Valor nutricional de algumas espécies consumidas em Portugal

Dissertação de mest., Biologia Marinha, Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve, 2009Neste estudo avaliou-se o valor nutricional de cinco espécies de peixe consumidas em Portugal – a perca do Nilo, uma espécie de água doce importada, e o robalo, pregado, sargo e corvina, quatro espécies produzidas em aquicultura. Os resultados revelaram que o pescado produzido em aquicultura apresenta teores de gordura e em ácidos gordos ω6 mais elevados do que algumas espécies selvagens, que decorrem da composição das rações fornecidas. Pretendeu-se, também, conhecer o efeito de alguns tratamentos culinários na composição química, tendo-se observado a perda de água e a consequente concentração de todos os outros nutrientes ao nível do músculo. Este trabalho permitiu verificar que a grelhagem e cozedura constituem duas alternativas saudáveis de confecção, visto que o consumo de 150 g das espécies consideradas fornece mais de 100 % da dose diária recomendada de ácidos gordos ω3 e teores apreciáveis de EPA+DHA constituindo, simultaneamente, uma refeição hipocalórica e com baixos níveis de colesterol

Climate change and emerging chemical contaminants in marine organisms: Bioaccumulation, ecotoxicology and public health impacts

Chemical contamination and climate change constitute two of the greatest environmental problems related with the increase of anthropogenic activities. Despite both factors acting alone can have negative effects at different levels of biological organization, as well as in seafood safety, the underlying interactions between them are still poorly understood. In this context, this PhD thesis aimed to assess the combined effects of seawater warming and/or acidification on the bioaccumulation of different emerging chemical contaminants (ECCs; MeHg, iAs, DCF, VFX, TCS, Decs, TBBPA, PFOS e PFOA) and ecotoxicological responses of two marine taxonomic groups (fish and bivalves). Overall, warming promoted the bioaccumulation of lipophilic and persistent ECCs (e.g. MeHg, Decs and TBBPA), suggesting increased risks of human exposure to these compounds through the consumption of contaminated seafood in tomorrow’s ocean. Conversely, warming and/or acidification elicited lower bioaccumulation of ionisable and/or less persistent compounds (e.g. iAs, VFX and TCS). Yet, this trend may not necessarily represent lower human risks, as it may be associated with enhanced biotransformation of parental ECCs, potentially representing increased levels of metabolites for which the toxicological attributes (to both biota and humans) are still unknown. Regarding the ecotoxicological effects, overall, the simultaneous exposure to ECCs, warming and acidification promoted more severe responses (at the biochemical, animal condition and behavioural levels) than the ones elicited when each stressor acted in isolation. Such results reveal that the exposure to ECCs in a climate change context will likely defy the resilience of marine organisms, particularly those inhabiting coastal areas. Hence, climate change will greatly challenge the sustainability and management of fisheries and aquaculture resources, thus, calling for urgent regulatory, mitigation and/or adaptive actions at a global scale

Paralytic shellfish toxins and ocean warming: bioaccumulation and ecotoxicological responses in jujvenile Gilthead Seabream (Sparus aurata)

