Pablo Muniz
Universidad de la República (Uruguay), IECA, Faculty Member
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Over the past 100 years, urban growth has been reaching extremely high rates worldwide. Human interaction with the ecosystem includes consumptive and nonconsumptive activities. The external supply of organic matter causes one of the most... more
Over the past 100 years, urban growth has been reaching extremely high rates worldwide. Human interaction with the ecosystem includes consumptive and nonconsumptive activities. The external supply of organic matter causes one of the most severe impacts on coastal marine environments. Montevideo City is currently suffering from the same environmental problems as other capital cities in the world, and its adjacent coastal zone has been influenced by anthropogenic alterations during the past 150 years. By integrating abiotic and biotic data, and using different statistical and ecological approaches, the coastal area of Uruguay close to Montevideo City has been classified into four zones with different environmental quality and degree of anthropogenic perturbation. In this area, several environmental problems and their impacts on economic productivity, human, and ecosystem health are the outcome of political and socioeconomical factors. Therefore, governmental authorities need to follow the concept of sustainable use and development, to preserve and optimize the ecological quality of natural resources and to ensure the availability of this coastal ecosystem to future generations. Solutions to the conflictive uses of environment should be laid down on a solid scientific base to establish priorities and make the best decisions for its management and conservation.
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ABSTRACT The vertical distribution of macrobenthic fauna, heavy metals, and other physico-chemical and biological characteristics of the sediments were studied in three sediment layers (0–7, 8–14, 15–21 cm) at seven stations in the... more
ABSTRACT The vertical distribution of macrobenthic fauna, heavy metals, and other physico-chemical and biological characteristics of the sediments were studied in three sediment layers (0–7, 8–14, 15–21 cm) at seven stations in the Ubatuba region, north coast of São Paulo State, Brazil at several temporal and spatial scales. Six stations were located in the inner bay near the riverine run-off, and one was outside the bay, distant from the riverine influence. The samples were collected four times in 1 year, on a seasonal basis. Sediments were basis comprised predominantly of very fine sand and the vertical distribution of grain size was uniform to a depth of 21 cm in all stations. Higher values of total organic matter, organic carbon, sulphur, heavy metals and phaeopigments were recorded at the inner Ubatuba Bay stations, probably due to the riverine influence. C/N ratios indicated a mixed origin of organic matter with a major contribution of terrestrial material in the inner stations. The vertical distribution of heavy metals showed a slight decline with sediment depth in the inner stations, indicating the present contribution. Most of the macrofauna was found at the surface sediment layer. Biological data showed that in the inner stations of Ubatuba Bay, which are under the influence of urban sewage and are moderately polluted, the fauna was distributed more superficially within the substrate than in St. 7, which is located in the external portion of the bay distant from sewage inputs. The environmental quality of the sites studied varied little throughout the year, at least in relation to the variables considered here. Temporal variation in the vertical distribution of benthic fauna was not evident in the four sampling surveys analysed. Only minor changes in the vertical distribution of the total fauna were detected in the seasonal scale, with the organisms located less deep within the sediment column in summer, indicating some influence of the tourism impact and/or rainy season.
Research Interests: Zoology, Environmental Science, Oceanography, Marine Ecology, Biology, and 7 moreEcology, Fauna, Sediment, Shore, Organic Matter, Bay, and Subtropics
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Abstract − The taxonomic sufficiency approach has been proposed as a surrogate for the typical analysis of species-abundance data, especially in conditions involving prominent pollution gradients. Here, we evaluate the use of taxonomic... more
Abstract − The taxonomic sufficiency approach has been proposed as a surrogate for the typical analysis of species-abundance data, especially in conditions involving prominent pollution gradients. Here, we evaluate the use of taxonomic sufficiency with infralittoral ...
