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  • 1
    Publication Date: 2024-03-15
    Description: Sites with naturally high CO2 conditions provide unique opportunities to forecast the vulnerability of coastal ecosystems to ocean acidification, by studying the biological responses and potential adaptations to this increased environmental variability. In this study, we investigated the bivalve Ervilia castanea in coastal sandy sediments at reference sites and at volcanic CO2 seeps off the Azores, where the pH of bottom waters ranged from average oceanic levels of 8.2, along gradients, down to 6.81, in carbonated seawater at the seeps. The bivalve population structure changed markedly at the seeps. Large individuals became less abundant as seawater CO2 levels rose and were completely absent from the most acidified sites. In contrast, small bivalves were most abundant at the CO2 seeps. We propose that larvae can settle and initially live in high abundances under elevated CO2 levels, but that high rates of post-settlement dispersal and/or mortality occur. Ervilia castanea were susceptible to elevated CO2 levels and these effects were consistently associated with lower food supplies. This raises concerns about the effects of ocean acidification on the brood stock of this species and other bivalve molluscs with similar life history traits.
    Keywords: Abundance per area; Alkalinity, total; Alkalinity, total, standard error; Animalia; Aragonite saturation state; Aragonite saturation state, standard error; Ash mass; Benthic animals; Benthos; Bicarbonate ion; Bicarbonate ion, standard error; Biomass/Abundance/Elemental composition; Calcification/Dissolution; Calcite saturation state; Calcite saturation state, standard error; Calcium carbonate; Calcium carbonate, standard error; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard error; Carbon, organic, total; Carbon, organic, total, standard error; Carbon/Nitrogen ratio; Carbon/Nitrogen ratio, standard error; Carbonate ion; Carbonate ion, standard error; Carbonate system computation flag; Carbon dioxide; Chlorophyll a; Chlorophyll a, standard error; CO2 vent; Coast and continental shelf; DATE/TIME; Dry mass; Ervilia castanea; Event label; EXP; Experiment; Faial; Field observation; Fucoxanthin; Fucoxanthin, standard error; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Granulometry; Granulometry, standard error; Hydroxide ion; Hydroxide ion, standard error; Identification; LATITUDE; LONGITUDE; Mollusca; Nitrogen, total; Nitrogen, total, standard error; North Atlantic; OA-ICC; Ocean Acidification International Coordination Centre; Organic matter; Organic matter, standard error; Other studied parameter or process; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Partial pressure of carbon dioxide (water) at sea surface temperature (wet air), standard error; Percentage; pH; pH, standard error; Pigments; Pigments, standard error; Potentiometric; Potentiometric titration; Registration number of species; Replicate; Salinity; Salinity, standard error; Sample code/label; Sao_Miguel; Single species; Site; Size; Species; Temperate; Temperature, water; Temperature, water, standard error; Type; Uniform resource locator/link to reference
    Type: Dataset
    Format: text/tab-separated-values, 5812 data points
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  • 2
    Publication Date: 2013-10-17
    Description: Background: It is well established that males have lower fracture risk in comparison with females, which suggests a higher bone resistance in men. The aim of our study was to find out if in older patients with hip fragility fractures, gender has also an impact on trabecular bone material behaviour, specifically to determine whether trabecular mechanical properties under compressive loading differ between men and women who suffered a fragility hip fracture. Methods: Femoral epiphyses were consecutively collected during hip replacement surgery due to proximal femur fragility fracture. Trabecular bone cylinders were drilled and submitted to uniaxial compression tests and mechanical properties were assessed. Results: Seventy-three patients, 55 women (mean age 81 years and standard deviation of 7 years) and 18 men (mean age 81 years and standard deviation of 8 years) were evaluated. The ultimate stress of trabecular bone was significantly higher in men than in women: the median values and the interquartile range (IQR) were respectively 8.04(5.35-10.90) MPa vs. 4.46(3.02-7.73) MPa, (p-value = 0.005). The same difference between male and female was observed in the Young's modulus: 293.68(166.67-538.18) MPa vs. 174.26(73.07-322.28) MPa,(p-value = 0.028), and also in the energy to failure: 0.25(0.07-0.42) MJ/m3 vs. 0.11(0.05-0.25) MJ/m3, (p-value = 0.058). These differences were also verified after adjusting the analysis for age in a multivariate model analysis.ConclusionsOur observations demonstrated that, even in a population who suffered a fragility hip fracture, men still have higher trabecular bone mechanical properties in comparison with women.
