|
|
|
Registros recuperados: 138 | |
|
|
Dimeet, Joel. |
Une évaluation du gisement d'oursins du golfe du Morbihan a été réalisée en 2008.Six stations ont été échantillonnées : Stibiden, Roc'h Vihan, Port Blanc, Kerners, Hent tenn et Brannec, une station de plus que les années précédentes Pour les cinq stations communes à 2007 et 2008 l'augmentation de la population d'oursins est de 5 % en global et de 25% pour les individus commerciaux. Les densités totales varient entre 87 et 136 individus pour 100 m2 et les densités commerciales entre 56 et 87 oursins pour 100m2. La densité maximale d'oursins commerciaux a été observée à Port blanc. Les tailles des oursins s'échelonnent entre 22mm et 88mm. 63% des oursins échantillonnés avaient une taille supérieure à la taille de première commercialisation, soit 55mm. |
Tipo: Text |
Palavras-chave: Density; Size; Sampling; Survey; Gulf of Morbihan; Layer; Urchin; Densité; Taille; Évaluation; Échantillonnage; Golfe du Morbihan; Gisement; Oursin. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/rapport-6775.pdf |
| |
|
|
Sammouth, Sophie; Roque D'Orbcastel, Emmanuelle; Gasset, Eric; Lemarie, Gilles; Breuil, Gilles; Marino, Giovanna; Coeurdacier, Jean-luc; Fivelstad, Sveinung; Blancheton, Jean-paul. |
Sea bass (Dicentrarchus tabrax) (135 +/- 4 g) were reared under tank-based recirculating aquaculture system for a 63-day period at four densities: 10, 40, 70, 100 kg m(-3). Fish performance, stress indicators (plasma cortisol, proteonemia plus other blood parameters-Na+, K+, glucose, pH, total CO2- and water quality were monitored. At the end of the 63-day period, resistance to infection was also studied by a nodavirus challenge. A 25-day test was performed on fish from two extreme densities (10 and 100 kg m(3)) and one intermediate density (40 kg m(3)). With regards to the different density treatments, there was no significant difference between the daily feed intake (DFI) and the specific growth rate (SGR) up to a density of 70 kg m(-3). No significant... |
Tipo: Text |
Palavras-chave: Welfare; Performance; European sea bass; Recirculating system; Density. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6761.pdf |
| |
|
| |
|
|
Galeron, Joelle; Sibuet, Myriam; Mahaut, Ml; Dinet, A. |
Three major size classes of the benthic metazoan communities (megafauna, macrofauna and meiofauna) were investigated simultaneously at 3 sites in the tropical Northeast Atlantic. The sites varied in their level of surface primary productivity (eutrophic, mesotrophic and oligotrophic). Results for 3 cruises in 3 seasons (Eumeli 2, winter 1991; Eumeli 3, autumn 1991; Eumeli 4, spring 1992) are given for each size class in terms of taxonomic composition, density and biomass. The benthic communities did not exhibit evidence of seasonal variation, but there were substantial differences in the quantitative structure of the metazoan communities between the 3 sites. Total metazoan density and biomass, as well as density and biomass of each size class, decreased... |
Tipo: Text |
Palavras-chave: Deep sea; Tropical Atlantic; Meiofauna; Macrofauna; Megafauna; Taxonomic composition; Density; Biomass; Environmental conditions. |
Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00000/10519/7602.pdf |
| |
|
|
Maguire, Julie A.; Fleury, Pierre-gildas; Burnell, Gavin M.. |
(Not controled OCR) Because biological systems do not work in isolation, behavioral, biochemical, and physiological tests can give an overview of an individual's vital processes and reaction to stress. Two stress gradients were applied in this study, a short acute desiccation stress and a long-term density stress. These stress gradients were used to assess the usefulness of various techniques for quality assessment: namely, a standard salinity stress test, condition index, recessing speed of the scallop, adenylic energetic charge (AEC). and percentage carbohydrate content of the striated muscle. The results showed that AEC could be used effectively to measure the effect of a short-term stress. In the striated muscle. AEC levels were useful in... |
Tipo: Text |
Palavras-chave: Density; Desiccation; Quality; Stress; Pecten maximus. |
Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/1999/publication-2450.pdf |
| |
|
| |
|
| |
|
| |
|
| |
|
|
Lorance, Pascal; Souissi, Sami; Uiblein, Franz. |