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Research Interests: Geology and Oceanography
Abstract The 2009–2010 “El Nino”-Southern Oscillation (ENSO) event was characterized by a warm-phase leading to a five-fold increase in the Rio de la Plata river flow and an associated change in trophic state because of organic... more
Abstract The 2009–2010 “El Nino”-Southern Oscillation (ENSO) event was characterized by a warm-phase leading to a five-fold increase in the Rio de la Plata river flow and an associated change in trophic state because of organic enrichment. We analyzed the biotic response of benthic communities to such an increased trophic state during this ENSO event using community and biotic indices (diversity indices and AMBI). Polychaeta exhibited the highest richness and second the most abundant values while the small gastropod Heleobia australis was the most abundant and frequent species. An increase in richness and diversity of Polychaeta was associated to a concomitant increase of RdlP flow and the organic enrichment of the macrobenthic species. Community indices (richness and diversity) showed variability at both temporal and spatial scale but only AMBI exhibited spatial variability without significant differences between contrasting environmental conditions (ENOS phases).
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Abstract Despite the increased and widespread usage of benthic indices for environmental health assessment, some methodological ambiguities remain to be solved. We tested the congruence and consistency of the benthic indices ITI, BO2A,... more
Abstract Despite the increased and widespread usage of benthic indices for environmental health assessment, some methodological ambiguities remain to be solved. We tested the congruence and consistency of the benthic indices ITI, BO2A, BENTIX, AMBI and M-AMBI in a subtropical estuary (Paranagua Bay, Brazil). Indices were applied to non-vegetated tidal flats increasingly contaminated by sewage to test: (i) correlations with molecular biomarkers of sewage (consistency); and (ii) evaluate the overall agreement/similarity of responses (congruence). The responses of the benthic indexes ITI, AMBI and BO2A were congruent among themselves and consistent with molecular biomarkers values. BENTIX and M-AMBI were less consistent and congruent and possibly need a readjustment of boundaries for subtropical habitats. The indices seemed robust to natural background yearly variations not related to contamination. Faecal sterols associated to nutrient contents suitably supported the validation of indices and could integrate reference conditions for sewage impacted coastal habitats. Benthic indices can successfully integrate management guidelines, but their suitable application demands further research on tolerance shifts of key indicator species.
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Limnoperna fortunei (golden mussel) is an alien mollusk in the Plata basin and is native from the Southeastern Asia. Its benthic patches generate macrofouling in hydraulic installations causing additional costs to the affected companies.... more
Limnoperna fortunei (golden mussel) is an alien mollusk in the Plata basin and is native from the Southeastern Asia. Its benthic patches generate macrofouling in hydraulic installations causing additional costs to the affected companies. The objective of this work is to determine the variation of abundance and the size of the valves larval stages of the golden mussel, establishing associations with the water quality parameters in the cooling systems in the three hydroelectric power stations (HP) of the reservoirs of the Negro River (Uruguay) that has been invaded by the species. In the three cooling systems the golden mussel larval density average showed associations with temperature of the water and the percentage of organic material of the column water. Larger larval abundances were registered during warm and minimum during cold months. For the three systems, is suggested a reproductive pause of the species at water temperatures lower than 18oC and the start of the larval cycle at...
Research Interests: Management, Biology, Macrofouling, Gestão, Mollusk, and 7 moreLarva, Manejo, Invasive Aquatic Species, Molusco, Mussel, Water Column, and Dreissena
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presented by Setembrino Petri Analyses of organic matter content, organic carbon, nitrogen, sulfur and granulometric variables were per-formed on 101 surface sediment samples from Ubatuba Bay in order to investigate the spatial... more
presented by Setembrino Petri Analyses of organic matter content, organic carbon, nitrogen, sulfur and granulometric variables were per-formed on 101 surface sediment samples from Ubatuba Bay in order to investigate the spatial distribution of organic matter, its origin and the relationships among its components. The samples were obtained with a manual corer, from water depths between 1 and 15m during 5 cruises of the R/V ‘‘Veliger II’’, two months apart. Pearson correlation, regression and Principal Component Analysis (PCA) statistical methods were used to analyze the data. Strong correlations between organic matter and fine sediment fractions were ob-tained. The PCA revealed at least two main sample groups that reflect the different environmental conditions prevalent in the bay. There is a simple linear relationship between organic carbon content and the organic matter content determined by the calcination technique. Taking into account that the analysis of organic matter content ...
