CHAPTER ONE
INTRODUCTION
Rivers as water bodies are important by being involved in maintaining a balance in the
ecosystem through supporting diverse plankton (phytoplankton and zooplankton) and other
organisms in the food chain. In the last decades, there has been a growing necessity for the
conservation of our resources, especially water. At the same time, growing populations,
progressive industrialization and intensification of agriculture are leading to increased pollution
of our surface waters (Mohammad and Saminu, 2012).
Adequate and safe water supply is therefore a pre-requisite for significant socio-economic
development of any community. Unfortunately, in many areas of the world, especially
developing countries including Nigeria, it is difficult to obtain a steady source of clean water for
drinking and for agricultural uses (Akpan-Idiok et al., 2012). Rivers are equally useful in
generating electricity, fisheries, irrigation and for domestic animals (Zakariya et al., 2011).
Water required for domestic consumption should be free from suspended solids and dissolved
impurities etc. (Alexander, 2008). Rivers constitute one of the major sources of water supply in
the world (Akpan-Idiok et al., 2012).
The assessment and continuous monitoring of the quality of water sourced from rivers can be
used to define existing conditions, detect trend and or establish sources of pollution. The quality
of water is often affected by rocks, soil and surface through which it flows and anthropogenic
(e.g. industrial, agricultural and mining) activities (WHO, 1996; Ibeto and Onianwa, 2011).
Several studies revealed that these activities coupled with atmospheric factors affect the
suitability of water for all purposes (Faniraan et al., 2001; Daghrah, 2009; Hakim et al., 2009;
El-Saeid et al., 2011; Al-Tabbal and Al-Zboon, 2012). Maitera et al. (2011) pointed out that
sources of water supply are susceptible to pollution due to heavy human dependency on them.
Urbanization, domestic and industrial activities thus have greatly contributed to increased scale
of pollution of rivers and other bodies of water (Ibeh and Mbah, 2007).
Chemical pollutants include heavy metals, which are elements having specific gravity greater
than 4.0 that is, at least 5 times that of water (Akan et al., 2010). The most common heavy metals
that humans are exposed to are aluminium, arsenic, cadmium, lead and mercury (Akan et al.,
2010). Heavy metals can cause serious health effects with varied symptoms depending on the
nature and quantity of the metal ingested (Adepoju-Bello and Alabi, 2005). Excess exposure to
these metals can however, be toxic (Akan et al., 2010).
Water physico-chemical parameters are known to affect the biotic component of an aquatic
environment in various ways (Ugwumba, 1993). The change in physical characteristics like
depth, temperature, transparency and chemical elements of water such as dissolved oxygen,
chemical oxygen demand, nitrate and phosphate provide valuable information of the quality of
the water, the source(s) of the variation and biodiversity (Mustapha, 2008).
Phytoplankton are microscopic aquatic plants, occurring as unicellular, colonial or filamentous
forms, without any resistance to currents and are free-floating or suspended in the open waters
(Zakariya et al., 2011). They are important water quality indicators because of their short life
cycles, ability to respond to environmental changes and species composition (Dokuli, 2003).
Algal abundance can be affected by turbidity levels.
INTRODUCTION
Rivers as water bodies are important by being involved in maintaining a balance in the
ecosystem through supporting diverse plankton (phytoplankton and zooplankton) and other
organisms in the food chain. In the last decades, there has been a growing necessity for the
conservation of our resources, especially water. At the same time, growing populations,
progressive industrialization and intensification of agriculture are leading to increased pollution
of our surface waters (Mohammad and Saminu, 2012).
Adequate and safe water supply is therefore a pre-requisite for significant socio-economic
development of any community. Unfortunately, in many areas of the world, especially
developing countries including Nigeria, it is difficult to obtain a steady source of clean water for
drinking and for agricultural uses (Akpan-Idiok et al., 2012). Rivers are equally useful in
generating electricity, fisheries, irrigation and for domestic animals (Zakariya et al., 2011).
Water required for domestic consumption should be free from suspended solids and dissolved
impurities etc. (Alexander, 2008). Rivers constitute one of the major sources of water supply in
the world (Akpan-Idiok et al., 2012).
The assessment and continuous monitoring of the quality of water sourced from rivers can be
used to define existing conditions, detect trend and or establish sources of pollution. The quality
of water is often affected by rocks, soil and surface through which it flows and anthropogenic
(e.g. industrial, agricultural and mining) activities (WHO, 1996; Ibeto and Onianwa, 2011).
Several studies revealed that these activities coupled with atmospheric factors affect the
suitability of water for all purposes (Faniraan et al., 2001; Daghrah, 2009; Hakim et al., 2009;
El-Saeid et al., 2011; Al-Tabbal and Al-Zboon, 2012). Maitera et al. (2011) pointed out that
sources of water supply are susceptible to pollution due to heavy human dependency on them.
Urbanization, domestic and industrial activities thus have greatly contributed to increased scale
of pollution of rivers and other bodies of water (Ibeh and Mbah, 2007).
Chemical pollutants include heavy metals, which are elements having specific gravity greater
than 4.0 that is, at least 5 times that of water (Akan et al., 2010). The most common heavy metals
that humans are exposed to are aluminium, arsenic, cadmium, lead and mercury (Akan et al.,
2010). Heavy metals can cause serious health effects with varied symptoms depending on the
nature and quantity of the metal ingested (Adepoju-Bello and Alabi, 2005). Excess exposure to
these metals can however, be toxic (Akan et al., 2010).
Water physico-chemical parameters are known to affect the biotic component of an aquatic
environment in various ways (Ugwumba, 1993). The change in physical characteristics like
depth, temperature, transparency and chemical elements of water such as dissolved oxygen,
chemical oxygen demand, nitrate and phosphate provide valuable information of the quality of
the water, the source(s) of the variation and biodiversity (Mustapha, 2008).
Phytoplankton are microscopic aquatic plants, occurring as unicellular, colonial or filamentous
forms, without any resistance to currents and are free-floating or suspended in the open waters
(Zakariya et al., 2011). They are important water quality indicators because of their short life
cycles, ability to respond to environmental changes and species composition (Dokuli, 2003).
Algal abundance can be affected by turbidity levels.
