- to P-limitation in the reservoir, affecting the phytoplankton. Nutrient levels in Billings are currently between the expected concentrations in mesotrophic and eutrophic reservoirs (0.03 mg L−1 < TP < 0.42 mg L−1, 0.8 mg L−1 < TN < 7.6 mg L−1) and Chl a concentrations exceeded 34 μg L−1, median for the eutrophic waterbodies from the dataset. Although water quality in Billings has improved, nutrient inputs from Tietê River pumping episodes, diffuse and internal sources are still favoring biomass accrual and compromising water uses.

scholarly journals Trophic State Evolution over 15 Years in a Tropical Reservoir with Low Nitrogen Concentrations and Cyanobacteria Predominance

2016 ◽  
Vol 227 (3) ◽  
Author(s):  
Frederico Guilherme de Souza Beghelli ◽  
Daniele Frascareli ◽  
Marcelo Luiz Martins Pompêo ◽  
Viviane Moschini-Carlos
Keyword(s):  
Trophic State ◽  
Tropical Reservoir ◽  
State Evolution ◽  
Nitrogen Concentrations ◽  
Low Nitrogen

scholarly journals Understanding Water Use Conflicts to Advance Collaborative Planning: Lessons Learned from Lake Diefenbaker, Canada

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1756
Author(s):  
Jania Chilima ◽  
Jill Blakley ◽  
Harry Diaz ◽  
Lalita Bharadwaj
Keyword(s):  
Water Use ◽  
Flood Control ◽  
Collaborative Planning ◽  
Lessons Learned ◽  
Canadian Prairie ◽  
Water Users ◽  
Management Procedures ◽  
Lake Diefenbaker ◽  
Regulatory Instruments ◽  
Water Uses

Conflicts around the multi-purpose water uses of Lake Diefenbaker (LD) in Saskatchewan, Canada need to be addressed to meet rapidly expanding water demands in the arid Canadian prairie region. This study explores these conflicts to advance collaborative planning as a means for improving the current water governance and management of this lake. Qualitative methodology that employed a wide participatory approach was used to collect focus group data from 92 individuals, who formed a community of water users. Results indicate that the community of water users is unified in wanting to maintain water quality and quantity, preserving the lake’s aesthetics, and reducing water source vulnerability. Results also show these users are faced with water resource conflicts resulting from lack of coherence of regulatory instruments in the current governance regime, and acceptable management procedures of both consumptive and contemporary water uses that are interlinked in seven areas of: irrigation, industrial, and recreational water uses; reservoir water level for flood control and hydroelectricity production; wastewater and lagoon management; fish farm operations; and regional water development projects. As a means of advancing collaborative planning, improvements in water allocation and regulatory instruments could be made to dissipate consumptive use conflicts and fill the under-regulation void that exists for contemporary water uses. Additionally, a comprehensive LD water use master plan, as a shared vision to improve participation in governance, could be developed to direct the water uses that have emerged over time. This study suggests that these three areas are practical starting conditions that would enable successful collaborative planning for the seven areas of water uses. Focusing on these three areas would ensure the current and future needs of the community of water users are met, while avoiding reactive ways of solving water problems in the LD region, especially as the water crisis in the Canadian Prairie region where LD is located is expected to intensify.

scholarly journals Identification of Key Factors Affecting the Trophic State of Four Tropical Small Water Bodies

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1454 ◽  
Author(s):  
Homero Cuevas Madrid ◽  
Alfonso Lugo Vázquez ◽  
Laura Peralta Soriano ◽  
Josué Morlán Mejía ◽  
Gloria Vilaclara Fatjó ◽  
...  
Keyword(s):  
Trophic State ◽  
Nutrient Recycling ◽  
Water Bodies ◽  
Anthropogenic Source ◽  
Least Squares Regression ◽  
Trophic Conditions ◽  
Factors Affecting ◽  
Chl A ◽  
Small Water ◽  
Human Management