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The macrobenthic subtidal community was studied between April 1997 and April 1998 in Montevideo bay, an urban estuary located in the fluvio marine system of the Río de la Plata (Uruguay) that receives a variety of industrial and sewage... more
The macrobenthic subtidal community was studied between April 1997 and April 1998 in Montevideo bay, an urban estuary located in the fluvio marine system of the Río de la Plata (Uruguay) that receives a variety of industrial and sewage inputs. Monthly surveys were carried out at ten sampling stations where sediment samples were taken with a manual corer and analysed for granulometric parameters, organic matter content, chlorophyll a and phaeopigments content, redox potential, and macrobenthic fauna. The area presented high organic matter content in its sediments and several regions of the bottom were anoxic during a large part of the sampling period. The benthic macrofauna was dominated, both in numbers as well as in biomass, by the small surface deposit-feeder gastropod Heleobia cf. australis. Cluster analysis, Multidimensional Scaling and Canonical Correspondence Analysis revealed that the study area could be divided in two well-defined regions with different environmental charact...
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Abstract The Rio de la Plata drains waters of the second largest basin of South America. The coast of Uruguay is located in a high dynamic area, where the interactions between the Rio de la Plata and the Atlantic Ocean produce an... more
Abstract The Rio de la Plata drains waters of the second largest basin of South America. The coast of Uruguay is located in a high dynamic area, where the interactions between the Rio de la Plata and the Atlantic Ocean produce an important patterns of natural variability. Alongside this, the area is under growing local and regional human pressure. The Uruguayan coast is affected directly and indirectly by activities developed in the drainage basin. La Plata Basin is densely populated and heavily industrialized with significant pollution. The Parana and Uruguay Rivers and their tributaries contribute xenobiotics and nutrients, especially during the ENSO phases, when important discharges of freshwater affect the whole coast. Unsurprisingly, the most impacted region is near Montevideo, while, in general, the pollution and/or impact level in the small estuaries along the Rio de la Plata coastline is slightly lower. Although available environmental information in the Uruguayan coastal zone has improved during recent decades, it is still restricted to isolated areas and to some aspects of aquatic ecosystems only. The development and implementation of integrative baseline studies on these topics are highly relevant, in order to contribute to the conservation of these ecosystems in Uruguay.
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Los marcadores de dano genetico representan alertas tempranas de exposicion y efecto en organismos bioindicadores o centinelas en los ambientes que ocupan. Uno de los marcadores mas utilizados en animales acuaticos es el test de... more
Los marcadores de dano genetico representan alertas tempranas de exposicion y efecto en organismos bioindicadores o centinelas en los ambientes que ocupan. Uno de los marcadores mas utilizados en animales acuaticos es el test de micronucleos, que permite analizar el impacto sobre el ADN de xenobioticos presentes en sedimento o en agua. Es aplicable en una gran variedad de tejidos aunque mas ampliamente se utiliza en sangre o hemolinfa. Este es un indicador de dano cronico, es decir de exposicion continua a agentes mutagenicos a nivel aneugenico o clastogenico, del mismo modo que revela efectos citotoxicos que se registran de acuerdo a clasificaciones estandarizadas de las celulas observadas. El ensayo de electroforesis en celulas individuales, permite caracterizar y cuantificar el dano producido en la molecula de ADN, detectando desde rupturas de hebra simple hasta ligamientos cruzados o sitios alcali labiles. Incluso, es posible identificar regiones especificas del genoma, mas expu...
