An Assessment of the Nematode Population in the Benthic Zone of a Tidal Freshwater Body using the Lower Reaches of the New Calabar River as a Case Study

Abstract

An assessment of the Nematode population in the benthic zone of the New Calabar River, Choba, using the modified baermann’s method yielded eight (8) species of nematode. The nematode speciation includes: Tylenchorhynchus dubius (8.0%), Ditylenchus dipsaci (4.0%), Rotylenchus uniformis (4.0%), Rhabdolaimus sp (2.0%), Aphelenchoides ritzemabosi (2.0%), Tylenchus davainei (4.0%), Pratylenchus sp (4.0%), and Xiphenema sp (4.0%). The low species richness and abundance observed were attributed to a number of factors like seasonality and influx of pollutants into the river from the abattoir, market, poultry and other human disturbances. Furthermore, the intrusion of salt into the river through its tidal effect causes silting shoreline, nutrient enrichment (from abattoirs, poultry, industries, etc), human disturbances have caused a decline in the population of k-strategists and an increase in proportion of r-strategists of which some were “ideal” soil nematodes.

Keywords: Dredging, Tidal freshwater, Abattoir, nematodes, benthic zone