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Henrique N Cabral - One of the best experts on this subject based on the ideXlab platform.

  • influence of temperature in thermal and oxidative stress responses in Estuarine Fish
    Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2013
    Co-Authors: Diana Madeira, Henrique N Cabral, Luis Narciso, Catarina Vinagre, Mario Diniz
    Abstract:

    Abstract The influence of increasing temperatures in thermal and oxidative stress responses were studied in the muscle of several Estuarine Fish species ( Diplodus vulgaris, Diplodus sargus, Dicentrarchus labrax, Gobius niger and Liza ramada ). Selected Fish were collected in July at the Tagus estuary (24 ± 0.9 °C; salinity of 30 ± 4‰; pH = 8). Fish were subjected to a temperature increase of 1 °C.h − 1 until they reached their Critical Thermal Maximum (CTMax), starting at 24 °C (control temperature). Muscle samples were collected during the trial and results showed that oxidative stress biomarkers are highly sensitive to temperature. Results from stress oxidative enzymes show alterations with increasing temperature in all tested species. Catalase (CAT; EC 1.11.1.6) activity significantly increased in L. ramada, D. labrax and decreased in D. vulgaris . Glutathione S-transferase (GST; EC 2.5.1.18) activity increased in L. ramada , D. sargus , D. vulgaris , and D. labrax . In G. niger it showed a cycle of increase-decrease. Lipid peroxidation (LPO) increased in L. ramada , D. sargus and D. labrax . With respect to correlation analysis (Pearson; Spearman r ), the results showed that oxidation products and antioxidant defenses were correlated in L. ramada (LPO-CAT and LPO-GST, D. sargus (LPO-CAT), and D. labrax (LPO-CAT). Oxidative biomarkers were correlated with thermal stress biomarker (Hsp70) in L. ramada (CAT-Hsp70), D. vulgaris (LPO-Hsp70), D. labrax (GST-Hsp70) and G. niger (LPO-Hsp70). In conclusion, oxidative stress does occur with increasing temperatures and there seems to be a relation between thermal stress response and oxidative stress response. The results suggest that oxidative stress biomarkers should be applied with caution, particularly in field multi-species/multi-environment studies.

  • temporal variability in Estuarine Fish otolith elemental fingerprints implications for connectivity assessments
    Estuarine Coastal and Shelf Science, 2012
    Co-Authors: Travis S. Elsdon, Bronwyn M. Gillanders, Patrick Reissantos, Susanne E Tanner, Rita P Vasconcelos, Henrique N Cabral
    Abstract:

    The chemical composition of Fish otoliths can provide valuable information for determining the nursery value of estuaries to adult populations of coastal Fishes. However, understanding temporal variation in elemental fingerprints at different scales is important as it can potentially confound spatial discrimination among estuaries. Otolith elemental ratios (Li:Ca, Mg:Ca, Mn:Ca, Cu:Ca, Sr:Ca, Ba:Ca and Pb:Ca) of Platichthys flesus and Dicentrarchus labrax, from several estuaries along the Portuguese coast in two years and three seasons (spring, summer and autumn) within a year, were determined via Laser Ablation Inductively Coupled Plasma Mass Spectrometry. Elemental fingerprints varied significantly among years and seasons within a year but we achieved accurate classifications of juvenile Fish to Estuarine nursery of origin (77–96% overall cross-validated accuracy). Although elemental fingerprints were year-specific, variation among seasons did not hinder spatial discrimination. Estuarine fingerprints of pooled seasonal data were representative of the entire juvenile year class and attained high discrimination (77% and 80% overall cross-validated accuracy for flounder and sea bass, respectively). Incorporating seasonal variation resulted in up to an 11% increase in correct classification of individual estuaries, in comparison to seasons where accuracies were lowest. Overall, understanding the implications of temporal variations in otolith chemistry for spatial discrimination is key to establish baseline data for connectivity studies.

