New observations on the bluefin tuna trap fishery off southern Portugal (NE Atlantic) between 1998-2014: trends on potential catches, catch-at-size and sex ratios

This paper updates information previously presented on the bluefin tuna catches from a tuna trap fishery operating off the southern coast of Portugal (Algarve). Trends of intra- and interannual catches were analysed and relationships between the potential catches and ICCAT management regulations for the Mediterranean Sea explored. The catch rates of bluefin tuna in the tuna trap off the Algarve remained relatively low between 1998 and 2008, but were followed by increasingly high catches thereafter, with an observed peak during the 2011 season. Significant negative correlations were observed between the catches and the number of allowable fishing months for purse-seines, longlines and bait boats in the Mediterranean Sea, meaning that the catch increased as the number of allowable fishing months for those fishing gears decreased. On the other hand, a positive relationship was observed between the catches and the minimum landing size (MLS), meaning that the catch rates in the tuna trap increased as the MLS for bluefin tuna also increased. These results seem to corroborate other fisheries indicators regarding the recovery of the Eastern Atlantic and Mediterranean Sea stock.FCT IF/00253/2014info:eu-repo/semantics/publishedVersio

Impacts of climate change on the biogeography of three amnesic shellfish toxin producing diatom species

Harmful algal blooms (HABs) are considered one of the main risks for marine ecosystems and human health worldwide. Climate change is projected to induce significant changes in species geographic distribution, and, in this sense, it is paramount to accurately predict how it will affect toxin-producing microalgae. In this context, the present study was intended to project the potential biogeographical changes in habitat suitability and occurrence distribution of three key amnesic shellfish toxin (AST)-producing diatom species (i.e., Pseudo-nitzschia australis, P. seriata, and P. fraudulenta) under four different climate change scenarios (i.e., RCP-2.6, 4.5, 6.0, and 8.5) up to 2050 and 2100. For this purpose, we applied species distribution models (SDMs) using four abiotic predictors (i.e., sea surface temperature, salinity, current velocity, and bathymetry) in a MaxEnt framework. Overall, considerable contraction and potential extirpation were projected for all species at lower latitudes together with projected poleward expansions into higher latitudes, mainly in the northern hemisphere. The present study aims to contribute to the knowledge on the impacts of climate change on the biogeography of toxin-producing miinfo:eu-repo/semantics/publishedVersio

Projecting future climate change-mediated impacts in Three Paralytic Shellfish Toxins-Producing dinoflagellate species

Simple Summary Harmful algal blooms present a particular risk for marine ecosystems and human health alike. In this sense, it is important to accurately predict how toxin-producing microalgae could be affected by future climate change. The present study applied species distribution models (SDMs) to project the potential changes in the habitat suitability and distribution of three key paralytic shellfish toxin (PST)-producing dinoflagellate species (i.e., Alexandrium catenella, A. minutum, and Gymnodinium catenatum), up to 2040/50 and 2090/2100, across four different greenhouse gas emission scenarios, and using four abiotic predictors (i.e., sea surface temperature, salinity, current velocity, and bathymetry). In general, considerable contractions were observed for all three species in the lower latitudes of their distribution, together with projected expansions into higher latitudes, particularly in the Northern Hemisphere. This study aims to entice further research on the future biogeographical impacts of climate change in toxin-producing microalgae species while, at the same time, helping to advise the correct environmental management of coastal habitats and ecosystems. Toxin-producing microalgae present a significant environmental risk for ecosystems and human societies when they reach concentrations that affect other aquatic organisms or human health. Harmful algal blooms (HAB) have been linked to mass wildlife die-offs and human food poisoning episodes, and climate change has the potential to alter the frequency, magnitude, and geographical extent of such events. Thus, a framework of species distribution models (SDMs), employing MaxEnt modeling, was used to project changes in habitat suitability and distribution of three key paralytic shellfish toxin (PST)-producing dinoflagellate species (i.e., Alexandrium catenella, A. minutum, and Gymnodinium catenatum), up to 2050 and 2100, across four representative concentration pathway scenarios (RCP-2.6, 4.5, 6.0, and 8.5; CMIP5). Despite slightly different responses at the regional level, the global habitat suitability has decreased for all the species, leading to an overall contraction in their tropical and sub-tropical ranges, while considerable expansions are projected in higher latitudes, particularly in the Northern Hemisphere, suggesting poleward distributional shifts. Such trends were exacerbated with increasing RCP severity. Yet, further research is required, with a greater assemblage of environmental predictors and improved occurrence datasets, to gain a more holistic understanding of the potential impacts of climate change on PST-producing species.info:eu-repo/semantics/publishedVersio

