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| Registros recuperados: 473 | |
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| Meiners, K. M.; Arndt, S.; Bestley, S.; Krumpen, T.; Ricker, Robert; Milnes, M.; Newbery, K.; Freier, U.; Jarman, S.; King, R.; Proud, R.; Kawaguchi, S.; Meyer, B.. |
| Antarctic pack ice serves as habitat for microalgae which contribute to Southern Ocean primary production and serve as important food source for pelagic herbivores. Ice algal biomass is highly patchy and remains severely undersampled by classical methods such as spatially restricted ice coring surveys. Here we provide an unprecedented view of ice algal biomass distribution, mapped (as chlorophyll a) in a 100 m by 100 m area of a Weddell Sea pack ice floe, using under-ice irradiance measurements taken with an instrumented remotely operated vehicle. We identified significant correlations (p < 0.001) between algal biomass and concomitant in situ surface measurements of snow depth, ice thickness, and estimated sea ice freeboard levels using a statistical... |
| Tipo: Text |
Palavras-chave: Sea ice properties; Snow; Freeboard; Chlorophyll a; Ice algae; Biomass. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00398/50957/51721.pdf |
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| Dufour, P.; Cremoux, Jl.; Slepoukha, M.. |
| "In vitro" enrichment experiments on natural populations have been used to determine the nutrients controlling the potential biomass of phytoplancton in the Ebrié coastal lagoon. The limiting nutrients were generally nitrogen, phosphorus and carbon, in this order ; in three cases out of eleven, P and N act simultaneously ; in an extreme eutrophication case, N, P and C were all limiting. No effect was observed following addition of metals, vitamins or chelators. The limitations deduced from the enrichment experiments show a. good agreement with the elementary composition of the external medium ; in waters potentially limited by N alone, the dissolved inorganic nutrients have a N : P ratio lower than 25. The agreement is poorer when the sestonic N : P ratio... |
| Tipo: Text |
Palavras-chave: Lagune; Estuaire; Zone tropicale; Phytoplancton; Biomasse; Eléments limitants; Tests biologiques; Composition chimique; Coastal lagoon; Estuary tropical zone; Phytoplankton; Biomass; Limiting nutrients; Bioassay; Chemlcal composition. |
| Ano: 1979 |
URL: http://archimer.ifremer.fr/doc/00306/41689/40898.pdf |
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| Gaudy, R.; Guerin, J.p.. |
| Following are results obtained in our laboratory during breeding experiments with an harpacticoid copepod, Tisbe holothuriae. In small size volumes (200 ml), the potential production appears to be higher when an artificial compound food of animal substances is used instead of a vegetal diet. In medium volume experiments (100 l) the production is related to the surface available for animals in breeding tanks, Breeding in complete cycles can be obtained using various foods, but the quality of diet may markedly affect the characteristics of the vital cycle, such as the length of the fertility period and fecundity. Temperature has a crucial effect, chiefly on dynamic preoccesses, that is to say, developmental rate and average generation time. With different... |
| Tipo: Text |
Palavras-chave: Production; Dynamique des populations; Biomasse; Composition chimique élémentaire; Bilan énergétique; Copépodes harparcticoïdes; Production; Population dynamic; Biomass; Chemical elementary composition; Energy balance; Hapacticoïd copepods. |
| Ano: 1979 |
URL: http://archimer.ifremer.fr/doc/00306/41672/40881.pdf |
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| De Casamajor, Marie-noelle; Mahias, Jeremy; Bru, Noelle; Caill-milly, Nathalie. |
| A spatial sampling was carried out for stock assessment of sea urchin P. lividus throughout the Basque coast. A sampling, over the year, was conducted to study the reproductive cycle. This work took place over 2013 and 2014. Reproduction occurs once in spring, between May and August 2014. Among factors affecting the release of eggs, salinity, temperature and hydrodynamics show a significant inter-annual variability in the Basque coast. Thus, the period set in 2014, may fluctuate between years. For the stock, the results showed that 11.85 (+/-0.32) million individuals of harvestable biomass for 724 tones (+/- 137). Stock is spread over the entire surveyed area density and biomass decrease rapidly with depth, individuals are mainly located between 0 and 5 m.... |
| Tipo: Text |
