Nuevos aspectos sobre la ecología de los estados iniciales de desarrollo de Sardina pilchardus (Walbaum, 1792) en el norte del Atlántico ibérico

In the Atlantic Iberian estuaries, sardines tend to be a minor component of the ichthyoplankton assemblages, with rare occurrence largely restricted to estuarine mouths. However, this was not the case of the Lima estuary (NW Portugal), where sardines were the most abundant and frequently occurring marine taxon of the larval fish assemblages. Abundance of sardines collected during a two-year survey (2002-2004) ranged from 0.5 to 60.8 larvae/100 m3, with the majority still showing yolk and unpigmented eyes. Moreover, 80% of sardines were 8 days old or less and the total length ranged from 2 to 16 mm. Seasonal variations of sardine occurrence in the Lima estuary correlated with temporal variations of salinity and temperature in the water column. The unusually high river-flow observed during the winter of 2002-2003, which preceded the spring-summer abundance peak, seemed to act as a signal for the estuarine recruitment that was encountered. In addition, the estuarine occurrence of sardine larvae was also correlated with the intensity of summer upwelling, which was responsible for coastal depletion of sardine larvae resulting in estuarine low catches during the summer of 2002. The Lima estuary also revealed another peculiarity related to the lack of temporal synchrony between coastal spawning activity and occurrence of larvae within the estuary. The abundance peaks of newly-hatched larvae (autumn 2002 and spring-summer 2003) did not coincide with the winter-spring spawning pattern described earlier for the northern Iberian coast. Modifications of the spawning strategy of the northern Iberian sardine stock are discussed based on these new insights into the early life of S. pilchardus.Las sardinas tienden a ser un componente menor del ictioplancton de los estuarios atlánticos ibéricos. Su aparición es rara y restringida, en gran parte, a las desembocaduras de los ríos. Sin embargo, éste no fue el caso del estuario del río Lima (NW Portugal), donde las sardinas fueron la especie marina más abundante del ictioplanton estuarino. Las sardinas fueron recolectadas durante un período de dos años (2002-2004), y su abundancia varió entre 0.5-60.8 larvas/100 m3. La mayoría de dichas larvas todavía presentaban saco vitelino y ojos no pigmentados. Por otra parte, el 80% de las sardinas tenían 1 semana o menos de vida y su longitud total varió entre 2 y 16 mm. Las variaciones estacionales en la aparición de larvas de sardina en el estuario del río Lima se correlacionaron con fluctuaciones temporales de salinidad y de temperatura de la columna de agua. Los elevados caudales del río observados durante el invierno 2002-2003, que precedieron el pico de abundancia del primavera-verano, parecieron actuar como señal para el reclutamiento al estuario. Además, la aparición en el estuario de larvas de sardina también fue controlada por la intensidad del afloramiento de verano, responsable de la disminución de abundancia de larvas de sardina en la costa, lo que dio lugar a bajas capturas en el estuario durante el verano 2002. Además la inusual aparición de larvas de sardina, dentro del estuario del río Lima reveló otra particularidad relacionada con la carencia de sincronía temporal entre la actividad de freza y la aparición de larvas dentro del estuario. Los picos de abundancia de larvas recién eclosionadas (otoño 2002 y período de primavera-verano de 2003) no coincidieron con la época de puesta invernal previamente descrita para la costa norte de la península ibérica. Estos nuevos datos sobre la ecología de los estados iniciales de desarrollo de la sardina se discuten a la luz de las modificaciones de la estrategia reproductiva del stock de sardinas del norte del Atlántico ibérico

Plankton community and copepod production in a temperate coastal lagoon: what is changing in a short temporal scale?

Coastal lagoons are often exposed to intense short-term environmental changes and strong anthropogenic pressures influencing zooplanktonic communities and production. However, most works focus on long-term temporal scales using monthly or seasonal sampling strategies. The present study analysed the structure of the mesozooplanktonic assemblages, the production (egg production rates) and physiological condition (RNA:DNA ratio) of the copepod Acartia clausi in a temperate coastal lagoon (Ria Formosa) during the summer, using an intensive sampling approach. Salinity was the main factor affecting the short-term variability of mesozooplankton composition, followed by tidal phase (ebb tides) and semilunar cycle (spring tides). There was a positive relationship between the abundance of Appendicularia and the cladoceran Penilia avirostris with the toxic dinoflagellate Gymnodinium catenatum, suggesting no deleterious effects. The egg production rate of A. clausi was influenced by salinity and ammonia concentration, with a positive correlation between the egg productivity and the macronutrient, showing a possible adaptation of this calanoid species. The RNA:DNA index was positively related to egg production rate, suggesting that it is a good proxy for the reproductive output of copepods, even in short-term periods. This study shows that different timescales need to be included in regular monitoring of planktonic assemblages in coastal lagoons in order to understand the influence of environmental and anthropogenic variables on marine organisms.Investigador FCT Program: IF/01546/2015. European Regional Development Fund (COMPETE program- Operational Competitiveness Programme), and Portuguese national funds from FCT through projects MODELA (PTDC/MAR/098643/2008), UID/Multi/04326/2016, UID/Multi/04326/2019 and UID/MAR/04292/2013.info:eu-repo/semantics/publishedVersio

