First results on Microcystis ichthyoblabe Kutz. toxic bloom in the hypertrophic Oued Mellah reservoir (Morocco)

• Type: Article in International Scientific Journal
• Date: 2002

Authors

Sabour, B (Author) Other; Loudiki, M (Author) Other; Oudra, B (Author) Other; Oubraim, S (Author) Other; Fawzi, B (Author) Other; Fadlaoui, S (Author) Other; Chlaida, M (Author) Other; Vasconcelos, V (Author) FCUP

Journal

Title: Annales de Limnologie

Vol. 38

Pages: 13-22

ISSN: 0003-4088

Publisher: EDP Sciences

Indexing

ISI Web of Knowledge - 7 Citations

Scopus - 8 Citations

Scientific classification

FOS: Natural sciences > Earth and related Environmental sciences

Other information

Authenticus ID: P-000-QVB

DOI: 10.1051/limn/2002001

Abstract (EN): The Oued Mellah reservoir (33degrees30' N-07degrees20'W) is a shallow brackish lake located 25 km North of Casablanca. A study of the phytoplankton community of this lake shows that it is affected by potentially toxic blooms of Cyanobacteria and Haptophyceae. Microcystis ichthyoblabe (first time recorded from Morocco), Anabaena aphanizoinenoides, Oscillatoria chlorina (Cyanobacteria) and Prymnesium parvum (Haptophyceae) constitute the dominant phytoplankton taxa. M. ichthyoblabe starts its growth in late spring. In 1999, it formed a spectacular bloom during May-June, invading the lake with a maximal biomass of 298 mg(FW).L-1. This proliferation coincided with high temperatures, strong luminous intensity, alkaline pH and low to undetectable contents of nitrates and orthophosphates. The toxicity of the M. ichthyoblabe bloom material was first determined by mouse bioassay. Bloom material collected during the maximal development phase has an LD50 about 502 mg(DW).Kg(-1). Hepatotoxicity was confirmed by histopathological study. The total contents of microcystins determined by ELISA technique both for bloom material and the isolated strain are about 0.79 and 5.4 mug.g(DW)(-1) respectively. Analysis by HPLC-PDA allows the detection of I I variants of microcystins. The use of the microcystin-LR authentic sample showed the absence of this microcystin variant in the samples analysed.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10