Effects of Flooding on Dissolved and Suspended Nutrients in Small Diked Marshes

1986 ◽  
Vol 43 (10) ◽  
pp. 1999-2008 ◽  
Author(s):  
John A. Kadlec

Flooding ten 5- to 7-ha diked marshes in the Delta Marsh, Manitoba, to about 1 m above natural marsh levels did not increase dissolved or suspended nutrient concentrations in the surface water. Dissolved forms of N and P increased in interstitial water, possibly as a direct or indirect effect of death of emergent macrophytes (e.g. cattail, Typha spp.) and associated changes such as wave action and detritus deposition. Concentrations of suspended N, P and C decreased in surface water as a result of flooding, both in absolute terms and relative to concurrent increases shown by natural marsh controls. Concentrations of major ions (Ca2+, Mg2+, Na+, K+[Formula: see text] and Cl−) did not change in response to flooding, but did vary in time and space. A predicted decrease in the concentrations of major ions in interstitial water due to seepage of dilute surface water into the sediment was not detected.

1999 ◽  
Vol 39 (10-11) ◽  
pp. 173-176 ◽  
Author(s):  
Liesl Hill ◽  
Sebastian Jooste

With the increasing focus on environmental issues, the objective of this study is to evaluate the potential impact of contaminated sediments of the Blesbok Spruit near Witbank - which receives acid mine drainage (AMD) inter alia - on biota. Direct transfer of chemicals from sediments to organisms is considered to be a major route of exposure for many species, and therefore focusing attention on sediment contamination and highlighting the fact that sediments are an important resource. Acute toxicity tests were performed on Daphnia pulex using both extracted sediment interstitial water and surface water. Chemical analyses were also performed on the sediment, interstitial water and surface water samples. The toxicity results suggest that metal toxicity adds significantly to the toxicity of the stream water which is enhanced by the effect of pH. The pH of the stream and interstitial water was consistently below 4.5.


2008 ◽  
Vol 5 (4) ◽  
pp. 3457-3496 ◽  
Author(s):  
S. Juutinen ◽  
M. Rantakari ◽  
P. Kortelainen ◽  
J. T. Huttunen ◽  
T. Larmola ◽  
...  

Abstract. This study explores the variability in concentrations of dissolved CH4 and annual flux estimates in the pelagic zone in a statistically defined sample of 207 lakes in Finland. The lakes were situated representatively in the boreal zone, where the mean annual air temperature ranges from −2.8 to 5.9°C. We examined how lake CH4 dynamics related to regional lake types assessed according to the EU water framework directive. Ten lake types were defined on the basis of water chemistry, color, and size. Lakes were sampled for dissolved CH4 concentrations four times per year, at four different depths at the deepest point of each lake. We found that CH4 concentrations and fluxes to the atmosphere tended to be high in nutrient rich calcareous lakes, and that the shallow lakes had the greatest surface water concentrations. CH4 content in the hypolimnion was related to oxygen and nutrient concentrations, and lake depth or area. The surface water CH4 concentration was related to the depth or area of lake. Methane close to the bottom can be viewed as proxy of lake status in terms of frequency of anoxia and nutrient levels. Median CH4 release from randomly selected lakes was 45 mmol m−2 a−1. Shallow lakes had the highest median CH4 effluxes, with the clear shallow lake type having the smallest median. Our data, combined with other studies, suggest that lake surface area could be used for an approximation of CH4 release from lakes. Shallow small lakes common in boreal and arctic landscapes may have disproportional significance with respect to CH4 release.


2020 ◽  
Vol 44 (1) ◽  
pp. 30-43
Author(s):  
Jakob Walve ◽  
Maria Sandberg ◽  
Ragnar Elmgren ◽  
Christer Lännergren ◽  
Ulf Larsson

AbstractNutrient concentrations in coastal waters are influenced not only by land runoff, point sources, and water exchange with the sea but are also modified by settlement to and release from sediments. This complicates evaluation of measures to reduce nutrient loads. We used a mass-balance box model to calculate long-term (1968–2015) and seasonal source contributions to phosphorus (P) concentrations and cycling in the stratified Stockholm inner archipelago (IA), Baltic Sea. A drastic reduction of sewage P loads in the early 1970s reduced sewage from the major to a minor P source. Further P load reductions in the 1990s cut the direct contribution from the sewage point sources to the annual mean surface water P concentration from 10 μg l−1 (25%) to < 4 μg l−1 (12%). The largest contributions to the surface water P concentration are now (from 1996) inflowing seawater (37%), freshwater (25%), and P recycling from sediments below 20 m depth (26%). Variations in freshwater flushing give higher P concentrations in dry years, when dilution of P inputs from sediments and sewage is small, while in wet years, these inputs are greatly diluted. Source-partitioned phosphate uptake shows that the spring bloom is fueled mainly by P of seawater and freshwater origin, while the contribution from sewage point sources is minor. Since sediment P release is mostly recycled P from the settled spring bloom, the P inputs from seawater and freshwater are now the major drivers of the IA P cycle. Recycling of P from sediments boosts surface water P concentrations in autumn and winter, affecting management target concentrations.