    Electronic ISSN: 1471-2474
    Topics: Medicine
    Published by BioMed Central
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  • 3
    Publication Date: 2023-02-08
    Description: Mass mortality events involving marine taxa are increasing worldwide. The long-spined sea urchin Diadema africanum is considered a keystone herbivore species in the northeastern Atlantic due to its control over the abundance and distribution of algae. After a first registered mass mortality in 2009, another event off the coasts of Madeira archipelago affected this ecologically important species in summer 2018. This study documented the 2018 D. africanum mass mortality event, and the progress of its populations on the southern coast of Madeira island. A citizen science survey was designed targeting marine stakeholders to understand the extent and intensity of the event around the archipelago. Underwater surveys on population density prior, during and after the mass mortality, permitted an evaluation of the severity and magnitude of the event as well as urchin population recovery. A preliminary assessment of causative agents of the mortality was performed. The event was reported in the principal islands of the archipelago reducing the populations up to 90%. However, a fast recovery was registered during the following months, suggesting that the reproductive success was not compromised. Microbiological analyses in symptomatic and asymptomatic individuals, during and after the event, was not conclusive. Nevertheless, the bacteria Aeromonas salmonicida, or the gram-negative bacteria, or the interaction of different types of bacteria may be responsible for the disease outbreak. Further studies are needed to assess the role of pathogens in sea urchin mass mortalities and the compound effects that sea urchins have in local habitats and ecological functioning of coastal marine ecosystems.
    Type: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
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  • 4
    Publication Date: 2022-01-31
    Description: This manuscript reports the first sightings and collection of the swimming crab Cronius ruber (Lamarck, 1818) on the coast of Madeira Island, Portugal. After the recent record in the Canary Islands, this represents a further step northward on this species’ expansion in distribution in the eastern Atlantic. The crab was first spotted during underwater visual census surveys done by scuba diving in July 2018 and was repeatedly observed during the following months, in different locations on the south coast of Madeira. Analysis of temperature data from several geographic locations where C. ruber is present was performed to assess how thermal regimes and ongoing changes may influence this recent distribution shift. Current temperature trends in Madeira suggest that the arrival and establishment of C. ruber to Madeira might have been facilitated this thermophilic species, adding evidence for the ongoing tropicalization of this area. Finally, the current spread of C. ruber in both Canaries and Madeira island systems highlights the need for a long-term monitoring program targeting this and other non-indigenous species (NIS).
    Type: Article , PeerReviewed
    Format: text
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  • 5
    Publication Date: 2024-02-07
    Description: Macroalgal forests play a key role in shallow temperate rocky reefs worldwide, supporting communities with high productivity and providing several ecosystem services. Sea urchin grazing has been increasingly influencing spatial and temporal variation in algae distributions and it has become the main cause for the loss of these habitats in many coastal areas, causing a phase shift from macroalgae habitats to barren grounds. The low productive barrens often establish as alternative stable states and only a major reduction in sea urchin density can trigger the recovery of macroalgal forests. The present study aims to assess if the 2018 disease outbreak, responsible for a strong reduction in the sea urchin Diadema africanum densities in Madeira Island, was able to trigger a reverse shift from barren grounds into macroalgae-dominated state. By assessing the diversity and abundance of benthic sessile organisms, macroinvertebrates and fishes before, during and after that particular mass mortality event, we evaluate changes in benthic assemblages and relate them to variations in grazer and herbivore densities. Our results revealed a clear shift from barren state to a macroalgae habitat, with barrens characterized by bare substrate, sessile invertebrate and Crustose Coralline Algae (CCA) disappearing after the mortality event. Overall variations in benthic assemblages was best explained by four taxa (among grazers and herbivores species). However, it was the 2018 demise of D. africanum and its density reduction that most contributed to the reverse shift from a long stable barren state to a richer benthic assemblage with higher abundance of macroalgae. Despite this recent increase in macroalgae dominated habitats, their stability and persistence in Madeira Island is fragile, since it was triggered by an unpredictable disease outbreak and depends on how D. africanum populations will recover. With no control mechanisms, local urchin populations can easily reach the tipping point needed to promote a new shift into barren states. New conservation measures and active restoration are likely required to maintain and promote the local stability of macroalgal forests.
    Type: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
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  • 6
    Publication Date: 2024-02-07
    Description: Ctenophores are fragile gelatinous organisms whose diversity and distribution are relatively unknown. For the first time, the occurrence of four planktonic species, namely Ocyropsis crystallina, Eurhamphaea vexilligera, Cestum veneris, and Beroe sp., was reported from Madeira Archipelago waters (NE subtropical Atlantic). This report represents the northernmost records in the Eastern Atlantic Ocean for O. crystallina and E. vexilligera.
    Type: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
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  • 7
    Publication Date: 2024-02-07
    Description: Current trends in the global climate facilitate the displacement of numerous marine species from their native distribution ranges to higher latitudes when facing warming conditions. In this work, we analyzed occurrences of a circumtropical reef fish, the spotfin burrfish, Chilomycterus reticulatus (Linnaeus, 1958), in the Madeira Archipelago (NE Atlantic) between 1898 and 2021. In addition to available data sources, we performed an online survey to assess the distribution and presence of this species in the Madeira Archipelago, along with other relevant information, such as size class and year of the first sighting. In total, 28 valid participants responded to the online survey, georeferencing 119 C. reticulatus sightings and confirming its presence in all archipelago islands. The invasiveness of the species was screened using the Aquatic Species Invasiveness Screening Kit. Five assessments rated the fish as being of medium risk of establishing a local population and becoming invasive. Current temperature trends might have facilitated multiple sightings of this thermophilic species in the Madeira Archipelago. The present study indicates an increase in C. reticulatus sightings in the region. This underlines the need for updated comprehensive information on species diversity and distribution to support informed management and decisions. The spread of yet another thermophilic species in Madeiran waters provides further evidence of an ongoing tropicalization, emphasizing the need for monitoring programs and the potential of citizen science in complementing such programs.
