ASSESSMENT OF MACRO INVERTEBRATE SPECIES OF BAKAJEBA RESERVOIR, NIGER STATE

ASSESSMENT OF MACRO INVERTEBRATE SPECIES OF BAKAJEBA RESERVOIR,  NIGER STATE

ABSTRACT

Macro invertebrates are important part of the aquatic food chain, vectors of some diseases as well as indicators of pollution in an aquatic environment. A survey of macro invertebrates species of Bakajeba reserve in Niger State will be done to identify the species present in these water bodies. The scoop net method was used and supplemented by hand picking method to collect macro invertebrate samples. Results that will be obtained will show the various types micro invertebrates that are present  in the sample site. Analysis of variance will be used to show if there is a significant difference (p < 0.05) between the classes of macro invertebrates that will be sampled at the locations (Bakajeba Reserve).

CHAPTER ONE

INTRODUCTION

Macro invertebrates are those animals that have no backbone and can be seen with the naked eye and can be retained by a 0.02mm mesh net (Davis & Christidis, 1997). Macro invertebrates can be quite large and include organisms such as crayfish, snails, clams, mussels, limpets, beetles, caddisflies, stoneflies, mayflies, hellgrammites, dragonflies, true flies, and some moths. However most are very small. The most diverse group and commonest of freshwater macroinvertebrates are the insects which account for 70% of known species.

The presence and distribution of aquatic macro invertebrates in fresh water habitats, both streams, ponds and lakes is dependent on geographic location, elevation, stream gradient, flow rate and substrate type  (Barbour, Gerritson, Snyder &  Stribling, 1999). Macro invertebrates are an important part of the aquatic food chain. A good number of them are primary consumers feeding mainly on plant material such as leaves and woody material. Others are collectors or filter feeders sieving materials in suspension or on mud surfaces. The secondary consumers, the first level carnivores feed on these macro invertebrates and thus sustaining those higher in the trophic level such as fish, they thus play a crucial role in transfer of energy from primary producers and detritus to fish (Turcotte & Hamper, 1982).

Reservoirs are artificial water bodies whose dynamics and structures present a pattern of organization midway between those of rivers and lakes (Callisto et al., 2005). The ecological processes in these ecosystems are much more complex and variable than those found in natural lakes. Reservoirs are subject to distinguishable influences of the physical, chemical, and biological components of their tributaries (Torloni, 1994), as well as those caused by the principal land uses in the drainage basins.

These reservoir or ponds are a freshwater system and provide ideal habitat for most macro invertebrates. Some macro invertebrates have no history of serving as intermediate host of any disease, others have been associated with the transmission of many trematode diseases of man and livestock (Imafidon, 1991). Among the major diseases of which macro invertebrates such as gastropod snails serve as intermediate hosts are: schistosomiasis, fascioliasis and paragonimiasis. Schistosomiasis is of the greatest public health importance with about 200 million people infected in 76 endemic countries worldwide and about 600 million are at risk of infection (Omudu & Iyough, 2005).

STATEMENT OF THE PROBLEMS

In the past two decades, there has been a tremendous fear of a possible global biodiversity crisis arising out of a rapidly accelerating loss of species, populations and natural habitats such as tropical rainforests and wetlands. It has been estimated that more than half the habitable surface of the planet has already been altered by human activity (Hengeveld 1990). Also suggested is that we are on the verge of mass extinctions of species (McCarthy, 2002). These concerns stem from the realization that our knowledge of the diversity and variability of plants, animals, microorganisms and the ecosystems in which they occur is woefully incomplete. The global biodiversity crisis arising from overexploitation and pollution of water bodies is of great concern. Consequently, the degradation of water bodies necessitates regular assessment and management of Nigeria’s aquatic resources. The sediments of all water bodies, either lentic or lotic, contain vast numbers of micro invertebrate (species visible to the unaided eye) which are used to assess water quality in rivers (Elliot & Drake 1981). Not only are they numerically abundant, they are also taxonomically diverse. Hynes (1972) observed that the aquatic animals, which live on, in or near the substratum of running waters, include the nematodes, annelids, insects, crustaceans and molluscs. It is against this backdrop that this study seek to assess macro invertebrate species of Baka Jeba reservoir in Niger state.

OBJECTIVE OF THE STUDY

This study will aim at surveying and identifying macro invertebrates species found in Baka Jeba Reservoir in Niger State in order to provide information on distribution and abundance of these macro invertebrates species within these habitats.