Impacts of acute hypoxia on the short-snouted seahorse metabolism and behaviour

Seahorses are one of the most unique and enigmatic animals, recognized as flagship species for several conservation issues. Unfortunately, seahorses' populations have been declining and their unique lifestyle may constrain the ability of these animals to evolve in the future climate scenarios. They inhabit shallow coastal waters that display daily or seasonal environmental fluctuations. Yet, few studies have scrutinized the impacts of climate changes on these iconic species. Within this context, the objective of this work was to test the effects of an extreme hypoxia exposure (~27 % dissolved oxygen for approximately 7 h) on the metabolism, behaviour and food intake of the temperate seahorse Hippocampus hippocampus. Regarding metabolism, hypoxia exposure led to a significant reduction in metabolic rates and an increase in ventilation rates. Seahorses showed signs of movement lethargy under oxygen depletion. The results show that a small but extreme exposure to hypoxia is tolerable by seahorses despite inducing metabolic and behavioural changes, that may jeopardize the future development and survival of these iconic organisms.

A decade of urban fires: Portuguese events between 2013 and 2022

This study describes a dataset containing urban fire events that took place in mainland Portugal between 2013 and 2022. The Regulation n.º3317-A/2018, established by the Portuguese National Emergency and Civil Protection Authority (Autoridade Nacional de Emergência e Proteção Civil, ANEPC), defines the Operations Management System (Sistema de Gestão de Operações, SGO). Among other attributions, this system allows to manage the lyfe-cycle of the urban fire events, from ignition to extinction, through the Operations Decision Support System (Sistema de Apoio à Decisão Operacional, SADO). This system supports the systematic collection of a minimum set of data on each event. All instances included in the dataset were retrieved from SADO. To make the data suitable for analytic purposes, several pre-processing actions were taken, including the steps of data transformation and cleaning. The dataset was further validated by a set of technical procedures aiming to verify both data correctness and utility. The final dataset provides the most recent multi-year record of Portuguese urban fires including 27 variables on 72641 events.

Re-assessing the effectiveness of wire-marking to mitigate bird collisions with power lines: A meta-analysis and guidelines for field studies

The expansion of overhead power lines worldwide challenges companies of energy transmission and distribution, regulators and environmental consultants, among other stakeholders, to effectively mitigate their negative impacts on wildlife. Wire-marking is currently the most widespread and recommended measure to reduce bird collisions with these infrastructures. Nevertheless, and despite its importance for a bird-friendly development of energy projects, there is still much uncertainty about what explains wire-marking effectiveness. We performed an extensive literature review and meta-analysis to evaluate the overall effectiveness of wire-marking in reducing bird collisions with power lines, including the possible influencing factors of power line voltage, habitat and type of device. We gathered data from 35 field studies across the world (which included 66 trials) assessing the effectiveness of wire-marking based on regular carcass searches beneath power lines. Overall, wire-marking reduced bird collisions with power lines by half (50.4%; 95% Confidence Interval Estimate: 40.4-58.8%), although this estimate of effectiveness is lower than the one reported in a meta-analysis performed in 2011. Despite the effort to include both peer-reviewed and grey literature studies in the present meta-analysis, the risk of publication bias could not be entirely excluded and may be still overestimating the true overall effect of wire-marking. High heterogeneity among the study outcomes hindered the power to detect clear moderating effects, with none of explanatory variables being statistically significant. Large between-study heterogeneity is (to some extent) explained by the variety of anti-collision devices available, wire-marking intensities used and ecological circumstances in which the experiments were carried out. Nonetheless, it may be also related to within-study methodological biases and reporting gaps in the existing field studies. Robust experimental designs (ideally using Before-After-Control-Impact approaches), comprehensive reporting of results and broad dissemination of study findings are needed to increase the statistical power of future meta-analyses. Ways to achieve these improvements in field studies are presented in detail. Their inclusion in future meta-analyses will increase the knowledge on the drivers of wire-marking effectiveness, which is critical to better inform decision-making processes and environmental management plans.

Effects of elevated carbon dioxide on the hematological parameters of a temperate catshark

Atmospheric CO₂ levels have been rising due to an increase in anthropic activities and its implications over marine ecosystems are unprecedented. The present study focused on the effects of ocean acidification (OA) on key hematological parameters of the juvenile small-spotted catsharks (Scyliorhinus canicula). Eggs were reared throughout the entire embryogenesis (~4 months) plus 5 additional months, in two experimental treatments (control: pCO₂  ~ 400 μatm; and high CO₂ : pCO₂  ~ 900 μatm, Δ -0.3 pH units). After blood collection, the following hematological parameters were evaluated: (a) normal blood cells count (erythrocytes, leukocytes, and thrombocytes), (b) presence of erythrocytes with nuclear abnormalities, and (c) erythrocyte nucleus to cytoplasmic ratio. Concomitantly, to determine the cardiac and hematopoietic conditions, the spleen and heart to body ratios were also assessed. The present findings indicate that the measured variables may not be affected by elevated pCO₂ in this temperate species, as no significant differences were observed between treatments across all the endpoints tested. Nonetheless, it is worth mentioning a decreasing trend observed in a number of thrombocytes associated with OA, which should foster further investigation, regarding other aspects of their coagulation response. Along with OA, other stressors are expected to impact marine life, such as warming and hypoxia. Thus, future research should aim to investigate the cumulative effect of these stressors on hematological parameters in sharks.

