2.5. Zooplankton identifi cation
A total of 5 ml from each of the 40 ml sub
samples was identifi ed to 3 major groups of zooplankton:
cladoceran, copepod and rotifer. Zooplankton
samples were counted and identifi ed in a
Sedgewick-Rafter counting chamber under a bright
fi eld microscope. All samples were identifi ed to the
level of genus and species where possible using
the key of Shiel (1995) and Bayly (1992). Species
richness was counted as the number of taxa per unit
sample (100 g DW sediment) (McCune, Grace 2002)
and abundance was measured as total individual
per 100 g DW.