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Sfriso, A; Facca, C; Ceoldo, S; Silvestri, S; Ghetti, Pf. |
Nutrient concentrations have been investigated in the Venice lagoon for three scenarios: abnormal growth of nuisance macroalgae, decrease of macroalgal dominance and intense catching of the bivalve Tapes philippinarum Adams and Reeve by means of hydraulic and mechanical dredges. Total nitrogen and organic and total phosphorus monitored in June 1087, 1993 and 1998 showed significant changes both in concentrations and distribution. The disappearance of macroalgal blooms and the starting of intense clam fishing activities affected mainly organic phosphorus concentrations which, between 1987 and 1998, decreased from 104 +/- 42 to 59 +/- 31 mug cm(-3), accounting for 27% (1987) and 16% (1998) of total phosphorus, respectively. Peak values also decreased... |
Tipo: Text |
Palavras-chave: Sels nutritifs; Sédiments superficiels; Biomasse microalgale; Lagune de Venise; Nutrient concentrations; Surface sediments; Macroalgal biomass; Clam fishing; Venice lagoon. |
Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00322/43280/43015.pdf |
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Nascimento,Lilian Rodrigues do; Sifeddine,Abdelfettah; Torgan,Lezilda Carvalho; Albuquerque,Ana Luiza Spadano. |
The composition and spatial variation of diatom assemblage in surface sediments of Caçó Lake (shallow, mesotrophic and weakly acid lake - Maranhão State, Brazil) were analyzed in order to know the distribution pattern of the species along the lake during rainy season (April 1999). Four zones were established in the lake based on 21 diatoms species and habitat affinities. The first three zones (prime three meters deep to six meters deep) were marked by the occurrence of Pinnularia gigas, Frustulia rhomboides, Encyonopsis krasskei, Eunotia camelus, E. femoriformis and E. monodon. Zone IV (seven to nine meters deep) was inhabited mainly by Surirella biseriata and Fragilariforma floridana. During the beginning of the rainy season, the diatom assemblage in Caçó... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Diatoms; Shallow lake; Surface sediments; Caçó Lake; Brazil. |
Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132010000100030 |
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