2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Marusia Rentería-Villalobos ◽  
Manuel Reyes Cortés ◽  
Juan Mantero ◽  
Guillermo Manjón ◽  
Rafael García-Tenorio ◽  
...  

The main interest of this study is to assess whether uranium deposits located in the San Marcos outcrops (NW of Chihuahua City, Mexico) could be considered as a source of U-isotopes in its surrounding environment. Uranium activity concentrations were determined in biota, ground, and surface water by either alpha or liquid scintillation spectrometries. Major ions were analyzed by ICP-OES in surface water and its suspended matter. For determining uranium activity in biota, samples were divided in parts. The results have shown a possible lixiviation and infiltration of uranium from geological substrate into the ground and surface water, and consequently, a transfer to biota. Calculated annual effective doses by ingestion suggest that U-isotopes in biota could not negligibly contribute to the neighboring population dose. By all these considerations, it is concluded that in this zone there is natural enhancement of uranium in all environmental samples analyzed in the present work.


1997 ◽  
Vol 48 (5) ◽  
pp. 371 ◽  
Author(s):  
Philip H. Towler ◽  
J. David Smith

The residence time of particulate and dissolved 210Pb in the upper layer of the western equatorial Pacific Ocean is examined. Activities of dissolved 226Ra, dissolved and particulate 210Pb, and particulate 210Po were determined to a depth of 300 m in a series of depth profiles collected along a transect across the equator at 155˚E in November 1993. Total 210Pb in the surface water decreased from 2·7 Bq m-3 at 10˚N to 1·8 Bq m-3 at 10˚S. Dissolved 210Pb generally decreased with depth but showed subsurface (100–150 m) maxima at 10˚N and 5˚N. The nutrient concentrations at 300 m were highest at these stations, suggesting some degree of upwelling. Calculations indicate that the residence times of dissolved (<0·45 µm) and particulate (>0·45 µm) 210Pb in the top 300 m were 4·6–9·6 years and 0·15–0·29 year respectively.


2003 ◽  
Vol 38 (2) ◽  
pp. 335-359 ◽  
Author(s):  
Gerald R. Ontkean ◽  
David S. Chanasyk ◽  
Sandi Riemersma ◽  
D. Rodney Bennett ◽  
Jerry M. Brunen

Abstract A three-year study was conducted to examine the effects of a prairie wetland enhanced for waterfowl habitat on surface water quality in the Crowfoot Creek watershed in southern Alberta, Canada. Monitoring was carried out at the Hilton wetland from mid-March to the end of October in 1997 to 1999 at two inflow sites and one outflow site. Data were collected on flow, total phosphorus (TP), total nitrogen (TN), total suspended solids (TSS), and fecal coliform (FC) bacteria. Nutrient concentrations were highest in the spring, and decreased during the remainder of the monitoring period each year. Nutrient concentrations did not change significantly within the wetland due to the form of nutrient, reduced retention times for nutrient uptake, and the addition of nutrients to the water through sediment release and decomposition of organic matter. The wetland acted as both a source and a sink for nutrients, depending on flow volumes. TSS concentrations decreased significantly from inflow to outflow, indicating sedimentation occurred in the wetland. FC bacteria levels were lowest in the spring and increased during the post-spring runoff (PSRO) period. FC bacteria counts decreased significantly within the wetland throughout the entire year. The Hilton wetland was effective in reducing the amounts of TSS and FC bacteria exported from the wetland; however, there was no significant change in nutrient status.


2013 ◽  
Vol 68 (6) ◽  
pp. 1280-1287 ◽  
Author(s):  
P. Han ◽  
K. Vijayaraghavan ◽  
S. Reuben ◽  
E. S. Estrada ◽  
U. M. Joshi

One of the most effective mitigative approaches to eutrophication is the reduction of nutrient loading into water bodies. Bioremediation presents an economically viable and ecologically sustainable technology to nutrient pollution control taking advantage of the remarkable ability of plants and their associated microbial community to assimilate and remove nutrients from the environment. In this study, four emergent macrophytes (Cyperus haspan, Pandanus amaryllifolius, Pontederia cordata and Thalia geniculata) and two floating plants (Hygroryza aristata and Pistia stratiotes) were deployed in bank-side treatment beds and comparatively assessed for their remediative capabilities for nutrient control. P. stratiotes exhibited the highest removal efficiency for both nitrate and phosphate among the six plant species studied. Emergent macrophytes, P. amaryllifolius, C. haspan and P. cordata, were also found to be highly effective in nutrient uptake exhibiting removal efficiencies up to 100%. With the exception of T. geniculata, depletion of nutrients as a result of plant uptake significantly impeded the natural colonization of algae invariably leading to improvements in water quality in terms of turbidity and pH. Suppression of algae proliferation by T. geniculata was not preceded by a reduction in nutrient concentrations suggesting that T. geniculata may be directly inhibiting algal growth through allelopathy.


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