  • ecological quality assessment of transitional waters based on Fish assemblages in portuguese estuaries the Estuarine Fish assessment index efai
    Ecological Indicators, 2012
    Co-Authors: Henrique N Cabral, Catarina Goncalves, Rita Gamito, Vanessa F Fonseca, Jose Lino Costa, Karim Erzini, Jorge M S Goncalves, J Martins, Laura Rabelo Leite, J P Andrade
    Abstract:

    The assessment of water quality has changed markedly worldwide over the last years, especially in Europe due to the implementation of the Water Framework Directive. Fish was considered a key-element in this context and several Fish-based multi-metric indices have been proposed. In this study, we propose a multi-metric index, the Estuarine Fish Assessment Index (EFAI), developed for Portuguese estuaries, designed for the overall assessment of transitional waters, which could also be applied at the water body level within an estuary. The EFAI integrates seven metrics: species richness, percentage of marine migrants, number of species and abundance of Estuarine resident species, number of species and abundance of piscivorous species, status of diadromous species, status of introduced species and status of disturbance sensitive species. Fish sampling surveys were conducted in 2006, 2009 and 2010, using beam trawl, in 13 Estuarine systems along the Portuguese coast. Most of the metrics presented a high variability among the transitional systems surveyed. According to the EFAI values, Portuguese estuaries presented a “Good” water quality status (except the Douro in a particular year). The assessments in different years were generally concordant, with a few exceptions. The relationship between the EFAI and the Anthropogenic Pressure Index (API) was not significant, but a negative and significant correlation was registered between the EFAI and the expert judgement pressure index, at both estuary and water body level. The ordination analysis performed to evaluate similarities among North-East Atlantic Geographical Intercalibration Group (NEAGIG) Fish-based indices put in evidence four main groups: the French index, since it is substantially different from all the other indices (uses only four metrics based on densities); indices from Ireland, United Kingdom and Spain (Asturias and Cantabria); the Dutch and German indices; and the indices of Belgium, Portugal and Spain (Basque country). The need for detailed studies, including comparative approaches, on several aspects of these assessment tools, especially in what regards their response to anthropogenic pressures was stressed.

  • inter and intra Estuarine Fish assemblage variability patterns along the portuguese coast
    Estuarine Coastal and Shelf Science, 2011
    Co-Authors: Susana Franca, Marco Costa, Henrique N Cabral
    Abstract:

    Abstract Estuaries along the Portuguese coast differ considerably in terms of their structure, geomorphologic and hydrologic characteristics. They play an important ecological role for different Fish species, namely acting as important nursery areas. The Fish assemblages of nine estuaries of the Portuguese coast were investigated in order to evaluate their main inter- and intra-Estuarine variability patterns. Fish sampling surveys were conducted in May and July 2006, covering the full Estuarine gradient. The different saline areas in each estuary were mapped using a Geographic Information System and Fish assemblages’ were described and compared using a functional guilds approach. Generalized linear models were used to relate Fish species richness to geomorphologic, hydrologic and environmental characteristics of the estuaries considered and correspondence analyses were performed to evaluate similarities in Fish assemblages’ structure. At a large scale, river flow was the most important factor explaining the variability in species richness in estuaries along the Portuguese coast. At a regional scale, different abiotic factors explained the occurrence and abundance of Fish species in the estuaries. Nonetheless, the overall role of the estuary was strongly related with the dominant saline zone within each estuary.

