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| Registros recuperados: 65 | |
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| Gauthier, Olivier; Sarrazin, Jozee; Desbruyeres, Daniel. |
| Our knowledge of species diversity in deep-sea chemosynthetic communities has come a long way since their discovery in the late 1970s, However, their study poses serious challenges that are linked to their remoteness, the variable selectivity and effectiveness of sampling tools in different conditions, a lack of consensus on the size compartments and sieve size used in practice, and the persistent discovery of species that are previously unknown to science. Still, with increasing accessibility and new sampling tools, quantitative data are becoming both more frequent and extensive, reducing limitations in the estimation and comparison of species diversity. Here, we review the literature for common difficulties encountered in the measurement and comparison... |
| Tipo: Text |
Palavras-chave: Deep-sea ecosystems; Chemosynthetic community; Species diversity; Richness; Evenness; Rarefaction; Diversity profiles; Diversity ordering; Alpha diversity; Statistical analysis. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00001/11274/7842.pdf |
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| Mante, C; Durbec, Jp; Dauvin, Jc. |
| Statistical analysis of long-term changes in marine communities generally involves recourse to multivariate methods. Some of these, such as Correspondence Analysis (CA), are very sensitive to the presence of rare species in the data, whereas other methods, such as Principal Components analysis (PCA) or Multidimensional Scaling (MDS) are only sensitive to the dominant species. Thus, it is necessary to identify rare species. We used an original method of species determination, based on a multinomial scheme and permitting the generalization of the classical presence/absence coding from a probabilistic viewpoint. This selection method was applied to the identification of the different categories of species (rare, intermediate or dominant) that constitute the... |
| Tipo: Text |
Palavras-chave: Statistical analysis; Probability; Long-term changes; Macrobenthic community. |
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00093/20428/18095.pdf |
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| Lakshmanaperumalsamy, P; Chandramohan, D; Natarajan, R. |
| A seasonal study on the occurrence and distribution of total aerobic microbial population (TMP), total aerobic heterotrophic bacteria (THB), actinomycetes and fungi in the sediments of Vellar Estuary, South India (11 degree 29'N 79 degree 46'E) was carried out during Jan. to Dec. 1975. Sediment samples were collected at monthly intervals, from 4 stations and analysed microbiologically. In general, bacterial population was found to be dominant followed by actinomycetes and fungi. The max peak for TMP, THB and fungi were recorded in Nov. in all stations. Monsoon season supported TMP, THB and fungi to a high level and it was summer for actinomycetes. Statistical analysis (Kendall's tau) showed a significantly positive correlation among TMP, THB, actinomycetes... |
| Tipo: Text |
Palavras-chave: Actinomycetes; Population number; Statistical analysis; Seasonal variations; Fungi; Bacteria; Sediment analysis; Microbiological analysis. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-943.pdf |
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| Mili, S.; Jarboui, O.; Missaoui, H.. |
| Pour l’étude biométrique de la squille Squilla mantis, un échantillonnage régulier a été réalisé dans le golfe de Tunis, le golfe de Hammamet et le golfe de Gabès de janvier 2005 à décembre 2006. Les équations morphométriques de la squille, dans le golfe de Gabès, ont montré que la croissance relative du telson, celle de la masse totale et celle de la masse éviscérée par rapport à celle du céphalothorax sont caractérisées par une allométrie positive. Par contre, la longueur totale croît négativement par rapport à celle du céphalothorax. Pour le golfe de Hammamet, ces caractères ont une croissance marquée par une allométrie négative à part la masse éviscérée. Les équations morphométriques de la squille du golfe de Tunis ont montré une allométrie positive... |
| Tipo: Journal Contribution |
Palavras-chave: Biometrics; Comparative studies; Population dynamics; Population structure; Statistical analysis; Squilla mantis; Http://aims.fao.org/aos/agrovoc/c_46197. |
| Ano: 2008 |
URL: http://hdl.handle.net/1834/4241 |
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| Pérez, M.; Massa, A.M.; Cordo, H.D.. |