Palavras-chave: Oursin commun; Stock; Biomasse; Reproduction; Côte basque; Conditions environnementales; Sea urchin; Stock; Biomass; Reproduction; Basque coast; Environmental conditions. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00218/32889/31373.pdf |
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| Bec, Beatrice; Collos, Yves; Souchu, Philippe; Vaquer, Andre; Lautier, Jacques; Fiandrino, Annie; Benau, Laurent; Orsoni, Valerie; Laugier, Thierry. |
| We explored the role of natural and anthropogenic environmental perturbations in shaping the community structure and dynamics of pico- and nanophytoplankton in coastal waters. The distribution patterns of phycoerythrin-rich picocyanobacteria (PE-CYAN) and phycocyanin-rich picocyanobacteria (PC-CYAN), autotrophic picoeukaryotes (PEUK) and nanophytoplankton (NANO) were examined over a period of 3 yr in 24 Mediterranean coastal lagoons displaying wide trophic gradients (from 0.2 to 630 mu g chlorophyll a [chl a] l(-1)) and salinity gradients (from fresh to marine waters). In summer, picoplanktonic abundances reached 3 x 10(8) cells l(-1), 5 x 10(9) cells l(-1) and 6 x 10(10) cells l(-1) for PE-CYAN, PC-CYAN and PEUK, respectively. PE-CYAN and PC-CYAN showed... |
| Tipo: Text |
Palavras-chave: Autotrophic picoeukaryotes; Picocyanobacteria; Nanophytoplankton; Abundance; Biomass; Eutrophication; Mediterranean lagoons. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00031/14267/11547.pdf |
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| Maestrini, S; Robert, J. |
| Microalgal population of oyster ponds is dominated by several tychobenthic diatoms which provide a very good food to grow oysters. The mechanisms which allow them to dominate have been put under research. H.P.L.C. analysis demonstrated 17 amino acids amounted 10-17% of total DON, i.e. 0.6-11.5 mu g-at/l nitrogen. Serin and glycin were the most abundant. None of the substances was related to the presence of oyster. Glutamic acid, alanin and ornithin concentrations showed the greatest variations; they are suspected to play the major role as nutrient source. Screening of nutritional capabilities of ten local isolates of micro-algae to use 42 organic substances as sole source of nitrogen, demonstrated urea, glutamic acid and hypoxanthin are assimilated by all... |
| Tipo: Text |
Palavras-chave: Bacillariophyceae; Bivalvia; Biomass; Pond culture; Algal settlements; Oyster culture; Nutritive value; Dissolved organic nitrogen. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-1531.pdf |
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| Moriarty, M.; Sell, A. F.; Trenkel, Verena; Lynam, C. P.; Burns, F.; Clarke, E. D.; Greenstreet, S. P. R.; Mcgonigle, C.. |
| An experiment during a fisheries independent survey in the North Sea was conducted to test whether sampling effort could be reduced without a significant loss in data precision. To examine potential effects of reducing tow duration from the standard 30 min to a proposed 15 min estimates of species encounter rates, species richness, and estimates of abundance, biomass, and body size were analysed. Results show species richness estimates are lower in the short tow category. While biomass and abundance at length and body size are significantly affected by the change in tow duration, estimates of Large Fish Indicator, the Typical length and Mean-max length are not significantly affected by the regime change. The results presented here suggest that a reduction... |
| Tipo: Text |
Palavras-chave: Abundance; Biomass; Body size; Fisheries independent survey; IBTS; International Bottom Trawl Survey; Linear mixed model; North Sea; Species diversity. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00439/55028/60477.pdf |
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| Maurer, Daniele; Borel, Michel; Dreno, Jean-paul. |
| L'élaboration d'un modèle de gestion d'un bassin conchylicole nécessite, en particulier, la connaissance de l’évolution des stocks d'huîtres d'une année à l'autre afin d'en apprécier l'influence éventuelle sur le rendement. Le présent travail décrit la méthodologie utilisée et les résultats obtenus au cours de la première estimation du stock d'huîtres Crassostrea gigas en élevage dans le bassin d'Arcachon en 1985. Cette estimation nécessite l'utilisation simultanée de photographies aériennes (évaluation de la surface réellement exploitée ) et de sondages-terrain (évaluation de la biomasse par unité de surface). Ces derniers ont également permis de valider les résultats obtenus par photographie. En 1985, le taux d'exploitation variait, selon la zone... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Biomasse; Bassin d'Arcachon; Crassostrea gigas; Biomass; Bay of Arcachon. |
