Browsing by Author "Rosa, Rui"
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- Climate change impacts on seagrass meadows and macroalgal forests: an integrative perspective on acclimation and adaptation potentialPublication . Duarte, Bernardo; Martins, Irene; Rosa, Rui; Matos, Ana R.; Roleda, Michael Y.; Reusch, Thorsten B. H.; Engelen, Aschwin; Serrao, Ester; Pearson, Gareth; Marques, João C.; Caçador, Isabel; Duarte, Carlos M.; Jueterbock, AlexanderMarine macrophytes are the foundation of algal forests and seagrass meadows-some of the most productive and diverse coastal marine ecosystems on the planet. These ecosystems provide nursery grounds and food for fish and invertebrates, coastline protection from erosion, carbon sequestration, and nutrient fixation. For marine macrophytes, temperature is generally the most important range limiting factor, and ocean warming is considered the most severe threat among global climate change factors. Ocean warming induced losses of dominant macrophytes along their equatorial range edges, as well as range extensions into polar regions, are predicted and already documented. While adaptive evolution based on genetic change is considered too slow to keep pace with the increasing rate of anthropogenic environmental changes, rapid adaptation may come about through a set of non-genetic mechanisms involving the functional composition of the associated microbiome, as well as epigenetic modification of the genome and its regulatory effect on gene expression and the activity of transposable elements. While research in terrestrial plants demonstrates that the integration of non-genetic mechanisms provide a more holistic picture of a species' evolutionary potential, research in marine systems is lagging behind. Here, we aim to review the potential of marine macrophytes to acclimatize and adapt to major climate change effects via intraspecific variation at the genetic, epigenetic, and microbiome levels. All three levels create phenotypic variation that may either enhance fitness within individuals (plasticity) or be subject to selection and ultimately, adaptation. We review three of the most important phenotypic variations in a climate change context, including physiological variation, variation in propagation success, and in herbivore resistance. Integrating different levels of plasticity, and adaptability into ecological models will allow to obtain a more holistic understanding of trait variation and a realistic assessment of the future performance and distribution of marine macrophytes. Such multi-disciplinary approach that integrates various levels of intraspecific variation, and their effect on phenotypic and physiological variation, is of crucial importance for the effective management and conservation of seagrasses and macroalgae under climate change.
- Corrigendum: The significance of cephalopod beaks as a research tool: An updatePublication . Xavier, José C.; Golikov, Alexey V.; Queirós, José P.; Perales-Raya, Catalina; Rosas-Luis, Rigoberto; Abreu, José; Bello, Giambattista; Bustamante, Paco; Capaz, Juan Carlos; Dimkovikj, Valerie H.; González, Ángel F.; Guímaro, Hugo; Guerra-Marrero, Airam; Gomes-Pereira, José N.; Hernández-Urcera, Jorge; Kubodera, Tsunemi; Laptikhovsky, Vladimir; Lefkaditou, Evgenia; Lishchenko, Fedor; Luna, Amanda; Liu, Bilin; Pierce, Graham J.; Pissarra, Vasco; Reveillac, Elodie; Romanov, Evgeny V.; Rosa, Rui; Roscian, Marjorie; Rose-Mann, Lisa; Rouget, Isabelle; Sánchez, Pilar; Sánchez-Márquez, Antoni; Seixas, Sónia; Souquet, Louise; Varela, Jaquelino; Vidal, Erica A. G.; Cherel, YvesIn the published article, there was an error in the author list, and author Jorge Hernández-Urcera was erroneously excluded. The corrected author list appears below.
- Does Ocean Sunfish Mola spp. (Tetraodontiformes: Molidae) represent a risk for Tetrodotoxin Poisoning in the Portuguese Coast?Publication . Baptista, Miguel; Braga, Ana Catarina; Rosa, Rui; Reis Costa, PedroTetrodotoxin (TTX) is a potent neurotoxin naturally occurring in terrestrial and marine organisms such as pufferfish. Due to the risk of TTX poisoning, fish of Tetraodontidae family and other puffer-related species must not be placed in the EU markets. This restriction applies to fish of the family Molidae even though no data on toxins’ occurrence is available. In this study, the presence of TTX and its analogues was investigated in the main edible tissue (the white muscle) and the main xenobiotics storage organ (the liver) of ocean sunfish Mola spp. (n = 13) from the South Portuguese coast. HILIC-MS/MS analyses did not reveal TTX in the analyzed samples, suggesting an inexistent or very limited risk of TTX poisoning.
- Gymnodinium catenatum paralytic Shellfish toxin production and photobiological responses under marine heat wavesPublication . Lopes, Vanessa M.; Court, Mélanie; Seco, Martim Costa; Borges, Francisco O.; Vicente, Bernardo; Lage, Sandra; Braga, Ana Catarina; Duarte, Bernardo; Santos, Catarina Frazão; Amorim, Ana; Reis Costa, Pedro; Rosa, RuiMarine 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.
