Santiago Andrade - Academia.edu (original) (raw)

Papers by Santiago Andrade

Environmental Monitoring and Assessment, 2001

The concentrations of lead, cadmium, copper, chromium, iron, manganese and zinc in surface sedime... more The concentrations of lead, cadmium, copper, chromium, iron, manganese and zinc in surface sediments collected from Potter Cove, in the 25 de Mayo Island (King George Island), Antarctica, and its drainage basin, were measured by atomic absorption spectroscopy. The obtained results were use to determine the areal and vertical distribution of the metals of in the Cove and potential sources of these metals to this environment. The geochemical data suggest that most of the metals found in Potter Cove constitute a redistribution of autochthonous materials within the ecosystem. Therefore, the metal concentrations can be considered to be present at natural background levels in surface sediments.

Ecotoxicology and Environmental Safety, 2006

Aquatic Conservation: Marine and Freshwater Ecosystems, 2006

1. The concentration and distribution of several hydrographical variables from Mar Chiquita coast... more 1. The concentration and distribution of several hydrographical variables from Mar Chiquita coastal lagoon, Argentina, were measured monthly over a year in order to quantify their seasonal variations. Temperature, salinity, inorganic nutrient concentrations (nitrate, nitrite, phosphate, silicate) in the water column, and photosynthetic pigments (chlorophyll a and phaeopigments) in suspended particulate matter (SPM), were measured using internationally standardized analytical methods.

Wetlands Ecology and Management, 2001

Total Hg contents from abiotic (surface sediments and suspended particulate matter) and biologica... more Total Hg contents from abiotic (surface sediments and suspended particulate matter) and biological (crabs, fishes and halophytes) compartments from Bahía Blanca estuary and Mar Chiquita Coastal Lagoon, Argentina, have been monitored since the 1980 s. At Bahía Blanca estuary, high Hg concentrations were recorded during the early 1980 s in surface sediments (0.34 ± 0.22 µg/g) and suspended particulate matter (0.19 ± 0.10 µg/g). Fish species, Mustelus schmitti (0.89 ± 0.29 µg/g), Paralichthys brasiliensis (0.85 ± 0.18 µg/g) and Micropogonias furnieri (0.37 ± 0.11 µg/g) also presented high Hg concentrations. The large industrial nucleus located within the estuary has been identified as the main metal source for this environment. Hg contents from the same area during 1996-1998 were significantly lower: surface sediments (0.164 ± 0.023 µg/g), suspended particulate matter (0.048 ± 0.0017 µg/g), fish Micropogonias furnieri (0.13 ± 0.02 µg/g) and crab Chasmagnathus granulata (0.334 ± 0.071 µg/g). This trend of environmental detoxification is probably related with (i) the technological changes incorporated by the local industry, (ii) a most adequate management of industrial effluents, and (iii) the removal of great sediment volume by dredging and refill.

Science of the Total Environment, 1997

Trace-metal contents were recorded for the epilithic antarctic lichens Usnea aurantiacoatra and U... more Trace-metal contents were recorded for the epilithic antarctic lichens Usnea aurantiacoatra and U. antartica, sampled close to the Argentine scientific station 'Jubany' on '25 de Mayo' (King George) Island, in the Southern Shetland Archipelago (Antarctica). The corresponding heavy-metal levels have been measured through atomic absorption spectrophotometry, following internationally accepted analytical methods. The results obtained support the hypothesis that an atmospheric circulation of trace metals exists on the assessed area, and the activities developed at the different scientific stations located on this island would be a potential source of heavy metals to the evaluated environment. The geographical distribution of trace metals atmospherically transported in the area close to 'Jubany Station' was studied through the corresponding metal contents of the assessed lichens. Finally, the suitability of both analyzed lichen species, Usnea aurantiacoatra and U. antartica, as biological indicators for quantitative monitoring of airborne metals for this antarctic environment was recognized. 0 1997 Elsevier Science B.V.