  • efficacy of adapted Estuarine Fish based multimetric indices as tools for evaluating ecological status of the marine environment
    Marine Pollution Bulletin, 2008
    Co-Authors: Sofia Henriques, Miguel Pessanha Pais, Maria Jose Costa, Henrique N Cabral
    Abstract:

    The assessment of ecological status of marine Fish communities required by the marine strategy framework directive (MSFD) emphasises the need for Fish-based ecological indices in marine waters. In this study we adapt five Estuarine multimetric indices to the marine environment and apply them in three types of substrates, analysing the metrics responsible for the obtained patterns of ecological status. The results show inefficiency of the community degradation index (CDI) and the biological health index (BHI) in ecological status assessment and disagreement between the Estuarine biotic integrity index (EBI), the Estuarine Fish community index (EFCI) and the transitional Fish classification index (TFCI). Analysis of individual metrics suggests lack of representativeness and consideration for the particularities of each substrate's typical Fish communities. None of the tested indices were efficient on the marine environment, urging the need for new marine indices that account for differences between types of substrate and depth.

Jo Ann M. Burkholder - One of the best experts on this subject based on the ideXlab platform.

  • Re-evaluation of the Relationship between Pfiesteria and Estuarine Fish Kills
    Ecosystems, 2003
    Co-Authors: Cavell Brownie, Jo Ann M. Burkholder, Robert E. Reed, Yongqiang Tang
    Abstract:

    In recent years, Fish kills along the mid-Atlantic US coast have become an increasing problem, with important economic, environmental, and public health implications (Glasgow and others 1995; Burkholder 1998; Grattan and others 1998; Haselow and others 2001; Shoemaker and Hudnell 2001). Research into the causes of these Fish kills is ongoing, and monitoring and surveillance programs have been instituted to investigate (among other factors) the role of actively toxic forms of two known species within the dinoflagellate genus Pfiesteria (Burkholder and others 1995, 2001a; Steidinger and others 1996; Burkholder and Glasgow 1997; Glasgow and others 2001b). In their recent analyses of the relationship between Pfiesteria and Fish kills, Burkholder and others (1999) and Stow (1999) stated, as others have noted previously (Meyer and Barclay 1990), that it is difficult to establish the causes of Estuarine Fish kills at the ecosystem level. The evaluation of Burkholder and others (1999) was based on the biology and toxic behavior of Pfiesteria, as well as empirical sampling of field Fish kill events then in progress, as supported by laboratory analyses of samples collected from each Fish kill. In contrast, Stow (1999) conducted theoretical probability calculations and argued that information demonstrating the presence of toxic Pfiesteria during Fish kills was insufficient to prove that there was a cause-and-effect

  • field ecology of toxic pfiesteria complex species and a conservative analysis of their role in Estuarine Fish kills
    Environmental Health Perspectives, 2001
    Co-Authors: Jo Ann M. Burkholder, Michael A Mallin, Nora J Deamermelia, Robert E. Reed
    Abstract:

    Within the past decade, toxic Pfiesteria outbreaks have been documented in poorly flushed, eutrophic areas of the largest and second largest estuaries on the U.S. mainland. Here we summarize a decadal field effort in Fish kill assessment, encompassing kills related to Pfiesteria (49 major kills in North Carolina estuaries since 1991 and 4 in Maryland estuaries in 1997) and to other factors such as low oxygen stress (79 major Fish kills in North Carolina estuaries). The laboratory and field data considered in developing our protocols are described, including toxic Pfiesteria behavior, environmental conditions conducive to toxic Pfiesteria activity, and impacts of toxic clonal Pfiesteria on Fish health. We outline the steps of the standardized Fish bioassay procedure that has been used since 1991 to diagnose whether actively toxic Pfiesteria was present during Estuarine Fish kills. Detailed data are given for a 1998 toxic Pfiesteria outbreak in the Neuse Estuary in North Carolina to illustrate of the full suite of diagnostic steps completed. We demonstrate that our conservative approach in implicating toxic Pfiesteria involvement in Fish kills has biased in favor of causes other than Pfiesteria. Data are summarized from experiments that have shown stimulation of toxic Pfiesteria strains by nutrient (N, P) enrichment, supporting field observations of highest abundance of toxic strains in eutrophic estuaries. On the basis of a decade of research on toxic Pfiesteria, we present a conceptual model of the seasonal dynamics of toxic strains as affected by changing food resources and weather patterns. We also recommend protocols and research approaches that will strengthen the science of Fish kill assessment related to Pfiesteria and/or other causative factors.

