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In a period when the Iberian sardine stock abundance is at its historical minimum, knowledge of the sardine juvenile’s distribution is crucial for the development of fishery management strategies. Generalized additive models were used to relate juvenile sardine presence with geographical variables and spawning grounds (egg abundance) and to model juvenile abundance with the concurrent environmental conditions. Three core areas of juvenile distribution were identified: the Northern Portuguese shelf (centred off Aveiro), the coastal region in the vicinity of the Tagus estuary, and the eastern Gulf of Cadiz. Spatial differences in the relationship between juvenile presence and egg abundances suggest that essential juvenile habitat might partially differ from the prevailing spawning grounds. Models also depicted significant relationships between juvenile abundance, temperature and geographical variables in combination with salinity in the west and with zooplankton in the south. Results indicate that the sardine juvenile distribution along the Iberian Peninsula waters are an outcome of a combination of dynamic processes occurring early in life, such as egg and larva retention, reduced mortality and favourable feeding grounds for both larvae and juveniles. En un periodo de mínimo histórico para el stock de sardina ibérica, el conocimiento de la distribución de los juveniles de sardina resulta crucial para el desarrollo de estrategias de gestión pesquera. Se usaron modelos aditivos generalizados para relacionar la presencia de los juveniles de sardina con las variables geográficas y las principales zonas de desove (abundancia de huevos) y a su vez para relacionar la abundancia de los juveniles con las condiciones ambientales adyacentes. Se identificaron tres zonas centrales: la plataforma norte portuguesa (centrada enfrente de la localidad de Aveiro), la zona costera próxima al estuario del Tajo y la parte este del golfo de Cádiz. Las diferencias espaciales encontradas en la relación entre la presencia de juveniles y la abundancia de huevos sugieren que el hábitat esencial de los juveniles puede diferir parcialmente de las zonas de desove existentes. Los modelos también señalaron relaciones significativas entre la abundancia de juveniles, la temperatura, y las variables geográficas combinadas con la salinidad en el oeste y con el zooplancton en el sur. Los resultados indican que la distribución de los juveniles de sardina a lo largo de las aguas de la Península Ibérica resulta de la combinación de procesos dinámicos que se dan en edades tempranas, cómo la retención de huevos y larvas, una mortalidad reducida y zonas de nutrición con condiciones favorables tanto para larvas cómo para juveniles.

International audience; 1. Elemental analysis of biological calcified structures (e.g. fish otoliths, mollusc shelves, coral skeletons or fish and shark bones) provides invaluable information regarding ecological processes for many aquatic species. Despite this importance, the reduction of the raw data obtained through Laser-ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS) (i.e. the conversion of the machine raw signal into elemental concentrations) remains a challenge as the tools developed so far for carrying out this task have important limitations for aquatic ecologists. 2. Here, we introduce the elementr R-package which provides a handy, reliable and transparent way to reduce elemental data acquired from spot or transect LA-ICPMS analysis of biological calcified structures. This free and open-source software, implemented based on state-of-the-art literature, handles data from both standards and samples, allowing fast and simultaneous calculations of concentration for any chemical element, correction for potential machine drift, and realignment and averaging for sample replicates when needed. 3. The major attributes of elementr are: (i) its user-friendly graphical interface which provides widgets to set all the reduction settings (i.e. no programming skills are required to run it), (ii) its reactivity whereby the software continuously observes any setting change made by the user, re-calculates and displays all updated results, allowing therefore users to visually check the validity of their settings and to tune them if needed and (iii) an object oriented underlying that facilitates subsequent handling of LA-ICPMS data in R. 4. Despite the elementr design being most suited to the needs of aquatic ecologists, its use could be broadened to other research fields (i.e. geology, material engineering) due to its flexibility. Moreover, the open-source approach used for programming this software allows its expansion in order to refine calculation procedures or to add new functionalities.

