Groundwater and Surface Water Interactions in Relation to Natural and Anthropogenic Environmental Changes

2016 ◽  
pp. 289-326 ◽  
Author(s):  
Mohammad Safeeq ◽  
Ali Fares
Keyword(s):  
Surface Water ◽  
Environmental Changes

scholarly journals Moderate Seasonal Dynamics Indicate an Important Role for Lysogeny in the Red Sea

2021 ◽  
Vol 9 (6) ◽  
pp. 1269
Author(s):  
Ruba Abdulrahman Ashy ◽  
Curtis A. Suttle ◽  
Susana Agustí
Keyword(s):  
Surface Water ◽  
Mitomycin C ◽  
Red Sea ◽  
Environmental Changes ◽  
Viral Infections ◽  
High Salinity ◽  
High Surface ◽  
Temperate Phage ◽  
Viral Dynamics ◽  
Second Year

Viruses are the most abundant microorganisms in marine environments and viral infections can be either lytic (virulent) or lysogenic (temperate phage) within the host cell. The aim of this study was to quantify viral dynamics (abundance and infection) in the coastal Red Sea, a narrow oligotrophic basin with high surface water temperatures (22–32 °C degrees), high salinity (37.5–41) and continuous high insolation, thus making it a stable and relatively unexplored environment. We quantified viral and environmental changes in the Red Sea (two years) and the occurrence of lysogenic bacteria (induced by mitomycin C) on the second year. Water temperatures ranged from 24.0 to 32.5 °C, and total viral and bacterial abundances ranged from 1.5 to 8.7 × 106 viruses mL−1 and 1.9 to 3.2 × 105 bacteria mL−1, respectively. On average, 12.24% ± 4.8 (SE) of the prophage bacteria could be induced by mitomycin C, with the highest percentage of 55.8% observed in January 2018 when bacterial abundances were low; whereas no induction was measurable in spring when bacterial abundances were highest. Thus, despite the fact that the Red Sea might be perceived as stable, warm and saline, relatively modest changes in seasonal conditions were associated with large swings in the prevalence of lysogeny.

Untangling transient groundwater mixing and travel times with noble gas time series and numerical modeling

2020 ◽  
Author(s):  
Andrea L. Popp ◽  
Álvaro Pardo-Álvarez ◽  
Oliver S. Schilling ◽  
Stéphanie Musy ◽  
Andreas Scheidegger ◽  
...  
Keyword(s):  
Surface Water ◽  
Environmental Changes ◽  
Noble Gas ◽  
Gas Analysis ◽  
Marginal Effect ◽  
Travel Times ◽  
Groundwater Pumping ◽  
Mountainous Regions ◽  
Mixing Ratios ◽  
Groundwater Mixing

<p class="western"><span lang="en-US">The quality and quantity of alluvial groundwater in mountainous areas are particularly susceptible to the effects of climate change, as well as increasing pollution from agriculture and urbanization. Understanding mixing between surface water and groundwater as well as groundwater travel times in such systems is thus crucial to sustain a safe and sufficient water supply. We used a novel combination of real-time, in-situ noble gas analysis to quantify groundwater mixing of recently infiltrated river water (<em>F<sub>rw</sub></em><!-- Please note that everything in “$$” will look differently once submitted -->) and regional groundwater, as well as travel times of <em>F<sub>rw</sub></em> during a two-month groundwater pumping test carried out at a drinking water wellfield in a prealpine valley in Switzerland. Transient groundwater mixing ratios were calculated using helium-4 concentrations combined with a Bayesian end-member mixing model. Having identified the groundwater fraction of <em>F<sub>rw</sub></em> consequently allowed us to infer the travel times from the stream to the wellfield, estimated based on radon-222 activities of <em>F<sub>rw</sub></em>. Additionally, we compared and validated our tracer-based estimates of <em>F<sub>rw</sub></em> using a calibrated surface water-groundwater model. Our findings show that (i) mean travel times of <em>F<sub>rw</sub></em> are in the order of two weeks, (ii) during most of the experiment, <em>F<sub>rw</sub></em> is substantially high (~70\%), and (iii) increased groundwater pumping only has a marginal effect on groundwater mixing ratios and travel times. The high fraction of <em>F<sub>rw</sub></em> in the abstracted groundwater and its short travel times emphasize the vulnerability of mountainous regions to present and predicted environmental changes.</span></p>