  • novel toxic dinoflagellate causes epidemic disease in Estuarine Fish
    Marine Pollution Bulletin, 1996
    Co-Authors: Edward J Noga, L Khoo, J B Stevens, Z Fan, Jo Ann M. Burkholder
    Abstract:

    A newly discovered dinoflagellate is responsible for major Fish kills in US Atlantic Coast estuaries. We report that exposure to this dinoflagellate also causes skin ulcers in Fish. Skin damage begins as epithelial erosion, which progresses to complete epithelial loss. Fish that recover from acute toxin exposure develop bacterial and/or fungal-infected skin ulcers that are typical of many spontaneous skin ulcer epidemics occurring in Estuarine Fish species along the Atlantic Coast of the US. Our data provide the first direct cause-and-effect link between a specific environmental stressor and a naturally-occurring, infectious disease in a Fishery population.

  • new phantom dinoflagellate is the causative agent of major Estuarine Fish kills
    Nature, 1992
    Co-Authors: Jo Ann M. Burkholder, Edward J Noga, Cecil H Hobbs, Howard B Glasgow
    Abstract:

    A WORLDWIDE increase in toxic phytoplankton blooms over the past 20 years1,2 has coincided with increasing reports of Fish diseases and deaths of unknown cause3. Among estuaries that have been repeatedly associated with unexplained Fish kills on the western Atlantic Coast are the Pamlico and Neuse Estuaries of the southeastern United States4. Here we describe a new toxic dinoflagellate with 'phantom-like' behaviour that has been iden-tified as the causative agent of a significant portion of the Fish kills in these estuaries, and which may also be active in other geographic regions. The alga requires live finFish or their fresh excreta for excystment and release of a potent toxin. Low cell densities cause neurotoxic signs and Fish death, followed by rapid algal encystment and dormancy unless live Fish are added. This dinoflagellate was abundant in the water during major Fish kills in local estuaries, but only while Fish were dying; within several hours of death where carcasses were still present, the flagellated vegetative algal population had encysted and settled back to the sediments. Isolates from each event were highly lethal to finFish and shellFish in laboratory bioassays. Given its broad temperature and salinity tolerance, and its stimulation by phosphate enrichment, this toxic phytoplankter may be a widespread but undetected source of Fish mortality in nutrient-enriched estuaries.

Tavis K Anderson - One of the best experts on this subject based on the ideXlab platform.

  • life cycle mediated effects of urbanization on parasite communities in the Estuarine Fish fundulus heteroclitus
    PLOS ONE, 2019
    Co-Authors: James M Alfieri, Tavis K Anderson
    Abstract:

    This study examined the relationship between urbanization and parasite community structure in the Estuarine Fish, Fundulus heteroclitus. We measured landscape and physicochemical factors associated with urbanization at 6 sites from 4 collection periods. Concurrently, we quantified the metazoan parasite community in F. heteroclitus collected at those sites, with 105 Fish studied per site during the 4 collection periods. Parasite community composition differed among sites. Host size was the most important variable for direct life-cycle parasite assemblages and indirect life-cycle parasites at the individual Fish level, while landscape and physicochemical factors determined the structure of indirect life-cycle parasite assemblages at the population scale. Variation in the prevalence and intensity of infection of two indirect life-cycle parasites, Lasiocotus minutus and Glossocercus caribaensis, were the primary parasites that drove differences across sites. Variation in the presence/absence of these indirect life-cycle parasite species was associated with sediment Ni concentrations, patch density, and marsh size. Our data support the hypothesis that urbanization, acting at both landscape and physicochemical scales, can have a significant impact on parasite community structure. This, however, varied by parasite life history: there was little effect of urbanization on the prevalence and intensity of direct life-cycle parasites, but significant variation was detected for indirect life-cycle parasites. This study demonstrates how anthropogenically driven landscape change influences fine-scale population dynamics of parasites.

