Maren Ortiz-zarragoitia | Universidad del Páis Vasco (UPV/EHU) (original) (raw)

Papers by Maren Ortiz-zarragoitia

Research paper thumbnail of Antioxidant enzymes and peroxisome proliferation in relation to contaminant body burdens of PAHs and PCBs in bivalve molluscs, crabs and fish from the Urdaibai and Plentzia estuaries (Bay of Biscay)

Aquatic Toxicology, Jul 1, 2002

With the aim of studying levels of antioxidant and peroxisomal enzymes and the structure of perox... more With the aim of studying levels of antioxidant and peroxisomal enzymes and the structure of peroxisomes in relation to body burdens of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), mussels Mytilus galloprovincialis, oysters Crassostrea sp., crabs Carcinus maenas and mullets Mugil cephalus were sampled in two Basque estuaries (Bay of Biscay): Urdaibai (Laida, Txatxarramendi, Arteaga, and downstream a sewage treatment plant-STP) and Plentzia. In general, animals showed higher concentrations of contaminants in winter than in summer and no relevant differences were detected among locations. Conversely, antioxidant enzyme activities were higher in summer. Enzyme expression was studied in mullets using immunochemical methods. By immunoblotting season-dependent differences were detected for Mn-superoxide dismutase (Mn-SOD). As for the immunohistochemical staining, mullets sampled in summer in Plentzia showed significantly higher optical densities for acyl-CoA oxidase and lower for both Cu,Zn-SOD and Mn-SOD than those collected downstream a STP as well as higher catalase immunostaining than those collected in winter. Peroxisomal volume density (V(vp)) of mussels sampled in Laida and Txatxarramendi did not show seasonal variations, while for oysters collected in Laida and Arteaga V(vp) was higher in summer. Crab and mullet V(vp) were also higher in summer. In conclusion, the estuaries of Urdaibai and Plentzia can be considered as low to moderately polluted areas and levels of PAHs and PCBs do not show marked variations apart from seasonal variations. Animals can be adapted to low pollution conditions and, under these circumstances, seasonal factors might affect biomarker responses to a greater extent than pollution variations.

Research paper thumbnail of Endocrine disruption in mussel populations from the Biosphere's Reserve of Urdaibai (North Iberian Peninsula)

Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, Sep 1, 2008

mixtures-additivity, antagonism or synergism-were investigated with the method of isoboles. The U... more mixtures-additivity, antagonism or synergism-were investigated with the method of isoboles. The UV-filter mixtures led to a dosedependent VTG induction in fish and all estrogenic mixture activities were additive. These results indicate that the observed additive interaction of UV-filters may also be of relevance in mixtures of other environmental xenoestrogens. UV-filter residues should therefore also be taken into account when performing hazard and risk assessment of xenoestrogens in the aquatic ecosystem.

Research paper thumbnail of Cold sediment microbial community shifts in response to crude oil water-accommodated fraction with or without dispersant: a microcosm study

Environmental Science and Pollution Research, Jan 25, 2023

Research paper thumbnail of High production of transfer RNAs identifies the presence of developing oocytes in ovaries and intersex testes of teleost fish

Marine Environmental Research

Research paper thumbnail of Apoptosis and autophagy-related gene transcription during ovarian follicular atresia in European hake (Merluccius merluccius)

Marine Environmental Research

Follicular atresia is an energy-saving oocyte resorption process that can allow the survival of f... more Follicular atresia is an energy-saving oocyte resorption process that can allow the survival of female fish when environmental conditions are unfavourable and at the expense of fecundity. This study investigated the transcription levels of apoptosis and autophagy-related genes during atresia in the European hake that can show episodes of increased follicular atresia throughout the reproductive cycle. 169 female individuals were collected from the Bay of Biscay, and the ovaries were analysed using histological and molecular methods. Different levels of atresia were histologically detected in 73.7% of the ovaries analysed and the TUNEL assay identified apoptotic nuclei in follicles from both previtellogenic and vitellogenic stages. Transcripts of beclin-1 and ptenb were upregulated in the ovaries containing atretic follicles, whereas p53, caspase-3, cathepsin D and dapk1 were upregulated only in ovaries presenting vitellogenic atretic follicles. Our results indicate different implications of apoptotic vs autophagic processes leading to atresia during oocyte development, vitellogenesis being the moment of maximal apoptotic and autophagic activity in atretic hakes. The analysed genes could provide early warning biomarkers to identify follicular atresia in fish and evaluate fecundity in fish stocks.