Research Interests: Physics and Humanities
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Los poliquetos (Annelida) son organismos en íntimo contacto con el sedimento donde viven y el agua sobrenadante. El estrés ambiental genera rápidas respuestas en estos organismos que se reflejan en los individuos y sus poblaciones, por lo... more
Los poliquetos (Annelida) son organismos en íntimo contacto con el sedimento donde viven y el agua sobrenadante. El estrés ambiental genera rápidas respuestas en estos organismos que se reflejan en los individuos y sus poblaciones, por lo que se utilizan como indicadores biológicos de disturbios y de calidad ambiental. Los poliquetos han sido ampliamente utilizados en monitoreo ambiental y en bioensayos, y muchos estudios ecotoxicológicos se realizan con poliquetos. En casi todos los hábitats bentónicos estos organismos juegan un papel muy importante en la organización y estructura de las comunidades bentónicas y redes tróficas. Son un ítem fundamental en la alimentación de otros invertebrados y de aves migratorias y peces. Los poliquetos también tienen importancia económica para la industria farmacéutica, y de alimentos concentrados para especies marinas de cultivo (peces y crustáceos), en el campo médico y en la bioingeniería, además de la recreativa (acuarofilia, carnada) y por s...
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Resumen: Los primeros registros de poliquetos publicados para el Uruguay datan de finales del siglo XIX y corresponden a trabajos puntuales de cientificos extranjeros, y recien a partir de 1970 los registros se hacen mas constantes,... more
Resumen: Los primeros registros de poliquetos publicados para el Uruguay datan de finales del siglo XIX y corresponden a trabajos puntuales de cientificos extranjeros, y recien a partir de 1970 los registros se hacen mas constantes, destacandose la aparicion de varios registros de investigadores locales. Hacia finales del siglo pasado y especialmente a partir del ano 2000, se realizaron varios trabajos de indole ecologico/ambiental que incluyen registros de poliquetos. A pesar de esto, las identificaciones a nivel especifico solo ocurren en el caso de los organismos mas abundantes, quedando la gran mayoria de los ejemplares clasificados en familia y/o genero, denotando la falta de especialistas nacionales en el grupo. El desarrollo de varios estudios en la zona estuarina de Montevideo y costa Este, contribuyeron con informacion ecologica acerca de poliquetos, focalizando el uso de estos como indicadores de diferentes grados/tipos de perturbaciones ambientales. Dos grandes trabajos d...
Research Interests: Geography and Humanities
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La Bahia de Montevideo (BM) es un estuario urbano que sustenta el desarrollo de actividades diversas (puerto de Montevideo, industria, pesca artesanal, recreacion), siendo necesario su monitoreo permanente. El uso de moluscos como... more
La Bahia de Montevideo (BM) es un estuario urbano que sustenta el desarrollo de actividades diversas (puerto de Montevideo, industria, pesca artesanal, recreacion), siendo necesario su monitoreo permanente. El uso de moluscos como especies centinela se ha convertido en una importante herramienta para evaluar calidad ambiental, sin embargo no existen antecedentes de estudios de genotoxicidad in vivo en moluscos estuarinos en nuestro pais. Heleobia cf. australis y Erodona mactroides son moluscos que toleran sedimentos impactados y se encuentran en casi todos los ecosistemas costeros del litoral uruguayo, por lo cual se escogieron como biomonitores para analizar los efectos geneticos de los contaminantes a traves del ensayo cometa, que permite cuantificar la extension del dano genetico. Para los analisis se colectaron individuos vivos de ambas especies de la zona de la BM, de la zona costera adyacente y de la Laguna Garzon. Esta ultima, se utilizo como poblacion control debido a que pr...
