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- Evaluating dolphin interactions with bottom-set net fisheries off Southern Iberian Atlantic watersPublication . Vighnesh Samel; Flávia Carvalho; Magda Frade; Marçalo, Ana; Erzini, Karim; Gonçalves, Jorge Manuel SantosThe present study, covering 2018-2022, evaluated the cetacean interactions with a bottom-set net fishery along the mainland Portuguese Southern coast (Algarve), estimating bycatch, depredation, gear damage and net length influence on Landing per Unit Effort (LPUE). The fishery employed various m & eacute;tiers (gillnets - mesh sizes: < 60, 60-75, 80 and 220 mm; trammel nets - 120 inner and 640 mm outer panels). Observations from 655 hauls revealed depredation by bottlenose dolphins in 17.7 % of hauls, while bycatch (isolated events of 4 bottlenose dolphins and one common dolphin) occurred in < 1 %. Depredation typically results in heavy damage to the net and occurs throughout the year, with elevated rates observed during the spring and winter months. Depredation rates varied among m & eacute;tiers, being higher in gears targeting red mullet and hake. The impact of depredation on LPUE varied based on net length and the targeted fish species. However, when comparing LPUE in hauls without depredation, there was no significant influence on the total and hake LPUE for nets shorter or longer than 6 km (p > 0.05). Interestingly, in hauls targeting red mullets without depredation, nets shorter than 6 km had a significantly higher LPUE (p < 0.01) compared to nets 6 km or longer, suggesting that longer nets increase fishing effort due to prolonged soaking times and a higher likelihood of depredation.
- Leader material and bait effects on target and bycatch species caught in an Atlantic Ocean pelagic longline fisheryPublication . Casaca Santos, Catarina; Santos, Miguel N.; Rosa, Daniela; Coelho, RuiThe influence of bait type and leader material on target and bycatch species was assessed through fishing experiments in the Portuguese shallow pelagic longline fishery in the Atlantic Ocean. Wire leaders were found to decrease catch rates of commercially valuable species such as bigeye tuna and yellowfin tuna, while increasing catch rates of elasmobranchs, including the blue shark and shortfin mako. The odds ratios of capture swordfish and tunas also decrease when using wire leaders, while elasmobranchs have higher odds ratios of capture and athaulback mortality when using wire leaders. Squid bait led to higher catches of targeted tuna species, however it also resulted in higher catches of marine turtles. For most of the taxa caught at-haulback mortality risk was found to be higher on squid bait, which may be related with increased deep-hooking events. While bait type and leader material did not significantly affect size selectivity for most species, wire leaders were found to retain larger blue sharks and fish bait attracted smaller-sized swordfish. This study showed that banning wire leaders on pelagic longline fisheries is an effective measure for reducing the retention of pelagic shark species, particularly of large size blue sharks.
- Decoding chemical profiles and biological activities of aerial parts and roots of Eryngium thorifolium Boiss by HPLC-MS/MS, GC-MS and in vitro chemical assaysPublication . Gokhan Zengin; Sakina Yagi; Omayma A. Eldahshan; Abdel Nasser Singab; Selami Selvi; Rodrigues, Maria João; Custódio, Luísa; Stefano Dall’Acqua; Sathish Kumar M Ponnaiya; Shaza H. AlyEryngium species are widely distributed and primarily utilised for medicinal and culinary purposes. This study aimed to evaluate the chemical composition, antioxidant, enzyme inhibition, and cytotoxic properties of various extracts from the aerial parts and roots of E. thorifolium Boiss. The chemical composition of ethyl acetate, methanol, and water extracts was analysed using High-Performance Liquid Chromatography-Electrospray Ionization Tandem Mass Spectrometry (HPLC-ESI-MS/MS), while the hexane ones were examined using Gas Chromatography-Mass Spectrometry (GC-MS) analysis. The most predominant class of secondary metabolites identified were fatty acid amides and flavonoids as hexose conjugates. Extracts from the aerial parts exhibited the highest antioxidant activity, with the methanol and water extracts showing the best anti- 2,2-diphenyl-1-picrylhydrazyl (DPPH) (21.9 mg trolox equivalent (TE)/g) and anti- 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (89.26 mg TE/g) activities. Enzyme inhibition tests revealed that the hexane extract from the roots had the highest anti-acetylcholinesterase activity (2.49 mg galantamine equivalent (GALAE)/g). Additionally, both the hexane and ethyl acetate extracts from the aerial parts demonstrated the highest antibutyrylcholinesterase activity (3.13 and 3.71 mg GALAE/g, p ≥ 0.05). At a concentration of 100 μg/mL, all extracts from the roots and aerial parts, except the water one, displayed potent cytotoxicity against the human embryonic (HEK 293) and murine macrophages (RAW 264.7) cell lines, with cellular viability ranging from 1.66 to 2.62% compared to the control (0.5% DMSO) (89.2 and 95.1%, respectively). Through network pharmacology and molecular docking, the phytochemicals of E. thorifolium show significant potential as natural compounds targeting key proteins involved in cancer progression, including Bcl-2, c-KIT, PI3K, and AKT. Their binding affinities and predicted interactions highlight their possible therapeutic applications in managing various cancers. These findings suggested E. thorifolium is a promising source of phytochemicals targeting specific oxidative stresslinked diseases, including cancer, diabetes and neurodegenerative disorders.
