RESUMEN
This study investigates for the first time the presence of microplastics in sediment, water, and benthic organisms (foraminifera) of a marine cave in the Gulf of Orosei (Sardinia, Italy). Microplastics were found in all water, and sediment samples with similar shapes, sizes, and compositions; identified items were mainly fragments and fibers constituted by PVC and polyethylene. Their provenance was supposed to be predominantly from the sea than from the seasonal freshwater supplies from the karst system. Foraminiferal assemblages were mainly constituted by calcareous hyaline taxa in the outer station, while in the inner ones, the agglutinated Eggerelloides advenus was dominant. FTIR analyses on agglutinated shells identified polyethylene. Microplastic items are collected by the foraminifers and sediment grains building the shell chambers. This is the first study providing evidence that marine caves may be collectors of microplastics and that, in these habitats, microplastics enter the biotic matrix at the protist's level.
Asunto(s)
Foraminíferos , Contaminantes Químicos del Agua , Microplásticos , Plásticos/análisis , Sedimentos Geológicos/análisis , Monitoreo del Ambiente , Contaminantes Químicos del Agua/análisis , Italia , Polietileno/análisis , Agua/análisisRESUMEN
In the 20th century an important industrial plant operated on the coastal area of Bagnoli. After its closing, an integrated study of environmental characterisation aimed at restoration started. The survey conducted was based on chemical and sedimentological analyses integrated with benthic foraminifera analyses. Statistical analysis of the data shows sectors with a distinct type and degree of pollution. Particularly, pollution linked to the silty sediment fraction, mainly due to Pb and Zn, was recognised in front of the southern sector of the plant. The study of benthic foraminifera provides evidence for a pollution-tolerant character in some species like Haynesina germanica and Quinqueloculina parvula. In addition, two species among the 113 recognised show high percentages of abnormal specimens. These percentages show a statistical correlation with some pollutants (PAHs, Mn, Pb and Zn). In addition, Energy Dispersive Spectrometry shows small amounts of Fe ions included in deformed tests of Miliolinella subrotunda. Because the number of these deformations is positively correlated to the concentration of PAHs, Mn and Zn, the inability of some specimens to exclude the foreign elements from the crystalline reticulum of the test could be attributed to the potential toxic effect of these pollutants.
Asunto(s)
Amoeba , Monitoreo del Ambiente/métodos , Contaminación Ambiental/análisis , Sedimentos Geológicos/análisis , Metales/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Químicos del Agua/análisis , Amoeba/crecimiento & desarrollo , Amoeba/aislamiento & purificación , Animales , Ciudades , Recolección de Datos , Monitoreo del Ambiente/estadística & datos numéricos , Contaminación Ambiental/estadística & datos numéricos , Geografía , Industrias , Italia , Plomo/análisis , Manganeso/análisis , Minería , Análisis de Componente Principal , Zinc/análisisRESUMEN
The use of benthic foraminifera as ecological indicators in submarine caves of temperate seas have never been studied before and it represents a new approach, verified by this research. The Bel Torrente submarine cave (Gulf of Orosei, Sardinia, Italy) was surveyed by GUE (Global Underwater Explorers) scuba divers in order to georeferencing the cave before positioning the sampling stations, from the entrance to 430â¯m inside the cave. A total of 15 water samples were collected to investigate abiotic parameters (temperature, salinity, pH) while 15 sediment samples were collected to analyze grain size and benthic foraminifera. Benthic foraminifera, investigated for the first time in a submarine cave of temperate areas, were exclusively found from the entrance to 300â¯m inside the cave. Species distribution and assemblage diversity have been found to be correlated to the environmental gradient towards the inner cave, mainly due to the decreasing of temperature and salinity and the increasing of the flow energy. Water acidification seems responsible for the transition from a calcareous hyaline-dominated assemblage to an agglutinant-dominated one, occurring between 120 and 150â¯m from the entrance. Common taxa of the Sardinian coastal marine area are present only close to the entrance of the cave, while species found in the inner part are nearly exclusively epifaunal clinging/attached or infaunal taxa, with tolerance for wide variability of environmental parameters, such as Gavelinopsis praegeri, and opportunist infaunal taxa such as Eggerella advena. The agglutinant taxa found in the cave are conversely very rare in coastal marine assemblages of the area. This suggests a very efficient dispersal mechanism for the colonization of the caves, involving probably juvenile foraminifera at a "propagule" stage.