| Patagonian smoothhound (Mustelus schmitti) is one of the predominant cartilaginous fishes of the Argentine Sea (SW Atlantic Ocean). It is caught, mainly, in the coastal multispecific fishery with nearly other 30 bony and cartilaginous species. The group is known as ‘variado costero’. In this work the smoothhound abundance indices (CPUE) and standardized efforts for the 1992-2008 period in the area between 34~’S-42~’S were estimated. The General Lineal Model (GLM) and data derived from the argentine commercial fleet were used. Other aspects that could affect estimates and trends of the annual indices were also analyzed. Mean CPUE values estimated with the GLM, considered as annual standardized abundance indices, show an increasing trend as of 2000; the... |
| Tipo: Journal Contribution |
Palavras-chave: Abundance; Catch/effort; Coastal fisheries; Statistical analysis; Mustelus schmitti; Marine environment. |
| Ano: 2011 |
URL: http://hdl.handle.net/1834/4881 |
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| Dato, C.V.; Bambill, G.A.; Cañete, G.R.; Villarino, M.F.; Aubone, A.. |
| Based on the comparison between length composition of landings and that of research cruises, filtered by the selectivity of the mesh used by the commercial fleet, to rebuild length distribution of catches, an indirect quantitative method was developed and used to estimate, in weight and number, the individuals discarded by the commercial fleet south of 41° S. Discards ranged between 15,563 and 46,113 annual tons in the 1986-1993 period which represented 10-13% in weight and 28-32% in number of actual catches, composed of around 87% of individuals age group 1, 12% of age group 2 and the rest of individuals age groups 0 and 3. |
| Tipo: Journal Contribution |
Palavras-chave: Gadoid fisheries; Commercial fishing; Statistical analysis; Statistical analysis; Http://aims.fao.org/aos/agrovoc/c_7378. |
| Ano: 2006 |
URL: http://hdl.handle.net/1834/1587 |
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| Ehrhardt, N.M.; Legault, C.; Prenski, L.B.. |
| In this work we present a process of risk analysis related to the adoption of a Total Allowable Catch (TAC)based in series of allowable biological catches which contain uncertainty derived of the recruitment patterns which characterize the stock. With the information obtained by the F0,1, and F30. RDP, the exploitation ratio and with the 500 values of the projected biomass of 1995 obtained by Monte Carlo simulation, we calculate the distribution of the allowable biological catches under a scheme of F0,1, and F30. RDP andfor a natural mortality of 0.38. The selected TAC is expected to beas closer as possible to the reference fishery mortality F0,1, and F30. RDP. As a result of the present risk analysis in this study in Macruronus magellanicus of the SW... |
| Tipo: Journal Contribution |
Palavras-chave: Fishery management; Risks; Biomass; Statistical analysis; Gadoid fisheries; Fishery management; Biomass; Statistical analysis; Http://aims.fao.org/aos/agrovoc/c_24026; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_7378. |
| Ano: 1997 |
URL: http://hdl.handle.net/1834/1936 |
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| Ben Amor, M. M.; Ben Salem, M.; Capapé, C.. |
| De juin 2002 à juin 2005, 267 syngnathes aiguilles, <Syngnathus acus> Linnaeus, 1758, ont été récoltés dans les eaux tunisiennes: 204 dans Bahiret El Biban (Tunisie méridionale), 24 dans la lagune Sud de Tunis et 39 devant La Goulette (Tunisie septentrionale). Trois types d'études ont été effectués à partir de l’ensemble des variables biométriques: la première repose sur l'analyse de la variance et de la moyenne à l'aide du test "F" de Ficher et du test "t" de Student; la deuxième est fondée sur l’analyse de la multivariance (ANOVA); et la troisième est fondée sur des analyses multidimensionnelles. La première et la deuxième études ont montré des différences significatives dans les variances et les moyennes pour la plupart des caractères examinés,... |
| Tipo: Journal Contribution |
Palavras-chave: Biometrics; Biopolymorphism; Population genetics; Statistical analysis. |
| Ano: 2008 |
URL: http://hdl.handle.net/1834/4234 |
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| Feki-Sahnoun, W.. |
| Le long des côtes du golfe de Gabès, les données collectées dans le cadre du Réseau de Surveillance du Phytoplancton et des Phycotoxines (REPHY), constituent une base pertinente pour examiner la structure et la dynamique des communautés phytoplanctoniques à grandes échelles temporelle (1997-2007) et géographique (l’ensemble de littoral du golfe). S’appuyant sur les données du REPHY, l’objectif de cette étude était de décrire les principales formes de variabilité des communautés phytoplanctoniques observées sur nos côtes. Les schémas de la variabilité des populations phytoplanctoniques ont été examinés à différentes échelles temporelles et géographiques à l’aide de méthodes statistiques multivariées. Dans un premier temps, l’analyse de la dynamique des... |
| Tipo: Theses and Dissertations |
Palavras-chave: Phytoplankton; Temporal variations; Geographical distribution; Statistical analysis; Models. |
| Ano: 2013 |
URL: http://hdl.handle.net/1834/5444 |
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| Registros recuperados: 65 | |
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