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- Early life stage mechanisms of an active fish species to cope with ocean warming and hypoxia as interacting stressorsPublication . Lima, André R.A.; Booms, Emily M.; Lopes, Ana Rita; Martins-Cardoso, Sara; Novais, Sara C; Lemos, Marco F.L.; Ribeiro, Laura; Castanho, Sara; Candeias-Mendes, Ana; Pousão-Ferreira, Pedro; Faria, Ana M.Ocean’s characteristics are rapidly changing, modifying environmental suitability for early life stages of fish. We assessed whether the chronic effects of warming (24 ◦C) and hypoxia (<2–2.5 mg L− 1 ) will be amplified by the combination of these stressors on mortality, growth, behaviour, metabolism and oxidative stress of early stages of the white seabream Diplodus sargus. Combined warming and hypoxia synergistically increased larval mortality by >51%. Warming induced faster growth in length and slower gains in weight when compared to other treatments. Boldness and exploration were not directly affected, but swimming activity increased under all test treatments. Under the combination of warming and hypoxia, routine metabolic rate (RMR) significantly decreases when compared to other treatments and shows a negative thermal dependence. Superoxide dismutase and catalase activities increased under warming and were maintained similar to control levels under hypoxia or under combined stressors. Under hypoxia, the enzymatic activities were not enough to prevent oxidative damages as lipid peroxidation and DNA damage increased above control levels. Hypoxia reduced electron transport system activity (cellular respiration) and isocitrate dehydrogenase activity (aerobic metabolism) below control levels. However, lactate dehydrogenase activity (anaerobic metabolism) did not differ among treatments. A Redundancy Analysis showed that ~99% of the variability in mortality, growth, behaviour and RMR among treatments can be explained by molecular responses. Mortality and growth are highly influenced by oxidative stress and energy metabolism, exhibiting a positive relationship with reactive oxygen species and a negative relationship with aerobic metabolism, regardless of treatment. Under hypoxic condition, RMR, boldness and swimming activity have a positive relationship with anaerobic metabolism regardless of temperature. Thus, seabreams may use anaerobic reliance to counterbalance the effects of the stressors on RMR, activity and growth. The outcomes suggests that early life stages of white seabream overcame the single and combined effects of hypoxia and warming.
- Targeted sequencing of mitochondrial genes reveals signatures of molecular adaptation in a nearly panmictic small pelagic fish speciesPublication . Baltazar-Soares, Miguel; Lima, André R.A.; Silva, GonçaloOngoing climatic changes, with predictable impacts on marine environmental conditions, are expected to trigger organismal responses. Recent evidence shows that, in some marine species, variation in mitochondrial genes involved in the aerobic conversion of oxygen into ATP at the cellular level correlate with gradients of sea surface temperature and gradients of dissolved oxygen. Here, we investigated the adaptive potential of the European sardine Sardina pilchardus populations offshore the Iberian Peninsula. We performed a seascape genetics approach that consisted of the high throughput sequencing of mitochondria's ATP6, COI, CYTB and ND5 and five microsatellite loci on 96 individuals coupled with environmental information on sea surface temperature and dissolved oxygen across five sampling locations. Results show that, despite sardines forming a nearly panmictic population around Iberian Peninsula, haplotype frequency distribution can be explained by gradients of minimum sea surface temperature and dissolved oxygen. We further identified that the frequencies of the most common CYTB and ATP6 haplotypes negatively correlate with minimum sea surface temperature across the sampled area, suggestive of a signature of selection. With signatures of selection superimposed on highly connected populations, sardines may be able to follow environmental optima and shift their distribution northwards as a response to the increasing sea surface temperatures.