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

Local indicators for global species: Pelagic sharks in the tropical northeast Atlantic, Cabo Verde islands region

Pelagic sharks are an important bycatch in pelagic fisheries, especially for drifting longlines targeting swordfish. In the Cabo Verde Archipelago (tropical NE Atlantic), pelagic shark catches can reach a significant proportion of the total catches. Due to the increased concern on the status of pelagic shark species, this study was developed to enhance the current knowledge of those sharks in the Cabo Verde region in comparison to the adjacent areas, especially associated with European Union (EU) pelagic longline fishing activity. Stock status indicators for the two main species, blue shark (Prionace glauca) and shortfin mako (Isurus oxyrinchus), were developed, based on fisheries data from logbooks and onboard scientific observers, including analysis of size frequency distributions and standardized catch-per-unit-of-effort (CPUE) indexes over time. The standardized CPUEs have been stable or increasing for both species in the past 10 years, indicating no signs of local depletion. In terms of sizes, the blue shark catch is composed mainly of adults, which can be a sign of a stable population. On the contrary, the catch of shortfin mako is composed mainly of juveniles, which in conjunction of a decrease of mean size might be a cause of concern, highlighting possible overfishing on the species in the region. Thirty satellite tags, 25 archival miniPATs and 5 SPOT GPS, were deployed in the Cabo Verde Exclusive Economic Zone (EEZ), showing that those species are highly mobile. The biomass and size distributions were modeled with spatial and seasonal models (GAMs) identifying locations where juveniles are predominantly concentrated and that should be prioritized for conservation. This work presents new information on the status of pelagic sharks in the Cabo Verde region in the context of those highly migratory species, and can now be used to promote more sustainable fisheries in the region.FCT IF/00253/2014, SFRH/BD/136074/2018, SFRH/BD/139187/2018, EU/MARE/2012/21: “Scientific advice for fisheries beyond EU waters”, specifically within Specific Contract N° 7: “The provision of advice on the conservation of pelagic sharks associated to fishing activity under EU Sustainable Fisheries Partnership Agreements in the Atlantic Ocean”.info:eu-repo/semantics/publishedVersio

Gymnodinium catenatum paralytic Shellfish toxin production and photobiological responses under marine heat waves

Marine heatwaves (MHWs) have doubled in frequency since the 1980s and are projected to be exacerbated during this century. MHWs have been shown to trigger harmful algal blooms (HABs), with severe consequences to marine life and human populations. Within this context, this study aims to understand, for the first time, how MHWs impact key biological and toxicological parameters of the paralytic shellfish toxin (PST) producer Gymnodinium catenatum, a dinoflagellate inhabiting temperate and tropical coastal waters. Two MHW were simulated—category I (i.e., peak: 19.9 ◦C) and category IV (i.e., peak: 24.1 ◦C)—relative to the estimated baseline in the western coast of Portugal (18.5 ◦C). No significant changes in abundance, size, and photosynthetic efficiency were observed among treatments. On the other hand, chain-formation was significantly reduced under category IV MHW, as was PSP toxicity and production of some PST compounds. Overall, this suggests that G. catenatum may have a high tolerance to MHWs. Nevertheless, some sublethal effects may have occurred since chain-formation was affected, suggesting that these growth conditions may be sub-optimal for this population. Our study suggests that the increase in frequency, intensity, and duration of MHWs may lead to reduced severity of G. catenatum blooms.info:eu-repo/semantics/publishedVersio

How the impact of stress changes with simultaneous administration of cocaine in rats?