- Hot and toxic: accumulation dynamics and ecotoxicological responses of mussel Mytilus galloprovincialis exposed to marine biotoxins during a marine heatwavePublication . Dias, Marta; Özkan, Busenur; Ramos, João; Marques, António; Rosa, Rui; Reis Costa, Pedro; Maulvault, Ana LuísaClimate change is increasing marine heatwaves (MHWs) frequency and severity worldwide. These extreme events often cause bivalves' mass mortality and facilitate the growth, proliferation and dispersion of toxinproducing microalgae blooms associated with threats to seafood safety. Yet, the interactive effects between MHW and uptake of marine biotoxins by biota are a novel topic still lacking thorough research, from both the ecotoxicological and seafood safety standpoints. This study assessed the effects of a MHW event on the accumulation/elimination dynamics of diarrhetic shellfish toxins in Mytilus galloprovincialis exposed to Prorocentrum lima and the ecotoxicological responses of mussels co-exposed to these two stressors. Results showed that acute exposure to +4 degrees C reduced toxins accumulation (-49 %) and elimination (-77 %) compared to control temperature. Moreover, exposure to MHW and toxins affected mussels' antioxidant activity, lipid and protein damage, and metabolism in a tissue-specific manner. These findings highlight that M. galloprovincialis can face higher vulnerability to toxins when MHW events strike.
- Impacts of climate change on the biogeography of three amnesic shellfish toxin producing diatom speciesPublication . Borges, Francisco O.; Lopes, Vanessa M.; Santos, Catarina Frazão; Reis Costa, Pedro; Rosa, RuiHarmful 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 mi
- Impacts of deoxygenation and hypoxia on shark embryos anti-predator behavior and oxidative stressPublication . Varela, Jaquelino; Martins Rebocho, Sandra; Court, Melanie; Santos, Catarina Pereira; Paula, José Ricardo; Ferreira, Inês João; Diniz, Mário; Repolho, Tiago; Rosa, RuiSimple Summary Despite their importance, sharks are among the most endangered ocean species. In addition to overexploitation and the destruction of their natural habitat, climate change is also known to pose a serious threat to them. Among the physico-chemical changes associated with climate change, oxygen loss has been the least studied in terms of its effect on shark physiology and behavior. In this study, we evaluated the impact of deoxygenation (93% air saturation) and hypoxia (26% air saturation) on the anti-predatory behavior and physiology of temperate shark embryos. We found that hypoxia caused a high mortality (44%), significantly increased embryo movement within capsules, and, consequently, reduced the freezing response behavior (a behavior that allows embryos to be unnoticed by predators). Regarding oxidative stress, most biomarkers analyzed were not impacted by the experimental treatments. Overall, our results suggest that the temperate shark's early life stages showed a certain degree of resilience to deoxygenation but not to hypoxia. Climate change is leading to the loss of oxygen content in the oceans and endangering the survival of many marine species. Due to sea surface temperature warming and changing circulation, the ocean has become more stratified and is consequently losing its oxygen content. Oviparous elasmobranchs are particularly vulnerable as they lay their eggs in coastal and shallow areas, where they experience significant oscillations in oxygen levels. Here, we investigated the effects of deoxygenation (93% air saturation) and hypoxia (26% air saturation) during a short-term period (six days) on the anti-predator avoidance behavior and physiology (oxidative stress) of small-spotted catshark (Scyliorhinus canicula) embryos. Their survival rate decreased to 88% and 56% under deoxygenation and hypoxia, respectively. The tail beat rates were significantly enhanced in the embryos under hypoxia compared to those exposed to deoxygenation and control conditions, and the freeze response duration showed a significant opposite trend. Yet, at the physiological level, through the analyses of key biomarkers (SOD, CAT, GPx, and GST activities as well as HSP70, Ubiquitin, and MDA levels), we found no evidence of increased oxidative stress and cell damage under hypoxia. Thus, the present findings show that the projected end-of-the-century deoxygenation levels elicit neglectable biological effects on shark embryos. On the other hand, hypoxia causes a high embryo mortality rate. Additionally, hypoxia makes embryos more vulnerable to predators, because the increased tail beat frequency will enhance the release of chemical and physical cues that can be detected by predators. The shortening of the shark freeze response under hypoxia also makes the embryos more prone to predation.