    Type: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
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  • 8
    Publication Date: 2024-02-07
    Description: Seagrass meadows are globally recognized as important coastal habitats due to the various ecological functions and ecosystem services they provide. Substantial global decline of seagrass habitats has been recorded over the last decades, underlining the need for extensive studies, including monitoring and mapping these habitats across their distributional range. Cymodocea nodosa (Ucria) Ascherson is the only seagrass species reported in the archipelago of Madeira (NE Atlantic) and systematic or reliable information of its occurrence is very scarce and mostly anecdotal. This study reports the discovery of a yearly-persistent patch of C. nodosa in the southeast coast of Madeira and provides insights into key ecological and biological aspects (e.g. density, leaf length, associated fauna and flora). Seasonal monitoring surveys over a 3-year period, indicate that (1) the patch has increased in size and shoot density over the study period, and (2) leaf lengths follow a typical seasonal pattern over the year. Accounts of past destruction of seagrass meadows in the island, underline the importance of continuous monitoring of the patch and adjacent areas to reveal how the current seagrass patch develops (i.e. patch continuity and/or disappearance), if it integrates a larger meadow and whether anthropogenic pressures as coastal development and/or associated terrigenous sediment runoff events will affect its resilience.
    Type: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
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  • 9
    Publication Date: 2017-01-19
    Description: Invasion by non-native tree species is an environmental and societal challenge requiring predictive tools to assess invasion dynamics. The frequent scale mismatch between such tools and on-ground conservation is currently limiting invasion management. This study aimed to reduce these scale mismatches, assess the success of non-native tree invasion and determine the environmental factors associated to it. A hierarchical scaling approach combining species distribution models (SDMs) and satellite mapping at very high resolution (VHR) was developed to assess invasion by Acacia dealbata in Peneda-Gerês National Park, the only national park in Portugal. SDMs were first used to predict the climatically suitable areas for A. dealdata and satellite mapping with the random-forests classifier was then applied to WorldView-2 very-high resolution imagery to determine whether A. dealdata had actually colonized the predicted areas (invasion success). Environmental attributes (topographic, disturbance and canopy-related) differing between invaded and non-invaded vegetated areas were then analyzed. The SDM results indicated that most (67%) of the study area was climatically suitable for A. dealbata invasion. The onset of invasion was documented to 1905 and satellite mapping highlighted that 12.6% of study area was colonized. However, this species had only colonized 62.5% of the maximum potential range, although was registered within 55.6% of grid cells that were considerable unsuitable. Across these areas, the specific success rate of invasion was mostly below 40%, indicating that A. dealbata invasion was not dominant and effective management may still be possible. Environmental attributes related to topography (slope), canopy (normalized difference vegetation index (ndvi), land surface albedo) and disturbance (historical burnt area) differed between invaded and non-invaded vegetated area, suggesting that landscape attributes may alter at specific locations with Acacia invasion. Fine-scale spatial-explicit estimation of invasion success combining SDM predictions with VHR invasion mapping allowed the scale mismatch between predictions of invasion dynamics and on-ground conservation decision making for invasion management to be reduced. Locations with greater potential to suppress invasions could also be defined. Uncertainty in the invasion mapping needs to be accounted for in the interpretation of the results.
    Electronic ISSN: 1424-2818
    Topics: Biology
    Published by MDPI Publishing
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  • 10
    Publication Date: 2018-06-14
    Description: Water, Vol. 10, Pages 773: Improved Assessment of Energy Recovery Potential in Water Supply Systems with High Demand Variation Water doi: 10.3390/w10060773 Authors: Laura Monteiro João Delgado Dídia I. C. Covas Enhancing energy efficiency of water supply systems by recovering part of the excessive pressure is currently an issue of growing interest for water companies. The installation of micro hydro plants for energy recovery can be profitable in sites with excessive pressure, though requiring proper technical and economical evaluation. This paper presents a methodology for assessing the energy recovery potential in water supply systems under high seasonal demand variation. The methodology is based on the calculation of head and flow rate conditions that maximize energy production for a specific energy recovery technology, given available head and flow rate ranges. The methodology is applied to the inlet of a storage tank of a water transmission system using hourly collected data over one year. Results show that, in systems of high variability of flow rate, the installation of turbomachines in parallel is necessary for maximizing energy recovery and that the developed methodology returns lower, but more realistic, energy production estimates than other approaches based on average head and flow rate data.
    Electronic ISSN: 2073-4441
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI Publishing
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