Asunto(s)
Monitoreo del Ambiente , Foraminíferos/crecimiento & desarrollo , Sedimentos Geológicos , Italia , Océanos y MaresRESUMEN
Intensive exploitation of base metal deposits in the Sulcis-Iglesiente district (Sardinia, Italy), lasted from the 1850s to the 1990s, determined a high environmental impact on the coastal area, but the effects on marine environment have never been investigated. A marine sediment core, dated with 14C, was characterized for grain size, chemical and mineralogical composition, in order to reconstruct the sedimentary history of the area and to assess the environmental impact of mining. The comparison of chemical and mineralogical characteristics of recent sediments with those of pre-industrial age allowed discriminating the real anthropogenic impact from the natural metal enrichment. The correspondence, in the upper core, of anthropogenic trace metal enrichment with the presence of mine waste minerals is attributed to the exploiting over industrial scale; the still high metal enrichment in sediment surface levels suggests a still existing impact due to mine dumps and tailings weathering.
Asunto(s)
Monitoreo del Ambiente , Metales/análisis , Minería , Sedimentos Geológicos , ItaliaRESUMEN
The study of benthic foraminifera in sediment cores provides the opportunity to recognize environmental changes, including those due to the anthropogenic impact. The integration of these data with chemical-physical parameters provides a comprehensive quality assessment. This research was applied to a sediment core collected in the Augusta bay, where a very large commercial and military harbor and one of the largest petrochemical poles in Europe are present. Inside the petrochemical area also operated, from 1958 to 2003, a chlor-alkali plant with mercury cell technology which caused anthropic contamination of surrounding land and marine areas. The sediment core was collected in front of this plant and characterized for grain size and pollutants directly associated to chlor-alkali activity, such as mercury (Hg), barium (Ba), polychlorobiphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). Composition of foraminiferal assemblages and faunal parameters such as specific diversity, faunal density, abundance of abnormal specimens, and foraminiferal size were investigated as potential indicators of environmental status. Statistical analysis indicated a main common origin for Hg, Ba, and PCBs and the influence of pollutants on species distribution and faunal diversity and density. Exceptionally high Hg concentrations (63-680 mg/kg d.w.) were recorded in the whole core, where the geochronological study attributed the most contaminated levels to the period of maximum activity of the chlor-alkali plant, while a decrease of contamination was recorded after the stop of the activity. Distinct foraminiferal assemblages identified different ecozones along the core, which suggested decreasing anthropogenic impact from the bottom to the top.
Asunto(s)
Monitoreo del Ambiente/métodos , Foraminíferos/química , Foraminíferos/efectos de los fármacos , Sedimentos Geológicos/química , Bario , Hidrocarburos Aromáticos , Mercurio , Industria del Petróleo y Gas , SiciliaRESUMEN
The determination of background concentration values (BGVs) in areas, characterised by the presence of natural geochemical anomalies and anthropogenic impact, appears essential for a correct pollution assessment. For this purpose, it is necessary to establish a reliable method for determination of local BGVs. The case of the Orbetello lagoon, a geologically complex area characterized by Tertiary volcanism, is illustrated. The vertical concentration profiles of As, Cd, Cr, Cu, Hg, Ni, Pb and Zn were studied in four sediment cores. Local BGVs were determined considering exclusively samples not affected by anthropogenic influence, recognized by means of multivariate statistics and radiochronological dating ((137)Cs and (210)Pb). Results showed BGVs well-comparable with mean crustal or shale values for most of the considered elements except for Hg (0.87 mg/kg d.w.) and As (16.87 mg/kg d.w.), due to mineralization present in the catchment basin draining into the lagoon.
Asunto(s)
Monitoreo del Ambiente/métodos , Contaminantes Ambientales/análisis , Sedimentos Geológicos/química , Oligoelementos/análisis , Radiación de Fondo , Radioisótopos de Cesio/análisis , Italia , Radioisótopos de Plomo/análisis , Análisis Multivariante , Datación Radiométrica , Erupciones Volcánicas , Contaminantes Químicos del Agua/análisisRESUMEN
The Augusta harbour is affected by high anthropogenic impact due to intense harbour activity and a large chemical and petrochemical pole. Thirty-seven sediment samples were collected during an environmental characterization project and analyzed for grain size, chemical parameters (Al, As, Cd, Cr, Cu, Fe, Hg, Ni, Pb, Zn and V) and foraminifera, the last one generally being used as ecological indicators of environmental quality. Anthropogenic enrichment was recognized for As, Cu, Hg, Pb and Zn and, among these, Hg showed very high concentrations (up to 191 mg kg(-1) d.w.) often associated in the southern sector of the study area to very high PCB levels (up to 0.83 mg kg(-1)). In this area, an assemblage dominated by Rosalina bradyi and Quinqueloculina lata was recognized. This assemblage shows a clear decrease of foraminiferal density and diversity and, at the same time, increased dominance with respect to the assemblage characterizing the central and northern less polluted sectors, in which Miliolinella subrotunda prevails. Quinqueloculina lata was demonstrated to be a stress-tolerant species because it was not influenced by sediment texture, but positively correlated with the concentration of Hg, PCBs and PAHs. The environmental stress shown by the high-dominance of the Ammonia tepida assemblage was attributed mainly to the influence of stream mouths, which determine environmental instability. Foraminiferal assemblages showed a clear response to environmental degradation in the most polluted area but, at the same time, they demonstrated a high adaptation to pollution.
