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Registros recuperados: 13 | |
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Berger, Laurent; Poncelet, Cyrille; Trenkel, Verena. |
Fish schools can be insonified simultaneously with multifrequency echosounders (e.g. Simrad EK60s) and a multibeam echosounder (e.g. Simrad ME70). This paper presents a method for combining these data to improve estimates of the relative frequency response r(f) of fish schools. Values of r(f) are now commonly used to classify echoes in fishery surveys. The data from the roll- and pitch-stabilized, high-resolution ME70 are used to correct beam-width effects in the multifrequency EK60 data. First, knowing the exact position and orientation of the transducers and the position of the vessel, the echoes are placed into a common geographic coordinate system. Then, the EK60 data are rejected if they do not include a significant percentage of the fish school... |
Tipo: Text |
Palavras-chave: Species identification; Scomber scombrus; Sardina pilchardus; Pelagic fish; Acoustics. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6590.pdf |
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Gatti, Paul; Cominassi, Louise; Duhamel, Erwan; Grellier, Patrick; Le Delliou, Herve; Le Mestre, Sophie; Petitgas, Pierre; Rabiller, Manuella; Spitz, Jerome; Huret, Martin. |
There is a growing interest in monitoring body condition of marine organisms in the context of the ecosystem approach to fisheries and global change. Fish condition is under the influence of environmental variability on seasonal scale, but also on longer timescales. It represents a good indicator of habitat quality or individual fitness, and is also a relevant parameter to evaluate energy transfer through the trophic chain. However, the sources of variability in fish condition need to be accurately understood and the significance of existing indices has to be correctly assessed. Here, we measured the energy density, a precise and global indicator of fish bioenergetic condition, for anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) in the... |
Tipo: Text |
Palavras-chave: Energy density; Calorimetry; Small pelagic fish; Engraulis encrasicolus; Sardina pilchardus; Northeast Atlantic. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00416/52754/53615.pdf |
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Véron, Matthieu; Duhamel, Erwan; Bertignac, Michel; Pawlowski, Lionel; Huret, Martin; Baulier, Loic. |
Age and size at maturation appear as key parameters governing the dynamics of a population as they affect growth rate, fecundity, and survival. The expression of such life history traits is determined by genetic make-up and modulated by environmental factors mainly through phenotypic plasticity. Moreover, fishing, besides decreasing population size and changing demographic composition can alter allelic frequencies through fisheries-induced evolution by selecting for some particular traits. In the Bay of Biscay, a decreasing trend in both sardine body condition and size-at-age has recently been pointed out at the population level. The Probabilistic Maturation Reaction Norm (PMRN) approach was applied to help disentangle phenotypic plasticity and genetic... |
Tipo: Text |
Palavras-chave: Fisheries-induced evolution; Body condition; Phenotypic plasticity; Maturation; Growth; Sardina pilchardus; Bay of biscay. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00660/77203/78637.pdf |
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Queiros, Quentin; Fromentin, Jean-marc; Gasset, Eric; Dutto, Gilbert; Huiban, Camille; Metral, Luisa; Leclerc, Lina; Schull, Quentin; Mckenzie, David; Saraux, Claire. |
Small pelagic fish are key components of marine ecosystems and fisheries worldwide. Despite the absence of recruitment failure and overfishing, pelagic fisheries have been in crisis for a decade in the Western Mediterranean Sea because of a marked decline in sardine size and condition. This situation most probably results from bottom-up control and changes in the plankton community toward smaller plankton. To understand such an unusual phenomenon, we developed an original and innovative experimental approach investigating the mechanisms induced by a reduction in the quantity and size of sardine prey. While experimentations offer the unique opportunity to integrate behavior and ecophysiology in understanding key demographic processes, they remain rarely... |
Tipo: Text |
Palavras-chave: Experimentation; Small pelagics; Sardina pilchardus; Body condition; Bottom-up control. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00505/61669/65585.pdf |
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Silva, A; Carrera, P; Masse, Jacques; Uriarte, A; Santos, M; Oliveira, P; Soares, E; Porteiro, C; Stratoudakis, Y. |
This study describes broad-scale spatial variations in sardine growth across the northeastern Atlantic and Mediterranean waters using opportunistic samples collected in recent years. More detailed information on spatial, decadal and seasonal growth variations is provided for the Iberian-Biscay region using data collected in acoustic surveys since the mid-1980s. Growth curves are fitted to annual or monthly length-at-age data using a robust Von Bertalanffy model; parameters for recent samples are compared with literature information using an auximetric plot while differences between areas within the Iberian-Biscay region are tested by log-likelihood ratio tests. Sardine growth performance is generally lower in the Mediterranean and declines across the... |