- Impaired fish swimming performance following dietary exposure to the marine phycotoxin okadaic acidPublication . Corriere, Mauro; Baptista, Miguel; Paula, Jose R.; Repolho, Tiago; Rosa, Rui; Reis Costa, Pedro; Soliño, LuciaFish are frequently exposed to harmful algal blooms (HAB) and to related toxins. However, the biological effects of okadaic acid (OA), the most abundant and frequent HAB-toxin in Europe, South America and Asia, have been poorly investigated. In this study, fish swimming performance and metabolic rates were investigated in juveniles of Zebra seabream (Diplodus cervinus) exposed to OA-group toxins via dietary route, during three days. Fish fed on contaminated food accumulated up to 455.5 mu g OA equiv. Kg(-1). Significant lower mean critical swimming speed (Ucrit) were observed in fish orally exposed to OA (and its related isomer dinophysistoxin-1, DTX-1) than fish feeding on non-toxic diet. A tendency to higher demands of oxygen consumption was also recorded in OA-exposed fish at higher current velocities. This study indicates that fish may not be affected by OA-group toxins under basal conditions, but suggests a decrease in fitness linked to a reduction in swimming performance of fish exposed to OA under increased stimulus. OA and related toxins are suggested to have a cryptic effect on swimming performance that may be enhanced when fish deals with multiple stressors. Considering that a reduction in swimming performance may have impact on critical activities, such as foraging and escaping from predators, this study highlights the ecological risk associated with dinoflagellate toxic blooms, biotoxins food web transfer and fish contamination.
- Natural geochemical markers reveal environmental history and population connectivity of common cuttlefish in the Atlantic Ocean and Mediterranean SeaPublication . Rooker, Jay R.; Wells, R. J. David; Addis, Piero; Arrizabalaga, Haritz; Baptista, Miguel; Bearzi, Giovanni; Dance, Michael A.; Fraile, Igaratza; Lacoue-Labarthe, Thomas; Lee, Jessica M.; Megalofonou, Persefoni; Rosa, Rui; Sobrino, Ignacio; Sykes, António; Villanueva, RogerNatural markers (delta C-13 and delta O-18 stable isotopes) in the cuttlebones of the European common cuttlefish (Sepia officinalis) were determined for individuals collected across a substantial portion of their range in the Northeast Atlantic Ocean (NEAO) and Mediterranean Sea. Cuttlebone delta C-13 and delta O-18 were quantified for core and edge material to characterize geochemical signatures associated with early (juvenile) and recent (sub-adult/adult) life-history periods, respectively. Regional shifts in cuttlebone delta C-13 and delta O-18 values were detected across the 12 sites investigated. Individuals collected from sites in the NEAO displayed more enriched delta C-13 and delta O-18 values relative to sites in the Mediterranean Sea, with the latter also showing salient differences in both markers among western, central and eastern collection areas. Classification success based on cuttlebone delta C-13 and delta O-18 values to four geographical regions (NEAO, western, central and eastern Mediterranean Sea) was relatively high, suggesting that environmental conditions in each region were distinct and produced area-specific geochemical signatures on the cuttlebones ofS. officinalis. A modified delta C-13 and delta O-18 baseline was developed from sites proximal to the Strait of Gibraltar in both the NEAO and Mediterranean Sea to assess potential mixing through this corridor. Nearly, all (95%) of delta C-13 and delta O-18 signatures ofS. officinaliscollected in the area of the NEAO closest to the Strait of Gibraltar (Gulf of Cadiz) matched the signatures of specimens collected in the western Mediterranean, signifying potential movement and mixing of individuals through this passageway. This study extends the current application of these geochemical markers for assessing the natal origin and population connectivity of this species and potentially other taxa that inhabit this geographical area.
- Occurrence of basking shark Cetorhinus maximus in southern Portuguese waters: a two-decade surveyPublication . Couto, Ana; Queiroz, Nuno; Relvas, Paulo; Baptista, Miguel; Furtado, Miguel; Castro, Joana; Nunes, Maria; Morikawa, Hirofumi; Rosa, RuiThere is a general consensus that many shark species are declining in numbers. However, effective management measures often depend on knowing how trends in abundance and distribution are influenced by environmental conditions. Several efforts to describe the occurrence and distribution of basking sharks Cetorhinus maximus have been made in northern Europe, particularly around the UK, but nothing is known regarding their occurrence in southern areas, such as the south of Portugal. Using 2 decades of observational data collected in the south of Portugal, we show that the occurrence of basking sharks in the area was highly seasonal, with individuals being observed mainly during spring. Based on in situ and satellite-derived environmental variables and climate indices, we also demonstrate that temporal trends were associated with the beginning of the upwelling season and that the inter-annual changes were related to lower values of sea surface temperature, North Atlantic Oscillation index, upwelling index, 2-mo lagged chlorophyll a and 3-mo lagged Atlantic Multidecadal Oscillation index, and higher values of 2-mo lagged upwelling index. These findings suggest that basking sharks are associated with the expansion of cold waters following upwelling events in the region, probably due to the aggregation and increase of zooplankton. Although the temperature recorded during our study years ranged from 14 to 24 degrees C, sharks were mainly observed when temperatures were lower than 20 degrees C, corroborating their preference for colder water. This study provides the first knowledge on the habitat use of basking sharks in southern European Atlantic areas.