Research paper thumbnail of Assessment of the effects of discontinuous sources of contamination through biomarker analyses on caged mussels

Science of The Total Environment, 2018

• Heavy rains favor the discharge of contaminants from discontinuous sources. • Chemical analyses... more • Heavy rains favor the discharge of contaminants from discontinuous sources. • Chemical analyses succeeded in tracking contamination from discontinuous sources. • Measured contaminants did not reach levels affecting mussels health. • Changes in food availability provoked by rains may have affected mussels health.

Research paper thumbnail of Measuring biological responses at different levels of organisation to assess the effects of diffuse contamination derived from harbour and industrial activities in estuarine areas

Marine Pollution Bulletin, 2016

To evaluate the effects of diffuse contamination, biological measurements were applied in a scrap... more To evaluate the effects of diffuse contamination, biological measurements were applied in a scrap cargo harbour, a marina and an industrial area. Metal accumulation and biomarkers (survival in air, digestive gland and gonad histopathology, lysosomal membrane stability, intralysosomal metal accumulation, transcription of vitellogenin and MT20, peroxisome proliferation and micronuclei formation) were measured in transplanted mussels, together with metrics of benthic invertebrates. Benthic species were classified into ecological groups and univariate indexes were calculated. The marina showed high richness (16) and percentage of opportunistic species (55.1%) and low metal accumulation. Mussels in the scrap cargo harbour showed high metal accumulation, up-regulation of MT20 transcription, reduced health status (LP<6min) and increased micronuclei frequencies (up to 11.3‰). At the industrial area, low species richness (4) and badly organised assemblages were detected and chemical analyses indicated significant amounts of bioavailable metals. Overall, selected biological measurements showed potential for the assessment of diffuse contamination.

Research paper thumbnail of Method for the Molecular and Quantitative Identification of Oocytes and Their Developmental Stage in Teleost Fish Gonads

Research paper thumbnail of Reduced Survival and Disruption of Female Reproductive Output in Two Copepod Species (Acartia clausi and A. tonsa) Exposed to the Model Endocrine Disruptor 17α-Ethinylestradiol

Toxics

Estuaries are heavily impacted by pollutants from different sources such as urban sewage, industr... more Estuaries are heavily impacted by pollutants from different sources such as urban sewage, industrial waste and agricultural runoff. Endocrine-disrupting chemicals (EDCs) are very concerning pollutants to estuarine wildlife, but little is known about their impact on microscopic biota such as zooplankton. The aim of this work was to investigate the effects of a model EDC, the 17α-ethinylestradiol (EE2), on two copepod species inhabiting the Basque coast (Southeastern Bay of Biscay) estuaries: Acartia clausi (autochthonous neritic species) and Acartia tonsa (non-indigenous brackish species). Female copepods were collected at population maximum time (spring for A. clausi and summer for A. tonsa) and exposed individually to 5 ng/L (low), 5 µg/L (medium) and 500 µg/L EE2 (high) doses, from environmental concentrations found in sewage effluents to toxicological concentrations. After 24 h exposure, the survival rate of experimental individuals was checked and the lethal concentration LC50 w...

Research paper thumbnail of Ugalketako disrupzio endokrinoa Gernika eta Galindoko araztegien inguruko korrokoietan (Chelon labrosus)

I. Ikergazte: Nazioarteko ikerketa euskaraz. Kongresuko artikulu-bilduma

Research paper thumbnail of Use of Otolith Shape and Elemental Signatures to Infer the Population Structure of the Thicklip Grey Mullet Chelon labrosus in the Southern Bay of Biscay

SIBIC 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Research paper thumbnail of Legacy and Dispersant Influence Microbial Community Dynamics in Cold Seawater Contaminated by Crude Oil Water Accommodated Fractions

SSRN Electronic Journal, 2022

Research paper thumbnail of Variability of the reproductive cycle in estuarine and coastal populations of the mussel Mytilus galloprovincialis Lmk. from the SE Bay of Biscay (Basque Country)