SUMMARY Copper is an essential micronutrient, especially for photosyn-thetic organisms, but can b... more SUMMARY Copper is an essential micronutrient, especially for photosyn-thetic organisms, but can be toxic at high concentrations. In the past years, coastal waters have been exposed to an increase in copper concentration due to anthropogenic inputs. One well known case is the Chañaral area (Easter South Pacific coast), where a long term coastal copper enrichment event has occurred. That event strongly affected benthic marine diversity, including microbial communities. In this work, microcosm experiments were carried out to address the changes on picophytoplankton community composition of the disturbed area, when challenged to copper additions. Eukaryotic picophytoplankton communities from two areas were analyzed: one in the most copper-perturbed area and another at the north edge of the perturbed area. Flow cytometry data showed that 25 μg L −1 of copper addition exerted a positive effect in the growth kinetics on part of the eukaryotic picophytoplankton communities, independently of the site. 16S-plastid terminal restriction fragment length polymorphisms analysis suggested that eukaryotic picophy-toplankton display a short and directional response to high copper levels. Members of the Prasinophyceae class, a Coscinodiscophyceae diatom, as well as Phaeocystis, respond in a short time to the environmental disturbance, making them excellent candidates for further studies to evaluate phytoplanktonic species as sentinels for copper disturbances in coastal marine ecosystems.

Mangrove ecosystems are coastal estuarine systems confined to the tropical and subtropical region... more Mangrove ecosystems are coastal estuarine systems confined to the tropical and subtropical regions. The Estero Salado mangrove located in Guayaquil, Ecuador, has suffered constant disturbances during the past 20 years, due to industrial wastewater release. However, there are no published data for heavy metals present in its sediments and the relationship with anthropogenic disturbance. In the present study, metal concentrations were evaluated in surface sediment samples of the mangrove, showing that B, Cd, Cu, Pb, Se, V, and Zn levels exceeded those declared in international environmental quality standards. Moreover, several metals (Pb, Sn, Cd, Ag, Mo, Zn and Ni) could be linked to the industrial waste-water present in the studied area. In addition, heavy metal levels detected in this mangrove are higher than previous reports on mangrove sediments worldwide, indicating that this mangrove ecosystem is one of the most disrupted on earth.

Environmental Monitoring and Assessment, 2001

The concentrations of lead, cadmium, copper, chromium, iron, manganese and zinc in surface sedime... more The concentrations of lead, cadmium, copper, chromium, iron, manganese and zinc in surface sediments collected from Potter Cove, in the 25 de Mayo Island (King George Island), Antarctica, and its drainage basin, were measured by atomic absorption spectroscopy. The obtained results were use to determine the areal and vertical distribution of the metals of in the Cove and potential sources of these metals to this environment. The geochemical data suggest that most of the metals found in Potter Cove constitute a redistribution of autochthonous materials within the ecosystem. Therefore, the metal concentrations can be considered to be present at natural background levels in surface sediments.

Environmental Monitoring and Assessment, 2001

The concentrations of lead, cadmium, copper, chromium, iron, manganese and zinc in surface sedime... more The concentrations of lead, cadmium, copper, chromium, iron, manganese and zinc in surface sediments collected from Potter Cove, in the 25 de Mayo Island (King George Island), Antarctica, and its drainage basin, were measured by atomic absorption spectroscopy. The obtained results were use to determine the areal and vertical distribution of the metals of in the Cove and potential sources of these metals to this environment. The geochemical data suggest that most of the metals found in Potter Cove constitute a redistribution of autochthonous materials within the ecosystem. Therefore, the metal concentrations can be considered to be present at natural background levels in surface sediments.

OCEANOLOGIA

Concentrations of dissolved and particulate cadmium were measured in the water of the Bahía Blanc... more Concentrations of dissolved and particulate cadmium were measured in the water of the Bahía Blanca Estuary, one of the most highly industrialised regions in Argentina. Simultaneously, Cd contents were also determined in samples of phytoplankton. Thus, the estuary was characterised from the viewpoint of Cd occurrence. Additionally, a microscale environment was selected within the estuary in order to carry out an ecotoxicological study. Thus, environmental parameters ( i.e. temperature, salinity, nutrients, chlorophyll a ) were measured weekly at Puerto Cuatreros (in the inner estuary) during winter, when the phytoplankton bloom occurs; during the other seasons sampling was done twice a week. In addition, cells of the diatom Thalassiosira curviseriata - the dominant species in the phytoplankton bloom - were isolated and cultivated in the laboratory. The monoclonal cultures obtained were exposed to increasing concentrations of Cd under controlled environmental conditions and the growth...