- Editorial: Microplastics in the marine environment: Sources, distribution, biological effects and socio-economic impactsPublication . Frias, Cátia P.; Sul, Juliana A. Ivar do; Panti, Cristina; Lima, André R. A.inexistente
- Habitat suitability of two flagship species, hippocampus hippocampus and hippocampus guttulatus, in the Atlantic coast of the Iberian Peninsula - implications for conservationPublication . Peiffer, Friederike; Lima, André R.A.; Henriques, Sofia; Pardal, Miguel; Martinho, Filipe; Gonçalves, Jorge M.S.; Gonçalves, Emanuel J.; Correia, Miguel; Silva, Gonçalo Jorge FrancoAnthropogenic pressures on marine ecosystems are increasing worldwide, causing loss of biodiversity and ecosystem functioning, and driving species towards risk of extinction. To protect vulnerable species and habitats, Marine Protected Areas (MPAs) are increasingly established worldwide as conservation measures. Seahorses act as flagship species for coastal ecosystem conservation due to their charismatic appearance and high vulnerability to habitat degradation. Here, the habitat suitability of the two European seahorse species, Hippocampus hippocampus and Hippocampus guttulatus, was assessed along the western Iberian Peninsula, using an ensemble species distribution modelling approach. Furthermore, the coverage of their core habitat (relative habitat suitability (HS) ≥ 0.5) with MPAs was estimated. The results show that the main drivers for habitat suitability were distance to the coast, aspect of the seafloor, tidal amplitude, and temperature. However, the importance differed between the two species. The suitable habitat of H. hippocampus extended to higher distances to the coast, while H. guttulatus were mostly restricted to areas in the vicinity of the coast and facing away from the open sea (i.e., the westerly aspect of the seafloor). Furthermore, temperature contributes more to the variation in habitat suitability in H. hippocampus than in H. guttulatus. The areas with the highest habitat suitability are estuarine or inlet waters and sheltered coasts in northwestern Spain, central and south of Portugal. Both species’ core habitats are covered by about 19–20 % with implemented protected areas in Portugal. In comparison, there is less coverage for both species in Spain, with 12 % for H. guttulatus and 6 % for H. hippocampus. Besides, zones of full protection cover less than 0.5 % of
- Seasonal approach to forecast the suitability of spawning habitats of a temperate small pelagic fish under a high-emission climate change scenarioPublication . Lima, André R.A.; Garrido, Susana; Riveiro, I.; Rodrigues, Diana; Angélico, Maria M. P.; Gonçalves, Emanuel J.; Peck, Myron A.; Silva, GonçaloABSTRACT: Spawning habitats of cold-water, European small pelagic fishes have shifted poleward in the last three decades coincident with gradual ocean warming. We predicted present-day, season-specific habitat suitability for spawning by European sardine Sardina pichardus in the Atlantic Ocean and Mediterranean and Black Seas, and projected climate-driven changes in suitable areas from 2050-2099 under the IPCC – RCP 8.5 scenario. Sea surface temperature and distance to the coast had the greater influences in spawning habitats, reflecting the temperature- and coastal-dependent spawning of sardines. Chlorophyll-a was the third most important explanatory variable for spawning in winter to summer. Winds were predominantly important during autumn, whilst sea surface salinity was an important driver during spring and summer. Presentday, “hotspots” for spawning were identified in regions of highly productive, salty waters, where SST was between 6 and 18°C from autumn to spring or 16 and 25°C during summer and favourable winds occurred that would retain eggs and larvae closer to the coast (< 250 km). For future scenarios, forecasts indicate that environmental optima for spawning is projected to be in regions where SST varies between 11°C and 18°C from autumn to spring; and between 18°C and 24°C during summer. However, a negative relationship between phytoplankton productivity and habitat suitability induced by warming is likely to occur in the future. Projections suggest that suitable spawning habitats in all seasons will shift to higher latitudes, with a prominent range expansion along the coast of Norway during winter and autumn (> 83%). The total spawning area, however, was projected to contract in the future during spring (-10.5%) and autumn (-4.1%) due to losses of currently suitable areas along the Atlantic African Coast and Mediterranean Sea. Such regions currently support the greatest sardine stocks but climate-driven warming and decreased plankton productivity are projected to make these areas unsuitable for spawning and likely also for sardine fisheries in future.
- Forecasting shifts in habitat suitability across the distribution range of a temperate small pelagic fish under different scenarios of climate changePublication . Lima, André R.A.; Baltazar-Soares, Miguel; Garrido, Susana; Riveiro, I. (Isabel); Carrera, Pablo; Piecho-Santos, A. Miguel; Peck, Myron; Silva, GonçaloClimate change often leads to shifts in the distribution of small pelagic fish, likely by changing the matchmismatch dynamics between these sensitive species within their environmental optima. Using present-day habitat suitability, we projected how different scenarios of climate change (IPCC Representative Concentration Pathways 2.6, 4.5 and 8.5) may alter the large scale distribution of European sardine Sardina pilchardus (a model species) by 2050 and 2100. We evaluated the variability of species-specific environmental optima allowing a comparison between present-day and future scenarios. Regardless of the scenario, sea surface temperature and salinity and the interaction between current velocity and distance to the nearest coast were the main descriptors responsible for the main effects on sardine's distribution. Present-day and future potential “hotspots” for sardine were neritic zones (<250 km) withwater currents <0.4ms−1, where SST was between 10 and 22 °C and SSS>20 (PSU), on average.Most variability in projected shifts among climatic scenarioswas in habitats with moderate to low suitability. By the end of this century, habitat suitability was projected to increase in the Canary Islands, Iberian Peninsula, central North Sea, northern Mediterranean, and eastern Black Sea and to decrease in the Atlantic African coast, southwest Mediterranean, English Channel, northern North Sea and Western U.K. A gradual poleward-eastward shift in sardine distribution was also projected among scenarios. This shift was most pronounced in 2100 under RCP 8.5. In that scenario, sardines had a 9.6% range expansion which included waters along the entire coast of Norway up and into the White Sea. As habitat suitability is mediated by the synergic effects of climate variability and change on species fitness, it is critical to apply models with robust underlying species-habitat data that integrate knowledge on the full range of processes shaping species productivity and distribution.
