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1.
Article in English | MEDLINE | ID: mdl-38861850

ABSTRACT

Environmental factors play a key role in individual adaptation to different local conditions. Because of this, studies about the physiological and genetic responses of individuals exposed to different natural environments offer clues about mechanisms involved in population differentiation, and as a subsequent result, speciation. Marine environments are especially suited to survey this kind of phenomena because they commonly harbor species adapted to different local conditions along a geographic continuum. Silversides belonging to Odontesthes are commonly distributed in tropical and temperate regions of South America and exhibit noticeable phenotypic plasticity, which allows them to adapt to contrasting environments. In this study, the genetic expression of O. argentinensis sampled along the Uruguayan Atlantic coast and estuarine adjacent areas was investigated. In addition, the correlation between individual genotypes and environmental variables was also analysed in O. argentinensis and O. bonariensis. Results obtained suggest a differential expression pattern of low magnitude among individuals from the different areas sampled and a correlation between several SNP loci and environmental variables. The analyses carried out did not show a clear differentiation among individuals sampled along different salinity regimens, but enriched GOTerms seem to be driven by water oxygen content. On the other hand, a total of 46 SNPs analysed in O. argentinensis and O. bonariensis showed a correlation with salinity and temperature. Although none of the correlated SNPs and corresponding genes from our both analyses were directly associated with hypoxia, genes related to the cardiovascular system and muscle cell differentiation were found. All these genes are interesting candidates for future studies since they are closely related to the differentially expressed genes. Although salinity was also mentioned as an important parameter limiting introgression between O. argentinensis and O. bonariensis, it was found that salinity does not drive differential expression in O. argentinensis, but rather oxygen levels. Moreover, salinity does not directly affect the structure and genetic divergence of the populations, they appear to be structured based on their degree of isolation and geographical distance between them. Further studies, like genome-wide analyses, could help to elucidate additional genes adapted to the different environments in these silverside species.

2.
J Fish Biol ; 104(1): 315-319, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37726229

ABSTRACT

The lectotype specimen of Bryconamericus rubropictus (Berg) and its designation have remained imprecisely documented since its publication. The lack of a photograph or an unambiguous illustration, correct size, inaccurate labelling, and proper specimen separation has led to an uncertainty about the identity and nomenclatural status of the lectotype. We recovered and provided detailed morphological data on the specimen that must be recognised as the lectotype. This contribution brings stability and clarity on the nomenclatural status of the species and its type material.


Subject(s)
Characidae , Characiformes , Animals , Characidae/anatomy & histology , Brazil , Rivers
3.
Sci Total Environ ; 904: 166680, 2023 Dec 15.
Article in English | MEDLINE | ID: mdl-37659559

ABSTRACT

Recent studies established a strong connection between instrumental hydroclimatic changes in the Río de la Plata (RdlP) watershed and the influx of continental terrigenous material and productivity changes. This correspondence was further validated for the last millennium. Here, we identified centennial, multi-decadal, and interannual changes in diatom composition, as a proxy for La Plata Plume Water (PPW) discharge into the inner shelf. Core GeoB13813-4 diatom data were revisited, and grouped into freshwater, marine, and brackish categories for multivariate, timeseries, and correlation analyses. Such record exhibits a noteworthy resemblance to paleoclimatic and paleoceanographic variations throughout the past millennium. A Detrended Correspondence Analysis (DCA) on the dominant taxa, and Axis-1 revealed a salinity gradient over the past millennium. DCA1-scores exhibited significant correlation with reconstructions of El Niño Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), and the Atlantic Multidecadal Oscillation (AMO) over the same period. By plotting DCA1-scores, we inferred time intervals with varying levels of PPW influence. During ∼936-1500 CE, the PPW influence was weak, as the record was dominated by marine taxa, indicating lateral transport from the Brazilian upwelled water and a stronger influence of the Subtropical Shelf Water. After 1500 CE, a well-developed plume was inferred, with the highest influence occurring after 1800 CE, as evidenced by an increased presence of freshwater/brackish taxa. This increased PPW influence after 1500 CE can be attributed to the onset of more humid conditions and associated increased river discharge, particularly under El Niño conditions, with further ENSO intensification after 1800 CE. We identified significant centennial (250 years) and multidecadal cycles (25-50 years) in diatom community composition. These cycles are related to solar forcing, PDO, and AMO. During the 20th Century, cycles of 2 to 7 years were associated with interannual ENSO variability, while 40-year cycles were linked to AMO and PDO variability.