Due to their dimensions, small and shallow water bodies are more sensitive to changes in nutrient load, water flow, and human management. The four water bodies studied are small (area <0.01 km2), constantly supplied by a non-anthropogenic source of nutrients, and these water bodies present different trophic states: mesotrophic, eutrophic, and hyper-eutrophic. The objective of this study was to identify the key environmental factors that created differences in the trophic state of these adjacent shallow urban lakes by modeling chlorophyll-a (Chl a) through the application of the Partial Least Squares Regression (PLSR). The models (n = 36) explain 45.8–60.6% (R2), and predicts 39–52.9% (Q2) of the variance. Environmental variables were identified in the water bodies as critical factors of trophic state determination, water residence time (WRT), ions (e.g., Ca2+), and minerals as hydroxyapatite (HAP). These variables were related to processes that could improve trophic conditions, such as flushing and phosphorous precipitation. Conversely, N-NH3 concentration was associated with nutrient recycling, and found to be able to promote eutrophication.

scholarly journals Assessing the Trend of the Trophic State of Lake Ladoga Based on Multi-Year (1997–2019) CMEMS GlobColour-Merged CHL-OC5 Satellite Observations

Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6881
Author(s):  
Augustine-Moses Gaavwase Gbagir ◽  
Alfred Colpaert
Keyword(s):  
Water Quality ◽  
Trophic State ◽  
Current Knowledge ◽  
Management Strategies ◽  
Paper Mill ◽  
Warming Trend ◽  
Satellite Observations ◽  
Lake Ladoga ◽  
General Reference ◽  
Chl A

The trophic state of Lake Ladoga was studied during the period 1997–2019, using the Copernicus Marine Environmental Monitoring Service (CMEMS) GlobColour-merged chlorophyll-a OC5 algorithm (GlobColour CHL-OC5) satellite observations. Lake Ladoga, in general, is mesotrophic but certain parts of the lake have been eutrophic since the 1960s due to the discharge of wastewater from industrial, urban, and agricultural sources. Since then, many ecological assessments of the Lake’s state have been made. These studies have indicated that various changes are taking place in the lake and continuous monitoring of the lake is essential to update the current knowledge of its state. The aim of this study was to assess the long-term trend in chl-a in Lake Ladoga. The results showed a gradual reduction in chl-a concentration, indicating a moderate improvement. Chl-a concentrations (minimum-maximum values) varied spatially. The shallow southern shores did not show any improvement while the situation in the north is much better. The shore areas around the functioning paper mill at Pitkäranta and city of Sortavala still show high chl-a values. These findings provide a general reference on the current trophic state of Lake Ladoga that could contribute to improve policy and management strategies. It is assumed that the present warming trend of surface water may result in phytoplankton growth increase, thus partly offsetting a decrease in nutrient load. Precipitation is thought to be increasing, but the influence on water quality is less clear. Future studies could assess the current chemical composition to determine the state of water quality of Lake Ladoga.

Modèle de simulation de la gestion hydrologique

1988 ◽  
Vol 15 (2) ◽  
pp. 206-215
Author(s):  
J. Llamas ◽  
R. Fernandez ◽  
A. Galvache
Keyword(s):  
Water Resources ◽  
Water Resources Management ◽  
Flood Control ◽  
Optimal Management ◽  
Hydro Power ◽  
Resources Management ◽  
Management Procedures ◽  
Historical Management ◽  
Different Levels

In this article, a general methodology for simulation of water resources management is suggested. The research has been conducted in three different levels: a deep analysis of the historical management procedures, the development of some alternative ways to optimal management, and the establishment of planning criteria at short, middle, and long term. The main constraints, divided into three categories according to the severity of probable losses, have been defined as a function of several expected goals: hydro power, flood control, recreational activities, etc. The model was applied with excellent results to the upper region of the St. François river basin (Québec, Canada). Key words: simulation, resources management, mathematical models, optimization.

scholarly journals Linking groundwater – surface water exchange to food production and salmonid growth

2016 ◽  
Vol 73 (11) ◽  
pp. 1650-1660 ◽  
Author(s):  
Francine H. Mejia ◽  
Colden V. Baxter ◽  
Eric K. Berntsen ◽  
Alexander K. Fremier
Keyword(s):  
Surface Water ◽  
Water Temperature ◽  
Food Production ◽  
Water Exchange ◽  
Fish Growth ◽  
Nutrient Inputs ◽  
Resource Subsidies ◽  
Temperature Changes ◽  
Energetic Condition ◽  
Nitrogen Concentrations