- Integrated behavioural and physiological responses of sand smelt larvae to the effects of warming and hypoxia as combined stressorsPublication . Lima, André R.A.; Lopes, Ana Rita; Martins-Cardoso, Sara; Moutinho, Ariana B.; Lemos, Marco F.L.; Novais, Sara C; Faria, Ana M.Forecasts indicate that rising temperatures towards the future and the expansion of dead zones will change environmental suitability for fish early stages. Therefore, we assessed the chronic effects of warming (26 ◦C), hypoxia (<2–2.5 mg L− 1 ) or their combination on mortality rate, growth, behaviour, energy metabolism and oxidative stress using Atherina presbyter larvae as a model species. There were no differences between the treatments in terms of mortality rate. The combination of warming and hypoxia induced faster loss of body mass (+22.7%). Warming, hypoxia or their combination enhanced boldness (+14.7–25.4%), but decreased exploration (− 95%–121%), increased the time in frozen state (+60.6–80.5%) and depleted swimming speed (− 45.6–50.5%). Moreover, routine metabolic rate was depleted under hypoxia or under the combination of warming and hypoxia (− 56.6 and 57.2%, respectively). Under hypoxia, increased catalase activity (+56.3%) indicates some level of antioxidant defence capacity, although increased DNA damage (+25.2%) has also been observed. Larvae also exhibited a great capacity to maintain the anaerobic metabolism stable in all situations, but the aerobic metabolism is enhanced (+19.3%) when exposed to the combination of both stressors. The integrative approach showed that changes in most target responses can be explained physiologically by oxidative stress responses. Increased oxidative damages (lipid peroxidation and DNA damage) and increased interaction between antioxidant enzymes (superoxide dismutase and catalase) are associated to increased time in frozen state and decreased swimming activity, growth rates and boldness. Under all stressful situations, larvae reduced energy-consuming behaviours (e.g. depleted exploration and swimming activity) likely to stabilize or compensate for the aerobic and anaerobic metabolisms. Despite being an active small pelagic fish, we concluded that the sensitive larval phase exhibited complex coping strategies to physiologically acclimate under thermal and hypoxic stress via behavioural responses.
- Global patterns for the spatial distribution of floating microfibers: Arctic Ocean as a potential accumulation zonePublication . Lima, André R.A.; Ferreira, Guilherme V.B.; Barrows, Abigail P.W.; Christiansen, Katie S.; Treinish, Gregg; Toshack, Michelle C.Despite their representativeness, most studies to date have underestimated the amount of microfibers (MFs) in the marine environment. Therefore, further research is still necessary to identify key processes governing MF distribution. Here, the interaction among surface water temperature, salinity, currents and winds explained the patterns of MF accumulation. The estimated density of floating MFs is ~5900 ± 6800 items m 3 in the global ocean; and three patterns of accumulation were predicted by the proposed model: (i) intermediate densities in ocean gyres, Seas of Japan and of Okhotsk, Mediterranean and around the Antarctic Ocean; (ii) high densities in the Arctic Ocean; and (iii) point zones of highest densities inside the Arctic Seas. Coastal areas and upwelling systems have low accumulation potential. At the same time, zones of divergences between westerlies and trade winds, located above the tropical oceanic gyres, are predicted to accumulate MFs. In addition, it is likely that the warm branch of the thermohaline circulation has an important role in the transport of MFs towards the Arctic Ocean, emphasizing that surface water masses are important predictors. This study highlights that the Arctic Ocean is a dead end for floating MFs.
- Towards a unified eco-evolutionary framework for fisheries management: Coupling advances in next-generation sequencing with species distribution modellingPublication . Baltazar-Soares, Miguel; Lima, André R.A.; Silva, Gonçalo; Gaget, ElieThe establishment of high-throughput sequencing technologies and subsequent large-scale genomic datasets has flourished across fields of fundamental biological sciences. The introduction of genomic resources in fisheries management has been proposed from multiple angles, ranging from an accurate re-definition of geographical limitations of stocks and connectivity, identification of fine-scale stock structure linked to locally adapted subpopulations, or even the integration with individual-based biophysical models to explore life history strategies. While those clearly enhance our perception of patterns at the light of a spatial scale, temporal depth and consequently forecasting ability might be compromised as an analytical trade-off. Here, we present a framework to reinforce our understanding of stock dynamics by adding also a temporal point of view. We propose to integrate genomic information on temporal projections of species distributions computed by Species Distribution Models (SDMs). SDMs have the potential to project the current and future distribution ranges of a given species from relevant environmental predictors. These projections serve as tools to inform about range expansions and contractions of fish stocks and suggest either suitable locations or local extirpations that may arise in the future. However, SDMs assume that the whole population respond homogenously to the range of environmental conditions. Here, we conceptualize a framework that leverages a conventional Bayesian joint-SDM approach with the incorporation of genomic data. We propose that introducing genomic information at the basis of a joint-SDM will explore the range of suitable habitats where stocks could thrive in the future as a function of their current evolutionary potential.