Control estacional, lunar y mareal de la dinámica del ictioplancton en la interfaz entre un estuario templado y las aguas costeras adyacentes (oeste de Portugal)

Influence of season, lunar-tide cycle and tide on ichthyoplankton at the interface between Mondego estuary and the adjacent coast and on up-estuary transport was evaluated. Seasonal samples were collected at a fixed station at the mouth of the estuary during diel cycles, at neap and spring tides. Additionally, four sampling stations along the estuary were assessed. Pomatoschistus spp. was the main estuarine taxon, while Sardina pilchardus and Parablennius pilicornis were the most important marine species. Ichthyoplankton entrance and transport along the estuary presented a seasonal pattern with higher densities during summer. Lunar-tide cycle also represented an important influence, structuring communities that reach the estuary and their subsequent distribution. Solea senegalensis and Sardina pilchardus seemed to take advantage of spring tides to enter the estuary. S. pilchardus appear to be using tides to move upstream of the estuary. Ichthyoplankton entrance in the estuary seemed related to species spawning period, while its distribution within the estuary depends on in situ spawning and on the capacity of species to counteract currents and river flow. The present study provides a better understanding of ichthyoplankton dynamics at the interface of two coastal systems, reinforcing knowledge of the lunar-tide cycle influence on ichthyoplankton communities.Se estudió la influencia de la estación, ciclo lunar y mareas entre el estuario del Mondego y las aguas costeras adyacentes sobre el ictioplancton y el transporte de las larvas hasta el estuario. En cada estación del año, el ictioplancton fue muestreado en una estación fija situada en la desembocadura del estuario, realizandose ciclos diarios en mareas muertas y vivas. Además, fueron muestreadas otras cuatro estaciones en el estuario. Pomatoschistus spp. fue la principal especie estuarina mientras que Sardina pilchardus y Parablennius pilicornis fueron las especies marinas más importantes. La entrada de ictioplancton y transporte a lo largo del estuario presentaron un patrón estacional con mayores abundancias en verano. El ciclo lunar tuvo una importante influencia en la estructuración de las comunidades que llegan al estuario y su posterior distribución. Solea senegalensis y Sardina pilchardus parecen tomar ventaja de las mareas vivas para entrar en el estuario. S. pilchardus parece aprovechar las mareas para moverse hacia la parte alta del estuario. La entrada del ictioplancton en el estuario parece estar relacionada con el periodo de desove mientras que su distribución en el estuario depende del desove in situ así como de la capacidad de las especies de contrarrestar las corrientes y el caudal del río. Este estudio proporciona un mejor entendimiento de la dinámica del ictio- plancton en la interfaz de dos sistemas costeros y refuerza el conocimiento de la influencia del ciclo lunar de la marea en las comunidades ictioplanctónicas

Gadolinium ecotoxicity is enhanced in a warmer and acidified changing ocean as shown by the surf clam Spisula solida through a multibiomarker approach

Funding Information: This work was supported by Fundação para a Ciência e Tecnologia (FCT) , through the project Climatoxeel ( PTDC/AAG-GLO/3795/2014 ), by the Junior Researcher contract ( CEECIND/03517/2017 ), both awarded to Tiago F. Grilo, and the strategic project UIDB/04292/2020 granted to MARE and through project LA/P/0069/2020 granted to the Associate Laboratory ARNET . The work was also supported by the European Union's operation program Mar 2020 through the research project CEIC ( MAR-01.04.02-FEAMP-0012 ) awarded to Joana Raimundo. The Applied Molecular Biosciences Unit UCIBIO was financed by national funds from FCT ( UIDP/04378/2020 ). This work was also supported by the European Union through the grant ERC-2016-COG-725034 -ecotox awarded to Inês João Ferreira. Cátia Figueiredo acknowledges the FCT-PhD grant SFRH/BD/130023/2017 and the Early Career Research Grant awarded by National Geographic Society. Publisher Copyright: © 2022 The Author(s)Humans have exhaustively combusted fossil fuels, and released pollutants into the environment, at continuously faster rates resulting in global average temperature increase and seawater pH decrease. Climate change is forecasted to exacerbate the effects of pollutants such as the emergent rare earth elements. Therefore, the objective of this study was to assess the combined effects of rising temperature (Δ = + 4 °C) and decreasing pH (Δ = − 0.4 pH units) on the bioaccumulation and elimination of gadolinium (Gd) in the bioindicator bivalve species Spisula solida (Surf clam). We exposed surf clams to 10 µg L−1 of GdCl3 for seven days, under warming, acidification, and their combination, followed by a depuration phase lasting for another 7 days and investigated the Gd bioaccumulation and oxidative stress-related responses after 1, 3 and 7 days of exposure and the elimination phase. Gadolinium accumulated after just one day with values reaching the highest after 7 days. Gadolinium was not eliminated after 7 days, and elimination is further hampered under climate change scenarios. Warming and acidification, and their interaction did not significantly impact Gd concentration. However, there was a significant interaction on clam's biochemical response. The augmented total antioxidant capacity and lipid peroxidation values show that the significant impacts of Gd on the oxidative stress response are enhanced under warming while the increased superoxide dismutase and catalase values demonstrate the combined impact of Gd, warming & acidification. Ultimately, lipid damage was greater in clams exposed to warming & Gd, which emphasizes the enhanced toxic effects of Gd in a changing ocean.publishersversionpublishe

