Mercury dynamics in a changing coastal area over industrial and post-industrial phases

2020 ◽  
Author(s):  
Ginevra Rosati ◽  
Cosimo Solidoro ◽  
Donata Melaku Canu
Keyword(s):  
Atmospheric Deposition ◽  
Environmental Changes ◽  
Sediment Resuspension ◽  
Field Studies ◽  
Ecosystem Approach ◽  
Venice Lagoon ◽  
Biogeochemical Model ◽  
Anthropogenic Pressures ◽  
The One ◽  
Post Industrial

<p>The Venice Lagoon (Mediterranean Sea) is a shallow coastal lagoon that have been subjected to several anthropogenic pressures, including significant Hg loadings from industrial activities. Inorganic Hg is methylated to neurotoxic MeHg in lagoon water and sediment, posing the ecosystem wealth at risk.</p><p>Here, we use a biogeochemical model to investigate the long-term dynamics of Hg species in the Venice Lagoon from the pre-industrial period to the post-industrial period (1900-2100), also taking into account environmental changes occurred in the lagoon such as eutrophication, and the increase of sediment resuspension driven by manila clam harvesting.</p><p>Time-variable Hg emissions from industries were estimated from available information about industrial production and technology-dependent emissions factors, while Hg loading species from other sources (river, atmospheric deposition, urban wastes) where estimated through downscaling from global studies, using observations from previous field studies (1970 - 2010) as constraints. The impacts of future trends of Hg atmospheric deposition are explored through scenario analysis. </p><p>Modeled Hg species are in a satisfactory agreement with the available observations. In the current postindustrial phase, Hg<sub>T</sub> in the lagoon waters comes mostly from sediments, while MeHg comes primarily from the watershed.</p><p>We estimate in ∼56 kg y<sup>-1</sup> the HgT export for 2019 to the Adriatic Sea, which includes ∼0.13 kg y<sup>-1</sup> of MeHg. Both Hg and MeHg concentrations are decreasing since outputs slightly exceed inputs. The analysis of Hg and MeHg reservoirs and fluxes reveals the impacts of the changes in environmental conditions on Hg fluxes. On the one hand, eutrophication has enhanced sediment deposition to the seabed, causing a maximum in sediment Hg concentrations when Hg inputs were already declining; on the other hand, the enhanced sediment resuspension due to clam harvesting led to increased Hg fluxes from the sediment to the water, also causing a redistribution of Hg from the central lagoon to the northern and southern areas, as reported by observational studies. These results emphasize the importance of adopting an ecosystem approach when investigating Hg dynamics, considering the different uses of the ecosystem.</p>

scholarly journals Seabed Resuspension in the Chesapeake Bay: Implications for Biogeochemical Cycling and Hypoxia

2020 ◽  
Vol 44 (1) ◽  
pp. 103-122
Author(s):  
Julia M. Moriarty ◽  
Marjorie A. M. Friedrichs ◽  
Courtney K. Harris
Keyword(s):  
Organic Matter ◽  
Chesapeake Bay ◽  
Water Column ◽  
Primary Productivity ◽  
Environmental Changes ◽  
Light Attenuation ◽  
Sediment Resuspension ◽  
Nitrogen Dynamics ◽  
Biogeochemical Model ◽  
Order Of Magnitude

AbstractSediment processes, including resuspension and transport, affect water quality in estuaries by altering light attenuation, primary productivity, and organic matter remineralization, which then influence oxygen and nitrogen dynamics. The relative importance of these processes on oxygen and nitrogen dynamics varies in space and time due to multiple factors and is difficult to measure, however, motivating a modeling approach to quantify how sediment resuspension and transport affect estuarine biogeochemistry. Results from a coupled hydrodynamic–sediment transport–biogeochemical model of the Chesapeake Bay for the summers of 2002 and 2003 showed that resuspension increased light attenuation, especially in the northernmost portion of the Bay, shifting primary production downstream. Resuspension also increased remineralization in the central Bay, which experienced larger organic matter concentrations due to the downstream shift in primary productivity and estuarine circulation. As a result, oxygen decreased and ammonium increased throughout the Bay in the bottom portion of the water column, due to reduced photosynthesis in the northernmost portion of the Bay and increased remineralization in the central Bay. Averaged over the channel, resuspension decreased oxygen by ~ 25% and increased ammonium by ~ 50% for the bottom water column. Changes due to resuspension were of the same order of magnitude as, and generally exceeded, short-term variations within individual summers, as well as interannual variability between 2002 and 2003, which were wet and dry years, respectively. Our results quantify the degree to which sediment resuspension and transport affect biogeochemistry, and provide insight into how coastal systems may respond to management efforts and environmental changes.