Marine pollution bulletin, Jan 15, 2014

Mangrove ecosystems are coastal estuarine systems confined to the tropical and subtropical region... more Mangrove ecosystems are coastal estuarine systems confined to the tropical and subtropical regions. The Estero Salado mangrove located in Guayaquil, Ecuador, has suffered constant disturbances during the past 20 years, due to industrial wastewater release. However, there are no published data for heavy metals present in its sediments and the relationship with anthropogenic disturbance. In the present study, metal concentrations were evaluated in surface sediment samples of the mangrove, showing that B, Cd, Cu, Pb, Se, V, and Zn levels exceeded those declared in international environmental quality standards. Moreover, several metals (Pb, Sn, Cd, Ag, Mo, Zn and Ni) could be linked to the industrial wastewater present in the studied area. In addition, heavy metal levels detected in this mangrove are higher than previous reports on mangrove sediments worldwide, indicating that this mangrove ecosystem is one of the most disrupted on earth.

Oceanologia, 2000

The Bahía Blanca Estuary includes a large tidal plain with an area close to 1150 km 2 . Mud is pr... more The Bahía Blanca Estuary includes a large tidal plain with an area close to 1150 km 2 . Mud is predominant in its sediments, where a significant population of the crab Chasmagnathus granulata lives during the whole year. Moreover, there are important urban and industrial discharges into this environment.

Environmental Earth Sciences, 2011

The removal of Pb 2? from aqueous solution by two Brazilian rocks that contain zeolites-amygdaloi... more The removal of Pb 2? from aqueous solution by two Brazilian rocks that contain zeolites-amygdaloidal dacite (ZD) and sandstone (ZS)-was examined by batch experiments. ZD contains mordenite and ZS, stilbite. The effects of contact time, concentration of metal in solution and capacity of Na ? to recover the adsorbed metals were evaluated at room temperature (20°C). The sorption equilibrium was reached in the 30 min of agitation time. Both materials removed 100% of Pb 2? from solutions at concentrations up to 50 mg/L, and at concentrations larger than 100 mg/L of Pb 2? , the adsorption capacity of sandstone was more efficient than that of amygdaloidal dacite due to the larger quantities and the type of zeolites (stilbite) in the cement of this rock. All adsorbed Pb 2? was easily replaced by Na ? in both samples. The analysis of the adsorption models using nonlinear regression revealed that the Sips and the Freundlich isotherms provided the best fit for the ZS and ZD experimental data, respectively, indicating the heterogeneous adsorption surfaces of these zeolites.

OCEANOLOGIA

The Bahía Blanca Estuary includes a large tidal plain with an area close to 1150 km2. Mud is pred... more The Bahía Blanca Estuary includes a large tidal plain with an area close to 1150 km2. Mud is predominant in its sediments, where a significant population of the crab Chasmagnathus granulata lives during the whole year. Moreover, there are important urban and industrial discharges into this environment. Cd and Pb concentrations were determined in samples of water (for both dissolved and suspended particulate matter) and surface sediments (total and 63 µm fractions). Organic matter was analysed in the sediments, while temperature, salinity, pH and dissolved oxygen were measured in the estuarine water. The metal concentrations determined in this study were: 1.47 ± 1.08 µg Cd g–1 and 14.68 ± 4.31 µg Pb g–1 in surface sediments; 2.21 ± 1.33 µg Cd g–1 and 25.70 ± 7.09 µg Pb g–1 in the <63 µm sediment fraction; 0.18 ± 0.11 µg Cd g–1 and below the analytical detection limit of Pb in suspended particulate matter. Furthermore, dissolved Cd and Pb were lower than the norms for marine and es...

