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| Registros recuperados: 25 | |
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| Pete, Romain; Guyondet, Thomas; Bec, Beatrice; Derolez, Valerie; Cesmat, Ludovic; Lagarde, Franck; Pouvreau, Stephane; Fiandrino, Annie; Richard, Marion. |
| The decrease of microbial and nutrient inputs from the watershed has long dominated lagoon ecosystem management objectives. Phytoplankton biomass and abundance have drastically decreased for more than a decade and Zostera meadow have gradually recovered, expressing lagoon ecosystem restoration such as Thau lagoon. Do the progressive achievement of the good ecological status of the Thau lagoon possibly threatens the shellfish industry in terms of production and oyster quality, by reducing the carrying capacity? To provide answers about the right balance to be achieved between conservation and exploitation, a new numerical tool was developed to help in decision-making. We hereby propose to incorporate a Dynamic Energy Budget type shellfish production model... |
| Tipo: Text |
Palavras-chave: Shellfish farming; Carrying capacity; Stakeholder implication; Nitrogen and phosphorus inputs; Water frame directive; Ecological indicators; Phytoplankton depletion; Coupled biogeochemical-deb model. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00622/73395/75312.pdf |
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| Grant, J; Bacher, Cedric; Cranford, P; Guyondet, T; Carreau, M. |
| A fully-coupled biological-physical-chemical model of a coastal ecosystem was constructed to examine the impact of suspended mussel culture on phytoplankton biomass in Tracadie Bay, Prince Edward Island, Canada. Due to the extent of mussel culture there, we hypothesised that shellfish filtration would control the concentration and distribution of phytoplankton and other suspended particles in the bay. Circulation was delineated with a tidally-driven 2D numerical model and used to drive an ecosystem model with a focus on pelagic components including phytoplankton production, nutrients, detritus, and mussels. The benthos were treated as a sink. Nutrients and seston were forced by tidal exchange and river input, with phytoplankton additionally forced by... |
| Tipo: Text |
Palavras-chave: Towed sensors; Nutrient dynamics; Circulation model; Phytoplankton; Carrying capacity; Shellfish aquaculture; Estuaries; Ecosystem model. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-6951.pdf |
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| Guyondet, T.; Comeau, L. A.; Bacher, Cedric; Grant, J.; Rosland, R.; Sonier, R.; Filgueira, R.. |
| A spatially explicit coupled hydrodynamic-biogeochemical model was developed to study a coastal ecosystem under the combined effects of mussel aquaculture, nutrient loading and climate change. The model was applied to St Peter's Bay (SPB), Prince Edward Island, Eastern Canada. Approximately 40 % of the SPB area is dedicated to mussel (Mytilus edulis) longline culture. Results indicate that the two main food sources for mussels, phytoplankton and organic detritus, are most depleted in the central part of the embayment. Results also suggest that the system is near its ultimate capacity, a state where the energy cycle is restricted to nitrogen-phytoplankton-detritus-mussels with few resources left to be transferred to higher trophic levels. Annually, mussel... |
| Tipo: Text |
Palavras-chave: Climate change; Nutrient loading; Mussel culture; Carrying capacity; Coastal ecosystem; Numerical modelling. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00275/38624/37191.pdf |
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| FERNANDES, A. A. O.; MACHADO, F. H. F.; ANDRADE, J. M. de S.; MENEZES, F. A. B. de; CATUNDA, A. G.; FIGUEIREDO, E. A. P. de. |
| Resumo: As taxas de parição, mortalidade de adultos e gemelidade de caprinos nativos e ovinos Morada Nova, foram avaliadas de 1977 a 1979, em três tipos de pastagens - Nativa de Caatinga, Nativa Raleada e de capim-buffel (Cenchrus ciliaris L.). O ensaio foi conduzido na Fazenda Iracema, da Empresa de Pesquisa Agropecuária do Ceará - EPACE -, em Quixadá, CE. As taxas de parição foram diferentes para anos, espécies, anos x espécies e espécies x pastagens. Os caprinos apresentaram 55,7%, 91,6% e 70,8% de parição e os ovinos, 89,1%, 85,2% e 86,9% em 1977, 1978 e 1979, respectivamente. A taxa de gemelidade foi significativamente maior nos caprinos (43,0%) que nos ovinos (25,8%). As taxas de mortalidade de adultos foram diferentes para anos, espécies, anos x... |