Hydrogeochemical characteristics at Cape Lamb, Vega Island, Antarctic Peninsula

2012 ◽  
Vol 24 (6) ◽  
pp. 591-607 ◽  
Author(s):  
L. Moreno ◽  
A. Silva-Busso ◽  
J. López-Martínez ◽  
J.J. Durán-Valsero ◽  
C. Martínez-Navarrete ◽  
...  
Keyword(s):  
Surface Water ◽  
Antarctic Peninsula ◽  
Climate Warming ◽  
Significant Influence ◽  
Water Samples ◽  
Environmental Changes ◽  
Hydrological Cycle ◽  
Surface Water Chemistry ◽  
Ocean Spray ◽  
Hydrological Cycles

AbstractEnvironmental changes in the northern Antarctic Peninsula provide a sensitive local indicator of climate warming. A consequence of these changes is the activation of surface and subsurface hydrological cycles in areas where water, in colder conditions, would remain frozen. This paper analyses the effects of hydrological cycle activation at Cape Lamb, Vega Island. The conclusions are based on hydrochemistry and isotope interpretation of 51 representative water samples from precipitation, streams, lakes, ice, snow and groundwater. Based on these results relationships between the different components of the hydrological cycle are proposed. This paper highlights the important contribution of groundwater to surface water chemistry, the disconnection of the lakes from the overall flow, the lack of an ocean spray signature in surface water and groundwater and the significant influence of windblown dust in the composition of the analysed waters.

scholarly journals Water column distribution and carbon isotopic signal of cholesterol, brassicasterol and particulate organic carbon in the Atlantic sector of the Southern Ocean

2013 ◽  
Vol 10 (4) ◽  
pp. 2787-2801 ◽  
Author(s):  
A.-J. Cavagna ◽  
F. Dehairs ◽  
S. Bouillon ◽  
V. Woule-Ebongué ◽  
F. Planchon ◽  
...  
Keyword(s):  
Surface Water ◽  
Organic Carbon ◽  
Southern Ocean ◽  
Water Column ◽  
Particulate Organic Carbon ◽  
Environmental Changes ◽  
Surface Concentration ◽  
Polar Front ◽  
Atlantic Sector ◽  
Organic C

Abstract. The combination of concentrations and δ13C signatures of Particulate Organic Carbon (POC) and sterols provides a powerful approach to study ecological and environmental changes in both the modern and ancient ocean. We applied this tool to study the biogeochemical changes in the modern ocean water column during the BONUS-GoodHope survey (February–March 2008) from Cape Basin to the northern part of the Weddell Gyre. Cholesterol and brassicasterol were chosen as ideal biomarkers of the heterotrophic and autotrophic carbon pools, respectively, because of their ubiquitous and relatively refractory nature. We document depth distributions of concentrations (relative to bulk POC) and δ13C signatures of cholesterol and brassicasterol combined with CO2 aq. surface concentration variation. While the relationship between CO2 aq. and δ13C of bulk POC and biomarkers have been reported by others for the surface water, our data show that this persists in mesopelagic and deep waters, suggesting that δ13C signatures of certain biomarkers in the water column could be applied as proxies for surface water CO2 aq. We observed a general increase in sterol δ13C signatures with depth, which is likely related to a combination of particle size effects, selective feeding on larger cells by zooplankton, and growth rate related effects. Our data suggest a key role of zooplankton fecal aggregates in carbon export for this part of the Southern Ocean (SO). Additionally, in the southern part of the transect south of the Polar Front (PF), the release of sea-ice algae during the ice demise in the Seasonal Ice Zone (SIZ) is hypothesized to influence the isotopic signature of sterols in the open ocean. Overall, the combined use of δ13C values and concentrations measurements of both bulk organic C and specific sterols throughout the water column offers the promising potential to explore the recent history of plankton and the fate of organic matter in the SO.

scholarly journals Assessment of the ecological state of the surface waters of the Nikitinsky fish passage channel during dredging work

2019 ◽  
Vol 135 ◽  
pp. 01016
Author(s):  
Sergey Strelkov ◽  
Ludmila Boronina ◽  
Andrey Sorokin ◽  
Kirill Kondrashin ◽  
Roman Petrov
Keyword(s):  
Surface Water ◽  
Surface Waters ◽  
Environmental Changes ◽  
Surface Water Quality ◽  
Ecological Monitoring ◽  
Fish Passage ◽  
Ecological Condition ◽  
Adult Fish ◽  
Long Period ◽  
Integral Indicator