Research Interests: Humanities and Biology
Research Interests: Mechanical Engineering, Artificial Neural Networks, Uncertainty, Measurement Errors, Regression Analysis, and 11 moreError Analysis, Maintenance Engineering, Error Correction, Temperature measurement, Thermal Analysis, Predictive Maintenance, Field of View, Artificial Neural Network, Electrical And Electronic Engineering, Measurement Uncertainty, and Neural nets
The Rio de la Plata Estuary (RdlP) is a fluvio-marine system that drains into the Southwestern Atlantic Ocean with the Parana and Uruguay rivers as main tributaries. The estuary is fed by a 3,100,000km2 catchment area which extends over... more
The Rio de la Plata Estuary (RdlP) is a fluvio-marine system that drains into the Southwestern Atlantic Ocean with the Parana and Uruguay rivers as main tributaries. The estuary is fed by a 3,100,000km2 catchment area which extends over the territories of Argentina, Paraguay, Brazil, Bolivia and Uruguay (Acha et al ., 2008). The RdlP exhibits significant natural decadal- and annual-scale, hydrodynamic and oceanographic variability associated with the Pacific Decadal Oscillation (PDO), the Atlantic Multidecadal Oscillation (AMO) and the El Nino/La Nina Southern Oscillation (ENSO) (Depetris and Pasquini, 2007b; Chiessi et al ., 2009; Garreaud et al ., 2009). Such variability affects the moisture budget over the surrounding continental areas and leads, thus, to changes in the river discharge. PDO is associated with ENSO as both appear to display similar hydrological responses, though their inherent mechanisms are not yet fully understood (Garreaud et al ., 2009). In this sense, warm an...
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Previous studies have demonstrated that macro-scale climatic events such as ENSO, cause changes in meteorological and hydrological conditions, inducing physicochemical changes in the water column, as well as in coastal and estuarine... more
Previous studies have demonstrated that macro-scale climatic events such as ENSO, cause changes in meteorological and hydrological conditions, inducing physicochemical changes in the water column, as well as in coastal and estuarine communities in the Atlantic Ocean. Rio de la Plata (RdlP) is the second largest estuary of South America, where ENSO is a macro-scale environmental driving force. In this paper, the species composition, abundance, as well as the temporal and horizontal variation of the mesozooplankton in the north coast of the RdlP during 2009-2010 ENSO were analyzed. Zooplankton samples were collected with sub-surface trawls in fifteen stations during eleven sampling surveys. Physico-chemical parameters of the water column (temperature, salinity, dissolved oxygen, turbidity, and chlorophyll a) were determined and related to the RdlP flows. The holoplankton was dominated by estuarine copepod (Acartia tonsa), freshwater cladocerans (Bosmina hagmanni, Ceriodaphnia dubia, M...
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This paper aims to test the suitability of some biotic indices for their application in Southeast Caspian Sea. For this purpose, the ecological quality of the Gomishan lagoon was assessed using three biotic indices (AMBI, BENTIX, BOPA)... more
This paper aims to test the suitability of some biotic indices for their application in Southeast Caspian Sea. For this purpose, the ecological quality of the Gomishan lagoon was assessed using three biotic indices (AMBI, BENTIX, BOPA) during summer and autumn 2010. The results from the application of the biotic indices do not highlight a clear distinction between the stations. The results show that two of the indices (AMBI and BENTIX) are very close in terms of diagnosis (good and high) and seem to generally perform better than BOPA. In addition, Principal Component Analysis (PCA) based on abiotic parameters showed clear spatial and temporal differences in environmental variables. However, at this shallow sites with low human pressure and high water residence times, such benthic community composition can be associated with physical stress due to salinity increase and to changes in environmental characteristics, triggered by conventional seasonal variations. Natural variability of t...
Reason for addendum: During the preparation of the original manuscript, a scientific work that dealt precisely with Polychaeta as environmental indicators in Patagonia was not considered. This being the first and only work regarding this... more
Reason for addendum: During the preparation of the original manuscript, a scientific work that dealt precisely with Polychaeta as environmental indicators in Patagonia was not considered. This being the first and only work regarding this subject, it was reasonable and necessary to incorporate this information.
