Chemical composition and phase identification of sodium titanate nanostructures grown from titania by hydrothermal processing

Fine titanium dioxide particles were hydrothermally treated in a sodium hydroxide aqueous solution. The treatment extended from 1 to 6 days leading to belt-like and wire-like structures of a metastable phase of sodium titanate, with typical widths and diameters between 8 and 40 nm, and lengths from 100nm to several micrometers. These conclusions are supported by X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectroscopy and high resolution transmission electron microscopy. The latter method revealed two set of space fringes with characteristic distances of 0.29 and 0.34 nm. These distances could correspond to the lattice spacing of ½#2;311#3; and ½#2;111#3; planes in Na2Ti6O13 compounds. The nanomaterial was found to be stable up to temperatures as high as 200 or 400 #4;C depending on the reaction time and the concentration.We acknowledge to Mr. Andrés Ibáñez for recording the XRD patterns.V.M.F. acknowledges grant FONDECYT 1040954. A.Z.A. acknowledges grant FUNDACION ANDES under contract No. C-13876

Exploitation status of cardinalfish (Epigonus crassicaudus) in Chile

The exploitation status of cardinalfish (Epigonus crassicaudus) yielded in Chile between 33° to 41°S was analyzed. An indirect assessment was performed between 1997 and 2003 through size-structured model with a transition matrix defining the changes among sizes. The model was calibrated using size structures, official landings, catch-per-unit of effort (CPUE) taken from commercial fishing logbooks and standardized by generalized linear models (GLM). After 7 years of an intense fishery activity, we concluded that the cardinalfish resource in Chile is on the recruitment overfishing limit. On 2003, the spawning biomass with respect to the virginal spawning biomass is close to 40%. The biological references points (BRP) based on spawning per recruit biomass (SPR) support this assesment because the fishing mortality level on 2003 (Fact) was very close to fishing mortality level of 40% of SRP at virginal value (F40%).PublishedBesugo, Cardinalfis

Factors affecting catch rates of yellow squat lobster (Cervimunida johni) in the northern zone of Chile

An analysis was made of the factors affecting the catch rates of the yellow squat lobster (Cervimunida johni) in Chile’s northern region (26°03’-32°10’S) by reviewing commercial fishing logbooks from 1993 to 2003. Factors evaluated included years, months, depth stratum, fishing areas and fleet characteristics as linear predictors in a generalized linear model (GLM) in order to explain variability in the catch rate. In contrast with other fisheries, with this resource the technical characteristics of the fleet and its’ specialization poorly explain variations in catch rate; temporal factors and their interaction were, however, highly significant. The results of this study, together with the life history of the resource, allow the supposition that standardized catch rates are appropriate as an index of relative abundance in this fishery.PublishedGenaralized linear mode

Final Report. Activity 2: demersal fish SUBPESCA Kingclip 2011 / March 2011.

El objetivo de este estudio es actualizar el conocimiento del estado del recurso congrio dorado (Genypterus blacodes) en el área marítima administrativa de su pesquería (41°28’-57°00’S) y recomendar la Captura Total Permisible (CTP) d elos stocks respectivos para la temporada extractiva del 2011.The aim of this study is to update knowledge of the status of the resource cusk (Genypterus blacodes) in the management of their fishery sea (41 ° 28’-57 ° 00’S) and recommend the Total Allowable Catch (CTP) d elos respective stocks quarrying for the season 2011Unpublishe

Effect of fishing tactics on the standardization of cardinalfish (Epigonus crassicaudus) catch rates in the demersal multispecies fishery off central Chile

We analyzed the allocation of effective fishing effort and the standardization of cardinalfish (Epigonus crassicaudus) catch rates in the multispecies demersal trawl fishery off central Chile. The period analyzed covered from 1997 to 2004 and included detailed information about fishing hauls. Each haul that contained cardinalfish was assigned into a particular fishing tactic (cluster) by using multivariate analysis of their catch composition. The catch rate standardization was carried out by generalized linear models (GLM). Three fishing tactics were discovered: the first directed effort at cardinalfish, the second at common hake (Merluccius gayi gayi), and the third at Patagonian grenadier (Macruronus magellanicus). Fishing tactic was used as an explanatory variable in the proposed GLM. The fishing tactic effect was one of the most important factors in explaining the variance in the GLM. These results are discussed in the context of how the assignation of a fishing tactic allows unbiased abundance indices to be obtained in this kind of multispecies demersal fishery.