International Aquatic Research, 2017

Mussel commercial production depends on wild populations to obtain the seed. Therefore, any new f... more Mussel commercial production depends on wild populations to obtain the seed. Therefore, any new farming initiative needs deep knowledge on reproductive cycle of native mussel populations. The reproductive cycle of Mytilus galloprovincialis Lmk. from five sites, three estuarine and two coastal, along the coast of the Basque Country were assessed using gonad index and stereology over 2 consecutive years (2010 and 2011). Sex ratios, developmental stages of gonads, as well as reserve tissue cycle were analyzed. The onset of gametogenesis was observed from winter to spring, with spawning occurring from spring till summer. A resting phase followed with an increase in reserve tissues (adipogranular cells) was observed in fall. Mussels stayed ripe during winter until favorable environmental conditions were met in spring. Differences in reproductive cycles were found among populations, and also, year-to-year variability was observed within each population. In two of the studied sites asynchrony in the timing of spawning was observed between genders. These timing differences, however, did not prevent mussels at those sites from reproducing successfully. The Bidasoa estuary points to the potential of such studied sites for becoming the main source of wild mussel spats for future expected commercial mussel farming in the Basque Country. To ensure year-toyear maximum reproductive output, however, wild mussels harvest should be avoided from spring to the end of summer in this region.

Research paper thumbnail of Assessment of ecosystem health disturbance in mangrove-lined Caribbean coastal systems using the oyster Crassostrea rhizophorae as sentinel species

Science of The Total Environment, 2018

This investigation was aimed at contributing to develop a suitable multi-biomarker approach for p... more This investigation was aimed at contributing to develop a suitable multi-biomarker approach for pollution monitoring in mangrove-lined Caribbean coastal systems using as sentinel species, the mangrove cupped oyster, Crassostrea rhizophorae. A pilot field study was carried out in 8 localities (3 in Nicaragua; 5 in Colombia), characterized by different environmental conditions and subjected to different levels and types of pollution. Samples were collected in the rainy and dry seasons of 2012-2013. The biological effects at different levels of biological complexity (Stress-on-Stress response, reproduction, condition index, tissue-level biomarkers and histopathology) were determined as indicators of health disturbance, integrated as IBR/n index, and compared with tissue burdens of contaminants in order to achieve an integrative biomonitoring approach. Though modulated by natural variables and confounding factors, different indicators of oyster health, alone and in combination, were related to the presence of different profiles and levels of contaminants present at low-to-moderate levels. Different mixtures of persistent (As, Cd, PAHs) and emerging chemical pollutants (musk fragrances), in combination with different levels of organic and particulate matter resulting from seasonal oceanographic variability and sewage discharges, and environmental factors (salinity, temperature) elicited a different degree of disturbance in ecosystem health condition, as reflected in sentinel C. rhizophorae. As a result, IBR/n was correlated with pollution

Research paper thumbnail of Investigating the mechanisms by which environmental oestrogens affect male aggression and dominance hierarchies in fish

Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 2012

Research paper thumbnail of Steroidogenesis and phase II conjugation during the gametogenesis of thicklip grey mullet (Chelon labrosus) from a population showing intersex condition

General and Comparative Endocrinology, 2015

Steroidogenesis, the process by which steroid hormones are synthesized, involves a vast number of... more Steroidogenesis, the process by which steroid hormones are synthesized, involves a vast number of enzymes and biochemical pathways that are susceptible to chemical modulation. Endocrine disrupting compounds (EDCs) are of special concern since they can alter hormone homeostasis by interfering with synthesis, transport and elimination of hormones. It is important to understand gender differences and the natural variation in steroid balance through gamete development in fish exposed to EDCs. The aim of this study was to determine mRNA levels of genes encoding for Steroidogenic Acute Regulatory (star) protein; the steroidogenic enzymes P450 11β hydroxylase (cyp11b1) and P450 aromatase (cyp19a1a); as well as the phase II conjugation enzymes sulfotransferase (sult) and UDP-glucuronosyltransferase (ugt), together with the activity of P450 aromatase and plasma levels of 17β-estradiol (E2) and 11-ketotestosterone (11-KT), at different gametogenic stages and in intersex individuals of the thicklip grey mullet Chelon labrosus. Results demonstrated that the transcription levels of star, sult and ugt and levels of E2 and 11-KT in plasma significantly changed with the interaction between gender and reproductive stage. Cyp11b1 and cyp19a1a transcription levels were significantly different between genders while the activity of P450 aromatase varied significantly between genders and reproductive stages. Results from a multivariate assessment demonstrated that measured endpoints distinguished male, female and intersex mullets at immature gametogenic stage. Intersex distinction was based on sult, ugt and cyp19a1a transcript levels and P450 aromatase activity. The present work provides data to be used in future experimental designs with C. labrosus species, and gives new clues about the molecular events that lead to intersex occurrence in mullets.

