Seasonal variability of phytoplankton composition inside and outside the Marine Protected Areas of Joal-Fadiouth and Bamboung in Senegal (West Africa) [résumé]

2017

Colloque

Abdou Salam A.M., Ba N., Ndour I., Thiaw M., Brehmer Patrice

Brehmer Patrice (ed.), Ba B. (ed.), Kraus G. (ed.), International conference ICAWA 2016 : extended book of abstract : the AWA project : ecosystem approach to the management of fisheries and the marine environment in West African waters

Dakar : SRFC/CSRP ; IRD, 2017, p. 118 ISBN 978-2-9553602-0-5

ICAWA : International Conference AWA, 3., Dakar (SEN), 2016/12/13-15

Marine Protected Areas (MPAs) are considered tools for biodiversity and resource restoration and resilience. However, their role in improving the flow of matter through better productivity remains to be demonstrated. The present study aims to analyze the phytoplankton composition inside and outside two contrasted MPAs; Joal-Fadiouth (coastal) and Bamboung (estuary) at dry cold and wet hot seasons. Data were collected with plankton net of 20 ?m net mesh in April and September 2016. In the laboratory, by optical microscopy, the phytoplankton species were identified at the lowest possible taxonomic level by comparison of our data with those of taxonomy works. A total of 101 species belonging to 30 families were identified in the Bamboung MPA, compared with 98 species of 28 families in the Joal-Fadiouth MPA. In the latter MPA, the number of species was higher (40 species of 19 families) inside than outside (30 species of 18 families) the MPA in April i.e. the cold season. In September, i.e. the hot season, the number of species was higher (62 species of 16 families) outside than inside (50 species of 14 families). As for the Bamboung MPA, whatever the season (cold and hot), the number of species was respectively higher inside (58 species of 28 families and 61 species of 20 families) than outside (30 species of 18 families and 58 species of 20 families). However, even if both MPAs present similitude for the taxonomical composition, characteristic species of each environment have been encountered: Eucampia sp and Stephanopyxis pelagica in estuarine Bamboung MPA and Plagiogramma sp, Podocystis sp, Melosira sp and Rhabdonemma sp only encountered in Joal-Fadiouth (marine environment). Three species and / or groups of harmful algae blooms (HABs), Pseudonitzschia serieta in Joal-Fadiouth, Prorocentrium lima in Bamboung and Pseudonitzschia sp in both MPAs, were also encountered.

Sciences du milieu [021] ; Limnologie biologique / Océanographie biologique [034]

Fonds IRD [F A010071832]

fdi:010072143