Phycological Research, 2015

Chemical Speciation and Bioavailability, 2003

Aquatic toxicology (Amsterdam, Netherlands), 2014

The brown alga Dictyota kunthii is one of the dominant species in the coastal areas of northern C... more The brown alga Dictyota kunthii is one of the dominant species in the coastal areas of northern Chile affected by copper enrichment due to accumulated mining wastes. To assess its physiological plasticity in handling copper-mediated oxidative stress, 4-days copper exposure (ca. 100 μg/L) experiments were conducted with individuals from a copper impacted area and compared with the responses of plants from a non-impacted site. Several biochemical parameters were then evaluated and compared between populations. Results showed that individuals from the copper-impacted population normally displayed higher levels of copper content and antioxidant enzymes activity (catalase (CAT), ascorbate peroxidase (AP), dehydroascorbate reductase (DHAR), glutathione peroxidase (GP) and peroxiredoxins (PRX)). After copper exposure, antioxidant enzyme activity increased significantly in plants from the two selected sites. In addition, we found that copper-mediated oxidative stress was associated with a r...

Science of the Total Environment, 1997

Trace-metal contents were recorded for the epilithic antarctic lichens Usnea aurantiacoatra and U... more Trace-metal contents were recorded for the epilithic antarctic lichens Usnea aurantiacoatra and U. antartica, sampled close to the Argentine scientific station 'Jubany' on '25 de Mayo' (King George) Island, in the Southern Shetland Archipelago (Antarctica). The corresponding heavy-metal levels have been measured through atomic absorption spectrophotometry, following internationally accepted analytical methods. The results obtained support the hypothesis that an atmospheric circulation of trace metals exists on the assessed area, and the activities developed at the different scientific stations located on this island would be a potential source of heavy metals to the evaluated environment. The geographical distribution of trace metals atmospherically transported in the area close to 'Jubany Station' was studied through the corresponding metal contents of the assessed lichens. Finally, the suitability of both analyzed lichen species, Usnea aurantiacoatra and U. antartica, as biological indicators for quantitative monitoring of airborne metals for this antarctic environment was recognized. 0 1997 Elsevier Science B.V.

Environmental Monitoring and Assessment, 2001

The concentrations of lead, cadmium, copper, chromium, iron, manganese and zinc in surface sedime... more The concentrations of lead, cadmium, copper, chromium, iron, manganese and zinc in surface sediments collected from Potter Cove, in the 25 de Mayo Island (King George Island), Antarctica, and its drainage basin, were measured by atomic absorption spectroscopy. The obtained results were use to determine the areal and vertical distribution of the metals of in the Cove and potential sources of these metals to this environment. The geochemical data suggest that most of the metals found in Potter Cove constitute a redistribution of autochthonous materials within the ecosystem. Therefore, the metal concentrations can be considered to be present at natural background levels in surface sediments.

Ecotoxicology and Environmental Safety, 2006

Aquatic Conservation: Marine and Freshwater Ecosystems, 2006

1. The concentration and distribution of several hydrographical variables from Mar Chiquita coast... more 1. The concentration and distribution of several hydrographical variables from Mar Chiquita coastal lagoon, Argentina, were measured monthly over a year in order to quantify their seasonal variations. Temperature, salinity, inorganic nutrient concentrations (nitrate, nitrite, phosphate, silicate) in the water column, and photosynthetic pigments (chlorophyll a and phaeopigments) in suspended particulate matter (SPM), were measured using internationally standardized analytical methods.