Research paper thumbnail of Application of a battery of biomarkers in mussel digestive gland to assess long-term effects of the Prestige oil spill in Galicia and Bay of Biscay: Correlation and multivariate analysis

Journal of Environmental Monitoring, 2011

According to published reports, selected cell and tissue-level biomarkers revealed alterations in... more According to published reports, selected cell and tissue-level biomarkers revealed alterations in the health status of mussels collected after the Prestige oil spill (POS) in Galicia and the Bay of Biscay (2003-2006). Presently, univariate and multivariate analysis provides a comprehensive view of the whole data set. Correlation and principal component analysis (PCA) were performed using biomarkers corresponding to or derived from those data, say: induction, AOX(exp), and inhibition, AOX(eff), of Acyl-CoA oxidase enzyme activity; membrane labilisation period, LP, volume density, Vv(LYS), and surface-to-volume ratio, S/V(LYS), of digestive cell lysosomes; volume density of neutral lipids, Vv(NL); volume density of basophilic cells, Vv(BAS), mean luminal radius to mean epithelial thickness in digestive gland epithelium, MLR/MET; gonad index, GI; cumulative intensity of inflammatory responses, CI(IR) and parasitic infestation, CI(PI). The PCA results were used to classify sampling times and localities by means of hierarchical cluster analysis. Biomarkers were more frequently correlated with naphthalene than with total PAH concentration in mussel tissues. Many biological parameters were correlated with each other in agreement with their involvement in toxic processes or their role in the mussels' response against environmental insult. Naphthalene appears to be the most effective toxic herein, which supports that the reported effects may be mainly due to POS. According to the PCA, 4 groups of biomarkers explained 67.37% variability and the factors that most strongly contributed were S/V(LYS), CI(IR), Vv(BAS) and MLR/MET. These factors were used in the hierarchical cluster analyses carried out. The cluster analysis performed to classify sampling times discriminated 3 significantly different periods after POS: (a) a high affection period (until April-04); (b) the beginning of the recovery; and (c) an advanced recovery status in which geographical variability increased (from April-05 onwards). As regards the clustering of localities, major geographical differences were not detected but three outliers were identified: (a) early and highly impacted localities in Galicia and Bay of Biscay; (b) Aguiño that was characterised by extremely high Vv(BAS) during 2003; and (c) localities that were subjected to persistent chronic pollution.

Research paper thumbnail of Distribution of Organic Microcontaminants, Butyltins, and Metals in Mussels From the Estuary of Bilbao

Archives of Environmental Contamination and Toxicology, 2010

Research paper thumbnail of An integrated study of endocrine disruptors in sediments and reproduction-related parameters in bivalve molluscs from the Biosphere’s Reserve of Urdaibai (Bay of Biscay)

Marine Environmental Research, 2010

Research paper thumbnail of Immune responses and hematological variables of cultured great sturgeon (Huso huso) subjected to 11-ketotestosterone implantation

Despite studies on the effect of androgens in female teleost fish, many aspects of androgen suppl... more Despite studies on the effect of androgens in female teleost fish, many aspects of androgen supplementation in female sturgeon gametogenesis remain elusive. The aim of the study was to investigate the immunological and physiological responses of 4-year-old previtellogenic great sturgeon (Huso huso) (body weight 5580±165 g) to 11ketotestosterone (11-KT) implants. The fish were divided into two groups of 6 fish: 11-KT group, which received a single intraperitoneal implant of 2.5 mg 11-KT and a placebo group, which was implanted without 11-KT for 56 days. Just before implantation and on days 21 and 56 post-implantation, serum samples were taken to measure immune parameters (IgM, C3 and C4) and some related biochemical and hematological indices. Results showed a significant reduction in IgM concentrations after implantation in both the 11-KT and placebo groups (p<0.05). The concentration of C4 showed an opposite trend and significantly increased in both the placebo and 11-KT groups (...