Warmer seawater temperatures are expected to increase harmful algal blooms (HABs) occurrence, intensity, and distribution. Yet, the potential interactions between abiotic stressors and HABs are still poorly understood from ecological and seafood safety perspectives. The present study aimed to investigate, for the first time, the bioaccumulation/depuration mechanisms and ecotoxicological responses of juvenile gilthead seabream (Sparus aurata) exposed to paralytic shellfish toxins (PST) under different temperatures (18, 21, 24 °C). PST were detected in fish at the peak of the exposure period (day five, 0.22 µg g-1 N-sulfocarbamoylGonyautoxin-1-2 (C1 and C2), 0.08 µg g-1 Decarbamoylsaxitoxin (dcSTX) and 0.18 µg g-1 Gonyautoxin-5 (B1)), being rapidly eliminated (within the first 24 h of depuration), regardless of exposure temperature. Increased temperatures led to significantly higher PST contamination (275 µg STX eq. kg-1). During the trial, fish antioxidant enzyme activities (superoxide dismutase, SOD; catalase, CAT; glutathione S-transferase, GST) in both muscle and viscera were affected by temperature, whereas a significant induction of heat shock proteins (HSP70), Ubiquitin (Ub) activity (viscera), and lipid peroxidation (LPO; muscle) was observed under the combination of warming and PST exposure. The differential bioaccumulation and biomarker responses observed highlight the need to further understand the interactive effects between PST and abiotic stressors, to better estimate climate change impacts on HABs events, and to develop mitigation strategies to overcome the potential risks associated with seafood consumption.Agência financiadora European Union (EU) 678193 Portuguese Foundation for Science and Technology (FCT) IF/00253/2014 CEECIND/01739/2017 UID/Multi/04326/2019info:eu-repo/semantics/publishedVersio

Impact of a simulated marine heatwave in the hematological profile of a temperate shark (Scyliorhinus canicula)

As Earth's temperature continues to rise, sudden warming events, designated as marine heatwaves (MHWs), are becoming more frequent and longer. This phenomenon is already shown to significantly impact marine ecosystems and respective fauna. While experimental acclimation to higher temperatures is known to affect predatory behavior, metabolism and overall fitness of sharks, the effects of short-term exposure to high temperatures on sharks’ physiology has yet to be investigated in a MHW context. Thus, the aim of our work was to study the impact of a category II MHW (Δ3 °C, 15 days) on: i) hematological parameters (total erythrocytes, leukocytes, thrombocytes, erythrocyte nuclear abnormalities (ENAs) counts, and nucleus to cytoplasmic ratio), ii) heart and spleen to body ratios, and iii) ventilation rates of juvenile catsharks (Scyliorhinus canicula). We found that MHW exposure led to significant changes in normal blood cell counts, by lowering erythrocyte counts and nucleus to cytoplasm ratio, and increasing leukocyte and thrombocyte counts. Moreover, ventilation rates increased consistently over the course of the MHW. However, there were no changes regarding the presence of ENA, as well as spleen and heart to body ratios. Our findings indicate limited capabilities for coping with sudden warming events, suggesting potential disruption in shark physiological homeostasis as the frequency, duration and intensity of MHWs are expected to be strengthened.publishersversionpublishe

Impacts of ocean warming and acidification on the energy budget of three commercially important fish species

Funding This study was supported by the project FISHBUDGET -Effects of climate change on marine fish energy budgets (PTDC/BIA-BMA/28630/2017) from the Portuguese Foundation for Science and Technology (FCT). FCT also supported the contract of Patrícia Anacleto in the framework of the CEECIND 2017 (CEECIND/01739/2017). Acknowledgments This study benefited from the strategic project UIDB/04292/2020 awarded to MARE and through project LA/P/0069/2020 granted to the Associate Laboratory ARNET funded by the FCT/Ministério da Ciência, Tecnologia e Ensino Superior (MCTES), and through other national funds (UIDB/50006/2020). The authors thank the Sparos, Lda company for providing the fish feed, and Olhão Pilot Fish Farming Station team (EPPO-IPMA) for providing the juvenile fish for trials. Publisher Copyright: © 2022 The Author(s). Published by Oxford University Press and the Society for Experimental Biology.A mechanistic model based on Dynamic Energy Budget (DEB) theory was developed to predict the combined effects of ocean warming, acidification and decreased food availability on growth and reproduction of three commercially important marine fish species: white seabream (Diplodus sargus), zebra seabream (Diplodus cervinus) and Senegalese sole (Solea senegalensis). Model simulations used a parameter set for each species, estimated by the Add-my-Pet method using data from laboratory experiments complemented with bibliographic sources. An acidification stress factor was added as a modifier of the somatic maintenance costs and estimated for each species to quantify the effect of a decrease in pH from 8.0 to 7.4 (white seabream) or 7.7 (zebra seabream and Senegalese sole). The model was used to project total length of individuals along their usual lifespan and number of eggs produced by an adult individual within one year, under different climate change scenarios for the end of the 21st century. For the Intergovernmental Panel on Climate Change SSP5-8.5, ocean warming led to higher growth rates during the first years of development, as well as an increase of 32-34% in egg production, for the three species. Ocean acidification contributed to reduced growth for white seabream and Senegalese sole and a small increase for zebra seabream, as well as a decrease in egg production of 48-52% and 14-33% for white seabream and Senegalese sole, respectively, and an increase of 4-5% for zebra seabream. The combined effect of ocean warming and acidification is strongly dependent on the decrease of food availability, which leads to significant reduction in growth and egg production. This is the first study to assess the combined effects of ocean warming and acidification using DEB models on fish, therefore, further research is needed for a better understanding of these climate change-related effects among different taxonomic groups and species.publishersversionpublishe