Materials, energy, and organisms from groundwater serve as resource subsidies to lotic systems. These subsidies influence food production and post-emergent fish growth and condition through nutrient inputs and water temperature changes. To test whether post-emergent fish grew faster in gaining sites, we grew hatchery post-emergent salmon in enclosures, sampled periphyton, benthic invertebrates, and wild salmon, and modeled fish growth across a gradient of groundwater – surface water exchange. Fish grew almost twice as fast in gaining (2.7%·day−1) than in losing (1.5%·day−1) sites. Fish from transient sites grew as much as gaining sites, but their condition was significantly lower (18.3% vs. 20.7%). Results suggest that groundwater – surface water exchange affects fish growth and energetic condition through direct and indirect pathways. Elevated nitrogen concentrations and consistently warmer water temperature in gaining sites have a strong effect on basal production with subsequent effects on invertebrate biomass, fish growth, and condition. Findings highlight the importance of groundwater – surface water exchange as a subsidy to rearing salmon and may inform strategies for restoring fish rearing habitat.

Volcanic nutrient inputs and trophic state of Lake Caviahue, Patagonia, Argentina

2008 ◽  
Vol 178 (2) ◽  
pp. 205-212 ◽  
Author(s):  
Fernando L. Pedrozo ◽  
Pedro F. Temporetti ◽  
Guadalupe Beamud ◽  
Mónica M. Diaz
Keyword(s):  
Trophic State ◽  
Nutrient Inputs

scholarly journals ESTIMATION OF CHLOROPHYLL-A CONCENTRATION IN LAGUNA DE BAY USING SENTINEL-3 SATELLITE DATA

2019 ◽  
Vol XLII-4/W19 ◽  
pp. 125-132
Author(s):  
M. Conopio ◽  
R. K. Japor ◽  
A. C. Blanco ◽  
A. M. Tamondong
Keyword(s):  
Algal Blooms ◽  
Nutrient Inputs ◽  
Chl A ◽  
Estimation Algorithms ◽  
In Situ Data ◽  
Spectral Bands ◽  
Band Ratios ◽  
Laguna De Bay ◽  
Ocean Monitoring ◽  
Laguna Lake

Abstract. The mission of the European Space Agency’s Sentinel-3 satellite is to provide data for land and ocean monitoring purposes. Sentinel- 3’s Ocean and Land Colour Instrument (OLCI) data are being used largely for monitoring offshore and coastal waters but can also be used for inland waters including lakes. It has a spatial resolution of 300 meters, a temporal resolution of 2–3 days and contains 21 spectral bands. Laguna de Bay, with a surface area of around 930 km2, suffers from periodic algal blooms resulting from excessive nutrient inputs from surrounding watersheds. This study aims to assess the applicability of Sentinel-3 OLCI for estimating chlorophylla (chl-a) concentration in Laguna Lake. Several chl-a estimation algorithms (i.e., band ratios and indices) were tested for Sentinel 3 OLCI images and compared with in-situ data obtained using a chl-a sensor. A regression model comprising of individual spectral bands, band ratios, and band indices for chl-a estimation as independent variables was developed, yielding an adjusted R2 of 0.759 and RMSE of 1.19 ug/L. The model consists of R620, R674/R708, and RED/NIR. A map was produced showing the spatial distribution of chl-a in Laguna Lake, with most of the portion of the lake having a concentration ranging from 7.5 ug/L to 15 ug/L. This shows that Sentinel 3 OLCI images can be utilized for accurately estimating chl-a in Laguna Lake.

scholarly journals N and P as ultimate and proximate limiting nutrients in the northern Gulf of Mexico: Implications for hypoxia reduction strategies

2017 ◽  
Author(s):  
Katja Fennel ◽  
Arnaud Laurent
Keyword(s):  
Gulf Of Mexico ◽  
Primary Production ◽  
Statistical Regression ◽  
Nutrient Inputs ◽  
Nutrient Reduction ◽  
Total N ◽  
Northern Gulf Of Mexico ◽  
P Limitation ◽  
Hypoxic Area ◽  
Reduction Strategies