Research paper thumbnail of Antioxidant enzymes and peroxisome proliferation in relation to contaminant body burdens of PAHs and PCBs in bivalve molluscs, crabs and fish from the Urdaibai and Plentzia estuaries (Bay of Biscay)

Aquatic Toxicology, Jul 1, 2002

With the aim of studying levels of antioxidant and peroxisomal enzymes and the structure of perox... more With the aim of studying levels of antioxidant and peroxisomal enzymes and the structure of peroxisomes in relation to body burdens of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), mussels Mytilus galloprovincialis, oysters Crassostrea sp., crabs Carcinus maenas and mullets Mugil cephalus were sampled in two Basque estuaries (Bay of Biscay): Urdaibai (Laida, Txatxarramendi, Arteaga, and downstream a sewage treatment plant-STP) and Plentzia. In general, animals showed higher concentrations of contaminants in winter than in summer and no relevant differences were detected among locations. Conversely, antioxidant enzyme activities were higher in summer. Enzyme expression was studied in mullets using immunochemical methods. By immunoblotting season-dependent differences were detected for Mn-superoxide dismutase (Mn-SOD). As for the immunohistochemical staining, mullets sampled in summer in Plentzia showed significantly higher optical densities for acyl-CoA oxidase and lower for both Cu,Zn-SOD and Mn-SOD than those collected downstream a STP as well as higher catalase immunostaining than those collected in winter. Peroxisomal volume density (V(vp)) of mussels sampled in Laida and Txatxarramendi did not show seasonal variations, while for oysters collected in Laida and Arteaga V(vp) was higher in summer. Crab and mullet V(vp) were also higher in summer. In conclusion, the estuaries of Urdaibai and Plentzia can be considered as low to moderately polluted areas and levels of PAHs and PCBs do not show marked variations apart from seasonal variations. Animals can be adapted to low pollution conditions and, under these circumstances, seasonal factors might affect biomarker responses to a greater extent than pollution variations.

Research paper thumbnail of Endocrine disruption in mussel populations from the Biosphere's Reserve of Urdaibai (North Iberian Peninsula)

Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, Sep 1, 2008

mixtures-additivity, antagonism or synergism-were investigated with the method of isoboles. The U... more mixtures-additivity, antagonism or synergism-were investigated with the method of isoboles. The UV-filter mixtures led to a dosedependent VTG induction in fish and all estrogenic mixture activities were additive. These results indicate that the observed additive interaction of UV-filters may also be of relevance in mixtures of other environmental xenoestrogens. UV-filter residues should therefore also be taken into account when performing hazard and risk assessment of xenoestrogens in the aquatic ecosystem.

Research paper thumbnail of Cold sediment microbial community shifts in response to crude oil water-accommodated fraction with or without dispersant: a microcosm study

Environmental Science and Pollution Research, Jan 25, 2023

Research paper thumbnail of High production of transfer RNAs identifies the presence of developing oocytes in ovaries and intersex testes of teleost fish

Marine Environmental Research

Research paper thumbnail of Apoptosis and autophagy-related gene transcription during ovarian follicular atresia in European hake (Merluccius merluccius)

Marine Environmental Research

Follicular atresia is an energy-saving oocyte resorption process that can allow the survival of f... more Follicular atresia is an energy-saving oocyte resorption process that can allow the survival of female fish when environmental conditions are unfavourable and at the expense of fecundity. This study investigated the transcription levels of apoptosis and autophagy-related genes during atresia in the European hake that can show episodes of increased follicular atresia throughout the reproductive cycle. 169 female individuals were collected from the Bay of Biscay, and the ovaries were analysed using histological and molecular methods. Different levels of atresia were histologically detected in 73.7% of the ovaries analysed and the TUNEL assay identified apoptotic nuclei in follicles from both previtellogenic and vitellogenic stages. Transcripts of beclin-1 and ptenb were upregulated in the ovaries containing atretic follicles, whereas p53, caspase-3, cathepsin D and dapk1 were upregulated only in ovaries presenting vitellogenic atretic follicles. Our results indicate different implications of apoptotic vs autophagic processes leading to atresia during oocyte development, vitellogenesis being the moment of maximal apoptotic and autophagic activity in atretic hakes. The analysed genes could provide early warning biomarkers to identify follicular atresia in fish and evaluate fecundity in fish stocks.