Wetlands Ecology and Management, 2001

Total Hg contents from abiotic (surface sediments and suspended particulate matter) and biologica... more Total Hg contents from abiotic (surface sediments and suspended particulate matter) and biological (crabs, fishes and halophytes) compartments from Bahía Blanca estuary and Mar Chiquita Coastal Lagoon, Argentina, have been monitored since the 1980 s. At Bahía Blanca estuary, high Hg concentrations were recorded during the early 1980 s in surface sediments (0.34 ± 0.22 µg/g) and suspended particulate matter (0.19 ± 0.10 µg/g). Fish species, Mustelus schmitti (0.89 ± 0.29 µg/g), Paralichthys brasiliensis (0.85 ± 0.18 µg/g) and Micropogonias furnieri (0.37 ± 0.11 µg/g) also presented high Hg concentrations. The large industrial nucleus located within the estuary has been identified as the main metal source for this environment. Hg contents from the same area during 1996-1998 were significantly lower: surface sediments (0.164 ± 0.023 µg/g), suspended particulate matter (0.048 ± 0.0017 µg/g), fish Micropogonias furnieri (0.13 ± 0.02 µg/g) and crab Chasmagnathus granulata (0.334 ± 0.071 µg/g). This trend of environmental detoxification is probably related with (i) the technological changes incorporated by the local industry, (ii) a most adequate management of industrial effluents, and (iii) the removal of great sediment volume by dredging and refill.

Science of the Total Environment, 1997

Trace-metal contents were recorded for the epilithic antarctic lichens Usnea aurantiacoatra and U... more Trace-metal contents were recorded for the epilithic antarctic lichens Usnea aurantiacoatra and U. antartica, sampled close to the Argentine scientific station 'Jubany' on '25 de Mayo' (King George) Island, in the Southern Shetland Archipelago (Antarctica). The corresponding heavy-metal levels have been measured through atomic absorption spectrophotometry, following internationally accepted analytical methods. The results obtained support the hypothesis that an atmospheric circulation of trace metals exists on the assessed area, and the activities developed at the different scientific stations located on this island would be a potential source of heavy metals to the evaluated environment. The geographical distribution of trace metals atmospherically transported in the area close to 'Jubany Station' was studied through the corresponding metal contents of the assessed lichens. Finally, the suitability of both analyzed lichen species, Usnea aurantiacoatra and U. antartica, as biological indicators for quantitative monitoring of airborne metals for this antarctic environment was recognized. 0 1997 Elsevier Science B.V.

SUMMARY Copper is an essential micronutrient, especially for photosyn-thetic organisms, but can b... more SUMMARY Copper is an essential micronutrient, especially for photosyn-thetic organisms, but can be toxic at high concentrations. In the past years, coastal waters have been exposed to an increase in copper concentration due to anthropogenic inputs. One well known case is the Chañaral area (Easter South Pacific coast), where a long term coastal copper enrichment event has occurred. That event strongly affected benthic marine diversity, including microbial communities. In this work, microcosm experiments were carried out to address the changes on picophytoplankton community composition of the disturbed area, when challenged to copper additions. Eukaryotic picophytoplankton communities from two areas were analyzed: one in the most copper-perturbed area and another at the north edge of the perturbed area. Flow cytometry data showed that 25 μg L −1 of copper addition exerted a positive effect in the growth kinetics on part of the eukaryotic picophytoplankton communities, independently of the site. 16S-plastid terminal restriction fragment length polymorphisms analysis suggested that eukaryotic picophy-toplankton display a short and directional response to high copper levels. Members of the Prasinophyceae class, a Coscinodiscophyceae diatom, as well as Phaeocystis, respond in a short time to the environmental disturbance, making them excellent candidates for further studies to evaluate phytoplanktonic species as sentinels for copper disturbances in coastal marine ecosystems.

Mangrove ecosystems are coastal estuarine systems confined to the tropical and subtropical region... more Mangrove ecosystems are coastal estuarine systems confined to the tropical and subtropical regions. The Estero Salado mangrove located in Guayaquil, Ecuador, has suffered constant disturbances during the past 20 years, due to industrial wastewater release. However, there are no published data for heavy metals present in its sediments and the relationship with anthropogenic disturbance. In the present study, metal concentrations were evaluated in surface sediment samples of the mangrove, showing that B, Cd, Cu, Pb, Se, V, and Zn levels exceeded those declared in international environmental quality standards. Moreover, several metals (Pb, Sn, Cd, Ag, Mo, Zn and Ni) could be linked to the industrial waste-water present in the studied area. In addition, heavy metal levels detected in this mangrove are higher than previous reports on mangrove sediments worldwide, indicating that this mangrove ecosystem is one of the most disrupted on earth.

