Search Results (3,565)

Suspended solids are small particles transported in the water column, which can damage marine ecosystems and impair the health of aquatic organisms. This study evaluated the physiological responses of clams (Venerupis philippinarum) and Atlantic Bay scallops (Argopecten irradians) to suspended solid exposure. Four concentrations (100–1000 mg/L) were tested, with a control group maintained at 0 mg/L. At each time point (1, 2, 4, 6, 8, and 12 days), hemolymph samples were collected from five individuals per group to measure GOT, GPT, ALP, and cortisol. Exposure to suspended solids significantly increased these biochemical indicators compared with the control. Quantitative survival analysis showed that Venerupis philippinarum survival declined to 83.3% (25/30) at 500 mg/L and 76.7% (23/30) at 1000 mg/L after 5 days, while the control maintained 100% survival. In Argopecten irradians, survival remained close to 100% in most treatments, with a slight reduction to 83.3% (25/30) at 1000 mg/L. No mortality occurred in the control group without suspended solids, whereas mortality was evident under combined temperature stress and suspended solid exposure. These findings demonstrate that suspended solids induce stress responses in both species, with early mortality in Venerupis philippinarum likely caused by particle adhesion to the gills, leading to reduced respiratory efficiency. Full article

Published cosmogenic ¹⁰Be exposure ages from the terminal moraine of the Laurentide Ice Sheet (LIS) in northeastern North America have been interpreted to date the start of the retreat of the LIS at the Last Glacial Maximum (LGM) about 25 thousand years ago (ka). In contrast, published ¹⁴C accelerator mass spectrometry (AMS) dates for terrestrial plant macrofossils in LIS basal deglacial clay deposits range back to only ~16 calibrated (cal) ka, more consistent with the timing of glacio-eustatic rise and associated meltwater discharge to the North Atlantic and Gulf of Mexico associated with LGM deglaciation. We apply statistical models of geomagnetic secular variation, including dipole moment, to the latitudinal scaling of cosmic ray flux to see how well the age discrepancy can be addressed. A preferred new scaling, which is essentially time-invariant over the relevant LGM age range, shifts the exposure ages only a few thousand years younger. The age discrepancy may thus stem more from potential local biases toward higher ¹⁰Be concentrations (older apparent ages) at the terminal moraine sites, such as much higher ¹⁰Be production rates at the LIS front, and especially from inheritance. Such biases can be tested by obtaining primary ¹⁰Be calibration sites in the LGM time frame, and by more comprehensive sampling strategies for glaciated terrain to discern inheritance. Full article

Rugulopteryx okamurae is an invasive brown alga that has colonised Mediterranean and northeastern Atlantic coastlines, posing significant ecological and economic challenges. Its biomass is rich in structurally diverse metabolites—including polysaccharides (alginate, fucoidan, laminaran), phlorotannins, diterpenoids, fatty acids, and peptides—many of which exhibit notable antioxidant, anti-inflammatory, antimicrobial, and anticancer activities. Comparative assessment of extraction yields, structural features, and bioactivity data highlights phlorotannins and diterpenoids as particularly promising, demonstrating low-micromolar potencies and favourable predicted interactions with key inflammatory and apoptotic targets. Algal polysaccharides exhibit various bioactivities but hold strong potential for scalable and sustainable industrial applications. Emerging compound classes such as fatty acids and peptides display niche bioactivities; however, their structural diversity and mechanisms of action remain insufficiently explored. Insights from in vitro and in silico studies suggest that phlorotannins may modulate NF-κB and MAPK signalling pathways, while diterpenoids are implicated in the induction of mitochondrial apoptosis. Despite these findings, inconsistent extraction methodologies and a lack of in vivo pharmacokinetic and efficacy data limit translational potential. To overcome these limitations, standardized extraction protocols, detailed structure–activity relationship (SAR) and pharmacokinetic studies, and robust in vivo models are urgently needed. Bioactivity-guided valorisation strategies, aligned with ecological management, could transform R. okamurae biomass into a sustainable source for functional foods, cosmetics, and pharmaceuticals applications. Full article

The strategic position of the coast of the Kingdom of Seville, along the western route between the Mediterranean and the Atlantic, encouraged the presence of numerous fleets and merchant nations in its ports and waters. The proliferation of privateers and armed conflicts, both in Andalusian waters and beyond, had a significant impact on navigation and trade. This article examines the diplomatic strategies developed by the Genoese consuls in Seville to protect the interests of their nation in the maritime conflicts that affected them. Full article