Research paper thumbnail of Assessment of the effects of discontinuous sources of contamination through biomarker analyses on caged mussels

Science of The Total Environment, 2018

• Heavy rains favor the discharge of contaminants from discontinuous sources. • Chemical analyses... more • Heavy rains favor the discharge of contaminants from discontinuous sources. • Chemical analyses succeeded in tracking contamination from discontinuous sources. • Measured contaminants did not reach levels affecting mussels health. • Changes in food availability provoked by rains may have affected mussels health.

Research paper thumbnail of Measuring biological responses at different levels of organisation to assess the effects of diffuse contamination derived from harbour and industrial activities in estuarine areas

Marine Pollution Bulletin, 2016

To evaluate the effects of diffuse contamination, biological measurements were applied in a scrap... more To evaluate the effects of diffuse contamination, biological measurements were applied in a scrap cargo harbour, a marina and an industrial area. Metal accumulation and biomarkers (survival in air, digestive gland and gonad histopathology, lysosomal membrane stability, intralysosomal metal accumulation, transcription of vitellogenin and MT20, peroxisome proliferation and micronuclei formation) were measured in transplanted mussels, together with metrics of benthic invertebrates. Benthic species were classified into ecological groups and univariate indexes were calculated. The marina showed high richness (16) and percentage of opportunistic species (55.1%) and low metal accumulation. Mussels in the scrap cargo harbour showed high metal accumulation, up-regulation of MT20 transcription, reduced health status (LP&amp;amp;lt;6min) and increased micronuclei frequencies (up to 11.3‰). At the industrial area, low species richness (4) and badly organised assemblages were detected and chemical analyses indicated significant amounts of bioavailable metals. Overall, selected biological measurements showed potential for the assessment of diffuse contamination.

Research paper thumbnail of Method for the Molecular and Quantitative Identification of Oocytes and Their Developmental Stage in Teleost Fish Gonads

Research paper thumbnail of Reduced Survival and Disruption of Female Reproductive Output in Two Copepod Species (Acartia clausi and A. tonsa) Exposed to the Model Endocrine Disruptor 17α-Ethinylestradiol

Toxics

Estuaries are heavily impacted by pollutants from different sources such as urban sewage, industr... more Estuaries are heavily impacted by pollutants from different sources such as urban sewage, industrial waste and agricultural runoff. Endocrine-disrupting chemicals (EDCs) are very concerning pollutants to estuarine wildlife, but little is known about their impact on microscopic biota such as zooplankton. The aim of this work was to investigate the effects of a model EDC, the 17α-ethinylestradiol (EE2), on two copepod species inhabiting the Basque coast (Southeastern Bay of Biscay) estuaries: Acartia clausi (autochthonous neritic species) and Acartia tonsa (non-indigenous brackish species). Female copepods were collected at population maximum time (spring for A. clausi and summer for A. tonsa) and exposed individually to 5 ng/L (low), 5 µg/L (medium) and 500 µg/L EE2 (high) doses, from environmental concentrations found in sewage effluents to toxicological concentrations. After 24 h exposure, the survival rate of experimental individuals was checked and the lethal concentration LC50 w...

Research paper thumbnail of Ugalketako disrupzio endokrinoa Gernika eta Galindoko araztegien inguruko korrokoietan (Chelon labrosus)

I. Ikergazte: Nazioarteko ikerketa euskaraz. Kongresuko artikulu-bilduma

Research paper thumbnail of Use of Otolith Shape and Elemental Signatures to Infer the Population Structure of the Thicklip Grey Mullet Chelon labrosus in the Southern Bay of Biscay

SIBIC 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Research paper thumbnail of Legacy and Dispersant Influence Microbial Community Dynamics in Cold Seawater Contaminated by Crude Oil Water Accommodated Fractions

SSRN Electronic Journal, 2022

Research paper thumbnail of Variability of the reproductive cycle in estuarine and coastal populations of the mussel Mytilus galloprovincialis Lmk. from the SE Bay of Biscay (Basque Country)