Chlorophyll-a (Chl a) is a key parameter for the assessment of water quality in coastal and shelf environments. The availability of satellite ocean colour offers the potential of monitoring these regions at unprecedented spatial and temporal scales, as long as a high level of accuracy can be achieved. To use satellite derived Chl a to monitor these environments, it is imperative that rigorous accuracy assessments are undertaken to select the most accurate ocean colour algorithm(s). To this end, the accuracy of a range of ocean colour Chl a algorithms for use with Medium Imaging Resolution Spectrometer (MERIS) Level 2 (L2) Remote Sensing Reflectance (R-rs), using two different atmospheric correction (AC) processors (COASTCOLOUR and MERIS Ground Segment processor version 8.0 - MEGS8.0), were assessed in North West European waters. A total of 594 measurements of R-rs(lambda) and/or Chl a were made in the North Sea, Mediterranean Sea, along the Portuguese Coast English Channel and Celtic Sea between June 2001 and March 2012, where Chl a varied from 0.2 to 35 mg m(-3). The following algorithms were compared: MERIS Case 1 water Chl a algorithm OC4Me, the MERIS Case 2 algorithm Algal Pigment 2 (AP2), the MODIS-Aqua Case 1 Chl a algorithm OC3 adapted for MERIS (OC3Me), the MODIS-Aqua Garver-Siegel-Maritorena algorithm (GSM) adapted for MERIS and the Gohin et al. (2002) algorithm for MERIS (005Me). For both COASTCOLOUR and MEGS8.0 processors, OC5Me was the most accurate Chl a algorithm, which was within similar to 25% of in situ values in these coastal and shelf waters. The uncertainty in MEGS8.0 R(rs)4442) (similar to 17%) was slightly higher compared to COASTCOLOUR (similar to 12%) from 0.3 to 7 mg m(-3) Chl a, but for R-rs(560)the uncertainty was lower for MEGS8.0 (similar to 10%) compared to COASTCOLOUR (similar to 13%), which meant that MEGS8.0 Chl a was more accurate than COASTCOLOUR for all of the Chl a algorithms tested. Compared to 005Me, OC4Me tended to over-estimate Chl a, which was caused by non-algal SPM especially at values >14 g M-3. GSM also over-estimated Chl a, which was caused by variations in absorption coefficient of coloured dissolved organic matter at 442 nm (a(CDOM)(442)). AP2 consistently under-estimated Chl a, especially when non-algal SPM was >4 g m(-3). (C) 2016 Published by Elsevier Inc. All rights reserved. Natural Environment Research Council's National Capability - The Western English Channel Observatory (WCO), NEODAAS European Union - INTERREG IVA 2 Mers Seas Zeeen Cross-border Cooperation Programme [07-027-FR-ISECA] European Space Agency [4000113691/15/I-LG] AQUA-USERS project (EU 7th Framework Programme) [607325] Natural Environment Research Council [pml010008, pml010007]

The benthic genus Ostreopsis contains toxic-bloom forming species and is an important cause of concern in warm-temperate and tropical waters. On the coast of Portugal, NE Atlantic, the occurrence of Ostreopsis cf. siamensis and Ostreopsis cf. ovata has been reported since 2008 and 2011, respectively. This work aims to understand the favorable conditions for high concentrations of Ostreopsis cells in the plankton at two sites, Lagos and Lisbon Bays, located in the South and West coast of Portugal, respectively. This study is based on weekly Ostreopsis abundance data in the plankton, from 2011 to 2017, daily satellite and in situ sea surface temperature (SST), and meteorological and sea state parameters, namely wind stress and significant wave height. The molecular identification of local Ostreopsis spp. is also presented. The maximum cell densities occur between late-summer and autumn. The distribution range of Ostreopsis cf. ovata is restricted to the South coast, while Ostreopsis cf. siamensis has a wider distribution range, being also present on the West coast. In the study period, there was only one occurrence of Ostreopsis spp., in Lagos Bay, with concentrations within the alert phase of monitoring. In Lagos Bay, high Ostreopsis spp. concentrations were related with positive SST anomalies. These high concentrations were often recorded after a period of almost 2-weeks to more than 4-weeks of low sea state ( < 0.6 m), followed by short time events of onshore wind and moderate waves (0.6-1 m). The former conditions are interpreted as favoring bloom development on the substrate and the latter as causing the re-suspension of Ostreopsis cells in the water column. In Lisbon Bay, O. cf. siamensis occurred in the plankton in few occasions and no clear relation could be established with the studied environmental variables. It is here hypothesized that the recent records of O. cf. siamensis in Lisbon Bay may correspond to an early colonization stage of an invasion process. Knowledge gained on Ostreopsis dynamics along the Portuguese coast can be used for both the improvement of benthic harmful algal blooms (BHABs) monitoring in the region and as a basis to design forecasting models. FCTPortuguese Foundation for Science and Technology [SFRH/BPD/121365/2016, SFRH/BD/52560/2014, SFRH/BPD/63106/2009] MARE [UID/MAR/04292/2019] CCMAR [UID/Multi/04326/2013] IPMA [IPMA-BCC-2016-35, SNMB-Monitor/MARE2020]