Asunto(s)
Monitoreo del Ambiente , Foraminíferos/fisiología , Sedimentos Geológicos/análisis , Mercurio/análisis , Bifenilos Policlorados/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminación Ambiental/análisis , Foraminíferos/ultraestructura , Italia , Especificidad de la EspecieRESUMEN
Benthic foraminifera and sediment texture were studied on a total of 37 samples, collected from two brackish-water coastal basins: Fogliano Lake and Lungo Lake (central Italy). The research was performed as a preliminary low-cost survey to highlight the degree of the environmental stress and to recognize a possible anthropogenic disturbance. The sedimentological and foraminiferal data were processed by bivariate and multivariate statistical analysis. Three distinct assemblages, referable to different environments were recognized for the Fogliano Lake: inner, intermediate and outer lagoon. Only the outer lagoon assemblage was found in the Lungo Lake. The distribution of foraminifera in the Fogliano Lake suggests a natural environmental stress probably due to the ecological instability typical of marginal environments, while the absence of the inner and intermediate lagoon assemblages in the Lungo Lake suggests an environmental disturbance possibly related to human activities. An interdisciplinary survey including geochemical analyses is recommended in order to deduce the nature and degree of pollution in the Lungo Lake.
Asunto(s)
Monitoreo del Ambiente , Foraminíferos/fisiología , Sedimentos Geológicos/análisis , Agua de Mar , Biodiversidad , Foraminíferos/clasificación , Foraminíferos/ultraestructura , Italia , Microscopía Electrónica de Rastreo , Tamaño de la Partícula , Filogenia , Análisis de Componente Principal , Contaminantes Químicos del Agua/análisisRESUMEN
The coastal zone of Baia (Naples) is currently included in a protected marine area, but in past it was affected by strong anthropogenic pressure for commercial harbour activity. In order to investigate the impact of past activities, a multidisciplinary characterisation was undertaken to evaluate the environmental quality of marine sediments. Thirty-six grab samples were collected for grain-size, heavy metals, PAHs and PCBs analyses. Rose Bengal stained replicates were taken for the analysis of benthic foraminifera. Chemical analyses highlighted sediment pollution mainly due to Cu, Hg, Pb, Zn, PAHs and PCBs in the northern and southern part of the study area, where some sunken vessels had been present for many decades. Modifications of foraminiferal diversity and density, and increased percentage of abnormal specimens, were considered as indicators of environmental degradation. Correlation between faunal parameters and pollutant concentrations was found by means of statistical analysis. The highest degree of environmental stress shown by foraminifera in the northern sector could be referable to the high concentrations of PCBs (up to 144 ng g(-1) d.w.).
Asunto(s)
Biodiversidad , Monitoreo del Ambiente/métodos , Foraminíferos/fisiología , Sedimentos Geológicos/análisis , Análisis por Conglomerados , Foraminíferos/clasificación , Sedimentos Geológicos/química , Italia , Tamaño de la Partícula , Estrés Fisiológico , Contaminantes Químicos del Agua/análisisRESUMEN
The coastal zone of the disused industrial site of Bagnoli, has been studied since 1999 in order to highlight chemical and ecological features of pollution, mainly due to a steel plant. This further study was performed in order to check the foraminiferal response to changes in sediment grain-size and contaminant concentrations and to recognise the actual effects of the environmental stress determined by industrial pollution on the foraminiferal assemblages. This was attained by considering a wider area than in the previous studies so as to recognise the possible reference conditions. Very high contamination, mainly due to Cu, Fe, Hg, Mn, Ni, Pb, Zn and PAHs, was recorded in the marine sediments close to the steel plant. Contaminant concentrations and sediment composition were recognised as important factors influencing the foraminiferal response by means of statistical analysis. The foraminiferal abnormality index (FAI) is positively correlated with heavy metals concentration, exceeding the natural threshold in front of the plant. Furthermore, increasing pollution levels correspond to the increase of pollution-tolerant species in the assemblage.