First indication of deleterious impacts in white-seabream larvae (Diplodus sargus) survival and behaviour following acute venlafaxine exposure

Wastewater effluents are teeming with organisms, nutrients and chemical substances which water treatment processes fail to remove. Among these substances, pharmaceuticals such as antidepressants are a frequent occurrence, and have been reported to lead to severe effects in the physiology and behaviour of non-target marine species across taxa. Venlafaxine (VFX) is one of the most consistently prescribed substances for the treatment of human depressive disorders, acting as a serotonin and norepinephrine reuptake inhibitor. In the present study, the potential effects of this antidepressant on the survival and key behaviours (i.e. movement, aggression and foraging) of white seabream (Diplodus sargus) larvae were addressed. Larvae were submitted to an acute exposure of two different VFX treatments (low concentration, 10 µg L^-1; and high concentration, 100 µg L^-1) for a total of 48 h. Sampling took place after 24 and 48 h of exposure. Overall, results showed a significant effect of a two-day exposure to VFX in larvae of D. sargus. Survival was significantly reduced by exposure to a high concentration, but behavioural effects of antidepressant exposure were subtle: i.e. increased attack frequency and temporary modulation of capture success. Further research efforts should be directed towards evaluating the potential chronic effects of antidepressants in marine species, if we are to anticipate possible pressures on natural populations, and effectively advice policymakers towards the investment in new and more efficient methods of wastewater treatments.

Distinct Bleaching Resilience of Photosynthetic Plastid-Bearing Mollusks Under Thermal Stress and High CO2 Conditions

The impact of temperature on photo-symbiotic relationships has been highly studied in the tropical reef-forming corals but overlooked in less charismatic groups such as solar-powered sacoglossan sea slugs. These organisms display one of the most puzzling symbiotic features observed in the animal kingdom, i.e., their mollusk-plastid association, which enables them to retain photosynthetic active chloroplasts (i.e., kleptoplasts) retrieved from their algae feed sources. Here we analyze the impact of thermal stress (+4°C) and high pCO2 conditions (ΔpH = 0.4) in survival, photophysiology (i.e., bleaching, photosynthetic efficiency, and metabolism) and stress defense mechanisms (i.e., heat shock and antioxidant response) of solar-powered sacoglossan sea slugs, from tropical (Elysia crispata) and temperate (E. viridis) environments. High temperature was the main factor affecting the survival of both species, while pH only affected the survival of the temperate model. The photobiology of E. viridis remained stable under the combined scenario, while photoinhibition was observed for E. crispata under high temperature and high pCO2. In fact, bleaching was observed within all tropical specimens exposed to warming (but not in the temperate ones), which constitutes the first report where the incidence of bleaching in tropical animals hosting photosynthetic symbionts, other than corals, occurs. Yet, the expulsion of kleptoplasts by the tropical sea slug, allied with metabolic depression, constituted a physiological response that did not imply signs of vulnerability (i.e., mortality) in the host itself. Although the temperate species revealed greater heat shock and antioxidant enzyme response to environmental stress, we argue that the tropical (stenotherm) sea slug species may display a greater scope for acclimatization than the temperate (eurytherm) sea slug. E. crispata may exhibit increased capacity for phenotypic plasticity by increasing fitness in a much narrower thermal niche (minimizing maintenance costs), which ultimately may allow to face severe environmental conditions more effectively than its temperate generalist counterpart (E. viridis).

Small pelagics in a changing ocean: biological responses of sardine early stages to warming

Small pelagic fishes are known to respond rapidly to changes in ocean climate. In this study, we evaluate the effects of future environmental warming (+2°C) during the early ontogeny of the European sardine, Sardina pilchardus. Warming reduced the survival of 30-day-old larvae by half. Length at hatching increased with temperature as expected, but no significant effect was observed on the length and growth at 30 days post-hatching. Warming did not significantly affect the thermal tolerance of sardine larvae, even though the mean lethal temperature increased by 1°C. In the warm conditions, sardine larvae showed signs of thermal stress, indicated by a pronounced increase in larval metabolism (Q 10 = 7.9) and a 45% increase in the heat shock response. Lipid peroxidation was not significantly affected by the higher temperature, even though the mean value doubled. Warming did not affect the time larvae spent swimming, but decreased by 36% the frequency of prey attacks. Given the key role of these small pelagics in the trophic dynamics off the Western Iberian upwelling ecosystem, the negative effects of warming on the early stages may have important implications for fish recruitment and ecosystem structure.

Adults with Down syndrome: characterization of a Portuguese sample

INTRODUCTION

Down syndrome or Trisomy 21 affects physical, behavioral and cognitive development. Ageing people with Down syndrome may suffer from several comorbidities that interfere with their daily life.

OBJECTIVE

To analyze in a sample of adults with Down syndrome the presence of common medical diseases, regular use of medication, possible cognitive impairment and oral communication skills.

MATERIAL AND METHODS

The socio-demographic and clinical data of 209 Portuguese adults (20-58 years) with Down syndrome were collected. Twenty-six subjects were assessed with the WAIS-III. Data was statistically analyzed--SPSS (v.19).

RESULTS

Almost half (47.36%) of the sample suffers from comorbidities, with cardiac, psychiatric, epilepsy and hypothyroidism ranked as the most prevalent diseases. Seventy-two patients (34.45%) take medication that acts on the central nervous system. The WAIS-III results revealed IQ scores between 45-61 (mean = 49.65, SD = 4.93) and 141 individuals (67.5%) who can express themselves through basic oral language.

DISCUSSION

In line with other studies, these individuals are vulnerable to various comorbidities. Most have basic oral language, but the IQ values are in the 'extremely low' range, with better performance on verbal tasks.

CONCLUSION

The cognitive constraints and communication difficulties in the population with Down syndrome may difficult the early clinical recognition of comorbidities associated with ageing. The identification of new semiology, with caregiver support, is essential to ensure that appropriate care is provided to this population.