Seasonal occurrence and risk assessment of endocrine-disrupting compounds in Tagus estuary biota (NE Atlantic Ocean coast)

Funding Information: This work was supported by FEDER (Programa Operacional Competitividade e Internacionalização - COMPETE 2020), from PIDDAC through FCT/MCTES project POCI-01–0145-FEDER-028708-PTDC/ASP-PES/28708/2017 , by UIDB/50006/2020 and AgriFood XXI R&D&I project, operation No. NORTE-01–0145-FEDER-000041 , co-financed by the European Regional Development Fund ( ERDF ) through NORTH 2020 (Northern Regional Operational Program 2014/2020 ). Funding Information: Sara C. Cunha acknowledges FCT for IF/01616/2015 contract, IM acknowledges FCT for Ph.D. Grant DFA/BD/4413/2020 and PA acknowledges FCT for CEECIND/01739/2017 contract. Publisher Copyright: © 2022 The AuthorsEstuaries are continually threatened by anthropogenic pressures, consequently, a large group of contaminants harmful to human health affects the aquatic biota; therefore, it is necessary to monitor their quality. This study deals with the determination of a large group of compounds representing different endocrine-disrupting compounds (EDCs) classes [21 pesticides, 4 polycyclic musk fragrances, 4 UV-filters, 7 bisphenols, 6 polybrominated diphenyl ethers (PBDEs) and 8 of their methoxylated (MeO-BDEs)] in several estuarine species (fish, bivalves, crustaceans, earthworm, and macroalgae) collected seasonally along one year in two distinct areas of Tagus River estuary (“contaminated” vs. “clean” areas). The most abundant compounds found were galaxolide (HHCB) (81% positive samples; 0.04–74 ng/g ww), isoamyl 4-methoxycinnamate (IMC) (64%; 1.13–251 ng/g ww), alachlor (44%; 0.08–16 ng/g ww), and BDE-47 (36%; 0.06–2.26 ng/g ww). Polycyclic musks were the most frequent contaminants in fish (seabass, barbus, mullet, and sole) and macroalgae samples, while UV-filters were predominant in bivalves and crustaceans, and bisphenols in earthworms. Seasonal variation was verified for Σpesticides and Σmusks, with significantly higher levels in summer and autumn, whereas ΣUV-filters highest levels were found in spring and summer, and for ΣPBDEs statistically higher levels were registered in cold seasons (autumn and winter). Σbisphenols were significantly lower in spring than in the other seasons. In general, considering all species analysed in both areas, no statistically significant differences (p > 0.05) were verified between the two collection areas. Based on the estimated daily intake data, consumption of fish from this estuary is unlikely to be a human health concern, since the levels of contamination were below the toxicological threshold values. Overall, the data obtained in this study will allow regulatory authorities to identify and prioritize contaminants monitoring programs in estuaries, such as the case of bisphenol A, which was found, for the first time, in earthworm and clam species.publishersversionpublishe