  • life cycle mediated effects of urbanization on parasite communities in the Estuarine Fish fundulus heteroclitus
    bioRxiv, 2019
    Co-Authors: James M Alfieri, Tavis K Anderson
    Abstract:

    This study examined the relationship between urbanization and parasite community structure in the Estuarine Fish, Fundulus heteroclitus. We measured landscape and physicochemical factors associated with urbanization at 6 sites from 4 collection periods. Concurrently, we quantified the metazoan parasite community in Fundulus heteroclitus collected at those sites, with 105 Fish studied per site during the 4 collection periods. Parasite community composition differed between sites. Variation in the prevalence and intensity of infection of two indirect life-cycle parasites, Lasiocotus minutus and Glossocercus caribaensis, were the primary parasite species that determined this pattern. Sediment potassium and aquatic osmium were the most important physicochemical factors in structuring parasite communities, and habitat dominance was the most important landscape factor. Our data supports the hypothesis that urbanization, acting at both landscape and physicochemical scales, can have a significant impact on parasite community structure. This, however, varied by parasite life history: there was little effect of urbanization on the prevalence and intensity of direct life-cycle parasites, but significant variation was dedicated for indirect life-cycle parasites. This study demonstrates how anthropogenically driven landscape change influences fine-scale parasite population dynamics.

Nann A Fangue - One of the best experts on this subject based on the ideXlab platform.

  • divergent transcriptomic signatures in response to salinity exposure in two populations of an Estuarine Fish
    Evolutionary Applications, 2019
    Co-Authors: Ken M Jeffries, Richard E Connon, Christine E Verhille, Theresa F Dabruzzi, Monica Britton, Blythe Durbinjohnson, Nann A Fangue
    Abstract:

    In estuary and coastal systems, human demand for freshwater, climate change-driven precipitation variability, and extreme weather impact salinity levels, reducing connectivity between mesohaline coastal Fish populations and potentially contributing to genomic divergence. We examined gill transcriptome responses to salinity in wild-caught juveniles from two populations of Sacramento splittail (Pogonichthys macrolepidotus), a species of conservation concern that is endemic to the San Francisco Estuary, USA, and the lower reaches of its tributaries. Recent extreme droughts have led to salinities above the tolerance limits for this species, creating a migration barrier between these populations, which potentially contributed to population divergence. We identified transcripts involved in a conserved response to salinity; however, the more salinity-tolerant San Pablo population had greater transcriptome plasticity (3.6-fold more transcripts responded than the Central Valley population) and a response consistent with gill remodeling after 168 hr of exposure to elevated salinity. The reorganization of the gill in response to changing osmotic gradients is a process critical for acclimation and would facilitate enhanced salinity tolerance. We detected an upregulation of receptors that control the Wnt (wingless-type) cell signaling pathway that may be required for an adaptive response to increases in salinity, patterns not observed in the relatively salinity-sensitive Central Valley population. We detected 62 single nucleotide polymorphisms (SNPs) in coding regions of 26 transcripts that differed between the populations. Eight transcripts that contained SNPs were associated with immune responses, highlighting the importance of diversity in immune gene sequences as a defining characteristic of genomic divergence between these populations. Our data demonstrate that these populations have divergent transcriptomic responses to salinity, which is consistent with observed physiological differences in salinity tolerance.