4.
Rev. Asoc. Méd. Argent ; 136(3): 31-38, sept. 2023.
Article in Spanish | LILACS | ID: biblio-1553365

ABSTRACT

La viruela fue una de las enfermedades epidémicas más temidas desde la antigüedad debido a su alta mortalidad y a las secuelas que dejaba en aquellos que lograban sobrevivir. En el presente trabajo se abordará el ingreso de esta enfermedad en nuestro continente, así como su manifestación a través de epidemias, brotes y focos endémicos. Al mismo tiempo se verá qué reacciones provocó dentro del ámbito médico durante los años del Virreinato del Río de la Plata. Se analizarán los problemas que surgieron con el uso de la vacuna importada, así como el hallazgo de nuestra vacuna local, finalizando con los comienzos de la organización de los servicios de vacunación obligatoria. (AU)


Smallpox was one of the most feared epidemic diseases since ancient times due to its high mortality and the sequelae caused in those that managed to survive. In the present work, the introduction of this disease into our continent will be addressed as well as its manifestation through epidemics, outbreaks, and endemic foci. At the same time, the reactions this disease caused inside the medical field during the years of the Viceroyalty of the Río de la Plata will be observed. The problems that arose from the usage of the imported vaccine and the discovery of our local vaccine will be analyzed, and it will finish with the beginnings of the organization of the mandatory vaccination services. (AU)


Subject(s)
History, 16th Century , History, 17th Century , History, 18th Century , Smallpox/history , Smallpox/epidemiology , Smallpox Vaccine/history , Americas , Smallpox/prevention & control , Mass Vaccination/organization & administration , Disease Outbreaks/history , Vaccination/history , Epidemics/history
5.
Animals (Basel) ; 13(8)2023 Apr 08.
Article in English | MEDLINE | ID: mdl-37106848

ABSTRACT

Leatherback turtles migrate long distances between nesting beaches and distant foraging areas worldwide. This study analyzes the genetic diversity, life history stage, spatiotemporal distribution, and associated threats of a foraging aggregation in the Southwest Atlantic Ocean. A total of 242 leatherbacks stranded or bycaught by artisanal fisheries were recorded from 1997 to 2021 in Uruguay, with sizes ranging from 110.0 to 170.0 cm carapace lengths, indicating that the aggregation is composed of large juveniles and adults. Results of Bayesian mixed-stock analysis show that leatherbacks come primarily from the West African rookeries, based on mitochondrial DNA sequences obtained from 59 of the turtles representing seven haplotypes, including a novel one (Dc1.7). The main threat identified in the area is the fisheries bycatch but most of the carcasses observed were badly decomposed. There was significant seasonal and interannual variability in strandings that is likely associated with the availability of prey and the intensity of the fishing effort. Taken together, these findings reinforce the importance of these South American foraging areas for leatherbacks and the need to determine regional habitat use and migratory routes across the broader Atlantic region, in order to develop effective conservation measures to mitigate threats both at nesting beaches and foraging areas.

