TITLE:
Structure and Composition of Macroinvertebrates during Flood Period of the Nokoue Lake, Benin
AUTHORS:
Hamed Odountan, Youssouf Abou
KEYWORDS:
Nokoue Lake, Macroinvertebrate Community, Structure, Flood Period, Dominant Taxa
JOURNAL NAME:
Open Journal of Ecology,
Vol.6 No.2,
January
25,
2016
ABSTRACT: The
Nokoue Lake is the largest lake of Benin Republic and it is also considered as
one of the most productive lagoon ecosystems in West Africa. This productivity
is decreasing and thus raises productivity issue for a better management and
conservation. Macroinvertebrate can be useful for this purpose. A study was
conducted to assess the spatial variation of macroinvertebrates during high
flood period. A total of 3892 macroinvertebrates of fresh and brackish water
were sampled during the survey. Structural analysis of the macroinvertebrate
community revealed that it was made up of 16 orders, 48 families and 66 genera
dominated by Insecta compared to Mollusca, Crustacea and the Annelida. Insects were
dominated by Diptera (Chironomus sp.
and Tanytarsus sp.), Coleoptera
(Dystiscidae) and accounted for 57.1% of the sampled population. Mollusca, Crustacea,
Annelida and Arachnida were the following most abundant and represented 23.9%,
10.7%, 8.1% and 0.2% of the total population, respectively. The Evenness index
of Pielou was higher on the Station 8 (0.91 - 0.97), close to Oueme River.
However, no significant difference (p > 0.05) was observed neither between
station nor between month on the Shannon-Wiener index (2.06 - 4.31), Simpson
index (0.04 - 0.40) and the taxa number (10 - 27). Macroinvertebrate
assemblages and composition were primarily due to changes in water quality
dependent on hydroclimatic changes and probably to anthropogenic actions. This
suggests the need for real investigation of the macroinvertebrate biological
capacity when formulating conservation strategies for the Nokoue Lake.