The catch from bottom longline stations sampled from a series of research cruises around Lanzarote and Fuerteventura (Canary Islands, NE Atlantic) was analysed in terms of fish distribution, density and diversity. The distribution of the number of species and individuals caught per station appeared to fit well the Poisson and Exponential distribution function, respectively. In particular, the parameter of the Poisson's distribution appeared to provide an index of the point (at station scale) diversity, and its confidence interval, allowing for statistical comparisons. The relationships between point diversity, the alpha diversity (in the depth strata) and the beta diversity (along the depth gradient) were investigated. Around the islands, the density and... |
Tipo: Text |
Palavras-chave: Canary Islands; Probability distributions; Density; Diversity; Demersal fishes; Longline. |
Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/publication-566.pdf |
| |
|
|
Da Costa Gonzalez, Fiz; Barreiro, Berta; Ojea, Justa; Novoa, Susana; Martinez-patino, Dorotea. |
Commercial production of most bivalve species involves a phase of intermediate cultivation during which juveniles are grown under protected conditions until they can be transferred to the final grow-out location. Consequently, the aim of this study was investigating the effect of density on growth and survival in the intermediate culture of the razor clam Ensis arcuatus in raft. Two series of experiments were performed, using in the first experiment two holding systems: 5-L plastic bottles and PVC cylinders, both perforated, covered with a 1 mm mesh net to prevent razor clam escape and a 10-cm layer of coarse grained sand (300–1200 lm grain diameter). In this trial, two stocking densities were tested: 0.15 and 0.30 kg m-2. In the second one-two densities... |
Tipo: Text |
Palavras-chave: Ensis arcuatus; Intermediate culture; Density; Raft. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00166/27731/25980.pdf |
| |
|
|
Bodoy, A; Geiaron, P; Garnier, Jacqueline; Heurtebise, S. |
Two different biomasses (100 g multiplied by m super(-2) and 1 kg multiplied by m super(-2)) of oysters were put in identical sea-water ponds, thus leading to different trophic conditions, corresponding to rearing techniques. Changes in growth, biochemical composition and sexual maturation were recorded for two age groups. The first one included 9 month-old oysters and the second one 21 month-old oysters, at the beginning of the experiment. For both age groups, significant differences were observed in growth and biochemical composition. Lipids were accumulated faster for the lower biomass. However, the only difference concerning glycogen was observed on the older oysters. They showed a peak at the lowest biomass and a decrease at the larger biomass. Sexual... |
Tipo: Text |
Palavras-chave: Crassostrea gigas; Bivalvia; Sea water; Oyster culture; Glycogen; Age; Chemical composition; Lipids; Biochemistry; Sexual maturity; Rearing; Pond culture; Biomass; Growth; Density. |
Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/1992/acte-916.pdf |
| |
|
|
Camara, Ibrahima; Mignot, Juliette; Kolodziejczyk, Nicolas; Losada, Teresa; Lazar, Alban. |
This study investigates the physical processes controlling the mixed layer buoyancy using a regional configuration of an ocean general circulation model. Processes are quantified by using a linearized equation of state, a mixed-layer heat, and a salt budget. Model results correctly reproduce the observed seasonal near-surface density tendencies. The results indicate that the heat flux is located poleward of 10° of latitude, which is at least three times greater than the freshwater flux that mainly controls mixed layer buoyancy. During boreal spring-summer of each hemisphere, the freshwater flux partly compensates the heat flux in terms of buoyancy loss while, during the fall-winter, they act together. Under the seasonal march of the Inter-tropical... |
Tipo: Text |
Palavras-chave: Physical processes; Salt and heat budget; Density; Compensation. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00634/74636/74530.pdf |
| |
|
| |
|
|
Vergnon, Rémi; Blanchard, Fabian. |
The necessity to move from a traditional fishery management to an ecosystem approach is now acknowledged. Indicators are required to support the development of this approach. For example, community indicators have been proposed to assess the impact of fishing. We tested here the applicability of one such community indicator, the abundance-biomass comparison (ABC method), as a measure of the impact of bottom trawling (years of sampling: 2001 and 2003) on the benthic invertebrates-typically starfishes, crabs, squat lobsters, shrimps and large hard-shelled molluscs-of "Grande Vasiere", a major French fishing zone, in the Bay of Biscay. The ABC method is generally used as an impact indicator for different types of physical, biological and anthropogenic... |