International Aquatic Research, 2017

Mussel commercial production depends on wild populations to obtain the seed. Therefore, any new f... more Mussel commercial production depends on wild populations to obtain the seed. Therefore, any new farming initiative needs deep knowledge on reproductive cycle of native mussel populations. The reproductive cycle of Mytilus galloprovincialis Lmk. from five sites, three estuarine and two coastal, along the coast of the Basque Country were assessed using gonad index and stereology over 2 consecutive years (2010 and 2011). Sex ratios, developmental stages of gonads, as well as reserve tissue cycle were analyzed. The onset of gametogenesis was observed from winter to spring, with spawning occurring from spring till summer. A resting phase followed with an increase in reserve tissues (adipogranular cells) was observed in fall. Mussels stayed ripe during winter until favorable environmental conditions were met in spring. Differences in reproductive cycles were found among populations, and also, year-to-year variability was observed within each population. In two of the studied sites asynchrony in the timing of spawning was observed between genders. These timing differences, however, did not prevent mussels at those sites from reproducing successfully. The Bidasoa estuary points to the potential of such studied sites for becoming the main source of wild mussel spats for future expected commercial mussel farming in the Basque Country. To ensure year-toyear maximum reproductive output, however, wild mussels harvest should be avoided from spring to the end of summer in this region.

Research paper thumbnail of Assessment of ecosystem health disturbance in mangrove-lined Caribbean coastal systems using the oyster Crassostrea rhizophorae as sentinel species

Science of The Total Environment, 2018

This investigation was aimed at contributing to develop a suitable multi-biomarker approach for p... more This investigation was aimed at contributing to develop a suitable multi-biomarker approach for pollution monitoring in mangrove-lined Caribbean coastal systems using as sentinel species, the mangrove cupped oyster, Crassostrea rhizophorae. A pilot field study was carried out in 8 localities (3 in Nicaragua; 5 in Colombia), characterized by different environmental conditions and subjected to different levels and types of pollution. Samples were collected in the rainy and dry seasons of 2012-2013. The biological effects at different levels of biological complexity (Stress-on-Stress response, reproduction, condition index, tissue-level biomarkers and histopathology) were determined as indicators of health disturbance, integrated as IBR/n index, and compared with tissue burdens of contaminants in order to achieve an integrative biomonitoring approach. Though modulated by natural variables and confounding factors, different indicators of oyster health, alone and in combination, were related to the presence of different profiles and levels of contaminants present at low-to-moderate levels. Different mixtures of persistent (As, Cd, PAHs) and emerging chemical pollutants (musk fragrances), in combination with different levels of organic and particulate matter resulting from seasonal oceanographic variability and sewage discharges, and environmental factors (salinity, temperature) elicited a different degree of disturbance in ecosystem health condition, as reflected in sentinel C. rhizophorae. As a result, IBR/n was correlated with pollution

Research paper thumbnail of Investigating the mechanisms by which environmental oestrogens affect male aggression and dominance hierarchies in fish

Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 2012

Research paper thumbnail of Steroidogenesis and phase II conjugation during the gametogenesis of thicklip grey mullet (Chelon labrosus) from a population showing intersex condition

General and Comparative Endocrinology, 2015

Steroidogenesis, the process by which steroid hormones are synthesized, involves a vast number of... more Steroidogenesis, the process by which steroid hormones are synthesized, involves a vast number of enzymes and biochemical pathways that are susceptible to chemical modulation. Endocrine disrupting compounds (EDCs) are of special concern since they can alter hormone homeostasis by interfering with synthesis, transport and elimination of hormones. It is important to understand gender differences and the natural variation in steroid balance through gamete development in fish exposed to EDCs. The aim of this study was to determine mRNA levels of genes encoding for Steroidogenic Acute Regulatory (star) protein; the steroidogenic enzymes P450 11β hydroxylase (cyp11b1) and P450 aromatase (cyp19a1a); as well as the phase II conjugation enzymes sulfotransferase (sult) and UDP-glucuronosyltransferase (ugt), together with the activity of P450 aromatase and plasma levels of 17β-estradiol (E2) and 11-ketotestosterone (11-KT), at different gametogenic stages and in intersex individuals of the thicklip grey mullet Chelon labrosus. Results demonstrated that the transcription levels of star, sult and ugt and levels of E2 and 11-KT in plasma significantly changed with the interaction between gender and reproductive stage. Cyp11b1 and cyp19a1a transcription levels were significantly different between genders while the activity of P450 aromatase varied significantly between genders and reproductive stages. Results from a multivariate assessment demonstrated that measured endpoints distinguished male, female and intersex mullets at immature gametogenic stage. Intersex distinction was based on sult, ugt and cyp19a1a transcript levels and P450 aromatase activity. The present work provides data to be used in future experimental designs with C. labrosus species, and gives new clues about the molecular events that lead to intersex occurrence in mullets.