General practitioners and clinical pharmacology

1989 ◽  
Vol 4 (4) ◽  
pp. 241-244
Author(s):  
P. Lemoine
Keyword(s):  
Clinical Pharmacology ◽  
General Practitioners ◽  
Field Studies ◽  
Discussion Group ◽  
Group Method ◽  
Study Group ◽  
Test Drug ◽  
Monthly Basis ◽  
One Year ◽  
The One

SummaryIt is difficult to undertake field studies with non marketed psychotropic drugs because of two apparently contradictory conditions : on the one hand, the methodology has to be rigorously controlled, and on the other hand, such studies have to be carried out in their future environment by general practitioners (GPs). Bearing in mind the lack of training and experience regarding this kind of approach, the author adopted a discussion group method according to the techniques developed by M. Balint. The study group comprised five GPs, a clinical pharmacology expert and a doctor from the pharmaceutical laboratory which had developed the test drug. These persons met on a monthly basis over a one year period. In the present paper, the author indicates the benefits of such a methodology, based on six years’ experience and several trials, with special emphasis placed on the pedagogical aspects.

scholarly journals Reproduction and biomarker responses of Eisenia fetida after exposure to imidacloprid in biochar-amended soil

Biochar ◽  
2021 ◽  
Author(s):  
Ngitheni Winnie-Kate Nyoka ◽  
Ozekeke Ogbeide ◽  
Patricks Voua Otomo
Keyword(s):  
Eisenia Fetida ◽  
Field Studies ◽  
Application Rate ◽  
Land Application ◽  
Acetylcholinesterase Inhibition ◽  
Beneficial Effects ◽  
Pesticide Pollution ◽  
The One ◽  
The Impact ◽  
Amended Soil

AbstractTerrestrial and aquatic ecosystems are increasingly threatened by pesticide pollution resulting from extensive use of pesticides, and due to the lack of regulatory measures in the developing world, there is a need for affordable means to lessen environmental effects. This study aimed to investigate the impact of biochar amendment on the toxicity of imidacloprid to life-cycle parameters and biomarker responses of the earthworm Eisenia fetida. E. fetida was exposed to 10% biochar-amended and non-amended OECD artificial soils spiked with 0, 0.75, 1.5, 2.25 and 3 mg imidacloprid/kg for 28 days. An LC50 of 2.7 mg/kg was only computed in the non-amended soil but not in the biochar-amended soil due to insignificant mortality. The EC50 calculated in the non-amended soil (0.92 mg/kg) for reproduction (fertility) was lower than the one computed in the biochar amended (0.98 mg/kg), indicating a decrease in toxicity in the biochar-amended substrate. Significant weight loss was observed at the two highest imidacloprid treatments in the non-amended soil and only at the highest treatment in the biochar-amended substrate, further highlighting the beneficial effects of biochar. Catalase activity decreased significantly at the two highest concentrations of non-amended soil. Yet, in the amended soil, the activity remained high, especially in the highest concentration, where it was significantly higher than the controls. This indicated more severe oxidative stress in the absence of biochar. In all non-amended treatments, there was a significant acetylcholinesterase inhibition, while lower inhibition percentages were observed in the biochar-amended soil. In most endpoints, the addition of biochar alleviated the toxic effects of imidacloprid, which shows that biochar has the potential to be useful in soil remediation. However, there is still a need for field studies to identify the most effective application rate of biochar for land application.

scholarly journals A methodology to conduct wind damage field surveys for high-impact weather events of convective origin

2020 ◽  
Vol 20 (5) ◽  
pp. 1513-1531 ◽  
Author(s):  
Oriol Rodríguez ◽  
Joan Bech ◽  
Juan de Dios Soriano ◽  
Delia Gutiérrez ◽  
Salvador Castán
Keyword(s):  
Field Studies ◽  
High Impact ◽  
Strong Wind ◽  
Field Surveys ◽  
Weather Events ◽  
Straight Line ◽  
High Impact Weather ◽  
Strong Winds ◽  
Wind Events ◽  
The One