| Tipo: Artigo de periódico |
Palavras-chave: Parição; Gemelidade; Pastagem raleada; Gemelarity; Buffel grass (Cenchrus); Native species; Pasture feeding; Caprino; Ovino; Performance; Ganho de Peso; Mortalidade; Parto; Cenchrus ciliaris; Capim buffel; Capacidade de Suporte; Pastagem Nativa; Goats; Sheep; Animal performance; Parturition; Mortality; Pastures; Carrying capacity; Brazil; Semiarid soils.. |
| Ano: 1987 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/514183 |
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| Pouvreau, Stephane; Bacher, Cedric; Heral, Maurice. |
| A model of bioenergetics of the black pearl oyster (Pinctada margaritifera) was built to simulate growth, reproduction and spawning in suspended culture at field sites in Takapoto lagoon (French Polynesia). This model was based on allometric scaling of physiological functions and scope for growth (SFG) calculations. The input functions were clearance rate (CR, 1 day(-1)), retention efficiency (RE, %) for each kind of particle encountered in suspended matter, pseudofaeces and faeces productions (PF and F, mg C day(-1)), excretion and respiration rate (U and R, mg C day(-1)). The assimilated carbon (i.e., SFG, mg C day(-1)) was partitioned to the three internal state variables (somatic tissue, shell and gonad) according to the asymptotic increase of the... |
| Tipo: Text |
Palavras-chave: Pearl farming; Food depletion; Scope for growth; Carrying capacity; Suspension feeding; Tropical lagoon. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-380.pdf |
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| Trung Cong, Luong; Lemonnier, Hugues; Hochard, Sebastien; Royer, Florence; Letourneur, Yves. |
| This study was conducted to compare the effects of shrimp and rabbitfish in mono- and polyculture stocked at high biomass on production and environmental conditions in a mesocosm system. Shrimp (14 g) and/or rabbitfish (19 g) were stocked in four treatments with different density but with the same total biomass (236 g m−2), including shrimp monoculture (SM) (17 shrimp m−2), shrimp–fish polyculture (SF) (11 shrimp and 4 rabbitfish m−2), fish–shrimp polyculture (FS) (6 shrimp and 8 rabbitfish m−2) and fish monoculture (FM) (12 rabbitfish m−2). After 10 weeks of experiment, shrimp survival and biomass were low in the treatments where shrimp were dominant (SM, SF), while rabbitfish survival and biomass were high in all the treatments. Shrimp mortality was... |
| Tipo: Text |
Palavras-chave: Polyculture; Penaeidae; Siganidae; Integrated production; Carrying capacity; Pond ecology. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00355/46606/46468.pdf |
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| Heral, Maurice. |
| Growth of molluscs raised in coastal zones, where the water exchange rate is low, appears to be limited, once a certain biomass level is attained, by the availability of food, making it necessary to determine as accurately as possible the trophic capacity of an ecosystem. This paper analyses the various sources of food for molluscs. It would appear that dissolved organic substances play a major role, providing up to half the energy necessary for their metabolism. Particulate material is filtered by molluscs in proportion to their size, with optimum filtration rates varying with species. The negative effect on meat production of high mineraI seston rates is demonstrated, and an analysis provided of the respective role of each component of organic matter.... |
| Tipo: Text |
Palavras-chave: Evaluation; Carrying capacity; Molluscs; Ecosystems; Cochyliculture; Ecosytemes; Molluscs; Evaluation; Capacité biotique. |
| Ano: 1985 |
URL: http://archimer.ifremer.fr/doc/1985/acte-2945.pdf |
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| Souchu, Philippe; Vaquer A, André; Collos, Yves; Landrein, Sonia; Deslous-paoli, Jean-marc; Bibent, Bertrand. |