6.
Water Res ; 229: 119483, 2023 Feb 01.
Article in English | MEDLINE | ID: mdl-36528927

ABSTRACT

Major world river-estuaries integrate the hydrochemical characteristics of the basin with specific signatures which are maintained until complete mixing or discharge to the sea. The chemical signature of distinct water masses and the anthropogenic impact in the Upper Río de la Plata estuary (RLP) were evaluated by high-resolution continuous monitoring (i.e. every 200 m) of conductivity, turbidity, pH, temperature, chlorophyll a and coloured dissolved organic matter (CDOM), discrete analysis of suspended particulate matter (SPM) grain size composition combined with multivariate analysis (K-means clustering, Principal Component Analysis). The characteristic signatures of main RLP tributaries such as the Paraná River, yielding higher conductivity, CDOM, turbidity and coarser SPM, and the Uruguay River, with clearer, more eutrophic waters enriched in very fine SPM, were maintained 60 km seaward from the estuary head. Across the river, three water corridors with distinct signatures and variable widths (3-20 km) were identified reflecting the transition from Paraná to Uruguay River waters. Multivariate techniques also allowed the identification of a polluted coastal corridor (higher conductivity and CDOM and lower turbidity) impacted by wastewater discharges from the metropolitan Buenos Aires and La Plata cities extending 100 km seaward. The combined strategy of high-resolution monitoring, discrete sampling and multivariate techniques was a useful tool to identify water masses, corridors of flow and anthropogenic sources in a heavily urbanized estuary.


Subject(s)
Estuaries , Water Pollutants, Chemical , Argentina , Water/analysis , Chlorophyll A/analysis , Environmental Monitoring/methods , Rivers , Water Pollutants, Chemical/analysis , Multivariate Analysis
7.
Mar Pollut Bull ; 184: 114101, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36095966

ABSTRACT

Changes in species composition and relative abundance caused by pollution might have an impact on the community dynamics and ecosystem functioning. Macrobenthos are widely used as indicators of marine environmental health due to their sensitive to disturbance. The present study aims to evaluate spatial and temporal variability of functional diversity of macrobenthos of the Montevideo and Canelones coastal zone along a pre-established pollution gradient, based on Biological Traits Analysis, and functional diversity indices. Body-size", "Feeding-mode", "Habitat", and "Indicator-role" were useful proxies to detect changes in environmental conditions in organically enriched habitats. FRic, FEve and FDis detected temporal variations but only FRic registered spatial variations. Differences among surveys would mainly reflect environmental variability caused by the 2009-2010 El Niño-Southern Oscillation event. Finally, negative correlations between FEve and FDis with AMBI suggest both indices as useful proxies of benthic environmental health, with potential to be used in monitoring and quality assessment programs.


Subject(s)
Ecosystem , Estuaries , Environmental Monitoring , El Nino-Southern Oscillation , Environmental Pollution , Biodiversity
8.
Environ Sci Technol ; 55(19): 12914-12921, 2021 10 05.
Article in English | MEDLINE | ID: mdl-34553921

ABSTRACT

The long-term covariation (2002-2017) of lipids, polychlorinated biphenyls (PCBs), and sewage tracers was studied in the detritivorous fish (Prochilodus lineatus) and settling detritus from the Rio de la Plata. Fatty fish from polluted Buenos Aires area (BA) exhibited a significant decrease of muscle lipids (71 ± 12 to 29 ± 8.6% dry weight; p < 0.0001), triglycerides (94 to 85%, p < 0.001), and 18 carbon fatty acids (18C-FA: 59 ± 4.8 to 48 ± 1.4%; p < 0.01), reflecting a reduction of lipid accumulation, largely triglycerides enriched in 18C-FA, with a concomitant ∼20-times decline of PCBs (∼20 to >1 µg g-1 dw). The 2017 individuals of the BA series converged with leaner and more pristine northern fish (N), which showed no significant temporal variation (20 ± 10% lipids, 67 ± 8.7% triglycerides, 41 ± 8.1% 18C-FA, and 0.22 ± 0.42 µg g-1 dw PCB). In contrast, the fecal sterol tracer coprostanol remained abnormally higher in BA fish muscle with no significant temporal trend (120 ± 102 vs 6.6 ± 10 µg g-1 dw or 4.4 ± 2.8 vs 0.63 ± 1.2% sterols at N). The same pattern was observed in BA settling detritus, i.e., a temporal decrease of PCBs with high, stable coprostanol concentrations denoting sustained sewage inputs, while northern detritus was enriched in plant sterols. This long-term covariation of lipids and PCBs in fish muscle from polluted BA converging with more pristine and homogeneous northern specimens while maintaining a sewage-derived diet provides rare field evidence of the declining effect of PCBs controlling the temporal variation of muscular lipids in fish.