Abstract. Post-event damage assessments are of paramount importance to document the effects of high-impact weather-related events such as floods or strong wind events. Moreover, evaluating the damage and characterizing its extent and intensity can be essential for further analysis such as completing a diagnostic meteorological case study. This paper presents a methodology to perform field surveys of damage caused by strong winds of convective origin (i.e. tornado, downburst and straight-line winds). It is based on previous studies and also on 136 field studies performed by the authors in Spain between 2004 and 2018. The methodology includes the collection of pictures and records of damage to human-made structures and on vegetation during the in situ visit to the affected area, as well as of available automatic weather station data, witness reports and images of the phenomenon, such as funnel cloud pictures, taken by casual observers. To synthesize the gathered data, three final deliverables are proposed: (i) a standardized text report of the analysed event, (ii) a table consisting of detailed geolocated information about each damage point and other relevant data and (iii) a map or a KML (Keyhole Markup Language) file containing the previous information ready for graphical display and further analysis. This methodology has been applied by the authors in the past, sometimes only a few hours after the event occurrence and, on many occasions, when the type of convective phenomenon was uncertain. In those uncertain cases, the information resulting from this methodology contributed effectively to discern the phenomenon type thanks to the damage pattern analysis, particularly if no witness reports were available. The application of methodologies such as the one presented here is necessary in order to build homogeneous and robust databases of severe weather cases and high-impact weather events.

Characteristics of ships' depression waves and associated sediment resuspension in Venice Lagoon, Italy

2011 ◽  
Vol 85 (1-2) ◽  
pp. 45-56 ◽  
Author(s):  
John Rapaglia ◽  
Luca Zaggia ◽  
Klaus Ricklefs ◽  
Morgan Gelinas ◽  
Henry Bokuniewicz
Keyword(s):  
Sediment Resuspension ◽  
Venice Lagoon

scholarly journals Geographical vocabulary of the Shilan dialect of the Erzya-Mordovian language

2020 ◽  
Vol 12 (4) ◽  
pp. 358-367
Author(s):  
Nikolai V. Belenov
Keyword(s):  
Original Composition ◽  
Research Methods ◽  
Field Studies ◽  
The Other ◽  
Volga Region ◽  
The One ◽  
Xix Century ◽  
First Time ◽  
Source Materials ◽  
Made In

Introduction. The article presents the results of research of the geographical vocabulary of the Shilan dialect, one of the Erzya-Mordovian dialects of the Samara region, common among Erzya population of Shilan village in Krasnoyarsk region. The dialect belongs to rare Mordovian dialects of the Samara Volga region that were formed in the region since the middle of the XIX century, and therefore its research is of extra interest. Materials and Methods. The research methods are determined by the purpose and objectives of the study. The analysis of the geographical vocabulary of the Shilan dialect is carried out with the involvement of relevant items made in other Mordovian dialects of Samara region, adjacent territories of neighboring regions, as well as other territories of settlement of the Mordovians. Data on geographical vocabulary of the dialect introduced into research for the first time. The main source materials for the article is based on field studies in Silane village during the field seasons in 2017 and 2020, as well as in other Erzya-Mordovian and Moksha-Mordovian villages of Samara region and adjacent territories in 2015 – 2020. Results and Discussion. The study showed that the geographical vocabulary of the Shilan dialect of the Erzya-Mordovian language is significantly different from the corresponding lexical clusters in other dialects of the Mordovian region, which can be explained by natural geographical conditions surrounding Shilan village and the original composition of this lexical cluster of Erzya immigrants who founded this village. Conclusion. The analysis of the geographical vocabulary of the Shilan dialect allowed, on the one hand, to identify specific features of this cluster that distinguish it from the corresponding materials of other Mordovian dialects of the region, and, on the other hand, to identify common isoglosses between it and a number of the Erzya-Mordovian dialects of the Samara Volga region.

scholarly journals Blooms of aberrant planktic foraminifera across the K/Pg boundary in the Western Tethys: causes and evolutionary implications

Paleobiology ◽  
2018 ◽  
Vol 44 (3) ◽  
pp. 460-489 ◽  
Author(s):  
Ignacio Arenillas ◽  
José A. Arz ◽  
Vicente Gilabert
Keyword(s):  
Environmental Changes ◽  
Low Frequency ◽  
Meteorite Impact ◽  
Planktic Foraminifera ◽  
Western Tethys ◽  
Quantitative Studies ◽  
El Kef ◽  
Abnormality Index ◽  
The One ◽  
Aberrant Tests