Within biogeographic regions, local communities are structured mainly by abiotic (environmental) filtering, external resource supply, and biotic interactions. In recent years, we investigated abiotic filtering and external resource supply as drivers of the latitudinal distribution of rocky intertidal species along the Atlantic Canadian coast in Nova Scotia. Here, we evaluate biotic interactions between the main sessile species groups. Specifically, we studied abundance relationships between seaweeds and filter-feeding invertebrates and between barnacles and mussels using data collected at mid-to-high intertidal elevations at eight wave-exposed locations every summer from 2014 to 2017. We assessed such relationships for each location and year through generalized additive modeling (GAM). Of the 32 relationships evaluated for seaweeds vs. filter-feeders, 31% were significant and consistently negative, suggesting competitive interactions. For barnacles vs. mussels, 25% of the relationships were significant and mostly positive, consistent with facilitation of mussel colonization by barnacles in harsh environments. The variability explained by these models was moderate, however, between around 10% and 50%. Overall, these results suggest that interactions between the studied sessile species groups are infrequent and, when present, relatively weak in these highly stressful habitats, which supports current ecological theory on community organization. Full article

Protactinium-231 (²³¹Pa), a particle-reactive radionuclide derived from ²³⁵U decay, serves as a pivotal tracer in marine geochemistry and paleoceanography, offering unique insights into particle scavenging, deep ocean circulation, and sedimentary processes. This review synthesizes significant advances in ²³¹Pa research. A core application lies in utilizing the ²³¹Pa/²³⁰Th ratio as a sensitive proxy for reconstructing past Atlantic Meridional Overturning Circulation (AMOC) intensity, with compelling evidence indicating a substantially weakened AMOC during the Last Glacial Maximum compared to the Holocene. Major technological breakthroughs, particularly the advent of high-precision ICP-MS and TIMS methodologies, have revolutionized the quantification of ²³¹Pa in both dissolved and particulate phases, enabling spatial and temporal resolution. Looking forward, the integration of high-resolution sediment core analyses—featuring refined ²³¹Pa/²³⁰Th chronologies—with advanced climate models offers a powerful pathway to significantly enhance our mechanistic understanding of the ocean’s role in global climate regulation. This synergistic approach will help constrain the dynamics of oceanic overturning circulation and its critical functions in carbon sequestration and heat redistribution across past, present, and future climate scenarios. Full article

The Atlantic chub mackerel (Scomber colias) is a nutritionally valuable species with potential for inclusion in school canteens. This study aimed to develop and evaluate mackerel-based products processed through marination, vacuum packaging, and sous-vide cooking. Following collective interviews with school canteen staff to assess acceptability and logistical suitability, the preferred variants—raw, marinated, and sous-vide marinated fillets—were subjected to a 49-day refrigerated storage trial, during which physicochemical and microbiological parameters were monitored. Results showed that sous-vide processing significantly improved product stability, with enhanced water retention, reduced microbial growth (mesophile and psychrophile abundances below 7 log CFU/g up to day 21 vs. day 7 in raw and marinated fillets), and lower levels of spoilage indicators such as TVB-N, kept within acceptable limits of 25–35 mg N/100 g until day 28 of storage. Although sous-vide fillets showed slightly higher lipid oxidation (TBARS of 11.52 mg MDA/kg vs. 8.82 and 6.94 mg MDA/kg in marinated and raw fillets), they maintained superior texture and water retention. Overall, sous-vide proved highly effective in preserving the quality and extending the shelf-life of mackerel fillets, supporting its application in institutional food services as a strategy to promote healthier eating habits among children. Full article

This study evaluated the ability of a jasmine essential oil (JEO)-loaded nanoemulsion alone (WOM) and combined with modified atmosphere packaging (WOM-MAP) to extend the shelf life and maintain the quality of Atlantic salmon (Salmo salar) at 4 °C. The WOM was stabilized with oxidized corn starch (OCS) and whey protein (WP), and had a particle size of 255.7 nm and zeta potential of −25.43 mV. The treated salmon fillets were periodically analyzed for spoilage extent, texture, protein structure, and other quality parameters. The findings of this study showed that the salmon fillets treated with the WOM, particularly when combined with the MAP, was able to retain their original texture and taste to a great extent. Compared to the control check group (CK), the WOM and WOM-MAP treatments reduced bacterial counts by 2.1 log CFU/g and 2.4 log CFU/g, respectively, by the 20th day. Both the WOM and WOM-MAP treatments exhibited lower total volatile basic nitrogen and K values, prevented protein structural changes, and reduced free amino acid breakdown. These results indicate that the WOM effectively extends the shelf life and maintains the quality of Atlantic salmon, offering a promising natural preservative to preserve the quality and safety of seafood. Full article