Abstract. The occurrence of hypoxia in coastal oceans is a growing problem worldwide and clearly linked to anthropogenic nutrient inputs. While the need for reducing anthropogenic nutrient loads is generally accepted, it is costly and thus requires scientifically sound nutrient-reduction strategies. Issues under debate include the relative importance of nitrogen (N) and phosphorus (P), and the magnitude of reduction requirements. The largest anthropogenically induced hypoxic area in North American coastal waters (of 15,000 &amp;pm; 5,000 km2) forms every summer in the northern Gulf of Mexico where the Mississippi and Atchafalaya Rivers deliver large amounts of freshwater and nutrients to the shelf. A 2001 plan for reducing this hypoxic area by nutrient management in the watershed called for a reduction of N loads. Evidence of P limitation during the time of hypoxia formation has arisen since then, and has opened up the discussion about single versus dual nutrient reduction strategies for this system. Here we report the first systematic analysis of the effects of single and dual nutrient load reductions from a spatially explicit physical-biogeochemical model for the northern Gulf of Mexico. The model has been shown previously to skillfully represent the processes important for hypoxic formation. Our analysis of an ensemble of simulations with stepwise reductions in N, P and N&amp;P loads provides insight into the effects of both nutrients on primary production and hypoxia, and allows us to estimate what nutrient reductions would be required for single and dual nutrient reduction strategies to reach the hypoxia target. Our results show that, despite temporary P limitation, N is the ultimate limiting nutrient for primary production in this system. Nevertheless, a reduction in P load would reduce hypoxia because primary production in the region where density stratification is conducive to hypoxia development, but reduction in N load have a bigger effect. Our simulations show that, at present loads, the system is saturated with N, in the sense that the sensitivity of primary production and hypoxia to N load is much lower than it would be at lower N loads. We estimate that reduction of 63 % &amp;pm; 18 % in total N load or 48 % &amp;pm; 21 % in total N&amp;P load are necessary to reach a hypoxic area of 5,000 km2, which is consistent with previous estimates from statistical regression models and highly simplified mechanistic models.

scholarly journals Microbial nutrient limitation in arctic lakes in a permafrost landscape of southwest Greenland

2015 ◽  
Vol 12 (14) ◽  
pp. 11863-11890
Author(s):  
B. Burpee ◽  
J. E. Saros ◽  
R. M. Northington ◽  
K. S. Simon
Keyword(s):  
Nutrient Limitation ◽  
Enzyme Activities ◽  
Arctic Lakes ◽  
The Arctic ◽  
Nutrient Concentrations ◽  
Nutrient Inputs ◽  
P Limitation ◽  
Microbial P ◽  
Microbial Nutrient Limitation ◽  
Southwest Greenland

Abstract. Permafrost is degrading across regions of the Arctic, which can lead to increases in nutrient concentrations in surface freshwaters. The oligotrophic state of many arctic lakes suggests that enhanced nutrient inputs may have important effects on these systems, but little is known about microbial nutrient limitation patterns in these lakes. We investigated microbial extracellular enzyme activities (EEAs) to infer seasonal nutrient dynamics and limitation across 24 lakes in southwest Greenland during summer (June and July). From early to late summer, enzyme activities that indicate microbial carbon (C), nitrogen (N), and phosphorus (P) demand increased in both the epilimnia and hypolimnia by 74 % on average. Microbial investment in P acquisition was generally higher than that for N. Interactions among EEAs indicated that bacteria were primarily P limited. Dissolved organic matter (DOM, measured as dissolved organic carbon) was strongly and positively correlated with microbial P demand (R2 = 0.84 in July), while there were no relationships between DOM and microbial N demand. Microbial P limitation in June epilimnia (R2 = 0.67) and July hypolimnia (R2 = 0.57) increased with DOM concentration. The consistency of microbial P limitation from June to July was related to the amount of DOM present, with some low DOM lakes becoming N-limited in July. Our results suggest that future changes in P or DOM inputs to these lakes are likely to alter microbial nutrient limitation patterns.

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