Tipo: Text |
Palavras-chave: Iberian Biscay region; Spatio temporal variation; Growth; Sardina pilchardus. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4078.pdf |
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Menu, Clara. |
Small pelagic fish show a general decrease in size and body condition over the past two decades in the North-East Atlantic. The underlying factors are still not well understood, however recent studies point to a bottom-up control. In order to understand how the environment impacts the main biological functions, i.e. growth, reproduction and maintenance, we adopted a bioenergetic modelling framework based on the Dynamic Energy Budget theory. To improve the robustness of our study, we chose a comparative approach between two species, Engraulis encrasicolus and Sardina pilchardus, both living in three areas, namely the English Channel, the Bay of Biscay and the Gulf of Lion. Our model is calibrated over the Bay of Biscay and then applied to the other areas,... |
Tipo: Text |
Palavras-chave: Engraulis encrasicolus; Sardina pilchardus; Théorie Dynamic Energy Budget; Traits d'histoire de vie; Manche; Golfe de Gascogne; Golfe du Lion; Engraulis encrasicolus; Sardina pilchardus; Dynamic Energy Budget theory; Life history traits; English Channel; Bay of Biscay; Gulf of Lion. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00667/77900/80092.pdf |
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Chouvelon, Tiphaine; Strady, Emilie; Harmelin-vivien, Mireille; Radakovitch, Olivier; Brach-papa, Christophe; Crochet, Sylvette; Knoery, Joel; Rozuel, Emmanuelle; Thomas, Bastien; Tronczynski, Jacek; Chiffoleau, Jean-francois. |
Trace metal contamination in the European sardine and anchovy food web was investigated in the Gulf of Lions, NW Mediterranean Sea, including seawater and size fractions of plankton. The results highlighted: i) higher and more variable concentrations in the smaller plankton size classes for all metals except cadmium; ii) higher concentrations in anchovy versus sardine for all elements except lead; iii) different patterns of metal bioaccumulation through the food web: cobalt, nickel, copper, silver, lead and zinc displayed continuously decreasing concentrations (with the exception of increased zinc in fish only), while mercury concentrations dropped considerably in larger plankton size classes and rose significantly in fish. Lastly, cadmium concentrations... |
Tipo: Text |
Palavras-chave: Inorganic elements; Seawater; Size-classed plankton; Sardina pilchardus; Engraulis encrasicolus; Mediterranean Sea. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00511/62286/67906.pdf |
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Santos, Amp; Nieblas, Anne-elise; Verley, P.; Teles-machado, A.; Bonhommeau, Sylvain; Lett, C.; Garrido, S.; Peliz, A.. |
The European sardine (Sardina pilchardus) is the most important small pelagic fishery of the Western Iberia Upwelling Ecosystem (WIUE). Recently, recruitment of this species has declined due to changing environmental conditions. Furthermore, controversies exist regarding its population structure with barriers thought to exist between the Atlantic-Iberian Peninsula, Northern Africa, and the Mediterranean. Few studies have investigated the transport and dispersal of sardine eggs and larvae off Iberia and the subsequent impact on larval recruitment variability. Here, we examine these issues using a Regional Ocean Modeling System climatology (1989-2008) coupled to the Lagrangian transport model, Ichthyop. Using biological parameters from the literature, we... |
Tipo: Text |
Palavras-chave: Iberian Peninsula; Sardina pilchardus; Larval dispersal; Lagrangian transport; Ichthyop; Regional Ocean Modeling System. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00427/53814/54784.pdf |
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Joiris, C.R.; Holsbeek, L.; Laroussi, M.N.. |
This paper reports concentrations of total mercury and methylmercury in muscle, liver and gonads of two sardines (Sardinella aurita, n=184 and Sardina pilchardus, n=87) from three coastal areas off Tunisia. Mercury concentration in muscle and liver showed significant positive correlation with fish length (i.e. with age). The relative methylmercury concentration was high and constant in muscle (>85% MeHg), and was decreasing with age in liver (from 50% to 20%), which might reflect the existence of a slow demethylation process. From the geographic point of view, Hg concentration was similar in the northern and eastern areas (0.32 µg g-1 dw in muscle for Sardinella aurita, 0.41 for Sardina pilchardus), but significantly lower in the southern zone (0.19 and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sardina pilchardus; Sardinella aurita [round sardinella]. |
Ano: 1999 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=6838 |
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Registros recuperados: 13 | |
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