An Assessment of the Effect of Pollution on Zooplanktons in Calabar Great Kwa River, Nigeria

Abstract

Aim: Zooplanktons in the Calabar Great Kwa River were studied to assess the effect of pollution from human activities around the river on their respective abundance.
 Place and Duration of Study: Samples were collected at the Esuk Atu and Esuk Atimbo stations of the Calabar Great Kwa River. Identification of Zooplanktons was carried out at the Laboratory of the Department of Genetics and Biotechnology, University of Calabar, Calabar, Nigeria.
 Methodology: Collected samples were preserved, transferred to the laboratory, identified using a dissecting microscope and classified according to their different taxonomical groups.
 Results: The Results showed that zooplankton abundance and distribution recorded in the stations were low due to pollution and interference from high human activities around the river such as domestic solid wastes, sewage waste waters, industrial effluents, pesticides, sand mining activities, hydrocarbons and other toxic substances. In Esuk Atu, the total abundance of zooplanktons in the periods of sampling were 12, 6, 3 and 11, while the numbers of taxa represented in the periods of sampling were 4, 3, 1 and 4. In Esuk Atimbo, the total abundance of zooplanktons in the periods of sampling were 7, 5, 9 and 10 while the numbers of taxa represented in the periods of sampling were 3, 3, 3 and 2. The zooplankton taxa identified in station 1(Esuk Atu) are Cladoceran (38%), Ostracoda (22%), Copepoda (19%), Rotifera (12%), Lepidoptera (6%) and Protozoa (3%). The zooplankton taxa identified in station 2 (Esuk Atimbo) are Copepoda (26%), Cladoceran (23%), Nemata (23%), Lepidoptera (16%), Rotifera (6%), Polycheata (3%) and Paguridae (3%).
 Conclusion: These findings necessitate the need for the regulation and control of pollution from human activities around the Calabar Great Kwa River so as to ensure that the river is free from harmful contaminants thereby preserving the zooplanktons and other relevant organisms.