Subject(s)
Polychlorinated Biphenyls , Water Pollutants, Chemical , Animals , Environmental Monitoring , Fishes , Humans , Polychlorinated Biphenyls/analysis , Sterols , Water Pollutants, Chemical/analysis
9.
Zootaxa ; 4948(2): zootaxa.4948.2.8, 2021 Mar 19.
Article in English | MEDLINE | ID: mdl-33757030

ABSTRACT

The southernmost record of the neotropical genus Xenicola is documented. An apparently tiny population of X. dohrni, a species described long ago from southern Brazil without other published records, lives at the shore of the Río de la Plata, 1000 km further south. Perhaps it has been established there by means of floating vegetation. The acoustic communication of this species is also very interesting: The male produces with its minuscule tegmina brief signals with a carrier frequency range between 80 and 100 kHz. The female responds, and the male modifies its song when engaged in a duet. It modifies it further, when the female responds from very close. The paper includes a review of the records of Xenicola species on biodiversity observation platforms.


Subject(s)
Orthoptera , Acoustics , Animals , Argentina , Communication , Female , Male
10.
Biodivers Data J ; 8: e56850, 2020.
Article in English | MEDLINE | ID: mdl-33192152

ABSTRACT

BACKGROUND: South America hosts some of the world's most prominent biodiversity hotspots. Yet, Uruguay - a country where multiple major ecosystems converge - ranks amongst the countries with the lowest levels of available digital biodiversity data in the continent. Such prevalent data scarcity has significantly undermined our ability to progress towards evidence-based conservation actions - a critical limitation for a country with a strong focus on agricultural industries and only 1.3% of the land surface guarded by protected areas. Under today's rapid biodiversity loss and environmental changes, the need for open-access biodiversity data is more pressing than ever before. To address this national issue, Biodiversidata - Uruguay's first Consortium of Biodiversity Data - has recently emerged with the aim of assembling a constantly growing database for the biodiversity of this country. While the first phase of the project targeted vertebrate biodiversity, the second phase presented in this paper spans the biodiversity of plants. NEW INFORMATION: As part of the second phase of the Biodiversidata initiative, we present the first comprehensive open-access species-level database of the vascular plant diversity recorded in Uruguay to date (i.e. all species for which data are currently available and species presence has been confirmed). It contains 12,470 occurrence records from across 1,648 species and 160 families, which roughly represents 60% of the total recorded flora of Uruguay. The primary biodiversity data include extant native and introduced species from the lycophytes, ferns, gymnosperms and angiosperms groups. Records were collated from multiple sources, including data available in peer-reviewed scientific literature, institutional scientific collections and datasets contributed by members of the Biodiversidata initiative. The complete database can be accessed at the Zenodo repository: doi.org/10.5281/zenodo.3954406.

11.
Environ Sci Pollut Res Int ; 27(35): 44427-44439, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32767213

ABSTRACT

Microcystis is a frequent cyanobacterium bloom-forming with cosmopolitan distribution which can produce a hepatotoxin group called microcystins (MCs). These MCs are resistant to the traditional processes employed in the water treatment plants and they are often detected after conventional treatments. Because of this, the bio-removal studies have obtained a great interest in the last decades. In this work, a bacterial strain namely LG1 with the ability to remove microcystin-LR (MC-LR) under laboratory conditions was isolated from Rio de la Plata River and it was identified as Achromobacter spp. This ubiquitous bacterium was able to remove 79.5% MC-LR in 7 days with average removal time of 3.33 ± 0.08, 3.06 ± 0.05, and 2.77 ± 0.05 days at 28, 32, and 36 ± 1 °C, being higher at high temperature (36 °C) with an activation energy = 16.79 ± 1.99 kJ mol-1. LG1 grew better at higher temperature (from 28 to 36 ± 1 °C) increasing the specific growth rate (µ) and reducing 2-fold the lag phase duration (LPD) without significant differences (p > 0.05) between maximum population density (MPD). In addition, LG1 showed a lysis activity on two M. aeruginosa native strains in 7 days measured as chlorophyll a (Chl-a) concentration. The lysis activity increased around 2-fold when increasing the temperature from 28 to 36 ± 1 °C. This is the first report of an indigenous bacterium belonging to the genus Achromobacter spp. isolated from the Rio de la Plata River with the capacity to remove MC-LR and lysis activity on M. aeruginosa.


