Abundance Dynamic of Vibrio Cells Associated with Freshwater Shrimps Atyidae (Crustacea-Decapoda) in the Coastal Surface Waters of Cameroon (Central Africa): Assessment of the Role of some Environmental Factors
Résumé
The abundance dynamics of planktonic Vibrio cells and those associated with the
freshwater shrimps Atyidae were assessed in the coastal surface waters of
Cameroon (Central Africa). Two pathogenic species V. parahaemolyticus and V.
alginolyticus were identified. The concentration of Vibrio cells associated to
shrimps was relatively high, as compared to the planktonic cells. This
concentration was very high during the great rainy season. The concentration of
Vibrio associated with Atyidae undergoes variations under the effect of the
proliferation of shrimps and influenced by color and rainfall. The physico-chemical
analyses showed a strong organic pollution. Low nutrient levels suggested high
water column turnover rate, which Vibrio compensated for by using organic
matters leaking from shrimp. Stepwise regression analyses showed that the
concentration of plaktonic Vibrio cells increase significantly in response to changes
to dissolved oxygen and organic matter accumulated in the water column due to
anthropogenic activities. Vibrio associated with shrimp Atyidae in surface waters
are a real risk of public health.