The Brazilian Atlantic Forest is currently reduced to a few, small fragments surrounded by anthropic landscapes. Urban forest remnants play an important role in housing biodiversity in urbanized areas and enabling species dispersion between larger natural areas. Describing and monitoring the biodiversity in these anthropized environments is a useful tool for urban ecology and species conservation. By compiling long-term data, this study proposes a species list of tropical diurnal butterflies for an Atlantic Forest remnant in Southeastern Brazil and describes the temporal diversity patterns of the community. Inventories were carried out from the 1970s to 2000 to record butterfly incidence data in a 250 ha fragment of seasonal, semideciduous Atlantic Forest, resulting in a species list of 706 species presented here for the first time for the studied area. From 1998 to 2000, weekly standardized observations enabled inferences on temporal trends in butterfly diversity. Total species richness peaked in the climatic transitions, and a cycle of 52 weeks was reported for beta diversity. Butterfly families lack synchronized temporal fluctuations. Nymphalidae and specifically the fruit-feeding nymphalids were considered good surrogates for short-term studies and monitoring community changes. Full article

Hydrothermal vents are “oases” of biological productivity and endemicity on the seafloor. Chemosynthetic communities at deep-sea hydrothermal vents are characterized by high abundance and endemism. The distribution of species among these isolated habitats supports regional biodiversity and stability, so understanding the fundamental processes is a key target of conservation. Larval dispersal resulting from deep-ocean circulations is one of the major factors influencing the diversity and distributions of vent animals. By combining a biophysical model with biological larvae traits, we quantify potential larval dispersal of vent species via ocean circulation in the Azores Triple Junction. Here we present results from a biophysical model of larval dispersal run for the hydrothermal vent benthic mussel Bathymodiolus azoricus. Several scenarios were implemented, based on similar data sets, although changing values for one or two parameters, such as swimming behaviour and planktonic larvae duration. Results showed that larvae retention is the most common pattern from the Azores Triple Junction vent fields mussel. The Rainbow vent field is rather isolated, being the sink population of the Menez Gwen and Lucky Strike but with a very low number of larvae exchange. Results are discussed in the framework of spatial management to maintain the populations after an impact by natural or human disturbance. Full article

This study presents a comprehensive analysis of climate evolution in the Porto region (Northern Portugal) using 148 years (1863–2010) of continuous meteorological data from the Serra do Pilar weather station (WMO station 08546). The research employs both traditional linear statistical methods and advanced non-linear analysis techniques, including polynomial trend fitting and multidecadal oscillation analysis, to accurately characterize long-term climate patterns. Results reveal that linear trend analysis is misleading for this dataset, as both temperature and precipitation follow parabolic (U-shaped) distributions with minima around 1910–1970. The early period (1863–1900) exhibited higher values than the recent period, contradicting linear trend interpretations. Advanced analysis shows that the mean temperature follows a parabolic pattern (R² = 0.353) with the minimum around 1935, while precipitation exhibits similar behavior (R² = 0.053) with the minimum around 1936. Multidecadal oscillations are detected with dominant periods of 46.7, 15.6, and 10.0 years for temperature, and 35.0, 17.5, and 4.5 years for precipitation. Maximum temperatures show complex oscillatory behavior with a severe drop around 1890. Seasonal analysis reveals distinct patterns across all seasons: winter (+0.065 °C/decade) and autumn (+0.059 °C/decade) show warming trends in maximum temperatures, while spring (−0.080 °C/decade) and summer (−0.079 °C/decade) demonstrate cooling trends in minimum temperatures, with no significant trends in spring (+0.012 °C/decade) and summer (+0.003 °C/decade) maximum temperatures or winter (−0.021 °C/decade) and autumn (−0.035 °C/decade) minimum temperatures. The study identifies a significant change point in mean temperature around 1980, which occurs approximately one decade earlier than the global warming acceleration typically observed in the 1990s, suggesting regional Atlantic influences may precede global patterns. Extreme event analysis indicates stable frequencies of hot days (averaging 3.6 days/year above 25.0 °C) and heavy precipitation events (averaging 1.2 days/year above 234.6 mm) throughout the study period. These findings demonstrate that the Porto region’s climate is characterized by natural multidecadal variability rather than monotonic trends, with the climate system showing oscillatory behavior typical of Atlantic-influenced coastal regions. The results contribute to understanding regional climate variability and provide essential baseline data for climate change adaptation strategies in Northern Portugal. The results align with broader patterns of natural climate variability in the Iberian Peninsula while highlighting the importance of non-linear analysis for comprehensive climate assessment. Full article

