Top predators such as most shark species are extremely vulnerable to amassing high concentrations of contaminants, but not much is known about the effects that the contaminant body burden imparts on these animals. Species like the blue shark (Prionace glauca) are very relevant in this regard, as they have high ecological and socioeconomic value, and have the potential to act as bioindicators of pollution. This work aimed to assess if differences in contaminant body burden found in blue sharks from the Northeast Atlantic would translate into differences in stress responses.
View Article and Find Full Text PDFChemical pollution is a major threat to marine ecosystems, and top predators such as most shark species are extremely vulnerable to being exposed and accumulating contaminants such as metals and persistent organic pollutants (POPs). This work aimed to study the degree, composition, and the sources of contamination in the blue shark (Prionace glauca) inhabiting the Northeast Atlantic, as well as the potential risk faced by human consumers. A total of 60 sharks were sampled in situ aboard fishing vessels, and the concentrations of a set of metals and POPs were analysed in various tissues and complemented with stable isotope analyses.
View Article and Find Full Text PDFBioindicator species are increasingly valuable in environmental pollution monitoring, and elasmobranch species include many suitable candidates for that role. By measuring contaminants and employing biomarkers of effect in relevant elasmobranch species, scientists may gain important insights about the impacts of pollution in marine ecosystems. This review compiles biomarkers applied in elasmobranchs to assess the effect of pollutants (e.
View Article and Find Full Text PDFThe assessment of contaminant exposure in marine organisms often focuses on the most toxic chemical elements from upper trophic level species. Information on mid-trophic level species and particularly on potentially less harmful elements is lacking. Additionally, microplastics have been considered emergent contaminants in aquatic environments which have not been extensively studied in species from mid-trophic levels in food chains.
View Article and Find Full Text PDFMultidisciplinary approaches are essential to diligently assess environmental health status of ecosystems. In this study, year-round chemical elements' exposure and impacts were assessed on the wide-ranging Cory's shearwater Calonectris borealis breeding in Berlenga Island, offshore Portugal, North Atlantic Ocean. The aim was to identify potential contamination and oxidative stress sources associated with trophic ecology, habitat and spatial use, and foraging patterns.
View Article and Find Full Text PDFOne of the most landed sharks in Portuguese fisheries is the lesser-spotted dogfish (Scyliorhinus canicula), which is ever-present in Portuguese fish markets and consumed as cheap fish protein source. The focus of this study was to evaluate element contamination in consumed tissues of Atlantic S. canicula, with the intent of safeguarding possible public health issues.
View Article and Find Full Text PDFMetal pollution is currently a major issue in marine ecosystems, as organisms, and particularly seabirds, are exposed and accumulating increased levels from several anthropogenic sources. A set of 13 metals were quantified in two gull species breeding in sympatry, and in two distinct colonies separated by ca. 400 km.
View Article and Find Full Text PDFThe notion that thermal specialists from tropical regions live closer to their temperature limits than temperate eurytherms, seems too generalized. Species specific differences in physiological and biochemical stress reactions are linked to key components of organism fitness, like metabolic capacity, which indicates that acclimation potential across latitudes might be highly diverse rather than simplistic. In this study the exposure of a tropical (Holothuria scabra) and a temperate (Holothuria forskali) sea cucumber species to identical cold- and warm-acclimation stress was compared using the key metabolic parameters, respiration rate, enzyme activity (ETS, LDH, IDH), and energy reserve fractions (lipid, carbohydrate and protein).
View Article and Find Full Text PDFComp Biochem Physiol C Toxicol Pharmacol
November 2019
Inhibition of acetylcholinesterase (AChE) activity has been widely used to assess the exposure and effects of anticholinergic environmental contaminants in several species. The aim of this study was to investigate if sublethal concentrations of the organophosphorous pesticide chlorpyrifos (CPF), a well-known AChE inhibitor, would also affect cholinesterases (ChE) in Gibbula umbilicalis and if this inhibition would result in an alteration of its behaviour, in an attempt to link the effects observed at the cellular level with effects at higher levels of ecological relevance. The biochemical properties of ChEs in this species were first characterized through the assessment of different enzymatic forms present in the sea snail, using different substrates and selective inhibitors.
View Article and Find Full Text PDFComp Biochem Physiol C Toxicol Pharmacol
December 2017
The present study evaluated the effects of exposure to different target pCO levels: control (C: 370μatm, pH=8.15) and ocean acidification (OA: 710μatm, pH=7.85) on development and biochemical responses related with oxidative stress and energy metabolism during the crustacean Homarus gammarus (L.
View Article and Find Full Text PDFHolothuria scabra is the most valued and cultured tropical sea cucumber, given the great demand of this species for human consumption. However, despite its ecological and economic relevance, little is known regarding its immune responses under thermal stress. Here, the main goal was to study the response of sea cucumbers to temperature stress, assessing sub-organismal alterations and acclimation capacities of juveniles to temperature changes.
View Article and Find Full Text PDFMarine ecosystems are constantly being threatened by contaminants produced by human activities. There is an urge to better understand their impacts on marine organisms and develop reliable tools for biomonitoring studies, while also assessing their potential impacts on human health. Given their position on top of food webs, sharks are particularly susceptible to bioaccumulation, making them potential sentinel species of marine contamination.
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