Planktonic copepod community in the neritic area of the south western part of Tunis bay influenced by Meliane river supplies (south western Mediterranean sea)

Abstract

The Tunis bay is located in the North Estern coast of Tunisia and receives in its Western part flows from
Meliane River. Our study aims to describe the composition and the spatiotemporal distribution of planktonic
copepods in the bay in order to identify the effect of the Meliane River supplies on the community. A grid of 19
stations was investigated monthly from July 2004 to December 2004 using a 160 μm mesh size plankton net,
towed obliquely from the bottom to the surface. The planktonic copepod community was represented by 21 taxa of Calanoida, 4 taxa of Cyclopoida, 3 taxa of Poicilostomatoida and one species of Harpacticoida. The presence of freshwater taxa like Arctodiaptomus salinus, Microcyclops sp and Thermocyclops sp in the coastal stations indicated the meliane River flows. The copepod community dominated the mesozooplankton, they constituted 94% of total abundance. Two species (Oithona nana and Euterpina acutifrons) dominated the community showing a shift of the planktonic copepod
community structure to smaller-sized copepods carrying egg sacs due to anthropogenic supply increase.