International Journal of Animal and Veterinary Advances 1(2): 59-65, 2009 ISSN: 2041-2908 © Maxwell Scientific Organization, 2009 Submitted Date: July 30, 2009 Accepted Date: August 19, 2009 Published Date: October 30, 2009 Corresponding Author: J.F.N. Abowei, Department of Biological Sciences, Faculty of Science, Niger Delta University, Wilberforce, Island, Amassoma, Bayelsa State, Nigeria 59 Benthic Macro Invertebrate Fauna and Physico-chemical Parameters in Okpoka Creek Sediments, Niger Delta, Nigeria A.D.I. George, J.F.N. Abowei, and E.R. Daka 1 Department of Fisheries and Aquatic Environment, Faculty of Agriculture, Rivers State University of science and Technology, Port Harcourt, Rivers State, Nigeria 2 Department of Biological Sciences, Faculty of Science, Niger Delta University, Wilberforce Island, Amassoma, Bayelsa State, Nigeria 3 Department of Applied and Environmental Biology, Faculty of Science, Rivers State University of science and Technology, Port Harcourt, Rivers State, Nigeria Abstract: The benthic macro invertebrate fauna and physico-chemical parameters in Okpoka creek sediments was studied for a period of one year. A total of nineteen (19) species ( Ophidonais serpentina, Arenicola marina, Eunice harassi, Marphysa sanguinea, Capitella capitata, Notomastus latrella, Notomastus tenuis, Glycera capitata, Glycera convoluta, Nereis diversicolor, Nereis pelagica, Nereis virens, Nephthys hombergi, Nototropis swamidami, Cliberanus cooci, Iphinoe tripanosa, Chironomus ablabiesmia, Tellina nymphalis andTympanotonus fuscatus ) of benthic invertebrates’ fauna belonging four (4) phyla (Annelida, Amphipoda, Arthropoda and Mollusca), six (6) classes (Oligochaeta Polychaeta Crustacea Insecta Bivalvia and Gastropoda) and twelve (12) families (Naididae Arenicolidae Eunicidae Capitellidae Glyceridae Nereidae Nephthyldae Gammaridae Callianassidae Chironomidae Tellidae) were found in the Okpoka creek during the study. Polychaeta with six (6) families and twelve (12) species and percentage composition of 63.2% occurred most; followed by Crustacean with six (2) families and twelve (3) species and percentage composition of 15.8%. The rest families (Oligochaeta, Insecta, Bivalvia, Gastropoda) each with a family and specie occurred least. pH had a positive relationship with Ophidonais serpentine, Arenicola marina, Nereis diversicolor, Nereis pelagea, Nereis Virens, Nephthys hombergi, Iphinoe tripanosa and Tellina nymphalis, whereas temperature was strongly related with Arenicola marina, Notomastus latreila, Notomastus tenius, Marphysa sanguinea, Glycera convoluta, , Nereis diversicolor, Nereis pelagea, Nereis Virens, Nephthys hombergi, Iphinoe tripanosa and Tellina nymphalis, and Cliberanus cooci. A positive relationship exists between salinity and Notomastus latreila, Glycera convoluta Nototropis swamidami, Cliberanus cooci, Iphinoe tripanosa and Tellina nymphalis. Similarly, dissolved Oxygen and Notomastus latreila, Notomastus tenius, Eunice harassi , Marphysa sanguinea, Marphysa sanguinea, Nereis diversicolor, Nephthys hombergi, Clibernarius cooci, Iphinoe tripanosa and Tellina nymphalis. Strongly related. Biochemical Oxygen demand exhibited positive relationship with Ophidonais serpentine, Eunice harassi, Glycera capitata, Nereis diversicolor, Nereis pelagea, Nephthys hombergi, Nototropis swamidami and Tellina nymphalis. Conductivity related strongly with Ophidonais serpentine, Notomastus latreila , Marphysa sanguinea, Glycera convoluta, Nereis diversicolor, Nereis pelagea, Clibernarius cooci, Iphinoe tripanosa and Tympanotonus fuscatus. Key words: Benthic invertebrates, physico-chemical parameters, Okpoba creek sediments, Niger Delta, Nigeria INTRODUCTION Benthic macro fauna are those organisms that live on or inside the deposit at the bottom of a water body (Barnes and Hughes, 1988; Idowu and Ugwumba, 2005). In the brackish water ecosystem, they include several species of organisms, which cut across different phyla including annelids, coelenterates, molluscs, arthropods and chordates. These organisms play a vital role in the circulation and recirculation of nutrients in aquatic ecosystems. They constitute the link between the unavailable nutrients in detritus and useful protein materials in fish and shellfish. Most benthic organisms feed on debris that settle on the bottom of the water and in turn serve as food for a wide range of fishes (Imevbore and Bakare, 1970; Adebisi, 1989; Ajao 1990; Oke, 1990; Idowu and Ugwumba, 2005). They also accelerate the breakdown of decaying organic matter into simpler inorganic forms such as phosphates and nitrates (Gallep et al., 1978). All forms of aquatic plants, which are the first link of several food chains existing in aquatic environment, can utilize the nutrients. These organisms therefore form a major link in the food chain as most estuarine and marine fishes, birds and mammals depend directly or indirectly on the benthos for their food supply (Barnes and Hughes, 1988).