Fish passage channels along the main delta watercourses serve for upstream spawning of fish and stingrays of young and adult fish back to sea, thereby preserving and multiplying the biodiversity of the ecosystems of the Caspian basin. The flickering sections of the canal-fish passage require periodic dredging. When analyzing the ecological and geochemical situation of the territory, one of the most informative objects of research is surface water. Accumulating pollutants coming from watersheds over a long period of time, soils are an indicator of the ecological condition of the territory, a kind of integral indicator of the level of pollution. As part of the study, an assessment was made of the ecotoxicological state of the surface waters of the fish passage channel during dredging in the Volga delta, the environmental toxicological status of the coastal zone of the canal was analyzed according to accepted standards, possible adverse environmental changes were predicted, and proposals were developed for a program of production ecological monitoring the nature of changes in surface water quality as a major component of the ecosystem.

scholarly journals Responses of nitrogen stable isotopes in fish to phosphorus limitation in freshwater wetlands

2020 ◽  
pp. 41
Author(s):  
Jianming Hong ◽  
Binhe Gu
Keyword(s):  
Stable Isotopes ◽  
Surface Water ◽  
Total Phosphorus ◽  
Fish Species ◽  
Environmental Changes ◽  
Agricultural Runoff ◽  
South Florida ◽  
Freshwater Wetlands ◽  
Nitrogen Stable Isotopes ◽  
Ecological Changes

Human-induced eutrophication has altered ecological processes in aquatic ecosystems. Detection of ecological changes is a prerequisite for protecting ecosystems from degradation. In this study, nitrogen stable isotopes (δ15N) in fish are evaluated as indicators of environmental changes in south Florida wetlands. Stable nitrogen isotope (δ15N) data of select fish species and water quality collected from the Florida Everglades between the 1990s and 2000s were used to assess the relationship between total phosphorus concentrations and δ15N ratios. The δ15N ratios in nine of ten select fish species increase significantly as total phosphorus concentration in the surface water increases. There were significant relationships between total nitrogen concentration in the surface water and δ15N ratios in several fish species. The pattern of changes in δ15N ratios along nutrient gradients suggests that increased eutrophication is recorded as the δ15N ratios in fish. The lack of human wastewater loading, the dominance in agricultural runoff and the high TN:TP ratio suggest that phosphorus is the limiting factor driving ecosystem productivity and the changes of δ15N ratios in fish. Results from this analysis demonstrate that δ15N ratios in fish integrate biotic responses to eutrophic process over time and could be a robust indicator for early ecological changes.

scholarly journals Whole water column distribution and carbon isotopic composition of bulk particulate organic carbon, cholesterol and brassicasterol from the Cape Basin to the northern Weddell Gyre in the Southern Ocean

2012 ◽  
Vol 9 (2) ◽  
pp. 1667-1709 ◽  
Author(s):  
A.-J. Cavagna ◽  
F. Dehairs ◽  
V. Woule-Ebongué ◽  
S. Bouillon ◽  
F. Planchon ◽  
...  
Keyword(s):  
Surface Water ◽  
Organic Carbon ◽  
Southern Ocean ◽  
Water Column ◽  
Particulate Organic Carbon ◽  
Environmental Changes ◽  
Carbon Isotopic Composition ◽  
Organic C ◽  
Weddell Gyre ◽  
Cape Basin

Abstract. The combination of concentrations and δ13C signatures of Particulate Organic Carbon (POC) and sterols provides a powerful approach to study ecological and environmental changes both in the modern and ancient ocean, but its application has so far been restricted to the surface area. We applied this tool to study the biogeochemical changes in the modern ocean water column during the BONUS-GoodHope survey (Feb–Mar 2008) from Cape Basin to the northern part of the Weddell Gyre. Cholesterol and brassicasterol were chosen as ideal biomarkers of the heterotrophic and autotrophic carbon pools, respectively, because of their ubiquitous and relatively refractory nature. We document depth distributions of concentrations (relative to bulk POC) and δ13C signatures of cholesterol and brassicasterol from the Cape Basin to the northern Weddell Gyre combined with CO2 aq. surface concentration variation. While relationships between surface water CO2 aq. and δ13C of bulk POC and biomarkers have been previously established for surface waters, our data show that these remain valid in deeper waters, suggesting that δ13C signatures of certain biomarkers could be developed as proxies for surface water CO2 aq. Our data suggest a key role of zooplankton fecal aggregates in carbon export for this part of the Southern Ocean. We observed a general increase in sterol δ13C signatures with depth, which is likely related to a combination of particle size effects, selective feeding on larger cells by zooplankton, and growth rate related effects Additionally, in the southern part of the transect south of the Polar Front (PF), the release of sea-ice algae is hypothesized to influence the isotopic signature of sterols in the open ocean. Overall, combined use of δ13C and concentrations measurements of both bulk organic C and specific sterol markers throughout the water column shows the promising potential of analyzing δ13C signatures of individual marine sterols to explore the recent history of plankton and the fate of organic matter in the SO.

