Research Outputs
Non-indigenous species contribute equally to biofouling communities in international vs local ports in the Biobío region, Chile
Growing coastal urbanization together with the intensification of maritime traffic are major processes explaining the increasing rate of biological introductions in marine environments. To investigate the link between international maritime traffic and the establishment of non-indigenous species (NIS) in coastal areas, biofouling communities in three international and three nearby local ports along 100 km of coastline in south-central Chile were compared using settlement panels and rapid assessment surveys. A larger number of NIS was observed in international ports, as expected in these ‘invasion hubs’. However, despite a few environmental differences between international and local ports, the two port categories did not display significant differences regarding NIS establishment and contribution to community structure over the studied period (1.5 years). In international ports, the free space could be a limiting factor for NIS establishment. The results also suggest that local ports should be considered in NIS surveillance programs in Chile.
Spatial distribution of potentially harmful elements in urban soils, city of Talcahuano, Chile
The objective of this study is to ascertain the spatial distribution of Cu, Pb and Zn in order to determine the degree of contamination in urban soils from Talcahuano (Chile) and to identify the influence of possible contamination sources. A total of 420 samples were collected from the study area based on the following criteria: 140 topsoil samples (TS) (0–10 cm), 140 subsoil samples (SS) (10–20 cm) and 140 deep soil samples (DS) (150 cm). The soils were characterized for their physical characteristics such as grain size distribution, pH, organic matter content etc. and the concentrations of Cu, Pb and Zn were analyzed by Atomic Absorption Photospectrometry following Aqua Regia digestion. Correlations combined with spatial analysis were implemented in order to distinguish the sources of the trace metals and whether they are geogenic or anthropogenic of origin. Several simple and robust statistical methods were applied to the data sets in order to evaluate useful and robust background values. The degree of contamination along with the geoaccumulation index, enrichment factors and contamination factors were also evaluated. The median concentrations obtained for the studied trace metals includes: Cu 23.1 mg kg− 1, Pb 10.2 mg kg− 1 and Zn 56.7 mg kg− 1. In general, the concentrations of Cu, Pb and Zn decrease with depth however, in certain sites the subsoil samples (SS) levels show higher concentrations than topsoil samples (TS). A possible explanation could be related to the uncontrolled clandestine landfill sites using both construction material debris and/or industrial solid wastes. Correlation analysis suggests that Cu, Pb and Zn are contributed by external sources. The spatial distribution of Cu, Pb and Zn in topsoil samples (TS) displays a spatial pattern extending along major roadway environments and emission sources. Estimated background values determined with the iterative 2σ-technique yields 43.7 mg kg− 1 for Cu, 17.5 mg kg− 1 for Pb and 91.7 mg kg− 1 for Zn respectively. The geochemical index, enrichment factor and the contamination factor all register a moderate to high contamination level in some of the soil samples.
Distribución y concentración de Zn total en sedimentos del fiordo Aysén, sur de Chile, posterior al terremoto y tsunami de 2007
Entre febrero y mayo de 2007, se produjeron más de 1.200 movimientos sísmicos de una intensidad mayor de 3 grados Richter (i.e., enjambre) y un sismo de 6,2 grados, en el Fiordo Aysén, sur de Chile. El epicentro fue la Falla Liquiñe-Ofqui, ubicada perpendicular a la parte media del fiordo. Como resultado se produjo una avalancha de tierra y rocas en la costa y ondas de tsunami local, hacia la cabeza. Se analiza la posible suspensión y redistribución de Zn total en los sedimentos marinos del Fiordo Aysén, por efecto de la actividad sísmica ocurrida en el área. El muestreo se realizó durante la 13° campaña del Programa Cruceros de Investigación Marina en Áreas Remotas, (CIMAR13-FIORDO), en noviembre de 2007. Las estaciones muestreadas fueron las mismas elegidas en campañas anteriores, 1995 y 2001. Se analizaron extractos ácidos de las muestras por quintuplicado, en un espectrofotómetro de absorción atómica. Los resultados mostraron una alta variabilidad en la concentración de Zn entre las estaciones. Sin embargo, no se observaron diferencias significativas en las concentraciones de Zn total entre los sitios de muestreo, lo que sugeriría que la resuspensión y redistribución de los contenidos de Zn total en los sedimentos fue un proceso local leve, que sólo afectó a la parte media del fiordo en que se produjo avalanchas de tierra y piedras.
Characterization of Baker Fjord region through its heavy metal content on sediments (Central Chilean Patagonia)
The spatial distribution of heavy metals content (Ba, Cd, Cu, Pb, Sr and Zn) in sediments of the Baker Fjord and surrounding channels in the central region of the Chilean fjords (47°45'S, 48°15'S) is analyzed. The aim of the study was characterized the patterns of abundance and distribution of these metals in surface sediments. The area corresponds to a poorly studied zone with low human activity. Distribution patterns would be influenced by rainfall conditions (local erosion), fluvial (continental sediments carried by rivers), glacier (glacier flour) and estuarine circulation. Cluster analysis allows differentiation among the sampled sites and group with similar characteristics. Finally, the concentrations found were contrasted with average values of metamorphic rocks and show with some certainty that the values found for calendar for this area and the greatest concentrations are the result of natural enrichment.
