The Influence of Sawmill Wood Wastes on the Distribution and Population of Macroinvertebrates at Benin River, Niger Delta Area, Nigeria

Abstract

The impact of sawmill wood wastes on the distribution of benthic macroinvertebrates at the Sapele section of Benin River, Niger Delta, Nigeria, was investigated from March 2005 to August 2005. A total of 434 individuals were collected by kick-sampling method, representing 21 taxa of benthic macroinvertebrates. Three stations, 1, 2, and 3, were selected from upstream of the site, receiving wood wastes discharge, the impacted site and its down stream, respectively. Among the water quality variables, conductivity, dissolved oxygen, biochemical oxigen demand (BOD(5)), nitrate-nitrogen, phosphate-phosphorus, transparency, and alkalinity were significantly different (P<0.05) among the stations. Orthogonal comparison by Duncan's multiple range test showed that station 2 (the impacted site) was the cause of the difference. More sensitive species such as Ephemeroptera or Plecoptera were completely absent from station 2, the impacted site. Species abundance was similar in station 1 and 3, indicating that the wood wastes must have adversely affected the distribution of these macroinvertebrates, especially the intolerant species. The wood waste discharge not only altered the water chemistry, but also stimulated the abundance of less-sensitive macroinvertebrate species.

Response of macroinvertebrate communities to abattoir wastes and other anthropogenic activities in a municipal stream in the Niger Delta, Nigeria

“…These are characteristic species in water showing some degree of change in the quality of their trophic resources due to anthropogenic activities in the river. Their presence is a common feature of organically polluted water bodies in the Niger Delta (Chindah et al 1999;Ogbogu and Olajide 2002;Tyokumbur et al 2002;Atobatele et al 2005;Arimoro and Osakwe 2006) and elsewhere in the sub tropical region (Miserendino and Pizzolon 2000;Dyer et al 2003) and temperate regions (Solimini et al 2000;Negishi and Richardson 2003;Nedeau et al 2003) of the world. The improved taxa richness and diversity at site IV is an indication of recovery.…”

“…These activities cause diversity of stresses to aquatic systems and may affect biota at different spatial and temporal scales. Some identified stressors include discharge of untreated animal wastes from slaughter houses, livestock and fish farms (Mathooko 2001;Ruggiero et al 2003;Kirkague et al 2004), untreated sewage (Rueda et al 2002), wood wastes (Arimoro and Osakwe 2006), Storm water and laundering along urban tracts of stream (Walsh et al, 2002); old mine effluents (Nelson and Roline 2003).…”

“…Most rivers in developing nations including Nigeria are subjected to an increasing pollution load as a result of the inflow of effluents of different kinds from anthropogenic activities, which have become a major threatening factor to the quality of water particularly in the Niger Delta (Arimoro and Osakwe 2006). These activities cause diversity of stresses to aquatic systems and may affect biota at different spatial and temporal scales.…”

Zooplankton Community Responses in a Perturbed Tropical Stream in the Niger Delta, Nigeria~!2009-07-22~!2009-10-22~!2010-04-09~!

“…Many rivers in urban and semi urban areas of Nigeria have been used for disposals of both solid wastes and waste waters, usually untreated, and are thus adversely polluted. This high pollution status threatens and, in many cases, has already altered the ecological balance of most rivers in Nigeria [1][2][3]. Zooplankters offer several advantages as indicators of environmental quality in both lakes and rivers: as a group, they have worldwide distribution and the species composition and community structure are sensitive to changes in environmental conditions, nutrient enrichment [4][5][6] and different levels of pollution [7][8][9].…”

Effects of Cassava (Manihot esculenta Crantz) Effluents on Macroinvertebrate Assemblages in a Rainforest Lotic Freshwater Ecosystem, Southern Nigeria

“…This has caused deterioration in water qualities. Wade et al (2002), Walsh et al (2002) and Arimoro and Osakwe (2006) listed anthropogenic activities to include release or discharge of agricultural waste from agro-allied industries, refineries, human and animal waste, laundering, car washing and wood waste.…”