Subject(s)
Achromobacter , Cyanobacteria , Microcystis , Chlorophyll A , Marine Toxins , Microcystins , Temperature
12.
Hist. ciênc. saúde-Manguinhos ; 26(3): 1027-1037, jul.-set. 2019.
Article in Spanish | LILACS | ID: biblio-1039957

ABSTRACT

Resumen El surgimiento de la experiencia clínica en la medicina europea posee hoy numerosos estudios que han abordado su proceso de emergencia desde comienzos del siglo XIX. Con respecto a la indagación acerca de dicho proceso en el espacio del Río de la Plata, la historiografía ha brindado mayor atención al análisis del desarrollo institucional de la práctica médica, que a la elaboración que los médicos del escenario local llevaron a cabo sobre las obras más relevantes de la ciencia médica. Por lo tanto, la presente edición de la Disertación de la manía aguda (1827), del médico Diego Alcorta, busca arrojar nuevos indicios que permitan profundizar en el registro del desarrollo de la experiencia clínica, en el espacio rioplatense.


Abstract The rise of clinical experience in European medicine has by now been the subject of numerous studies dealing with the process of its emergence since the beginning of the nineteenth century. As regards research on this process in the River Plate area, the historiography has devoted more attention to analysis of the institutional development of medical practice than to local physicians' creation of the most important works of medical science. Therefore, this edition of the Disertación de la manía aguda (1827), by physician Diego Alcorta, seeks to shed new light on records of the development of clinical medicine in the River Plate área.


Subject(s)
Humans , History, 19th Century , General Practice , Argentina , Health/history , History, 19th Century
13.
Environ Pollut ; 252(Pt A): 146-154, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31146229

ABSTRACT

The accumulation of 17 human pharmaceuticals (HPs) was investigated in the muscle of three fish species characteristic of the "Rio de la Plata Basin" with different feeding habits and of relevance for human consumption: Megaleporinus obtusidens, Salminus brasiliensis, and Prochilodus lineatus. Fish were sampled in fall and spring from 8 localities distributed along 500 Km of the Uruguay River. Atenolol and carbamazepine were the most frequently detected HPs (>50%), but at concentrations always below 1 µg/kg wet weight (w/w). Hydrochlorothiazide, metoprolol, venlafaxine, propranolol, codeine, and the carbamazepine metabolite, 2-hydroxycarbamazepine, were accumulated at higher levels showing maximum concentrations between 1 and 10 µg/kg (w/w), but infrequently (<50%). The other HPs were always below 1 µg/kg (w/w) and at frequencies lower than 50%. Distinctive accumulation patterns were observed among species at different trophic levels. However, biomagnification trends were not identified for any compound. The highest number and concentration of HPs were found in M. obtusidens (omnivorous), followed by P. lineatus (detritivorous), and lastly S. brasiliensis (piscivorous). The most recurrent HPs (i.e. carbamazepine and atenolol) were present in all species, but others exclusively in one. Geographical variations were only found for carbamazepine and atenolol in M. obtusidens and P. lineatus, showing higher concentrations in localities closer to the Rio de la Plata estuary. Differences in the HPs concentrations among seasons were not identified. Acceptable daily intake and predicted no effect concentrations would indicate that measured muscle concentrations in fish from the Uruguay River do not pose a serious risk for human consumption nowadays. Further studies will be necessary for assessing the potential adverse effects on studied fish species.


Subject(s)
Characiformes/metabolism , Fishes/metabolism , Muscles/chemistry , Pharmaceutical Preparations/analysis , Rivers/chemistry , Water Pollutants, Chemical/analysis , Animals , Estuaries , Habits , Humans , Seafood , Seasons , South America , Uruguay
14.
J Parasitol ; 105(2): 222-231, 2019 04.
Article in English | MEDLINE | ID: mdl-30900944

