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| Registros recuperados: 61 | |
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| Lison De Loma, Thierry; Harmelin-vivien, Mireille; Naim, Odile; Fontaine, Marie France. |
| There has, as yet, been little study of nutrient disturbance and its consequences on the functional biology of primary consumers in coral reefs. The processing of epilithic algal communities by the damselfish Stegastes nigricans was investigated at La Reunion, at two sites of a fringing reef, oligotrophic for one and eutrophic for the other. Differences between sites were analyzed in quantifying organic matter, organic carbon, nitrogen, and organic 'nutrients' (carbohydrate, lipid and protein) in the algal food, the digestive contents and the faeces of S. nigricans. In the disturbed site, algal turfs and digestive contents presented significantly higher organic matter, organic carbon, nitrogen and organic nutrient values. Absorption efficiency of total... |
| Tipo: Text |
Palavras-chave: Régime herbivore; Stegastes; Récif corallien; Eutrophisation; La Réunion; Herbivory; Stegastes; Coral reef; Eutrophication; La Reunion. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00323/43376/42835.pdf |
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| Harzallah, Ali; Chapelle, Annie. |
| The Thau lagoon, located in southern France, suffers episodically in summer from anoxic crises known as 'malaigues'. Such crises mostly occur under warm conditions and low winds. In this paper we investigated effects of local weather conditions (air temperature, wind speed and precipitation over southern France), and two climate oscillations (the North Atlantic Oscillation and the El Ni (n) over tildeo Oscillation) on malaigue occurrences based on 33-year data series and dates when malaigues appeared. The study shows that the probability of occurrence of malaigues increases with increasing temperature and decreasing winds in August both mostly associated to the high phase of an index of North Atlantic Oscillation. Malaigues are found to be frequently... |
| Tipo: Text |
Palavras-chave: Lagoon; Thau; Malaigues; Anoxic crises; Climate variability; Lagune; Thau; Malaïgue; Eutrophisation; Variabilité climatique. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/publication-517.pdf |
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| Delgado, O; Ruiz, J; Perez, M; Romero, J; Ballesteros, E. |
| The effects of fish farming on a seagrass (Posidonia oceanica) meadow at Fornells Bay, Minorca (Balearic Islands) were studied. Changes in plant and meadow features (e.g. shoot morphology, shoot density, biomass, rhizome growth, nutrient and soluble sugars concentrations...) in three stations along a transect from a disturbed (organic pollution due to fish cultures) to an undisturbed site were assessed. The fish culture had ceased in 1991; however, seagrass decline, already reported in a previous study for the period 1988-1990, was still taking place at the time of sampling (July 1994). Differences between stations were very clear; the station closest to the fish cages showed reduced shoot density, shoot size, underground biomass, sucrose concentration and... |
| Tipo: Text |
Palavras-chave: Aquaculture; Phanérogame marine; Posidonia oceanica; Eutrophisation; Caractéristique du sédiment; Aquaculture; Seagrass; Posidonia oceanica; Eutrophication; Sediment characteristics. |
| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00325/43632/43250.pdf |
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| Baudrier, Jérôme. |
| The coastal area located between Quiberon and Noirmoutier is influenced by dilution plumes of the Loire and Vilaine rivers. Dysfunctions linked with a growing eutrophication of the environment have been observed over the last decades. Important imbalances such as massive deaths of the fauna in open embayments and more and more appearances of red tides give the area a unique character. Other environ mental problems are likely to disrupt human activites in the near future (bays silting up, quality of coastal water worsening, overfishing ...). This is why there is a real need to gather information on the subject. This will make it possible to identify problems and gaps in the area. Beside presenting pieces of information, the study offers various reflection... |
| Tipo: Text |
Palavras-chave: Loire; Vilaine; Panaches de dilution; Eutrophisation; Déséquilibres; Écosystème. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/00016/12702/9624.pdf |
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| Lemoine, Gérard. |
| Within the national molluscan monitoring network, a sedimentary study was carried out on five experimental sites located in southern Brittany (i.e., from Etel to Pen-Bé rivers). The study aimed to specify sediment integrating characteristics with regards to hydrobiological variables. Moreover, interactions between sediment and water column characteristics were specified. It appears that this approach is likely unappropriate to characterize interdical rearing area productivity. However, this approach can support the site evaluation on a long term basis to sustain shellfish culture management. This would require additional study to assess sediment reactivity to abnormal events like drastic salinity decrease. |
| Tipo: Text |
Palavras-chave: Sédiment; Ostréiculture; Estran; Phosphore; Eutrophisation; Sediment; Oyster culture; Intertidal area; Phosphorus; Eutrophication. |
| Ano: 1994 |
URL: http://archimer.ifremer.fr/doc/00102/21344/18967.pdf |
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| Merceron, Michel. |
| The yearly study of Ulva in Brittany aims at building a time series of its proliferations and corresponding nutrient loadings. The goal is to detect results of wilful loading reductions, and to distinguish them from natural variations. This first actually quantified study is the starting bench-mark of the process. Forty-five concerned sites were listed in 1997. They are nearly the same as in 1988, 1991 and 1994 (previous rough census). The Côtes d'Armor and then the Finistère are the most affected departments. The Morbihan is less and file et Vilaine not at all. Ulva biomass was precisely quantified in about fifteen locations during the growing season, along with nitrogen loadings of local streams (mostly nitrate). The fluxes of nitrogen - the limiting... |
| Tipo: Text |
Palavras-chave: Bretagne; Nitrate; Prolifération; Ulve; Eutrophisation; Brittany; Nitrate; Proliferation; Ulva; Eutrophication. |
| Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/1998/rapport-1580.pdf |
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| Merceron, Michel. |
| The 1998 survey of green tides on the Brittany coast was performed in the same way as that of 1997 in order to allow comparison. 11 includes an inventory ofail the concerned sites, and a precise assessment ofthirteen ofthem, the most loaded. On these ones, nitrogen fluxes were surveyed during the critical period, and the green seaweed stock on the beach and in the first waves was quantified. The climatic conditions were opposite between the two years, very dry in spring and summer 1997, and wet in 1998. The irradiance contrast was inverse, and less pronounced. The nitrate contents and mostly the flows were more important in 1998. They generated nitrogen fluxes about 3.3 times those of 1997. The total number of sites concerned in 1998 is clearly higher than... |
| Tipo: Text |
Palavras-chave: Bretagne; Nitrate; Prolifération; Ulve; Eutrophisation; Brittany; Nitrate; Proliferation; Ulva; Eutrophication. |
| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/1999/rapport-2665.pdf |
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| Registros recuperados: 61 | |
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