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A study on sediment surface diatom composition in relation to both protein/carbohydrate content and salinity was carried out in Montevideo Bay and the adjacent coastal zone. Samples were seasonally taken during one year along a human... more
A study on sediment surface diatom composition in relation to both protein/carbohydrate content and salinity was carried out in Montevideo Bay and the adjacent coastal zone. Samples were seasonally taken during one year along a human impact gradient, and the trophic conditions were assessed from the biochemical composition of the surface sediment organic matter. The co-occurrence of the marine-brackish (Actinocyclus curvatulus, Actinocyclus gallicus, Coscinodiscus excentricus, Coscinodiscus radiatus, Hyalodiscus subtilis, Paralia sulcata) and freshwater diatom flora (Aulacoseira granulata, Aulacoseira italica, Aulacoseira muzzanensis, Actinocyclus normanii, Amphora copulata, Cyclotella meneghiniana, Nitzschia linearis), suggests myxohaline estuarine conditions in the study area. The sampling stations located within the bay, close to several contamination sources, exhibited hypertrophic conditions as indicated by the highest levels of protein content, but also by the high relative ab...
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Estuaries are unique coastal ecosystems that sustain and provide essential ecological services for mankind. Estuarine ecosystems include a variety of habitats with their own sediment-fauna dynamics, all of them globally undergoing... more
Estuaries are unique coastal ecosystems that sustain and provide essential ecological services for mankind. Estuarine ecosystems include a variety of habitats with their own sediment-fauna dynamics, all of them globally undergoing alteration or threatened by human activities. Mangrove forests, saltmarshes, tidal flats and other confined estuarine systems are under increasing stress due to human activities leading to habitat and species loss. Combined changes in estuarine hydromorphology and in climate pose severe threats to estuarine ecosystems on a global scale. The ReBentos network is the first integrated attempt in Brazil to monitor estuarine changes in the long term to detect and assess the effects of global warming. This paper is an initial effort of ReBentos to review current knowledge on benthic estuarine ecology in Brazil. We herein present and synthesize all published work on Brazilian estuaries that has focused on the description of benthic communities and related ecologic...
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Situated opposite the Freshwater Front, Montevideo city with its more than 1.5 million inhabitants encircles Montevideo Bay, where one of the most active and polluted harbors in South America is located. Faecal sterols, trace metals,... more
Situated opposite the Freshwater Front, Montevideo city with its more than 1.5 million inhabitants encircles Montevideo Bay, where one of the most active and polluted harbors in South America is located. Faecal sterols, trace metals, organochlorine compounds and petroleum derivatives in the sediments of Montevideo Harbor were evaluated and their spatial distribution inside the harbor as well as in the input of two main tributary streams analyzed. Specifically for the harbor sites, a temporal comparison of metal and hydrocarbons was made with previous measurements taken 12 years ago. Clear changes were observed at these sites. The concentration of metals such as Pb, Cr and Zn have diminished, while aliphatic hydrocarbons have increased their values at almost all of the stations studied. Differences were observed between summer and winter suggesting sedimentation, input or hydrodynamic changes in the area. These results help one to understand the present situation and develop the mana...
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PanamJAS is a non-profit Journal supported by researchers from several scientific institutions. PanamJAS is currently indexed in
ABSTRACT The Río de la Plata estuary (RdlP) exhibits environmental gradients associated with the freshwater input and oceanic water intrusion. The aim of this study was to assess diatom species distribution in surface sediment samples... more
ABSTRACT The Río de la Plata estuary (RdlP) exhibits environmental gradients associated with the freshwater input and oceanic water intrusion. The aim of this study was to assess diatom species distribution in surface sediment samples related to such environmental gradients. The internal section of RdlP was dominated by Aulacoseira spp., Eunotia spp., Staurosirella martyi, Actinocyclus normanii and Thalassiosira baltica, indicatives of low salinity levels and high trophic conditions, associated with the riverine and estuarine regimes. The external section was dominated by Coscinodiscus radiatus, Thalassiosira spp., Paralia sulcata, Cyclotella striata, among other marine taxa, indicatives of high salinity and low trophic conditions, associated with the influence of the Southwestern Atlantic Ocean. Furthermore, the intermediate section presents a mixture of both diatom groups representing mixing conditions. The observed diatom species groups capture fairly well the RdlP environmental variability and can be reliably used for paleoenvironmental studies in this and other similar estuarine systems.
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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... more
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.