| Thau lagoon is a Mediterranean shellfish ecosystem with large biomasses of oysters growing in waters with high residence time due to low tidal ranges, The influence of filter feeders (oysters and their epibiota) on the spatial distribution of particulate and dissolved compounds in the water column of Thau lagoon was studied through its variation with time, In 1991/1992, daily variations were investigated in pens, corridors and outside shellfish farming zones for nutrients, chlorophyll a and primary production. Salinity, dissolved oxygen, nutrients, organic matter and chlorophyll a were also monitored in surface waters inside and outside shellfish farming zones each week from January 1993 to March 1994. The presence of shellfish farms led to a decrease by... |
| Tipo: Text |
Palavras-chave: Thau lagoon; Carrying capacity; Nutrient cycling; Phytoplankton; Suspension feeding bivalves. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-808.pdf |
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| Buestel, Dominique; Pouvreau, Stephane. |
| Results of research concerning the food of the pearl oyster Pinctada mai margaritifera are presented, by taking Takapoto atoll (Tuamotu archipelago, French Polynesia) as a study site. Monthly sampling of several parameters representative of bivalve environment and food (water temperature, salinity, mineral and organic matter, proteins, lipids and carbohydrates, chlorophyll a and phaeopigments) confirm and increase knowledge of the Takapoto lagoon hydrobiology. The variability of these parameters was analysed. Takapoto lagoon showed a remarkable spatial stability. Temporal variations showed a low seasonal trend. Local meteorology (wind, precipitation) had an influence on short-term variability (especially for mineral matter). Night and day rhythm also... |
| Tipo: Text |
Palavras-chave: Pinctada margaritifera; Matière en suspension; Capacité trophique; Huı̂tre perlière; Atoll; Pinctada margaritifera; Suspended matter; Carrying capacity; Pearl oyster; Atoll. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00000/10529/7078.pdf |
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| Goulletquer, Philippe; Joly, Jean-pierre; Gerard, Andre; Le Gagneur, Eric; Moriceau, Jacques; Peignon, Jean-marie; Heurtebise, Serge; Phelipot, Pascal. |
| Triploid oysters Crassllstrea gigas were: produced in 1990 by treating fertilized eggs with cytochalasin B (CS). Triploids, treated diploids, and controls were deployed early 1991 in a high carrying capacity ecosystem on the Eastern Coast of Normandy (France). A monthly monitoring in 1992 showed that triploids yielded significantly higher growth rate and biochemical composition. However, growth was more heterogeneous. No evidence was found for a length or weight bimodal frequency distribution within triploid groups after a 26 months rearing cycle. Triploids showed retardation of gametogenesis. Carbohydrates content in triploids remained almost constant (40%) from June to September. Their survival rates were significantly lower than controls. Moreover... |
| Tipo: Text |
Palavras-chave: Biochemical compostion; Survival; Carrying capacity; Triploid; Growth; Oysters; Crassostrea gigas; Composition biochimique; Survie; Capacité trophque; Triploïdes; Croissance; Huîtres; Crassostrea gigas. |
| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/1996/publication-3088.pdf |
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| Buestel, Dominique; Pouvreau, Stephane; Tiapari, Jerome; Bougrier, Serge; Chabirand, Jean-michel; Geairon, Philippe; Fougerouse, A. |
| A study of pearl oysters Pinctada margaritifera growth and mortality was done on a monthly basis between June 1990 and September 1991 in Takapoto atoll (Tuamotu archipelago). Meanwhile, sampling parameters representative of bivalves food showed a remarquable spatial stability whithin the lagoon. The amplitude of temporal variability varied in the order of some days. Carrying capacity appears low : energetic content of particulate material in waters is about 2 joules/liter, ten times lower than in temperate areas. On the opposite, seasonal effect is reduced and particulate food is always available. Oysters rearing conditions were appropriate during the studied period with a low mortality rate and a regular growth in size (from 97 mm to 136 mm). Pearls... |
| Tipo: Text |
Palavras-chave: Atoll; Pearl oyster; Carrying capacity; Growth; Pinctada margaritifera; Atoll; Huître perlière; Capacité Trophique; Croissance; Pinctada margaritifera. |
| Ano: 1995 |
URL: http://archimer.ifremer.fr/doc/1995/rapport-1642.pdf |
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| Registros recuperados: 25 | |
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