Research paper thumbnail of Application of a battery of biomarkers in mussel digestive gland to assess long-term effects of the Prestige oil spill in Galicia and Bay of Biscay: Correlation and multivariate analysis

Journal of Environmental Monitoring, 2011

According to published reports, selected cell and tissue-level biomarkers revealed alterations in... more According to published reports, selected cell and tissue-level biomarkers revealed alterations in the health status of mussels collected after the Prestige oil spill (POS) in Galicia and the Bay of Biscay (2003-2006). Presently, univariate and multivariate analysis provides a comprehensive view of the whole data set. Correlation and principal component analysis (PCA) were performed using biomarkers corresponding to or derived from those data, say: induction, AOX(exp), and inhibition, AOX(eff), of Acyl-CoA oxidase enzyme activity; membrane labilisation period, LP, volume density, Vv(LYS), and surface-to-volume ratio, S/V(LYS), of digestive cell lysosomes; volume density of neutral lipids, Vv(NL); volume density of basophilic cells, Vv(BAS), mean luminal radius to mean epithelial thickness in digestive gland epithelium, MLR/MET; gonad index, GI; cumulative intensity of inflammatory responses, CI(IR) and parasitic infestation, CI(PI). The PCA results were used to classify sampling times and localities by means of hierarchical cluster analysis. Biomarkers were more frequently correlated with naphthalene than with total PAH concentration in mussel tissues. Many biological parameters were correlated with each other in agreement with their involvement in toxic processes or their role in the mussels&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; response against environmental insult. Naphthalene appears to be the most effective toxic herein, which supports that the reported effects may be mainly due to POS. According to the PCA, 4 groups of biomarkers explained 67.37% variability and the factors that most strongly contributed were S/V(LYS), CI(IR), Vv(BAS) and MLR/MET. These factors were used in the hierarchical cluster analyses carried out. The cluster analysis performed to classify sampling times discriminated 3 significantly different periods after POS: (a) a high affection period (until April-04); (b) the beginning of the recovery; and (c) an advanced recovery status in which geographical variability increased (from April-05 onwards). As regards the clustering of localities, major geographical differences were not detected but three outliers were identified: (a) early and highly impacted localities in Galicia and Bay of Biscay; (b) Aguiño that was characterised by extremely high Vv(BAS) during 2003; and (c) localities that were subjected to persistent chronic pollution.

Research paper thumbnail of Distribution of Organic Microcontaminants, Butyltins, and Metals in Mussels From the Estuary of Bilbao

Archives of Environmental Contamination and Toxicology, 2010

Research paper thumbnail of An integrated study of endocrine disruptors in sediments and reproduction-related parameters in bivalve molluscs from the Biosphere’s Reserve of Urdaibai (Bay of Biscay)

Marine Environmental Research, 2010

Research paper thumbnail of Immune responses and hematological variables of cultured great sturgeon (Huso huso) subjected to 11-ketotestosterone implantation

Despite studies on the effect of androgens in female teleost fish, many aspects of androgen suppl... more Despite studies on the effect of androgens in female teleost fish, many aspects of androgen supplementation in female sturgeon gametogenesis remain elusive. The aim of the study was to investigate the immunological and physiological responses of 4-year-old previtellogenic great sturgeon (Huso huso) (body weight 5580±165 g) to 11ketotestosterone (11-KT) implants. The fish were divided into two groups of 6 fish: 11-KT group, which received a single intraperitoneal implant of 2.5 mg 11-KT and a placebo group, which was implanted without 11-KT for 56 days. Just before implantation and on days 21 and 56 post-implantation, serum samples were taken to measure immune parameters (IgM, C3 and C4) and some related biochemical and hematological indices. Results showed a significant reduction in IgM concentrations after implantation in both the 11-KT and placebo groups (p<0.05). The concentration of C4 showed an opposite trend and significantly increased in both the placebo and 11-KT groups (...