home icon user icon
Welcome to International Network for Natural Sciences | INNS Pub.
Home My Account
Submit Manuscript
double_slash
breadcumb_bg

Trends in macrobenthal biotypes of Imo River in a Nigerian Delta region

Paper Details

Research Paper 01/08/2011
Views (379) Download (13)
current_issue_feature_image
publication_file

Trends in macrobenthal biotypes of Imo River in a Nigerian Delta region

Dike Henry Ogbuagu, John Didacus Njoku, Adedolapo Abeke Ayoade
J. Bio. Env. Sci.1( 4), 22-28, August 2011.
Certificate: JBES 2011 [Generate Certificate]
Key: EntomofaunaMacrobenthosSand miningSpecies diversity

Abstract

Dynamics in macrobenthos abundance and diversity in sand-mined Imo River in Etche, South-eastern Nigeria has been investigated. While 14 representative species, comprising 3 classes (insect, oligochaeta, and gastropoda) were earlier identified in 2003, 9 species of these classes and 5 species comprising 2 classes only (insecta and oligochaeta) were identified in 2009 and 2010, respectively. Though Margalef’s diversity had increased from 1.67 in 2003 to 2.30 in 2009, it sharply decreased to 0.69 in 2010. Over these periods, entomofauna (class insecta) predominated the faunal assemblages with 8 species from 6 families in 2003, 7 species from 5 families in 2009, and 3 species from 2 families in 2010. Significant spatial variance inequality in macrobenthos abundance was observed at P<0.05 [F(240.54)>Fcrit(3.89)]. Further, there was variance inequality in means of macrobenthos abundance between 2003, 2009, and 2010 [F(6.54)>Fcrit(4.03)] at P<0.05. A further structure detection of mean difference revealed that inequality was most accounted for by the larva of the insect – Sialis luteria that was conspicuously absent in the 2009 and 2010 identifications. There was generally high interspatial communitydissimilarity, except an average similarity of 50% (0.50) recorded between locations 2 and 6, and 3 and 7 in 2009, as well as 50% between locations 1 and 3 and 2 and 6, and 67% between locations 2 and 7, and 3 and 7 in 2010. Benthic sediments were slightly acidic (6.95±0.01), with low nitrate (0.48±0.03), phosphate (0.72±0.04), and sulphate (44.35±1.57) concentrations. We suspect declining macroinvertebrate diversity and abundance in the river, and that ongoing anthropogenic perturbation (sand mining) contributes immensely to this paucity through the excavation and removal of benthal nutrients necessary for a thriving and diverse sediment community.

VIEWS 5
Cover PDF

American Public Health Association (APHA). 1998. Standard methods for the examination of water and wastewater, 20th ed. APHA/AWWA/WEF, Washington DC.

Bamikole WA, Ndubuisi A, Ochuko AP, Olaronke OOO. 2009. Macrobenthic fauna of Snake Island area of Lagos Lagoon, Nigeria. Res. Jr. Biol. Sc. 4(3), 272-276.

Harrison IJ, Stiassny MLJ. 1999. The quiet crisis: A preliminary listing of freshwater fishes of the World that are either extinct or “missing in action”. In R.D.E. MacPhee (ed.) Extinctions in Near Time: Causes, contexts, and consequences. Plenum Press, New York, p. 271-331.

Heyland JL, Herlinger TJ, Snouts TR, Ringwood AH, Van Dolah RF, Hackney CT, Nelson GA, Rosen JS, Kokkinakis SA. 1996. Environmental quality of estuaries of the Carolinian Province: 1994. Annual statistical summary for the 1994 EMAP-Estuaries Demonstration Project in the Carolinian Province.NOAA Technical Memorandum NOS ORCA 97.NOAA/NOS, Office of Ocean Resources Conservation and Assessment, Silver Spring, MD, p. 102.

Jokela J. 2010. Cause for concern: silent loss of freshwater diversity, Eawag News: Swiss Federal Inst. Aquat. Sc. Technol. 69e.

Margalef R. 1961. Communication of structure in plankton population. Limnology and Oceanography, 6, 124-128.

Mellanby, H. 1975. Animal life in freshwater.A guide to freshwater invertebrates.Chapman and Hall, London, UK.

Needham, PR. 1962. A guide to the study of freshwater biology, 5th edition. Holden Day, California, USA.

Ricciardi A, Rasmussen JB. 1999. Extinction rates of North American freshwater fauna. Conservation Biol. 3, 1220-1222.

Simboura N, Zenetus A, Panayotides P, Makia A. 1995. Changes in  benthic community structur along an environmental pollution gradient, Marine pollut. Bull., 30, 470-474.

Sikoki FD, Zabbey N. 2006. Environmental gradients and benthic community of the middle reaches of Imo River, South-Eastern Nigeria. Environ. Ecol. 24(1), 32-36.

Spaak P, Bauchrowitz M. 2010. Environmental influences and plankton dynamics. Eawag News: Swiss Federal Inst. Aquat. Sci. Technol. 25-27.

Tamuno PBL. 2005. Eco-livelihood assessment of inland river dredging: the Kolo and OtuokeCreeks, Nigeria, a case study. PhD Thesis, Loughbourogh University, p. 351.

Tingle CCD. 2002. Terrestrial invertebrates. Ecological monitoring methods for the assessment of pesticide impact in the tropics. I.F. Grant and C.C.D. Tingle (eds.), London: the University of Greenwich, p. 159-181.

Submit Manuscript