Malaria, caused by a protozoan parasite of the genus Plasmodium and transmitted by mosquitoes of the genus Anopheles, remains a significant vector-borne disease worldwide. In 2018, Paraguay became the first country in the Americas in 45 years to be certified malaria-free by the World Health Organization. Between 2016 and 2017, a period with no reported human malaria cases, the presence of Plasmodium spp. in Anopheles mosquitoes was investigated in the departments of Caaguazú and Alto Paraná. These studies found that the most prevalent Anopheles species in Paraguay, including Anopheles albitarsis (59.4%), Anopheles strodei (21.5%), and other Anopheles species in smaller proportions, were all negative to the parasite. The objective of this study was to re-evaluate these presence data and to define environmentally suitable areas for Anopheles spp. and their association with bioclimatic variables using DIVA-GIS/MaxEnt software for the entomological surveillance of malaria risk in Paraguay. Results showed that areas of bioclimatic suitability included the Humid Chaco, Cerrado, Paraná Atlantic Forest, and Southern Cone Mesopotamian savanna ecoregions. The most relevant climatic variables were the precipitation of the wettest month (contribution of 80.4%) and the precipitation of the driest month (contribution of 18.4%). Anopheles albitarsis, also reported as a vector of the Venezuelan equine encephalitis virus in neighbouring countries, was the most abundant mosquito species. Anopheles darlingi, the main vector of malaria in Paraguay, was not found. However, species richness indices (Chao/ACE) suggest that cryptic or sibling species may be present. Finally, the possible succession of Anopheles species and their geographical segregation are discussed in scenarios of entomological surveillance and epidemiological risk. Full article

The emergence and spread of pathogens pose significant challenges to the sustainability and productivity of aquaculture globally. For the Chilean salmon farming industry, salmonid rickettsial septicemia (SRS), caused by the facultative intracellular bacterium Piscirickettsia salmonis, constitutes one of the main disease challenges. In this study, the efficacy of various oral doses of florfenicol (FFC) (5, 7.5, and 10 mg/kg BW/day) against SRS was assessed in Atlantic salmon, when treatment was initiated at an early stage of infection. Since salmonids infected with P. salmonis typically lose appetite as the disease progresses, and the therapeutic FFC dose is dependent on a normal specific feeding rate (SFR), the treatments were administered 5 days post-challenge (DPC5). On the day of challenge, experimental fish were intraperitoneally (IP) injected with 0.2 mL of P. salmonis genogroup LF-89 inoculum (9.07 × 10⁷ CFU mL⁻¹). Fish mortality, behavior, clinical signs of disease, feed intake and SFR were monitored throughout the study. Conclusions: An important finding in this study was that all tested antibiotic doses halted disease progression and prevented mortality in fish challenged with P. salmonis when administered DPC5. In the control group, mortality reached 32.2% with fish displaying clinical signs of SRS. Full article

This study investigated the extent to which the North Atlantic Oscillation (NAO) modulated daily surface-level concentrations of ozone (O₃), nitrogen dioxide (NO₂), and sulfur dioxide (SO₂) on São Miguel Island, Azores, between 2017 and 2021. Using validated data from two air quality monitoring stations, São Gonçalo (SG) (urban background) and Ribeira Grande (RG) (semi-urban), we applied descriptive statistics, seasonal Pearson correlations, and robust linear regression models to assess pollutant responses to NAO variability. The results reveal a significant and positive association between NAO phases and O₃ concentrations, particularly in spring and summer. NO₂ levels exhibited a strong negative correlation with NAO during summer in urban settings, indicating enhanced atmospheric dispersion. In contrast, SO₂ concentrations showed weak and inconsistent relationships with the NAO index, likely reflecting the influence of local and episodic sources. These findings demonstrate that large-scale synoptic drivers such as the NAO can significantly modulate pollutant dynamics in island environments and should be integrated into air quality forecasting and environmental health planning strategies in small island territories. Full article

Very little is known about goose-beaked whales (Ziphius cavirostris) and Sowerby’s beaked whales (Mesoplodon bidens), especially off the western coast of Ireland, due to their elusive behaviors. This study aimed to characterize the acoustics of these beaked whales and investigate whether temporal patterns may affect their occurrences. Using passive acoustic monitoring (PAM), beaked whale bioacoustic clicks were manually analyzed, revealing different click frequency ranges than expected. Double clicks and echoes produced by both beaked whale species were also present, which have previously been infrequently observed in these species. The occurrence of beaked whales and the presence of double clicks and echoes were further investigated, along with how the diel cycle may affect these click characteristics. Hourly presence of goose-beaked whale double clicks and echoes was found to have significance for both day and night. There was no significance found for Sowerby’s beaked whale double clicks and echoes for day and night, along with the hourly occurrences of both beaked whales and the occurrence of other beaked whales. These findings highlight the need for future research on PAM and beaked whale acoustics, which could aid in better monitoring of their presence to address the impacts of human activities. Full article