La exposición al estrés aumenta la adquisición, mantenimiento y recaída de la adicción a las drogas, pero los efectos de la exposición concomitante a drogas y a estímulos estresantes severos no ha sido explorada. Nuestros estudios han sido realizados en ratas macho adultas Sprague-Dawley, distribuidas en 4 grupos en función de la inyección de cocaína y de la exposición a inmovilización (IMO). Los animales fueron inyectados con salino o con cocaína (30 mg/kg, ip) inmediatamente antes de 1 h de IMO. Los resultados indicaron que la exposición a la IMO indujo un incremento prolongado en los niveles plasmáticos de las hormonas del eje hipotálamo-pituitario-adrenal (HPA), corticosterona y hormona adrenocorticotrópica (ACTH), mientras que la cocaína únicamente incrementó la corticosterona pero con menor magnitud. La administración de cocaína disminuyó los niveles de ACTH (pero no de corticosterona) únicamente al finalizar la IMO, indicando la presencia de una leve sinergia negativa. Los efectos anorexígenos a largo plazo de la IMO se bloquearon parcialmente con la inyección de cocaína (sinergia negativa) la cual por ella misma también disminuía la ingesta de comida en los animales no estresados. Tanto la IMO como la cocaína redujeron la ganancia de peso corporal, aunque la disminución de peso corporal producida por la cocaína se demoró más en el tiempo y no se explicaba por los cambios en la ingesta de comida. Los efectos anhedónicos a largo plazo (medidos por la ingesta de soluciones de sacarina) no se afectaron por la administración de cocaína la cual por sí misma no tenía efecto. La exposición a la IMO indujo, veinticuatro horas después, un efecto ansiogénico en el laberinto elevado, que se acompañó por una disminución en la actividad locomotora. Aquí de nuevo la cocaína administrada simultáneamente con la IMO no modificó esta conducta. La conducta activa en el test de natación forzada (escape) no se afectó ni por la cocaína ni por la IMO, pero la IMO incrementó de forma modesta la natación suave en los animales no inyectados con cocaína. La IMO indujo también una sensibilización del eje HPA en respuesta a dos estímulos estresantes heterotípicos diferentes, mientras que los efectos de la cocaína sobre dicha sensibilización no fueron consistentes. La exposición a la IMO produjo también un efecto ansiogénico en el test de la respuesta acústica de sobresalto, efecto que se desvaneció después de veinticuatro horas, y la inyección de cocaína no modificó dicha conducta. Los animales administrados con cocaína en la primera exposición a la IMO no mostraron adaptación homotípica al estrés, al contrario de los animales solo expuestos a la IMO. El resultado principal de los estudios que utilizaron el c-fos como marcador de activación neuronal (ISH) indicaron que la cocaína bloqueó la activación inducida por la IMO en el accumbens, en el núcleo del lecho de la estría terminal y el dorsal del Rafe. Por otra parte, los estudios con RT-PCR mostraron que el incremento del factor liberador de la corticotropina (CRF) en la amígdala inducido tanto por la exposición a la cocaína como a la IMO (por separado) se bloqueó por la exposición simultánea a ambos estímulos. En general, la cocaína parece proteger más que exacerbar los efectos neurales, neuroendocrinos y conductuales de la exposición a un estímulo estresante severo, sugiriendo una sinergia negativa entre los dos estímulos.Exposure to stress increases the acquisition, maintenance and relapse of drug addiction, but the effects of concomitant exposure of drugs and acute severe stressors have not been explored. Our studies were conducted in adult male Sprague-Dawley rats, distributed into four groups in function of cocaine injection and exposure to immobilization (IMO). Animals were injected with saline or cocaine (30 mg/kg, ip) immediately before 1 h of IMO. Results indicated that exposure to IMO induced a prolonged increase in plasma ACTH and corticosterone levels, whereas cocaine only increased corticosterone with a less potent magnitude. Cocaine administration decreased ACTH levels (but not corticosterone) only at the end of IMO, reflecting a mild negative synergism. The long-term anorectic effects of IMO were partially blocked by cocaine injection (negative synergism) which itself also decreased food intake but only transiently and in non-stressed animals. Both IMO and cocaine reduced body-weight gain, although the decrease in weight gain induced by cocaine was delayed more in time and not explained by changes in food intake. The long-term anhedonic-like effects of IMO (measured by the intake of saccharine solutions) were not affected by cocaine administration that itself had no effect. Exposure to IMO induced, twenty-four hours later, an anxiogenic-like effect in the EPM test, accompanied by a decrease in motor activity. Here again cocaine was not able to modify this behaviour alone or concomitantly with IMO. The active behavior in the FST (struggling) was not affected neither by cocaine nor by IMO, but IMO modestly increased mild swimming in non-cocaine injected animals. IMO was able to induce a sensitization of the HPA axis in response to two different heterotypic stressors, although the effects of cocaine in sensitization were not consistent. The exposure to IMO produced an anxiogenic-like effect in the ASR test, effect that vanished after twenty-four hours, and cocaine injection did not modify this behavior. The animals administered with cocaine in the first exposure to IMO, showed no homotypic adaptation to stress, contrary to the animals that were only exposed to IMO. The main finding of the studies using c-fos as marker of neuronal activation (ISH) indicated that cocaine blocked the activation induced by IMO in the accumbens, the bed nucleus of the stria terminalis and the dorsal Rafe. On the other hand, the studies with RT-PCR showed that the increase in CRF in the amygdala induced by cocaine and by IMO was blocked by the simultaneous exposure to both stimuli. In general, cocaine does appear to protect more than exacerbate the neuroendocrine and behavioral effects of exposure to a severe stressor, suggesting a negative synergy between both stimuli