  • multiple sub lethal thresholds for cellular responses to thermal stressors in an Estuarine Fish
    Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2018
    Co-Authors: Ken M Jeffries, Nann A Fangue, Richard E Connon
    Abstract:

    Abstract Understanding physiological limits and the ability to acclimatize to changing conditions will determine whether species will be able to cope with further increases in water temperature. Changes in temperature may be considered to become stressful for an ectotherm when it results in reduced performance, which can lead to fitness level consequences. The relative intensity of the stressor as well as the duration of the exposure to the stressor will determine the response observed. Transcriptomic responses can potentially indicate thresholds where physiological performance begins to decline. An understanding of the cellular shifts throughout the temperature range that an organism experiences in the wild is often lacking, especially for species of conservation concern such as the delta smelt (Hypomesus transpacificus). We examined the expression of 15 genes that represented cellular responses related to stress, growth, cell proliferation and osmoregulation to show how the response patterns change to acute increases in temperatures that occur throughout the thermal distribution of the species. Several genes showed U-shaped or inverted U-shaped response patterns suggesting the presence of sub-lethal thresholds as temperatures increase. We also highlight the importance of including a temporal component to exposure studies as several genes showed a delay in the recovery to control levels at extreme temperatures. We propose that the non-linear response patterns represent sub-lethal thermal thresholds that can predict the severity of the response to thermal stressors. Identifying these sub-lethal thresholds can help differentiate between responses to routine increases in water temperature and responses that can lead to longer-term fitness impacts.

  • foraging and metabolic consequences of semi anadromy for an endangered Estuarine Fish
    PLOS ONE, 2017
    Co-Authors: Bruce G Hammock, Steven B Slater, Nann A Fangue, Randall D Baxter, Dennis E Cocherell, April Hennessy, Tomofumi Kurobe, Christopher Y Tai, Swee J Teh
    Abstract:

    Diadromy affords Fish access to productive ecosystems, increasing growth and ultimately fitness, but it is unclear whether these advantages persist for species migrating within highly altered habitat. Here, we compared the foraging success of wild Delta Smelt-an endangered, zooplanktivorous, annual, semi-anadromous Fish that is endemic to the highly altered San Francisco Estuary (SFE)-collected from freshwater (<0.55 psu) and brackish habitat (≥0.55 psu). Stomach fullness, averaged across three generations of wild Delta Smelt sampled from juvenile through adult life stages (n = 1,318), was 1.5-fold higher in brackish than in freshwater habitat. However, salinity and season interacted, with higher fullness (1.7-fold) in freshwater than in brackish habitat in summer, but far higher fullness in brackish than freshwater habitat during fall/winter and winter/spring (1.8 and 2.0-fold, respectively). To examine potential causes of this interaction we compared mesozooplankton abundance, collected concurrently with the Delta Smelt, in freshwater and brackish habitat during summer and fall/winter, and the metabolic rate of sub-adult Delta Smelt acclimated to salinities of 0.4, 2.0, and 12.0 psu in a laboratory experiment. A seasonal peak in mesozooplankton density coincided with the summer peak in Delta Smelt foraging success in freshwater, and a pronounced decline in freshwater mesozooplankton abundance in the fall coincided with declining stomach fullness, which persisted for the remainder of the year (fall, winter and spring). In brackish habitat, greater foraging 'efficiency' (prey items in stomachs/mesozooplankton abundance) led to more prey items per Fish and generally higher stomach fullness (i.e., a higher proportion of mesozooplankton detected in concurrent trawls were eaten by Fish in brackish habitat). Delta Smelt exhibited no difference in metabolic rate across the three salinities, indicating that metabolic responses to salinity are unlikely to have caused the stomach fullness results. Adult migration and freshwater spawning therefore places young Fish in a position to exploit higher densities of prey in freshwater in the late spring/summer, and subsequent movement downstream provides older Fish more accessible prey in brackish habitat. Thus, despite endemism to a highly-altered estuary, semi-anadromy provided substantial foraging benefits to Delta Smelt, consistent with other temperate migratory Fish.