| Ano: 1987 |
URL: http://archimer.ifremer.fr/doc/00102/21342/18965.pdf |
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| Aoki,C; Lopes,FS; de Oliveira,AMR; Souza,FL de; Marques,MR. |
| Large-bodied arthropods, such as cicadas, can be able to reallocate significant amounts of nutrients during adult emergence. Evidence suggests that Quesada gigas Olivier emergence constitutes an important nutrient flux from belowground to aboveground. The purpose of this study was to estimate the amount of nitrogen, proteins, and lipids resulting from the emergence of Q. gigas in an urban ecosystem in Central Brazil. Adult specimens captured from September to November 2006 were weighed and submitted to biochemical analysis. Population density was approximately 4,200 individuals per hectare. Mean individual dry mass was 1.03 g and contained 12.6% proteins, 8.4% lipids, and 5% nitrogen. Total biomass input from the species was 4.3 kg ha-1 y-1, with a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Annual cicada; Biomass; Energy; Nutrient cycling; Chain feed. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2011000400004 |
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| Silva-Pereira,Viviane da; Santos,Gilberto M.M.. |
| Hymenoptera such as bees and social wasps are regular floral visitors in "campos rupestres" vegetation. A community of bees and social wasps was studied during floral visitation in an area of "campos rupestres", at Chapada Diamantina, BA, Brazil, from September 2001 to April 2002. The community was described in relation to diversity, evenness, and dominance rank, considering the individuals abundance (H' = 2.14/ J' = 0.55) and biomass (H' = 2.34/ J' = 0.60). Thirty nine bee (588 individuals/ 15.742 g) and 11 social wasp species (52 individuals/ 2.156 g) were collected, being the first report of social wasps for the Brazilian "campos rupestres". The main species regarding number of individuals were Trigona spinipes (Fabricius), Apis mellifera L.,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Altitudinal field; Biomass; Chapada Diamantina; Community structure; Flower visitor. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2006000200003 |
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| Buriyo, A.S.; Kivaisi, A.K.. |
| Seasonal biomass variation and agar yield of G. salicornia (C. Ag.) Dawson from Oyster Bay, Dar es Salaam, and Chwaka Bay, Zanzibar, were determined, and some properties of the agar examined. Mean biomass and canopy cover values ranged from 21–60 g/m2 and 7– 20 %, respectively. The highest mean biomass and cover values were obtained during the SE monsoon. Agar yield varied from 13.7 to 30.2 % (dry weight) and was highest during the dry NE monsoon period. Alkali treatment generally reduced agar yield by 25–56 %. Gel strength of the agar gels ranged between 118 and 251 g/cm2 and was significantly higher during the NE monsoon period (t = 2.2; P = 0.04 and t = 8.9; P << 0.05) for samples collected from Oyster Bay and Chwaka Bay respectively). Mean gel... |
| Tipo: Journal Contribution |
Palavras-chave: Agar; Biomass. |
| Ano: 2003 |
URL: http://hdl.handle.net/1834/964 |
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| Carozza, C.R.; Hernandez, D.R.; Perrotta, R.G.. |
| Whitemouth croaker (Micropogonias furnieri)has a broad distribution along the Atlantic coast of the Americas, from Mexico to the south of the Province of Buenos Aires, Argentina. At the southern end of distribution, Argentina and Uruguay catch the species with different commercial fleet types bay or creek, coastal and off-shore and modalities of bottom trawling with doors and paired trawling. Maximum catches of both countries, that reached 60,000 t, were registered between 1995 and 1997. After that period a remarkable decrease was observed, specially in Argentina where catches remained at around 6,000 t over a total of 30,000 t for both countries. The commercial fleet was divided in three categories and the total area of study in three subareas: El Salado,... |
| Tipo: Journal Contribution |
Palavras-chave: Stock assessment; Catch/effort; Risks; Biomass; Depleted stocks; Mathematical models; Coastal fisheries; Commercial fishing; Stock assessment; Biomass; Mathematical models; Coastal fisheries; Http://aims.fao.org/aos/agrovoc/c_24251; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_24199; Http://aims.fao.org/aos/agrovoc/c_1696. |
| Ano: 2004 |
URL: http://hdl.handle.net/1834/1503 |
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| Registros recuperados: 473 | |
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