Diaz Ochoa, Javier Augusto
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Diaz Ochoa, Javier Augusto
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Diaz Ochoa, Javier Augusto
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javier.diaz@umag.cl
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JerarquĆa acadĆ©mica
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Ciencia Antartica y Subantartica
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PublicaciĆ³n DOI 10.5194/isprs-archives-xlii-3-w12-2020-385-2020
Importance of remote sensing for the study of spatial dynamics of estuarine neuston from southern Chile2020-11-04Zooplankton aggregation, hydrographic and remote sensing data were employed to relate the spatial dynamics of neustonic communities with chlorophyll a (Chl <i>a</i>) and suspended organic matter (SOM) at a spatial mesoscale (10 to 1000 km) in the southern Chilean fjords system along Magellan Strait, Chile (CIMAR 16: October/November 2010 and CIMAR 25; September/October 2019) in order to identify oceanographic process producing aggregation of neuston. Preliminary evidence of CIMAR 25 shows significant concentrations of Chl <i>a</i> and SOM around Dawson Island (DI), Magellan Strait. During CIMAR 16 important aggregation of specific neustonic taxa (copepodites of <i>Microsetella rosea</i>, larvae of the polychaete <i>Polygordius sp</i> and cyphonautes of the bryozoan <i>Membranipora isabelleana</i>) was observed around DI, Magellan Strait. Satelital images in the area of CIMAR 16 provide evidence of important aggregation of chlorophyll <i>a</i>/SOM around DI. CIMAR Cimar 25 showed that the Chl <i>a</i> and SOM aggregation around DI is recurrent and could to explain the high concentration of neuston around this island to spite of mesotrophic conditions. Remote sensing in this study area provides a tool to understanding oceanographic and topographic factors that potentially regulate the abundance and spatial distribution of surface zooplankton to spatial meso-scale along Magellan Strait. - Some of the metrics are blocked by yourconsent settings
PublicaciĆ³n DOI 10.5194/isprs-archives-xlii-3-w12-2020-385-2020Importance of remote sensing for the study of spatial dynamics of estuarine neuston from southern Chile2020-11-04Zooplankton aggregation, hydrographic and remote sensing data were employed to relate the spatial dynamics of neustonic communities with chlorophyll a (Chl <i>a</i>) and suspended organic matter (SOM) at a spatial mesoscale (10 to 1000 km) in the southern Chilean fjords system along Magellan Strait, Chile (CIMAR 16: October/November 2010 and CIMAR 25; September/October 2019) in order to identify oceanographic process producing aggregation of neuston. Preliminary evidence of CIMAR 25 shows significant concentrations of Chl <i>a</i> and SOM around Dawson Island (DI), Magellan Strait. During CIMAR 16 important aggregation of specific neustonic taxa (copepodites of <i>Microsetella rosea</i>, larvae of the polychaete <i>Polygordius sp</i> and cyphonautes of the bryozoan <i>Membranipora isabelleana</i>) was observed around DI, Magellan Strait. Satelital images in the area of CIMAR 16 provide evidence of important aggregation of chlorophyll <i>a</i>/SOM around DI. CIMAR Cimar 25 showed that the Chl <i>a</i> and SOM aggregation around DI is recurrent and could to explain the high concentration of neuston around this island to spite of mesotrophic conditions. Remote sensing in this study area provides a tool to understanding oceanographic and topographic factors that potentially regulate the abundance and spatial distribution of surface zooplankton to spatial meso-scale along Magellan Strait.1 - Some of the metrics are blocked by yourconsent settings
PublicaciĆ³n DOI 10.1016/j.ijsrc.2018.08.005Evaluation of redox-sensitive metals in marine surface sediments influenced by the oxygen minimum zone of the Humboldt Current System, Northern Chile2019-4; Marambio, YeryUpwelling coastal systems can be used to understand how dissolved oxygen and biological productivity control the accumulation of redox-sensitive metals in marine sediments. The aluminium (Al), cadmium (Cd), iron (Fe), nickel (Ni), molybdenum (Mo), vanadium (V), total organic carbon (TOC), total nitrogen (TN) and total sulfur (TS) contents in surficial sediment collected from different water depths (30, 70, and 120 m) in three northern Chilean bays influenced by coastal upwelling and oxygen minimum zones (OMZs) were measured. Principal component analysis (PCA), cluster analysis, and Spearman's rank correlation were used to identify the mechanisms responsible for the redox-sensitive metal accumulation. The content of redox-sensitive metals and organic components in sediment increased with increasing water column depth, whereas lithogenic metals decreased. In the Mejillones del Sur and Caldera bays, the enrichment factors of the redox-sensitive metals showed enrichment for all metals with depth. The Cd and V enrichments are mainly the product of biogenic flow to the seabed, and the Mo and Ni enrichments are due to preservation under low subsurface oxygen conditions. Sulfate reduction is not an important mechanism in the accumulation of redox-sensitive metals in the sediment of the three bays. The PCA showed that the behaviors of the redox-sensitive metals and organic components reflect differences in the effects of the OMZ in sediment along the coast of northern Chile, with a more intense OMZ in Mejillones del Sur bay and weaker OMZs in Caldera and Inglesa bays. However, the high degree of enrichment in redox-sensitive metals in Caldera Bay can be attributed to the intense activity of the mining industry near the bay, a situation that produces geochemical behavior similar to that observed in Mejillones del Sur Bay. (C) 2018 International Research and Training Centre on Erosion and Sedimentation/the World Association for Sedimentation and Erosion Research. Published by Elsevier B.V. All rights reserved.ScopusĀ© Citations 15 1 - Some of the metrics are blocked by yourconsent settings
PublicaciĆ³n DOI 10.1016/j.scitotenv.2023.162395Isotope geochemistry as a natural tag of fish in Patagonian freshwater environments: The invasive Chinook salmon case2023-5-15; ScopusĀ© Citations 9 4 - Some of the metrics are blocked by yourconsent settings
PublicaciĆ³n DOI 10.4067/s0718-686x2019000200019Abundance and spatial distribution of Polygordius (Polychaeta: Polygordiidae) neustonic exolarvae in estuaries from southern Chile2019-1-1; ; 2