  • sublethal salinity stress contributes to habitat limitation in an endangered Estuarine Fish
    Evolutionary Applications, 2016
    Co-Authors: Lisa M Komoroske, Ken M Jeffries, Richard E Connon, Jason Dexter, Matthias Hasenbein, Christine E Verhille, Nann A Fangue
    Abstract:

    As global change alters multiple environmental conditions, predicting species' responses can be challenging without understanding how each environmental factor influences organismal performance. Approaches quantifying mechanistic relationships can greatly complement correlative field data, strengthening our abilities to forecast global change impacts. Substantial salinity increases are projected in the San Francisco Estuary, California, due to anthropogenic water diversion and climatic changes, where the critically endangered delta smelt (Hypomesus transpacificus) largely occurs in a low-salinity zone (LSZ), despite their ability to tolerate a much broader salinity range. In this study, we combined molecular and organismal measures to quantify the physiological mechanisms and sublethal responses involved in coping with salinity changes. Delta smelt utilize a suite of conserved molecular mechanisms to rapidly adjust their osmoregulatory physiology in response to salinity changes in Estuarine environments. However, these responses can be energetically expensive, and delta smelt body condition was reduced at high salinities. Thus, acclimating to salinities outside the LSZ could impose energetic costs that constrain delta smelt's ability to exploit these habitats. By integrating data across biological levels, we provide key insight into the mechanistic relationships contributing to phenotypic plasticity and distribution limitations and advance the understanding of the molecular osmoregulatory responses in nonmodel Estuarine Fishes.

  • coupled downscaled climate models and ecophysiological metrics forecast habitat compression for an endangered Estuarine Fish
    PLOS ONE, 2016
    Co-Authors: Larry R Brown, Lisa M Komoroske, Richard E Connon, Wayne R Wagner, Tara Morganking, Jason T May, Nann A Fangue
    Abstract:

    Climate change is driving rapid changes in environmental conditions and affecting population and species' persistence across spatial and temporal scales. Integrating climate change assessments into biological resource management, such as conserving endangered species, is a substantial challenge, partly due to a mismatch between global climate forecasts and local or regional conservation planning. Here, we demonstrate how outputs of global climate change models can be downscaled to the watershed scale, and then coupled with ecophysiological metrics to assess climate change effects on organisms of conservation concern. We employed models to estimate future water temperatures (2010-2099) under several climate change scenarios within the large heterogeneous San Francisco Estuary. We then assessed the warming effects on the endangered, endemic Delta Smelt, Hypomesus transpacificus, by integrating localized projected water temperatures with thermal sensitivity metrics (tolerance, spawning and maturation windows, and sublethal stress thresholds) across life stages. Lethal temperatures occurred under several scenarios, but sublethal effects resulting from chronic stressful temperatures were more common across the estuary (median >60 days above threshold for >50% locations by the end of the century). Behavioral avoidance of such stressful temperatures would make a large portion of the potential range of Delta Smelt unavailable during the summer and fall. Since Delta Smelt are not likely to migrate to other estuaries, these changes are likely to result in substantial habitat compression. Additionally, the Delta Smelt maturation window was shortened by 18-85 days, revealing cumulative effects of stressful summer and fall temperatures with early initiation of spring spawning that may negatively impact fitness. Our findings highlight the value of integrating sublethal thresholds, life history, and in situ thermal heterogeneity into global change impact assessments. As downscaled climate models are becoming widely available, we conclude that similar assessments at management-relevant scales will improve the scientific basis for resource management decisions.

Angelo F Bernardino - One of the best experts on this subject based on the ideXlab platform.