ABSTRACT

Anisakid nematodes have a worldwide distribution and are associated with fishes, birds, and marine mammals from freshwater, brackish, and marine systems. The aims of this work are to report for the first time Contracaecum mirounga parasitizing the Magellanic penguin Spheniscus magellanicus, to report another Contracaecum species in the same host species, and to discuss the validity of Contracaeceum spheniscus. Several dead chicks, juveniles, and adults of S. magellanicus were collected along the Argentinean coast from 2002 to 2009. Nematodes were removed from digestive tracts and studied using both light and scanning electron microscopy. Nematode prevalences were 2.38% for C. mirounga and 12.5% for Contracaecum sp. Contracaecum mirounga was found in 1 penguin from Península Valdés, Chubut. This species is known as a specific parasite of marine mammals such as Pinnipedia, thereby suggesting that this nematode is not as specific as believed. Another species of Contracaecum sp. was found parasitizing 1 penguin from the Río de la Plata coast. It possessed an unusual interlabial morphology and arrangement of male caudal papillae. Despite the low prevalence, the distinct morphological features are convincing and support the presence of a new Contracaecum species. However, a formal description is not presented because sufficient male specimens are lacking. Finally, C. spheniscus is considered a junior synonym of Contracaecum pelagicum. Future molecular studies might be helpful to determine the real diversity of Contracaecum species parasitizing S. magellanicus considering the number of sibling species recognized among the anisakids.


Subject(s)
Ascaridida Infections/veterinary , Ascaridoidea/physiology , Bird Diseases/parasitology , Spheniscidae/parasitology , Animals , Argentina , Ascaridida Infections/parasitology , Ascaridoidea/classification , Ascaridoidea/ultrastructure , Atlantic Ocean , Female , Male , Microscopy, Electron, Scanning
15.
Environ Pollut ; 243(Pt A): 134-142, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30172119

ABSTRACT

This study explores in plankton samples the abundance, distribution, size, types (fibres and fragments), colours of the microplastics (MPs) and its relation with the characteristics of the plankton (size and morphology) of the Río de la Plata estuary. Water samples were collected in triplicate in freshwater-mixohaline tidal zone of the estuary, in ten sampling sites located along 150 km of coast, in two periods (September-November 2016 and April-June 2017). The results revealed the presence of MPs in all the samples analysed, with a dominance of fibres and sizes >500 ≤ 1000 µm, and blue colour being more frequent. The MPs distribution was significantly different among sampling sites, being more abundant in the most urbanized sites, sewage discharges and near the maximum turbidity front. The mean density, in the two samplings analysed, were 164 and 114 MPs m-3. The fibres amount was significantly different among sites. The MPs integrated a planktonic community dominated by pico-microphytoplankton, mainly conformed by filaments/chains and solitary forms and by micro-mesozooplankton. The comparative analysis of plankton and MPs demonstrated that a fraction of the latter showed a frequency range of size that coincides with the most common sizes of plankton (≤500 µm). The mean percentage of MPs items in relation to zooplankton was 0.36% (sampling 1) and 1.20% (sampling 2) and for phytoplankton was 0.0002% (sampling 1) and 0.0005% (sampling 2). The correlations between the MPs concentration and habitat quality (IHRPlata index) were statistically significant, on the contrary correlations between the MPs concentration and measured environmental variables were not found. The findings of this study emphasises the need for a better treatment of urban waste, which would contribute to reducing the entry of this pollutant into the ecosystem. The presence of microplastics in plankton samples on the coast of the Río de la Plata estuary.


Subject(s)
Estuaries , Plankton/metabolism , Plastics/pharmacokinetics , Animals , Ecosystem , Environmental Monitoring/methods , Fresh Water , Particle Size , Sewage , South America
16.
Chemosphere ; 206: 727-735, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29793064