Tipo: Text |
Palavras-chave: Atlantic Ocean; Inter annual variability; Density; Macrobenthos; ABC method; Fishing impact; Indicator; Bottom trawl survey. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2133.pdf |
| |
|
|
Davies, Peter; Arhant, Mael; Le Gac, Pierre Yves; Le Gall, Maelenn; Kemlin, Guillaume. |
There are more than a thousand species of bamboo and some of these contain large amounts of fibres with attractive properties. However, the extraction of the fibres without damaging them is difficult, requiring energy and special equipment. One solution is to use the bamboo in the form of thin strips taken from fibre-rich regions of the plant, as done by the Cobratex company in an innovative process. These contain the fibres but they are protected from damage and keep their alignment. This paper presents the results from a study of bamboo strips, alone and in an infused composite. The influence of seawater immersion is investigated. The composite weight gain is high, around 25 %, but most of the water is in the natural canals of the wood. The influence of... |
Tipo: Text |
Palavras-chave: Bamboo; Density; Mechanical properties; Wet aging. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00593/70534/68681.pdf |
| |
|
| |
|
|
Le Gall, Maelenn; Davies, Peter; Martin, Nicolas; Baley, Christophe. |
Density is one of the fundamental properties of fibres which reinforce polymer matrix composites, and is used both to estimate composite weight and to evaluate fibre content for property predictions. For traditional composites, reinforced by glass or carbon fibres, unique density values are well known for a particular fibre grade and provide reliable fibre content estimations and composite property predictions. However, this is not the case for natural fibres. This paper first reviews published density values for flax (Linum usitatissimum L.) fibres and describes the limitations of techniques used to measure fibre density. Significant variations in published densities are found, which can be related to the measurement method. New data quantify the... |
Tipo: Text |
Palavras-chave: Density; Flax; Archimedes; Pycnometer; Volume fraction; Tensile modulus. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00427/53875/55082.pdf |
| |
|
|
Le Menn, Monique; Malardé, Damien; David, Arnaud; Brault, Patrice; Grosso, Philippe; De Bougrenet De La Tocnaye, Jean-louis; Le Reste, Serge; Podeur, Christian. |
Salinity is the essential parameter for ocean dynamics studies. Its definition and using in the equations used to calculate the thermodynamic properties of seawater, were revised in 2010, opening the possibility of new sensors developments. In this context, NOSS (NKE Optical Salinity Sensor) has emerged as one of the first underwater instrument for in situ refractive index measurement in the past years open up the scope of possibilities to access to density parameter. This achievement is the fruit of the cooperation between several institutions and the fruit of several years of developments and trials. NOSS sensor is designed to be deployed in coastal environment and open-ocean waters up to 2000m, especially on profiling floats of the Argo network. |
Tipo: Text |
Palavras-chave: Salinity; Density; Ocean; Seawater; Refractive index; Sensor.. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00664/77601/79616.pdf |
| |
|
|
Faillettaz, Robin; Roger, Christophe; Mathieu, Michel; Robin, Jean-paul; Costil, Katherine. |
The presence of shells of the Atlantic rangia, Rangia cuneata, a brackish-water species native from the Gulf of Mexico also known as gulf wedge clam, was reported in 2017 on the French coasts of the English Channel, in the waterway that connects Caen to the sea. However, no information was available on whether a population of this alien species had successfully established in the region. Here, only empty shells—except for one live individual—were sampled in that waterway, and the sampling was shifted to the nearby marina of Ouistreham, where water is mesohaline (6.89 ± SD 0.06 PSU). In spring 2017, the mean density in the marina reached 110.45 ± 86.08 ind m-2, largely dominating the benthos community. The population was mostly composed of fairly large... |
Tipo: Text |
Palavras-chave: The Atlantic rangia; Alien species; Normandy (F); Brackish waters; Density; Growth; Reproduction. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00634/74623/74515.pdf |
| |
Registros recuperados: 138 | |
|
|
|