  • contamination and oxidative stress biomarkers in Estuarine Fish following a mine tailing disaster
    PeerJ, 2020
    Co-Authors: Fabricio â Gabriel, Rachel Ann Hauserdavis, Lorena Oliveira Souza Soares, Ana Carolina De Azevedo Mazzuco, Rafael Christian Chavez Rocha, Tatiana Saint D Pierre, Enrico Mendes Saggioro, Fabio Verissimo Correia, Tiago Osorio Ferreira, Angelo F Bernardino
    Abstract:

    Background: The Rio Doce estuary, in Brazil, was impacted by the deposition of iron mine tailings, caused by the collapse of a dam in 2015. Based on published baseline datasets, the estuary has been experiencing chronic trace metal contamination effects since 2017, with potential bioaccumulation in Fishes and human health risks. As metal and metalloid concentrations in aquatic ecosystems pose severe threats to the aquatic biota, we hypothesized that the trace metals in Estuarine sediments nearly two years after the disaster would lead to bioaccumulation in demersal Fishes and result in the biosynthesis of metal-responsive proteins. Methods: We measured As, Cd, Cr, Cu, Fe, Mn, Pb, Se and Zn concentrations in sediment samples in August 2017 and compared to published baseline levels. Also, trace metals (As, Cd, Cr, Cu, Fe, Hg, Mn, Pb, Se and Zn) and protein (metallothionein and reduced glutathione) concentrations were quantified in the liver and muscle tissues of five Fish species (Cathorops spixii, Genidens genidens, Eugerres brasilianus, Diapterus rhombeus and Mugil sp.) from the estuary, commonly used as food sources by local populations. Results: Our results revealed high trace metal concentrations in Estuarine sediments, when compared to published baseline values for the same estuary. The demersal Fish species C. spixii and G. genidens had the highest concentrations of As, Cr, Mn, Hg, and Se in both, hepatic and muscle, tissues. Trace metal bioaccumulation in Fish was correlated with the biosynthesis of metallothionein and reduced glutathione in both, liver and muscle, tissues, suggesting active physiological responses to contamination sources. The trace metal concentrations determined in Fish tissues were also present in the Estuarine sediments at the time of this study. Some elements had concentrations above the maximum permissible limits for human consumption in Fish muscles (e.g., As, Cr, Mn, Se and Zn), suggesting potential human health risks that require further studies. Our study supports the high biogeochemical mobility of toxic elements between sediments and the bottom-dwelling biota in Estuarine ecosystems.

  • metal contamination and oxidative stress biomarkers in Estuarine Fish following a mine tailing disaster
    bioRxiv, 2020
    Co-Authors: Fabricio â Gabriel, Rachel Ann Hauserdavis, Lorena Oliveira Souza Soares, Ana Carolina De Azevedo Mazzuco, Rafael Christian Chavez Rocha, Tatiana Saint D Pierre, Enrico Mendes Saggioro, Fabio Verissimo Correia, Tiago Osorio Ferreira, Angelo F Bernardino
    Abstract:

    The Rio Doce estuary in Brazil was impacted by the deposition of mine tailings caused by the collapse of a mining dam in 2015. Since the disaster, the estuary is experiencing chronic trace metal contamination effects, but potential trace metal accumulation in Fishes has not been reported. Trace metals in aquatic ecosystems pose severe threats to the aquatic biota, so we hypothesized that the accumulation of trace metals in Estuarine sediments nearly two years after the disaster would cause contaminant bioaccumulation, resulting in the biosynthesis of metal-responsive proteins in Fishes. We determined trace metal concentrations in sediment samples, metal concentrations, and quantified stress protein concentrations in the liver and muscle tissue of five different Fish species in the estuary. Our results revealed high concentrations of trace metals in Estuarine sediments when compared to published baseline values for this estuary. The demersal Fish species Cathorops spixii and Genidens genidens had the highest Hg, As, Se, Cr, and Mn concentrations in both hepatic and muscle tissues. Metal bioaccumulation in Fish was statistically correlated with the biosynthesis of metallothionein and reduced glutathione in both Fish liver and muscle tissue. The trace metals detected in Fish tissues resemble those in the contaminated sediments present at the estuary at the time of this study and were also significantly correlated to protein levels. Trace metals in Fish muscle were above the maximum permissible limits for human consumption, suggesting potential human health risks that require further determination. Our study supports the high biogeochemical mobility of trace metals between contaminated sediments and local biota in Estuarine ecosystems.