- Let’s measure it: an approach of high-resolution estimates of bottom fixed net fishing effort at national levelPublication . Sales Henriques, Nuno; Erzini, Karim; Gonçalves, Jorge Manuel Santos; Russo, TommasoFisheries are one of the most important food sources for human consumption whilst being amongst the most impacting and extractive activities happening within the marine environment, which makes it imperative to properly manage this activity. To improve fisheries management, the precise quantification of fishing effort is of the outmost importance. Yet, present methods for effort estimation, especially at broad scales, are hampered by difficulties in data access and usually rely on coarse effort metrics or on costly data collection for quantifying fishing effort with higher resolution. In the present work, we propose an approach of high-resolution fishing effort estimates of net fishing, as length of nets operated by a given fleet, at the national level. It relies on sampling of effort, derived from classified and easy to access vessel tracking data - AIS, and fishery dependent data - logbook and landings data. The proposed methodology combines trip-based effort estimates, derived from AIS data, as a foundation to extrapolate the total fishing effort, through the number of fishing trips linked to official landings and logbook data. It is estimated that in the years from 2014 to 2020 an average of 180 200 km of static nets (gillnets and trammel nets), which corresponds to approximately 4.5 and 210 times the lengths of the equator and the Portuguese Atlantic coastline respectively, are used in Portuguese mainland waters each year, by a fleet of slightly more than 100 vessels. The presented methodology allows to quantify and study the variation of the nominal fishing effort, at country level, with a higher resolution than what is usually used and at very low cost. We argue that such methodologies need to be developed and explored in order to have better and more comprehensive estimates of fishing effort which will contribute and improve the sustainable management of fisheries and the marine environment.
- Unveiling the agonistic properties of Preyssler-type Polyoxotungstates on purinergic P2 receptorsPublication . Poejo, Joana; Gumerova, Nadiia I.; Rompel, Annette; Mata, Ana M.; Aureliano, Manuel; Gutierrez-Merino, CarlosThe Preyssler-type polyoxotungstate ({P5W30}) belongs to the family of polyanionic metal-oxides formed by group V and VI metal ions, such as V, Mo and W, commonly known as polyoxometalates (POMs). POMs have demonstrated inhibitory effect on a significant number of ATP-binding proteins in vitro. Purinergic P2 receptors, widely expressed in eukaryotic cells, contain extracellularly oriented ATP-binding sites and play many biological roles with health implications. In this work, we use the immortalized mouse hippocampal neuronal HT-22 cells in culture to study the effects of {P5W30} on the cytosolic Ca2+ concentration. Changes in cytosolic Ca2+ concentration were monitored using fluorescence microscopy of HT-22 cells loaded with the fluorescent Ca2+ indicator Fluo3. 31P-Nuclear magnetic resonance measurements of {P5W30} indicate its stability in the medium used for cytosolic Ca2+ measurements for over 30 min. The findings reveal that addition of {P5W30} to the extracellular medium induces a sustained increase of the cytosolic Ca2+ concentration within minutes. This Ca2+ increase is triggered by extracellular Ca2+ entry into the cells and is dose-dependent, with a half-of-effect concentration of 0.25 ± 0.05 μM {P5W30}. In addition, after the {P5W30}-induced cytosolic Ca2+ increase, the transient Ca2+ peak induced by extracellular ATP is reduced up to 100% with an apparent half-of-effect concentration of 0.15 ± 0.05 μM {P5W30}. Activation of metabotropic purinergic P2 receptors affords about 80% contribution to the increase of Fluo3 fluorescence elicited by {P5W30} in HT-22 cells, whereas ionotropic receptors contribute, at most, with 20%. These results suggest that {P5W30} could serve as a novel agonist of purinergic P2 receptors.