ABSTRACT

Environmental liabilities have become one of the most important problems of the last years, especially those of contaminated sites located in urban areas which have been abandoned by pollution intensive industries. Such sites may contain hazardous materials that pose risks to human health and the environment. Industrial waste from the ancient sulfuric acid industry is scattered in a local area at the petrochemical pole in a sector of the Río de la Plata coastal plain. The aim of this work is to define the geochemical processes that determine the alteration of waste in the old sulfuric acid industry (OSAI) area and to study the migration of soluble pollutants to groundwater. A survey of soil and waste deposit was carried out and samples were examined by X-ray diffraction, under a scanning electron microscope and a polarizing microscope. Surface water and groundwater samples, both to the unconfined and semi-confined aquifers, were collected to determine electrical conductivity, pH and major elements. The results show the presence of minerals composed of sulfur associated with jarosite and iron oxides on superficial sediments. The detailed study of soil sediments together with that of the water physicochemical characteristics make it possible to understand the geochemical processes developed in soil that cause the high concentrations of sulfates in groundwater. Furthermore, high SO4-2 concentration registered in the semi-confined aquifer due to its infiltration from the unconfined aquifer shows that the industrial pollution has an important impact at local level. These results may contribute to the understanding of chemical processes and pollutants distribution in highly industrialized coastal plain areas.


Subject(s)
Environmental Monitoring/methods , Groundwater/chemistry , Industrial Waste/analysis , Water Pollutants, Chemical/chemistry , Argentina , Humans , Water Pollutants, Chemical/analysis
17.
Bull Environ Contam Toxicol ; 100(4): 472-476, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29487956

ABSTRACT

Polychaetes that inhabit the sediments of estuaries are important prey to many species all around the world. Laeonereis acuta is a deposit feeder living in estuaries along the Atlantic coast of South America. Ragworms accumulate metals from the sediment, and represent a means of entry of sediment contaminants into the trophic network. The concentrations of Zn, Pb, Cu, Cr and Cd were determined in polychaetes and sediments (total and extractable) from six estuarine beaches of Río de la Plata. The associations between total and extractable concentrations in sediment and accumulated concentrations in L. acuta were analyzed. Sediments extracted by weak acid digestion appear to be a good proxy model of bioavailable metal fractions in the sediment. The association between metals in sediment and polychaetes denotes the role of L. acuta as an important link in metal trophic transfer from sediments to potential fish and bird predators of the worm.


Subject(s)
Environmental Monitoring/methods , Estuaries , Geologic Sediments/chemistry , Metals, Heavy/analysis , Polychaeta/metabolism , Trace Elements/analysis , Water Pollutants, Chemical/analysis , Animals , Biological Availability , Metals, Heavy/metabolism , Models, Biological , Trace Elements/metabolism , Uruguay , Water Pollutants, Chemical/metabolism
18.
J Fish Biol ; 91(4): 1123-1138, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28868674

ABSTRACT

A new species of Astyanax is described from the upper Rio Paraguai basin, Mato Grosso State, Brazil. The new species can be distinguished from congeners by having the body intensely yellowish in life (v. silvery, reddish or lightly yellow) and by morphometric and meristics traits. Astyanax dolinae n. sp. cannot be assigned to any of the Astyanax species complex currently recognized for the genus. It is only known from the Dolina Água Milagrosa, a karstic sinkhole lake, entirely fed by groundwater, surrounded by Cerrado, the savannah-like vegetation of central South America.


Subject(s)
Characidae/classification , Animals , Brazil , Characidae/anatomy & histology , Ecosystem , Lakes , Social Isolation , Species Specificity
19.
Mar Pollut Bull ; 120(1-2): 387-395, 2017 Jul 15.
Article in English | MEDLINE | ID: mdl-28483142

ABSTRACT

The coastal plain of the middle estuary of the Río de la Plata is a highly industrialized area and is densely populated by sectors. The main human activity in the sector encompassed between the cities of Ensenada and Berisso is associated with the petrochemical industry. In this work, hydrogeochemical and isotopic characteristics of surface and groundwater in the impacted area are analyzed and the results are contrasted with those obtained in an undisturbed protected area. Major and trace elements were determined using standardized methods while the stable isotopes δ18O y δ2H were analyzed by mass spectroscopy. Human impact is evidenced by the occurrence of large variations in the major chemical composition of water, and also by the elevated concentrations of some trace elements that are not contributed from natural sources. These results may contribute to the understanding of chemical processes and pollutants distribution in highly industrialized coastal plain areas.


Subject(s)
Groundwater , Isotopes/analysis , Argentina , Cities , Environmental Monitoring , Humans , Water Pollutants, Chemical
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