Modern environment characterization of interdunal lakes in Inhambane province (SE Mozambique) as an analogue to understand past environmental changes

2020 ◽  
Author(s):  
Ana Gomes ◽  
Simon Connor ◽  
Maria João Martins ◽  
Brandon Zinsious ◽  
Célia Gonçalves ◽  
...  
Keyword(s):  
Surface Water ◽  
Environmental Changes ◽  
Fish Farming ◽  
Environmental Drivers ◽  
Dune System ◽  
Ground Control Points ◽  
Water Ph ◽  
Aerial Vehicle ◽  
The Mean

<p>To better understand Quaternary environmental changes in Southeastern Mozambique and their role in human evolution, it is first necessary to characterized the modern environment of this area and the environmental drivers on their evolution. For this reason, an international and interdisciplinary team interpreted the Inhambane Province’s geology, hydrographic and tectonic maps and open-access satellite imagery and derived products (for morphometric analysis and landscape interpretation). Inhambane province is in a coastal plain composed of a Pleistocene dune system, within which many lakes can be found. Additionally, a comprehensive review of the existing research for the region was conducted, to choose the most suitable lakes from which to collect sediment records for paleoenvironmental reconstructions. The team carried out fieldwork during the summer of 2019 in four of the selected interdunal lakes (Muangue, Nyalonzelwe, Nhambutse and Chivanene). During fieldwork the vegetation cover and the land uses were carefully described, and the lakes water column parameters were measured. Additionally, in the two lakes that presented the longest sedimentological records (Muangue and Nyalonzelwe), an unmanned aerial vehicle (UAV) survey was carried out to create high resolution maps and elevation models of the lakes and their surroundings. UAV flights were carried out at 25 and 60 m height, with a front and side overlap between 60 to 70 %, using georeferenced Ground control points (GCPs). The lakes’ areas vary between 0.4 (Muangue) to 0.8 km<sup>2</sup> (Chivanene). The longest sedimentological records were found in lakes with a water level 5 m above the Mean Sea Level (MSL) and surrounded by higher dunes (between 31 and 121 m elevation in relation to MSL). Most of the lake margins are used for agriculture, livestock and housing and some have fish farming. Regarding vegetation, between 16 families and 27 species were identified around Nhambutse and 27 families and 43 species around Muangue. The lakes’ maximum depths vary between 1 (Nhambutse) and 4.6 meters (Muangue). All lakes are freshwater except Nyalonzelwe, which is brackish. On average, surface water pH varies between 7.2 (Chivanene) and 9.12 (Nyalonzelwe). Surface water temperature varies between 25.03 (Nhambutse) and 26.6 ° C (Chivanene). All the collected data highlight the diversity of interdunal lake environments in the Inhambane Province, and how these environments may impact the sedimentological record. This work was supported by project PTDC/HAR-ARQ/28148/2017, funded by the Portuguese Foundation for Science and Technology.</p>

Application of a Simple Cold Stub to the Direct Observation of Frozen Hydrated Sand

1973 ◽  
Vol 31 ◽  
pp. 212-213
Author(s):  
John M. Wehrung ◽  
Richard J. Harniman
Keyword(s):  
United States ◽  
Surface Water ◽  
Direct Observation ◽  
Controlled Study ◽  
Clay Particles ◽  
Organic Debris ◽  
Rock Formations ◽  
Water Tables ◽  
Permeable Rock ◽  
Natural Means

Water tables in aquifer regions of the southwest United States are dropping off at a rate which is greater than can be replaced by natural means. It is estimated that by 1985 wells will run dry in this region unless adequate artificial recharging can be accomplished. Recharging with surface water is limited by the plugging of permeable rock formations underground by clay particles and organic debris.A controlled study was initiated in which sand grains were used as the rock formation and water with known clay concentrations as the recharge media. The plugging mechanism was investigated by direct observation in the SEM of frozen hydrated sand samples from selected depths.

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