Environmental Monitoring and Assessment, 2001

The concentrations of lead, cadmium, copper, chromium, iron, manganese and zinc in surface sedime... more The concentrations of lead, cadmium, copper, chromium, iron, manganese and zinc in surface sediments collected from Potter Cove, in the 25 de Mayo Island (King George Island), Antarctica, and its drainage basin, were measured by atomic absorption spectroscopy. The obtained results were use to determine the areal and vertical distribution of the metals of in the Cove and potential sources of these metals to this environment. The geochemical data suggest that most of the metals found in Potter Cove constitute a redistribution of autochthonous materials within the ecosystem. Therefore, the metal concentrations can be considered to be present at natural background levels in surface sediments.

Environmental Monitoring and Assessment, 2001

The concentrations of lead, cadmium, copper, chromium, iron, manganese and zinc in surface sedime... more The concentrations of lead, cadmium, copper, chromium, iron, manganese and zinc in surface sediments collected from Potter Cove, in the 25 de Mayo Island (King George Island), Antarctica, and its drainage basin, were measured by atomic absorption spectroscopy. The obtained results were use to determine the areal and vertical distribution of the metals of in the Cove and potential sources of these metals to this environment. The geochemical data suggest that most of the metals found in Potter Cove constitute a redistribution of autochthonous materials within the ecosystem. Therefore, the metal concentrations can be considered to be present at natural background levels in surface sediments.

OCEANOLOGIA

Concentrations of dissolved and particulate cadmium were measured in the water of the Bahía Blanc... more Concentrations of dissolved and particulate cadmium were measured in the water of the Bahía Blanca Estuary, one of the most highly industrialised regions in Argentina. Simultaneously, Cd contents were also determined in samples of phytoplankton. Thus, the estuary was characterised from the viewpoint of Cd occurrence. Additionally, a microscale environment was selected within the estuary in order to carry out an ecotoxicological study. Thus, environmental parameters ( i.e. temperature, salinity, nutrients, chlorophyll a ) were measured weekly at Puerto Cuatreros (in the inner estuary) during winter, when the phytoplankton bloom occurs; during the other seasons sampling was done twice a week. In addition, cells of the diatom Thalassiosira curviseriata - the dominant species in the phytoplankton bloom - were isolated and cultivated in the laboratory. The monoclonal cultures obtained were exposed to increasing concentrations of Cd under controlled environmental conditions and the growth...

Marine pollution bulletin, Jan 15, 2014

Mangrove ecosystems are coastal estuarine systems confined to the tropical and subtropical region... more Mangrove ecosystems are coastal estuarine systems confined to the tropical and subtropical regions. The Estero Salado mangrove located in Guayaquil, Ecuador, has suffered constant disturbances during the past 20 years, due to industrial wastewater release. However, there are no published data for heavy metals present in its sediments and the relationship with anthropogenic disturbance. In the present study, metal concentrations were evaluated in surface sediment samples of the mangrove, showing that B, Cd, Cu, Pb, Se, V, and Zn levels exceeded those declared in international environmental quality standards. Moreover, several metals (Pb, Sn, Cd, Ag, Mo, Zn and Ni) could be linked to the industrial wastewater present in the studied area. In addition, heavy metal levels detected in this mangrove are higher than previous reports on mangrove sediments worldwide, indicating that this mangrove ecosystem is one of the most disrupted on earth.

Oceanologia, 2000

The Bahía Blanca Estuary includes a large tidal plain with an area close to 1150 km 2 . Mud is pr... more The Bahía Blanca Estuary includes a large tidal plain with an area close to 1150 km 2 . Mud is predominant in its sediments, where a significant population of the crab Chasmagnathus granulata lives during the whole year. Moreover, there are important urban and industrial discharges into this environment.