Mercury in juvenile solea senegalensis: Linking bioaccumulation, seafood safety, and neuro-oxidative responses under climate change-related stressors

.Mercury (Hg) is globally recognized as a persistent chemical contaminant that accumulates in marine biota, thus constituting an ecological hazard, as well as a health risk to seafood consumers. Climate change-related stressors may influence the bioaccumulation, detoxification, and toxicity of chemical contaminants, such as Hg. Yet, the potential interactions between environmental stressors and contaminants, as well as their impacts on marine organisms and seafood safety, are still unclear. Hence, the aim of this work was to assess the bioaccumulation of Hg and neuro-oxidative responses on the commercial flat fish species Solea senegalensis (muscle, liver, and brain) co-exposed to dietary Hg in its most toxic form (i.e., MeHg), seawater warming (ΔT°C = +4 °C), and acidification (pCO2 = +1000 μatm, equivalent to ΔpH =-0.4 units). In general, fish liver exhibited the highest Hg concentration, followed by brain and muscle. Warming enhanced Hg bioaccumulation, whereas acidification decreased this element's levels. Neuro-oxidative responses to stressors were affected by both climate change-related stressors and Hg dietary exposure. Hazard quotient (HQ) estimations evidenced that human exposure to Hg through the consumption of fish species may be aggravated in tomorrow's ocean, thus raising concerns from the seafood safety perspective.publishersversionpublishe

Toxic elements and speciation in seafood samples from different contaminated sites in Europe

The presence of cadmium (Cd), lead (Pb), mercury (THg), methylmercury (MeHg), arsenic (TAs), inorganic arsenic (iAs), cobalt (Co), copper (Cu), zinc (Zn), nickel (Ni), chromium (Cr) and iron (Fe) was investigated in seafood collected from European marine ecosystems subjected to strong anthropogenic pressure, i.e. hotspot areas. Different species (Mytilus galloprovincialis, n=50; Chamelea gallina, n=50; Liza aurata, n=25; Platichthys flesus, n=25; Laminaria digitata, n=15; and Saccharina latissima, n=15) sampled in Tagus estuary, Po delta, Ebro delta, western Scheldt, and in the vicinities of a fish farm area (Solund, Norway), between September and December 2013, were selected to assess metal contamination and potential risks to seafood consumers, as well as to determine the suitability of ecologically distinct organisms as bioindicators in environmental monitoring studies. Species exhibited different elemental profiles, likely as a result of their ecological strategies, metabolism and levels in the environment (i.e. seawater and sediments). Higher levels of Cd (0.15–0.94 mg kg-1), Pb (0.37-0.89 mg kg-1), Co (0.48–1.1 mg kg-1), Cu (4.8–8.4 mg kg-1), Zn (75–153 mg kg-1), Cr (1.0–4.5 mg kg-1) and Fe (283–930 mg kg-1) were detected in bivalve species, particularly in M. galloprovincialis from Ebro and Po deltas, whereas the highest content of Hg was found in P. flesus (0.86 mg kg-1). In fish species, most Hg was organic (MeHg; from 69 to 79%), whereas lower proportions of MeHg were encountered in bivalve species (between 20 and 43%). The highest levels of As were found in macroalgae species L. digitata and S. latissima (41 mg kg-1 and 43 mg kg-1, respectively), with iAs accounting almost 50% of the total As content in L. digitata but not with S. latissima nor in the remaining seafood samples. This work highlights that the selection of the most appropriate bioindicator species is a fundamental step in environmental monitoring of each contaminant, especially in coastal areas. Furthermore, data clearly shows that the current risk assessment and legislation solely based on total As or Hg data is limiting, as elemental speciation greatly varies according to seafood species, thus playing a key role in human exposure assessment via food