Local indicators for global species: Pelagic sharks in the tropical northeast Atlantic, Cabo Verde islands region.

Pelagic sharks are an important bycatch in pelagic fisheries, especially for drifting longlines targeting swordfish. In the Cabo Verde Archipelago (tropical NE Atlantic), pelagic shark catches can reach a significant proportion of the total catches. Due to the increased concern on the status of pelagic shark species, this study was developed to enhance the current knowledge of those sharks in the Cabo Verde region in comparison to the adjacent areas, especially associated with European Union (EU) pelagic longline fishing activity. Stock status indicators for the two main species, blue shark (Prionace glauca) and shortfin mako (Isurus oxyrinchus), were developed, based on fisheries data from logbooks and onboard scientific observers, including analysis of size frequency distributions and standardized catch-per-unit-of-effort (CPUE) indexes over time. The standardized CPUEs have been stable or increasing for both species in the past 10 years, indicating no signs of local depletion. In terms of sizes, the blue shark catch is composed mainly of adults, which can be a sign of a stable population. On the contrary, the catch of shortfin mako is composed mainly of juveniles, which in conjunction of a decrease of mean size might be a cause of concern, highlighting possible overfishing on the species in the region. Thirty satellite tags, 25 archival miniPATs and 5 SPOT GPS, were deployed in the Cabo Verde Exclusive Economic Zone (EEZ), showing that those species are highly mobile. The biomass and size distributions were modeled with spatial and seasonal models (GAMs) identifying locations where juveniles are predominantly concentrated and that should be prioritized for conservation. This work presents new information on the status of pelagic sharks in the Cabo Verde region in the context of those highly migratory species, and can now be used to promote more sustainable fisheries in the region

Reproduction and respiration of a climate change indicator species: effect of temperature and variable food in the copepod Centropages chierchiae