- Optimization of strontium removal by tetraselmis chui grown in bubble column photobioreactorsPublication . Segovia-Campos, Inés; Filella, Montserrat; Zahid, Muhammad Saad Bin; Perron, Karl; Barreira, Luísa; Ariztegui, DanielGreen microalgae of the class Chlorodendrophyceae have recently attracted the interest of researchers due to their ability to form micropearls (intracellular inclusions of amorphous calcium carbonate) highly enriched in Sr. The marine species Tetraselmis chui (included in the class Chlorodendrophyceae) shows high uptake of both stable and radioactive Sr isotopes and has been suggested as a potential candidate for the development of new bioremediation tools regarding radioactive Sr-90 pollution. In this study, we optimized Sr removal from seawater by growing T. chui in 1-L bubble column photobioreactors (PBRs) with and without CO2 supply. Culturing T. chui in bubble column PBRs greatly improves cell production and Sr removal compared to previous studies. Furthermore, the addition of 10 mL L-1 h(-1) CO2 further accelerates T. chui growth and results in better Sr removal rates. This study presents promising results for the development of new bioremediation methods to treat Sr-90 pollution.
- Insight into the efficiency of microalgae’ lipidic extracts as photosensitizers for Antimicrobial Photodynamic Therapy against Staphylococcus aureusPublication . Mendonça, Inês; Silva, Daniela; Conde, Tiago; Maurício, Tatiana; Cardoso, Helena; Pereira, Hugo; Bartolomeu, Maria; Vieira, Cátia; Domingues, M. Rosário; Almeida, AdelaideAntibacterial resistance causes around 1.27 million deaths annually around the globe and has been recognized as a top 3 priority health threat. Antimicrobial photodynamic therapy (aPDT) is considered a promising alternative to conventional antibiotic treatments. Algal lipid extracts have shown antibacterial effects when used as photosensitizers (PSs) in aPDT. In this work we assessed the photodynamic efficiency of lipidic extracts of microalgae belonging to different phyla (Bacillariophyta, Chlorophyta, Cyanobacteria, Haptophyta, Ochrophyta and Rhodophyta). All the extracts (at 1 mg mL−1) demonstrated a reduction of Staphylococcus aureus >3 log10 (CFU mL−1), exhibiting bactericidal activity. Bacillariophyta and Haptophyta extracts were the top-performing phyla against S. aureus, achieving a reduction >6 log10 (CFU mL−1) with light doses of 60 J cm−2 (Bacillariophyta) and 90 J cm−2 (Haptophyta). The photodynamic properties of the Bacillariophyta Phaeodactylum tricornutum and the Haptophyta Tisochrysis lutea, the best effective microalgae lipid extracts, were also assessed at lower concentrations (75 μg mL−1, 7.5 μg mL−1, and 3.75 μg mL−1), reaching, in general, inactivation rates higher than those obtained with the widely used PSs, such as Methylene Blue and Chlorine e6, at lower concentration and light dose. The presence of chlorophyll c, which can absorb a greater amount of energy than chlorophylls a and b; rich content of polyunsaturated fatty acids (PUFAs) and fucoxanthin, which can also produce ROS, e.g. singlet oxygen (1O2), when photo-energized; a lack of photoprotective carotenoids such as β-carotene, and low content of tocopherol, were associated with the algal extracts with higher antimicrobial activity against S. aureus. The bactericidal activity exhibited by the extracts seems to result from the photooxidation of microalgae PUFAs by the 1O2 and/or other ROS produced by irradiated chlorophylls/carotenoids, which eventually led to bacterial lipid peroxidation and cell death, but further studies are needed to confirm this hypothesis. These results revealed the potential of an unexplored source of natural photosensitizers (microalgae lipid extracts) that can be used as PSs in aPDT as an alternative to conventional antibiotic treatments, and even to conventional PSs, to combat antibacterial resistance.