16 pages, 5 tables, 5 figures, Predator diet is expected to respond to changes in the abundance of important prey items. We investigated whether common dolphin diet has changed with changes in the pelagic fish community off the Iberian Peninsula in recent years, in particular with reference to the decline of sardine (Sardina pilchardus) and the increase of Atlantic chub mackerel (Scomber colias) and scads (Trachurus spp.), and estimated how much fish was removed by common dolphins in coastal waters of mainland Portugal. Based on analysis of stomach contents of stranded animals from 2010 to 2013 (n = 150), we related diet composition to sardine abundance, dolphin size and sex, season and region. Despite the decline in sardine stocks in recent years, sardines were the most important prey of common dolphins, as was previously reported in the 1990s, followed by chub mackerel and scads. However, small sardines have disappeared from the diet, consistent with recent poor recruitment to the stock. The relative importance of these pelagic species in the diet increased significantly with increasing dolphin length. The dietary importance of chub mackerel also varied regionally, with higher intake on the southern coast. Finally, we compared the estimated biomass of fish removed by dolphins with that taken by fisheries. We found that even with the severe quota restrictions on sardine catches, total biomass removed by fisheries was over five times greater than the estimated removal by common dolphins. Our results confirm the previously reported preference for energy-rich prey, especially sardine, suggesting that common dolphins in Portuguese waters specialise in feeding on this species, This work was funded by the projects SafeSea (EEA-Grants) and MarPro (European Commission Life Programme, NAT/PT/00038). This study received additional support from the Portuguese Foundation for Science and Technology (FCT) through grants SFRH/BPD/64889/2009 to A. Marçalo, SFRH/BD/51416/2011 to L. Nicolau, and SFRH/BD/30240/2006 to M. Ferreira. J. Giménez was supported by the Spanish Ministry of Economy and Competitiveness, through the Severo Ochoa Program for Centers of Excellence in R + D + I (SEV-2012-0262).

Statistical models are key for estimating fish distributions based on environmental variables, and validation is generally advocated as indispensable but seldom applied. Generalized Linear Models were applied to distributions of juvenile Solea solea, Solea senegalensis, Platichthys flesus and Dicentrarchus labrax in response to environmental variables throughout Portuguese estuaries. Species-specific Delta models with two sub-models were used: Binomial (presence/absence); Gamma (density when present). Models were fitted and tested on separate data sets to estimate the accuracy and robustness of predictions. Temperature, salinity and mud content in sediment were included in most models for presence/absence; salinity and depth in most models for density (when present). In Binomial models (presence/absence), goodness-of-fit, accuracy and robustness varied concurrently among species, and fair to high accuracy and robustness were attained for all species, in models with poor to high goodness-of-fit. But in Gamma models (density when present), goodness-of-fit was not indicative of accuracy and robustness. Only for Platichthys flesus were Gamma and also coupled Delta models (density) accurate and robust, despite some moderate bias and inconsistency in predicted density. The accuracy and robustness of final density estimations were defined by the accuracy and robustness of the estimations of presence/absence and density (when present) provided by the sub-models. The mismatches between goodness-of-fit, accuracy and robustness of positive density models, as well as the difference in performance of presence/absence and density models demonstrated the importance of validation procedures in the evaluation of the value of habitat suitability models as predictive tools. (C) 2013 Elsevier Ltd. All rights reserved.

The sex ratio is an important trait of natural populations and a key parameter for assessing the reproductive potential and stock status of exploited fish populations. In fisheries research, knowledge on spatial and temporal sex ratio variation can inform on the capacity of a population to support exploitation and environmental changes. Blue whiting (Micromesistius poutassou) shows sexual growth dimorphism after maturation, with females achieving greater lengths than males. The main goal of this work was to investigate seasonal patterns in the blue whiting sex distribution, size structure and condition in three areas along the Portuguese coast (north, southwest and south), based on bottom trawl surveys performed in autumn and winter between 1998 and 2015. Smaller blue whiting (12–24 cm) were found in shallow areas down to 250–300 m while larger individuals (>24 cm) were spread deeper down to 400–500 m. Condition factor Fulton K differed significantly between seasons in all the areas (F = 11.72; p-value

The concentrations of 16 trace elements were investigated and compared for the first time in the digestive and excreting tissues of two Nautilus species (Cephalopoda: Nautiloidea) from two geologically contrasted areas: (1) N. macromphalus from New Caledonia, a region characterized by its richness in nickel ores and its lack of tectonic activities and (2) N. pompilius from the Vanuatu archipelago showing high volcanic and tectonic activities. In both Nautilus species, results clearly highlighted that the digestive gland played a key role in the bioaccumulation and storage of Ag, Cd, Ce, Co, Cu, Fe, La, Nd, V, and Zn whereas As, Cr, Mn, Ni, Pb, and Se were accumulated in a greater extent in the excreting tissues (i.e. pericardial and renal appendages). Despite contrasting environments, no significant difference (p