The abundance of the calanoid copepod Centropages chierchiae has increased at the northern limits of its distribution in recent decades, mainly due to oceanic climate forcing, suggesting this as a key species in monitoring climate change. Laboratory experiments were conducted to study the combined effect of temperature, food type and concentration on the egg production rate (EPR) and hatching success (HS) of C. chierchiae. Females were fed on two monoalgal diets (Gymnodinium sp. and Phaeodactylum tricornutum) at two food concentrations and at three different temperatures (13, 19, 24C). Respiration rates of both genders were measured at four different temperatures (8, 13, 19, 24C). EPR was significantly different between temperatures and food concentrations, the maximum EPR being attained when the copepods were exposed to high food levels and at 19C. Prey type significantly influenced EPR; feeding on P. tricornutum resulted in higher egg production than Gymnodinium sp. HS was significantly lower at 13C than at 19 and 24C and higher with Gymnodinium sp. Respiration rates were sex independent and increased exponentially with temperature. To maintain basal metabolism, the minimum food intake of P. tricornutum ranged between 0.4 and 1.8 g C and for Gymnodinium sp. between 0.03 and 0.13 g C. Food intake was always higher than the metabolic demands, except for the highest temperature tested (24C). The present results confirm the sensitivity of C. chierchiae to temperature variations and may help in understanding the successful expansion of its distribution towards northern latitudes.Portuguese Science and Technology Foundation (FCT) [PTDC/MAR/098643/2008, PTDC/MAR/111304/2009, PTDC/MAR/0908066/2008]; FCT [SFRH/BD/28198/2006]; [SFRH/BPD/38332/2007

Complete blood count parameters as biomarkers of retinopathy of prematurity: a Portuguese multicenter study

© The Author(s) 2023. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.Purpose: To evaluate complete blood count (CBC) parameters in the first week of life as predictive biomarkers for the development of retinopathy of prematurity (ROP). Methods: Multicenter, prospective, observational study of a cohort of preterm infants born with gestational age (GA) < 32 weeks or birth weight < 1500 g in eight Portuguese neonatal intensive care units. All demographic, clinical, and laboratory data from the first week of life were collected. Univariate logistic regression was used to assess risk factors for ROP and then multivariate regression was performed. Results: A total of 455 infants were included in the study. The median GA was 29.6 weeks, and the median birth weight was 1295 g. One hundred and seventy-two infants (37.8%) developed ROP. Median values of erythrocytes (p < 0.001), hemoglobin (p < 0.001), hematocrit (p < 0.001), mean corpuscular hemoglobin concentration (p < 0.001), lymphocytes (p = 0.035), and platelets (p = 0.003) of the group of infants diagnosed with ROP any stage were lower than those without ROP. Mean corpuscular volume (MCV) (p = 0.044), red blood cell distribution width (RDW) (p < 0.001), erythroblasts (p < 0.001), neutrophils (p = 0.030), neutrophils-lymphocytes ratio (p = 0.028), and basophils (p = 0.003) were higher in the ROP group. Higher values of MCV, erythroblasts, and basophils remained significantly associated with ROP after multivariate regression. Conclusion: In our cohort, the increase in erythroblasts, MCV, and basophils in the first week of life was significantly and independently associated with the development of ROP. These CBC parameters may be early predictive biomarkers for ROP.Open access funding provided by FCT|FCCN (b-on). This work was supported by the Laboratório de Genética and the Instituto de Saúde Ambiental (ISAMB) of the Faculdade de Medicina of Universidade de Lisboa and the Instituto de Investigação Científica Bento da Rocha Cabral. The writing of the manuscript was also supported by funds from Fundação para a Ciência e a Tecnologia to ISAMB (ref. UIDB/04295/2020 and UIDP/04295/2020). This work was also part of a doctoral project funding by the company CUF with a PhD grant in Medicine awarded in 2021 and by the Portuguese Society of Ophthalmology with a PhD grant awarded in 2019.info:eu-repo/semantics/publishedVersio