- The archaeological visibility of chimpanzee (Pan troglodytes) nut-crackingPublication . Proffitt, Tomos; Pacome, Serge Soiret; Reeves, Jonathan S.; Wittig, Roman M.; Luncz, Lydia V.The earliest evidence for complex tool use in the archaeological record dates to 3.3 Ma. While wooden tools may have been used by our earliest ancestors, the evidence is absent due to poor preservation. However, insights into possible early hominin wooden tool use can be gained from observing the tool-use practices of our closest living relatives, chimpanzees (Pan troglodytes). By using stone hammers used to crack various nuts, chimpanzees leave a durable material signature comprised of formal tools and associated diagnostic fragments. While the archaeological evidence of chimpanzee wooden tool use is temporary, the combination of stone hammers and wooden anvils can create a more enduring lithic record. This study explores the lithic assemblages associated with wooden and stone anvil use at nut-cracking sites in Ta & iuml; National Park, C & ocirc;te d'Ivoire, using technological and use-wear analyses. Our results indicate clear differences in density, fracture patterns, and use-wear in the lithic records between wooden anvil and stone anvil sites. New archaeological excavations at six chimpanzee nut-cracking sites reveal that the anvils' material directly influences the visibility of nut-cracking evidence in the archaeological record. By examining the nature of the lithic signatures associated with wooden anvil and stone anvil use by chimpanzees, we can formulate hypotheses about the probability of such behaviors being preserved and identifiable in the Plio-Pleistocene hominin archaeological record. The variability in material signatures from nut-cracking on different anvils suggests that stone anvils leave a clear archaeological record. Evidence for wooden anvil use is likely underrepresented due to the more ephemeral nature of the associated percussive damage and material signature. It may, however, still be possible, albeit challenging, to identify wooden anvil use in the archaeological record.
- Paleolandscape evolution along the coasts of the Baixo Alentejo (Portugal) during the quaternaryPublication . Goy, J.L.; Roquero, E.; Zazo, C.; Moura, Delminda; Dabrio, C.J.; Boski, Tomasz; Martínez-Graña, A.; Lario, J.; Bardají, T.A detailed geomorphological mapping allowed to understand the complex relationships interplayed between local tectonics and sedimentation across the coastal area of the Baixo Alentejo (Portugal) all along the Quaternary. Different outcrops of coastal sediments between Sines and Vilanova de Milfontes permitted to reconstruct a general sequence of up to fifteen stair-cased marine terraces, while wide sequences of alluvial fans develop in the hinterland. The distinct geomorphological disposition of these alluvial fans together with the presence/absence of marine terraces, have allowed to define different phases of paleolandscape evolution based both in sea level changes and differential uplift. A dune system has been attributed to MIS 5e in basis of OSL, and C-14 and U-series dating permitted the adscription of a beach unit to MIS 5. These data allowed to stablish the relative chronology of the entire marine terrace sequence and to determine the vertical movement rates along the studied coastal area. The results give values ranging from slight uplift (+0.015mm/a) to subtle subsidence (-0.030 mm/a), coinciding with other author's determinations.
- Millennial‐Scale Climate Variability Potentially Shaped the Early Interglacial Optimum in Southern EuropePublication . Desprat, Stéphanie; Guillem, Gauthier; Sánchez Goñi, Maria Fernanda; Rodrigues, Teresa; Yin, Qiuzhen; Grimalt, Joan O.The seasonal and latitudinal distribution of insolation is considered the main factor controlling the magnitude and timing of interglacial periods. However, despite small differences in insolation forcing, vegetation and hydrology in southern Europe during past interglacials are variable and the gradual change in insolation cannot explain the observed short‐lived forest optimum. Here we focus on vegetation and hydroclimatic changes at orbital‐ and suborbital‐scales in southwestern Europe during two past warm interglacial periods with reduced ice‐sheets, namely Marine Isotope Stages (MIS) 9e and 5e. We provide new pollen and sea surface temperatures records for MIS 9e from IODP Site U1385. This pollen record shows a forest expansion in southern Iberia over a 14 ky interval, bracketed by the millennial‐scale cooling events of Termination IV and MIS 9d. Between 334.5 and 332.5 ka, forest expansion reached a maximum, suggesting increased winter moisture during early MIS 9e. Model‐data comparison for MIS 9e and 5e shows that insolation is the main driver of the orbital‐scale vegetation and precipitation changes in Iberia, atmospheric CO2 forcing playing a secondary role. The high‐frequency component of the MIS 9e and 5e forest timeseries highlights the early interglacial forest and precipitation maxima as prominent suborbital events lasting ∼2 ky. We propose that the primarily insolation‐driven forest and precipitation optima were fostered by the non‐equilibrium conditions generated by the millennial‐scale deglacial variability during the early interglacials. Additionally, the early end of these optima may have been favored by a cooling and drying event that is part of the persistent intra‐interglacial variability.