Habitat type drives the distribution of non-indigenous species in fouling communities regardless of associated maritime traffic
Biological invasions and changes in land and sea use are among the five major causes of global biodiversity decline. Shipping and ocean sprawl (multiplication of artificial structures at the expense of natural habitats) are considered as the major forces responsible for marine invasions and biotic homogenization. And yet, there is little evidence of their interplay at multiple spatial scales. Here, we aimed to examine this interaction and the extent to which the type of artificial habitat alters the distribution of native and non‐indigenous biodiversity. Location: Southeast Pacific—Central Chilean coastline.
Analytical testing of the interference standard method (IFS) for metals in wines by inductively coupled plasma mass spectrometry
An analytical testing study of interference standard method (IFS) for metals in wines with low and high residual sugar by inductively coupled plasma mass spectrometry (ICP-MS) was evaluated. Selection of IFS probes was based on the ions formed in the argon plasma, such as natural 38Ar+ or contaminant like 83Kr+ or also ions provided from the matrix sample (for instance, 13C+). The analytical signal was obtained from ratio between the original signals of the analyte and those of the IFS probe species. The accuracy was confirmed using a t-test statistic for comparison between the concentrations obtained by Flame Atomic Absorption Spectrometry (FAAS) and ICP-MS. In a first study, the IFS effect was analyzed by comparing the correlation coefficients obtained with or without dividing the analytical signal by the IFS. Using the 83Kr+ IFS probe provide always better results in the determination of Fe, Mn and Zn compared to 13C+ and 38Ar+.
Sources analysis and health risk assessment of trace elements in urban soils of Hualpen, Chile
Urban soils are a key component of urban ecosystems as they support biodiversity, provide foundation for infrastructure and play an important role in maintaining the environmental quality, being both a sink and a source of pollutants that have an effect in human health. The objectives of this study were (1) to determine the concentrations background of As, Co, Cr, Cu, Ni, Pb, V and Zn in the urban soils of Hualpen (Chile); (2) to assess the level of contamination in the urban soil based on different pollution indices; (3) to identify natural or anthropogenic sources in order to determine a spatial pattern of the pollutants and (4) to assess the health risks of trace metals in surface soils of Hualpen. A total of 153 samples were collected from the study area as follows: 51 topsoil samples (TS) (0–10 cm), 51 subsoil samples (SS) (10–20 cm) and 51 deep soil samples (DS) (150 cm). Multivariate statistics combined with spatial analysis were implemented in order to distinguish the sources. Several simple and robust statistical methods were applied to datasets in order to explore their potential in the evaluation of a useful and robust background values. The degree of contamination along with pollution indices were also evaluated. The median soil pseudo total concentrations of the elements were as follows: As 3 mg kg−1, Co 15 mg kg−1, Cr 14 mg kg−1, Cu 25 mg kg−1, Ni 36 mg kg−1, Pb 5 mg kg−1, V 97 mg kg−1 and Zn 51 mg kg−1. Multivariate analysis suggests that Cr, Pb, V and Zn are contributed by external sources. The spatial distribution of these elements displays a spatial pattern extending along industrial environments and emission sources. While the other elements show a spatial pattern with a few anthropogenic hot spots dispersed across Hualpen, they were influenced by both anthropogenic and geogenic inputs. The estimate background values determined with the DS samples with median absolute deviation (MAD) method were for As 5 mg kg−1, Co 20 mg kg−1, Cr 18 mg kg−1, Cu 33 mg kg−1, Ni 45 mg kg−1, Pb 3 mg kg−1, V 108 mg kg−1 and Zn 48 mg kg−1. The ecological indices register a moderate to considerable contamination in some soil samples. It was noted that the soils of Hualpen pose no carcinogenic risk, neither by inhalation nor by ingestion.
Distinguishing between natural and anthropogenic sources for potentially toxic elements in urban soils of Talcahuano, Chile
Purpose: The objectives of this study were (1) to determine the concentrations and background concentrations of Ba, Co, Cr, Mn, and Ni in the urban soils of Talcahuano (Chile); (2) assess the level of contamination in the urban soils based on different pollution indexes; and (3) to identify natural or anthropogenic sources in order to obtain a spatial distribution of the pollutants. Material and methods: A total of 420 samples were collected from the study area as follows: 140 topsoil samples (TS) (0–10 cm), 140 subsoil samples (SS) (10–20 cm), and 140 deep soil samples (DS) (150 cm). The soils were characterized, and the concentrations of Ba, Co, Cr, Mn, and Ni were analyzed by atomic absorption photospectrometry following aqua regia digestion. Correlations and principal component analysis combined with spatial analysis were implemented in order to distinguish the sources and their classification as geogenic or anthropogenic. Several simple and robust statistical methods were applied to datasets in order to explore their potential in the evaluation of a useful and robust background values. The degree of contamination along with the geoaccumulation index, enrichment factor, and contamination factor were also evaluated. Results and discussion: The median concentrations obtained for various elements includes Ba 461 mg kg−1, Co 82.7 mg kg−1, Cr 134 mg kg−1, Mn 311 mg kg−1, and Ni 56.1 mg kg−1. In general, the concentrations of Ba, Co, Cr, Mn, and Ni decrease with depth. Correlations and principal component analysis suggest that Cr, Mn, and Ni are contributed by external sources. The spatial distribution of Cr, Mn, and Ni in TS displays a spatial pattern extending along industrial environments and emission sources. Conclusions: The estimated background values determined with the iterative 2σ-technique includes 536 mg kg−1 for Ba, 95.9 mg kg−1 for Co, 208 mg kg−1 for Cr, 464 mg kg−1 for Mn, and 90.5 mg kg−1 for Ni. The geochemical index, enrichment factor, and the contamination factor register a moderate to considerable contamination in some soil samples.