Ocean warming, acidification, and rare earth elements exposure triggers a superior antioxidant response and pigment production in the adaptable Ulva rigida

European Union's operation program Mar 2020 through the research project CEIC (MAR-01.04.02-FEAMP-0012). Inês João Ferreira acknowledges the European Union research grant ERC-2016-COG-725034-ecotox. Publisher Copyright: © 2022 The Author(s)Anthropogenic increased atmospheric CO2 concentrations will lead to a drop of 0.4 units of seawater pH and ocean warming up to 4.8°C by 2100. Contaminant's toxicity is known to increase under a climate change scenario. Rare earth elements (REE) are emerging contaminants, that until now have no regulation regarding maximum concentration and discharge into the environment and have become vital to new technologies such as electric and hybrid-electric vehicle batteries, wind turbine generators and low-energy lighting. Studies of REE, namely Lanthanum (La) and Gadolinium (Gd), bioaccumulation, elimination, and toxicity in a multi-stressor environment (e.g., warming and acidification) are lacking. Hence, we investigated the algae phytoremediation capacity, the ecotoxicological responses and total chlorophyll and carotenoid contents in Ulva rigida during 7 days of co-exposure to La or Gd (15 µg L−1 or 10 µg L−1, respectively), and warming and acidification. Additionally, we assessed these metals elimination, after a 7-day phase. After one day of experiment La and Gd clearly showed accumulation/adsorption in different patterns, at future conditions. Unlikely for Gd, Warming and Acidification contributed to the lowest La accumulation, and increased elimination. Lanthanum and Gd triggered an adequate activation of the antioxidant defence system, by avoiding lipid damage. Nevertheless, REE exposure in a near-future scenario triggered an overproduction of ROS that requested an enhanced antioxidant response. Additionally, an increase in total chlorophyll and carotenoids could also indicate an unforeseen energy expense, as a response to a multi-stressor environment.publishersversionpublishe

Effect of temperature on the daily increment deposition in the Otoliths of European sardine Sardina pilchardus (Walbaum, 1792) Larvae

Otolith microstructure analysis is a valuable tool to evaluate the relationship between larval age and growth and how it relates to environmental variability. Otolith growth and daily increment deposition were analyzed in sardine (Sardina pilchardus) larvae reared in the laboratory under different temperatures (13, 15, and 17 °C), with a diet rich in microalgae, rotifers, and copepods Acartia grani. The number and width of growth increments, first-check and otolith diameter were determined in the otoliths and then related to larval age and total length. At hatching, the sagittal otoliths consisted of a lenticular core with a diameter of 10.56 μm (±1.07 μm SD). Somatic growth increased with the increasing temperature and the growth rate of larvae reared at 13 and 15 °C was significantly lower than for larvae reared at 17 °C. At 17 °C, otoliths exhibited a higher diameter with wider increments than at 13 °C. There was a high variability of increment counts-at-age for larvae reared within the same temperature treatment. The increase of growth increments with larval size was higher for larvae reared at 17 °C until 35 days post-hatching than those growing at 15 °C. Scanning electronic microscopy confirmed that increments are deposited daily, with an average width smaller than 1 µm and as low as 0.33 μm, therefore impossible to distinguish using light microscopy. At colder temperatures, larval otoliths had thinner and less marked increments and lower growth rates, which can lead to incorrect age determinations. The effect of temperature on the otolith microstructure can help in identifying strong temperature gradients experienced by wild sardine larvae.info:eu-repo/semantics/publishedVersio

Geoética e difusão do conhecimento da natureza

sem Informação2019 se inicia sob o impacto de grande tragédia, com efeitos ambientais devastadores e perda de centenas de vidas humanas. A ruptura da barragem VI de disposição de rejeitos de mineração de ferro, na Mina do Feijão, em Brumadinho, MG, no dia 25 de janeiro1514sem Informaçãosem Informaçãosem Informaçã