Author(s): Bel Hassen M, Drira Z, Hamza A, Ayadi H, Akrout F, et al.
Variations in phytoplankton pigments and community composition were examined in the Gulf of Gabes in relationship to water mass properties, characterised by the influence of the Modified Atlantic Water and by the thermal stratification. Data were collected on board the R/V Hannibal during July 2005.
Distinct water masses were identified using cluster analysis of temperature–salinity (T–S) characteristics. Three major clusters appeared based on the combined effects of temperature and salinity. The first cluster was identified as the cool and less salty bottom Modified Atlantic Water (MAW). The warmer and saltier Mediterranean Mixed Water (MMW) represented the second cluster. The third cluster was the Transition Water (TW) separating the two previous clusters.
The pigment and taxonomic composition of these water masses were examined. Chlorophyll a was rather low (<200 ng l−1). Chlorophyll b was generally the most abundant accessory pigment and fucoxanthin dominated the accessory pigments in the MAW. Proportions of chlorophyll a associated with different phytoplankton classes were estimated using CHEMTAX software, and did not present significant variations among water groups. The results pointed out variations in the relative contribution of each phytoplankton taxa in each station group. Chlorophytes and prasinophytes accounted for 65% of chlorophyll a in the MMW. Diatoms and chlorophytes were relatively abundant in the MAW contributing to almost 63% of chlorophyll a. An unstructured community, slightly dominated by prasinophytes, chlorophytes and cryptophytes, characterised the TW. Different trophic statuses were observed in these water masses, the MMW and the MAW being characterised by mesotrophy, while an oligotrophy was observed in the TW. Nutrient availability, particularly the P-limitation supported by the summer stratification, as revealed by the high N:P ratio (greater than 20), seems to enhance the development of small-sized phytoplankton, thereby supporting the regenerated production.
Author(s): Taylor DI, Nixon SW, Granger SL, Buckley BA
Author(s): Cardoso PG, Raffaelli D, Pardal MA
Author(s): Odum EP
Author(s): Mc Lusky DS
Author(s): Morrisey DJ, Skilleter GA, Ellis JI, Burns BR, Kemp CE, et al.
Author(s): Blanchet H, de Montaudouin X, Lucas A, Chardy P
Author(s): Den Hartog C
Author(s): Green EP, Short FT
Author(s): Waycott M, Duarte CM, Carruthers TJB, Orth RJ, Dennison WC, et al.
Author(s): Larkum AWD, Orth RJ, Duarte CM
Author(s): Hillman K, Mc Comb, AJ, Walker DI
Author(s): Hemminga MA, Duarte CM
Author(s): Williams SL, Heck Jr K.L.
Author(s): Duarte C.M
Author(s): Airoldi L, Beck MW
Author(s): Ganthy F, Sottolichio A, Verney R
Author(s): Do VT, de Montaudouin X, Blanchet H, Lavesque N
Author(s): Mosbahi N, Boudaya L, Dauvin JC, Neifar N
Author(s): Hamza F, Hammouda A, Chokri MA, Selmi S
Author(s): Mosbahi N, Pezy JP, Dauvin JC, Neifar L
Author(s): De Frenne P, Graae BJ, Rodríguez-Sanchez F, Kolb A, Chabrerie O, et al.
Author(s): de Montaudouin X, Blanchet H, Bazairi H, Nazik A, Desclaux-Marchand C, et al
Author(s): Hawkins SJ, Sugden HE, Mieszkowska N, Moore PJ, Poloczanska E, et al.
Author(s): Hinz H, Capasso E, Lilley M, Frost M, Jenkins SR
Author(s): Kröncke I, Reiss H, Eggleton JD, Aldridge J, et al.
Author(s): Bali M, Gueddari M
Author(s): Sammari C, Koutitonsky VG, Moussa M
Author(s): Abdennadher A, Ramirez F, Romdhane MS, Ruiz LJ, Sanpera C
Author(s): Hamza F, Hammouda A, Selmi S
Author(s): Plus M, Sebastien D, Gilles T, Isabelle A, de Montaudouin X, et al.
Author(s): Shannon CE, Weaver W
Author(s): Pielou EC
Author(s): Fauchald K., Jumars PA
Author(s): Hily C, Bouteille M
Author(s): Pranovi F, Curiel D, Rismondo A, Marzocchi M, Scattolin M
Author(s): Afli A, Ayari R, Brahim M
Author(s): Jumars PA, Dorgan KM, Lindsay SM
Author(s): Borja A, Franco J, Perez V
Author(s): Muxika I, Borja A, Bald J
Author(s): Dauvin JC, Ruellet T
Author(s): Dauvin JC, Ruellet T
Author(s): Lavesque N, Blanchet H, de Montaudouin X
Author(s): Do VT, Blanchet H, de Montaudouin X, Lavesque N
Author(s): Clarke KR, Gorley RN
Author(s): Ugland KI, Gray JS
Author(s): Boström C, Bonsdorff E
Author(s): Connolly RM
Author(s): Paula J, Fidalgo Ecosta P, Gove D
Author(s): Sfriso A, Birkemeyer T, Ghetti PF
Author(s): Fredriksen S, De Backer A, Böstrom C, Christie H
Author(s): Bowden DA, Rowden AA, Martin JA
Author(s): Barnes RSK, Barnes MKS
Author(s): Teixeira H, Salas F, Pardal MA, Marques JC
Author(s): Do VT, de Montaudouin X, Lavesque N, Blanchet H, Guyard H
Author(s): Duffy JE
Author(s): Bachelet G, de Montaudouin X, Auby I, Labourg PJ
Author(s): Yamada K, Hori M, Tanaka Y, Hasegawa N, Nakaoka M
Author(s): Leopardas V, Uy W, Nakaoka M
Author(s): van der Heide T, Govers LL, de Fouw J, Olff H, van der Geest M, et al.
Author(s): Cavanaugh CM
Author(s): Anderson AE
Author(s): Castel J, Labourg PJ, Escaravage V, Auby I, Garcia ME
Author(s): Reise K, Herre E, Sturm M
Author(s): Nakamura Y, Turner JT
Author(s): Coll M, Piroddi C, Steenbeek J, Kaschner K, Ben Rais Lasram F, et al.
Author(s): Pinardi N, Zavatarelli M, Arneri E, Crise A, Ravaioli M
Author(s): Bas C
Author(s): Albertelli G, Covazzi-Harriague A, Danovaro R, Fabiano M, Fraschetti S, et al.
Author(s): Salen-Picard C, Arlhac D
Author(s): Afli A, Boufahja F, Sadraoui S, Ben Mustapha K, Aissa P, et al.
Author(s): Blanchet H, Lavesque N, Ruellet T, Dauvin JC, Sauriau PG, et al.
Author(s): Reiss H, Kroncke I
Author(s): Hawkins SJ, Moore PJ, Burrows MT, Poloczanska E, Mieszkowska N, et al.
Author(s): Harley CDG, Hughes AR, Hultgren KM, Miner BG, Sorte CJB, et al.
Author(s): Helmuth B, Mieszkowska N, Moore P, Hawkins SJ