Environmental Earth Sciences, 2011

The removal of Pb 2? from aqueous solution by two Brazilian rocks that contain zeolites-amygdaloi... more The removal of Pb 2? from aqueous solution by two Brazilian rocks that contain zeolites-amygdaloidal dacite (ZD) and sandstone (ZS)-was examined by batch experiments. ZD contains mordenite and ZS, stilbite. The effects of contact time, concentration of metal in solution and capacity of Na ? to recover the adsorbed metals were evaluated at room temperature (20°C). The sorption equilibrium was reached in the 30 min of agitation time. Both materials removed 100% of Pb 2? from solutions at concentrations up to 50 mg/L, and at concentrations larger than 100 mg/L of Pb 2? , the adsorption capacity of sandstone was more efficient than that of amygdaloidal dacite due to the larger quantities and the type of zeolites (stilbite) in the cement of this rock. All adsorbed Pb 2? was easily replaced by Na ? in both samples. The analysis of the adsorption models using nonlinear regression revealed that the Sips and the Freundlich isotherms provided the best fit for the ZS and ZD experimental data, respectively, indicating the heterogeneous adsorption surfaces of these zeolites.

OCEANOLOGIA

The Bahía Blanca Estuary includes a large tidal plain with an area close to 1150 km2. Mud is pred... more The Bahía Blanca Estuary includes a large tidal plain with an area close to 1150 km2. Mud is predominant in its sediments, where a significant population of the crab Chasmagnathus granulata lives during the whole year. Moreover, there are important urban and industrial discharges into this environment. Cd and Pb concentrations were determined in samples of water (for both dissolved and suspended particulate matter) and surface sediments (total and 63 µm fractions). Organic matter was analysed in the sediments, while temperature, salinity, pH and dissolved oxygen were measured in the estuarine water. The metal concentrations determined in this study were: 1.47 ± 1.08 µg Cd g–1 and 14.68 ± 4.31 µg Pb g–1 in surface sediments; 2.21 ± 1.33 µg Cd g–1 and 25.70 ± 7.09 µg Pb g–1 in the <63 µm sediment fraction; 0.18 ± 0.11 µg Cd g–1 and below the analytical detection limit of Pb in suspended particulate matter. Furthermore, dissolved Cd and Pb were lower than the norms for marine and es...

Phycological Research, 2015

Chemical Speciation and Bioavailability, 2003

Aquatic toxicology (Amsterdam, Netherlands), 2014

The brown alga Dictyota kunthii is one of the dominant species in the coastal areas of northern C... more The brown alga Dictyota kunthii is one of the dominant species in the coastal areas of northern Chile affected by copper enrichment due to accumulated mining wastes. To assess its physiological plasticity in handling copper-mediated oxidative stress, 4-days copper exposure (ca. 100 μg/L) experiments were conducted with individuals from a copper impacted area and compared with the responses of plants from a non-impacted site. Several biochemical parameters were then evaluated and compared between populations. Results showed that individuals from the copper-impacted population normally displayed higher levels of copper content and antioxidant enzymes activity (catalase (CAT), ascorbate peroxidase (AP), dehydroascorbate reductase (DHAR), glutathione peroxidase (GP) and peroxiredoxins (PRX)). After copper exposure, antioxidant enzyme activity increased significantly in plants from the two selected sites. In addition, we found that copper-mediated oxidative stress was associated with a r...

Science of the Total Environment, 1997

Trace-metal contents were recorded for the epilithic antarctic lichens Usnea aurantiacoatra and U... more Trace-metal contents were recorded for the epilithic antarctic lichens Usnea aurantiacoatra and U. antartica, sampled close to the Argentine scientific station 'Jubany' on '25 de Mayo' (King George) Island, in the Southern Shetland Archipelago (Antarctica). The corresponding heavy-metal levels have been measured through atomic absorption spectrophotometry, following internationally accepted analytical methods. The results obtained support the hypothesis that an atmospheric circulation of trace metals exists on the assessed area, and the activities developed at the different scientific stations located on this island would be a potential source of heavy metals to the evaluated environment. The geographical distribution of trace metals atmospherically transported in the area close to 'Jubany Station' was studied through the corresponding metal contents of the assessed lichens. Finally, the suitability of both analyzed lichen species, Usnea aurantiacoatra and U. antartica, as biological indicators for quantitative monitoring of airborne metals for this antarctic environment was recognized. 0 1997 Elsevier Science B.V.