AbstractWe report a detailed study of the different categories and types of abnormal morphologies in planktic foraminifera recognizable in the lowermost Danian, mainly from the El Kef and Aïn Settara sections, Tunisia. Various types of abnormalities in the test morphology were identified, including protuberances near the proloculus, abnormal chambers, double or twinned ultimate chambers, multiple ultimate chambers, abnormal apertures, distortion in test coiling, morphologically abnormal tests, attached twins or double tests, and general monstrosities. Detailed biostratigraphic and quantitative studies of the Tunisian sections documented a major proliferation of aberrant planktic foraminifera (between approximately 5% and 18% in relative abundance) during the first 200 Kyr of the Danian, starting immediately after the Cretaceous/Paleogene (K/Pg) boundary mass extinction (spanning from theGuembelitria cretaceaZone to the lower part of theP. pseudobulloidesZone). This contrasts with the proportionately low frequency of aberrant tests (generally <2%) identified within the uppermost Maastrichtian, suggesting more stable environmental conditions during the last ~50–100 Kyr of the Cretaceous. Two main pulses with abundant aberrant tests were recognized in the earliest Danian, the one recorded in the well-known K/Pg boundary clay being the more intense of those (maxima of >18%). These main pulses of aberrants coincide approximately with relevant quantitative and evolutionary turnovers in the planktic foraminiferal assemblages. In this paper, we explore the relation of these high values of the foraminiferal abnormality index with the environmental changes induced by the meteorite impact of Chicxulub in Yucatan, Mexico, and the massive eruptions of the Deccan Traps, India.

scholarly journals Use of Thermodynamic Orientors to Assess the Efficiency of Ecosystems: A Case Study in the Lagoon of Venice

2002 ◽  
Vol 2 ◽  
pp. 255-260 ◽  
Author(s):  
Simone Bastianoni
Keyword(s):  
Aquatic Ecosystems ◽  
Fish Farming ◽  
Venice Lagoon ◽  
Ecological Systems ◽  
Actual State ◽  
Lagoon Of Venice ◽  
The Past ◽  
Comparison Results ◽  
The One

So-called orientors have been introduced at the interface between ecology and thermodynamics. Two have been chosen here to compare the characteristics of five ecological systems: exergy, which is related to the degree of organization of a system and represents the biogeochemical energy of a system, and emergy, which is defined as the total amount of solar energy directly or indirectly required to generate a product or a service. They represent two complementary aspects of a system: the actual state and the past work needed to reach that state. The ratio of exergy to the emergy flow indicates the efficiency of an ecosystem in producing or maintaining its organization.The main system under study is a portion of the Venice Lagoon, which is used as a fish farming basin. Four other aquatic ecosystems were considered for comparison. Results show that the ecosystem within the Venice Lagoon is the one with the highest efficiency in transforming the available inputs in organization of the system. This fact is due to human intervention, which is very limited but also very effective.

scholarly journals Calibrating a global three-dimensional biogeochemical ocean model (MOPS-1.0)

2017 ◽  
Vol 10 (1) ◽  
pp. 127-154 ◽  
Author(s):  
Iris Kriest ◽  
Volkmar Sauerland ◽  
Samar Khatiwala ◽  
Anand Srivastav ◽  
Andreas Oschlies
Keyword(s):  
Large Scale ◽  
Environmental Changes ◽  
Single Species ◽  
Ocean Model ◽  
Biogeochemical Model ◽  
Parameter Estimates ◽  
Spatial And Temporal Scales ◽  
Ocean Models ◽  
Biogeochemical Tracers ◽  
Parameter Values

Abstract. Global biogeochemical ocean models contain a variety of different biogeochemical components and often much simplified representations of complex dynamical interactions, which are described by many ( ≈ 10 to  ≈ 100) parameters. The values of many of these parameters are empirically difficult to constrain, due to the fact that in the models they represent processes for a range of different groups of organisms at the same time, while even for single species parameter values are often difficult to determine in situ. Therefore, these models are subject to a high level of parametric uncertainty. This may be of consequence for their skill with respect to accurately describing the relevant features of the present ocean, as well as their sensitivity to possible environmental changes. We here present a framework for the calibration of global biogeochemical ocean models on short and long timescales. The framework combines an offline approach for transport of biogeochemical tracers with an estimation of distribution algorithm (Covariance Matrix Adaption Evolution Strategy, CMA-ES). We explore the performance and capability of this framework by five different optimizations of six biogeochemical parameters of a global biogeochemical model, simulated over 3000 years. First, a twin experiment explores the feasibility of this approach. Four optimizations against a climatology of observations of annual mean dissolved nutrients and oxygen determine the extent to which different setups of the optimization influence model fit and parameter estimates. Because the misfit function applied focuses on the large-scale distribution of inorganic biogeochemical tracers, parameters that act on large spatial and temporal scales are determined earliest, and with the least spread. Parameters more closely tied to surface biology, which act on shorter timescales, are more difficult to determine. In particular, the search for optimum zooplankton parameters can benefit from a sound knowledge of maximum and minimum parameter values, leading to a more efficient optimization. It is encouraging that, although the misfit function does not contain any direct information about biogeochemical turnover, the optimized models nevertheless provide a better fit to observed global biogeochemical fluxes.

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