Society of African Journal Editors

Larhyss Journal

TROPHIC STATUT FROM VODROBOUE LAGOON WATERS AND ITS MOUTH (SOUTH-EAST, CÔTE D’IVOIRE)

Authors: M. P. ADON, J.E. NIAMIEN-EBROTTIE, A. OUATTARA, G. GOURENE

Journal: Larhyss Journal

Assessment of the trophic status from Vodroboué lagoon and its mouth was carried out by adapting data from the European Framework Directive on Water (DCE) and lotic waters. I n situ measurements of dissolved oxygen (O 2 ), pH, temperature (Tº) and transparency (Tr), sampling nitrate and phosphate collected using the hydrological bottle were performed at stations E, V1, V2 and V3 in 2014-2015 and 2016-2017 periods between 8 and 12h. The samples were filted with plankton net of mesh size 20μm for phytoplankton. The Tº and pH values have indicated poor state of the water mass compared to the O 2 , NO 3 - and PO 4 3- which have indicated a good state of this water. 285 taxa divided into 264 and 460 taxa were identified in 2014-2015 and 2016-2017, respectively. The highest phytoplankton density characterized by picophytoplankton dominance (87200 10 7 cells.L -1 ) and nanophytoplankton (60730 and 129490 10 7 cells.L -1 ) in 2014-2015 and 2016-2017, respectively and results of the Shannon comprised between 0.18 and 1.47 have indicated a eutrophe water mass.