TABLE OF CONTENTS
Title Page i
Declaration ii
Dedication iii
Certification iv
Acknowledgements v
Table of Contents vi
List of Tables xi
List of Figures xii
List of Plates xiii
Abstract xiv
CHAPTER
1: INTRODUCTION
1.1. Background of Study 1
1.1.1 Industrial discharge and oil spill 3
1.1.2 Municipal and agricultural waste 4
1.1.3 Urban run- off 5
1.1.4 Future management strategy for surface water quality monitoring in Nigeria 6
1.2 Justification of the Study 10
1.3 Significance of Study 12
1.4 Aim and Objectives of the Study 12
CHAPTER 2: REVIEW OF RELATED LITERATURE
2.1 Historical Background 13
2.2 Impacts of Human Activities on the Water
Quality 14
2.3 Impacts of Human Activities on the
Sediment and Macro Benthos 28
CHAPTER 3: MATERIALS AND METHODS
3.1 Description of Study Area 39
3.2 Field Study 40
3.3 Reconnaissance Survey 41
3.4 Sampling Stations 43
3.5 Sample Collections/Analysis 46
3.5.1 Water
sample collection for physicochemical parameters analysis 46
3.5.1.1 Water
temperature 52
3.5.1.2
Hydrogen ion (PH) 52
3.5.1.3 Dissolved
oxygen 52
3.5.1.4 Electrical
conductivity 52
3.5.1.5 Total
dissolved solids (TDS) 53
3.5.1.6 Turbidity 53
3.5.1.7 Biological oxygen demand 53
3.5.1.8 Chemical oxygen demand (COD) 54
3.5.1.9 Total alkalinity 55
3.5.1.10 Bicarbonate 55
3.5.1.11 Silica 56
3.5.1.12 Chloride 56
3.5.1.13 Total
suspended solids (TSS) 57
3.5.1.14 Nitrate-nitrogen (No3-N) 58
3.5.1.15 Ammonia-
nitrogen (NH3-N) 58
3.5.1.16 Sulphate 59
3.5.1.17 Phosphate (PO4-3) 60
3.5.2 Collection
of samples for heavy metals/ total hydrocarbon 60
3.5.3 Analysis
of sediments and macro-benthos sample for heavy metal/ total hydrocarbon 61
3.5.3.1 Determination
of heavy metals in sediment samples 61
3.5.3.2 Determination
of heavy metal in benthic organisms 61
3.5.3.3 Determination
of total hydrocarbon in water samples 62
3.5.3.4 Determination
of total hydrocarbon in sediment samples 62
3.6 Health
Risk Assessment 63
3.7 Data
Analysis 63
CHAPTER 4: RESULTS
4.1 Physico-chemical Parameters 65
4.1.1 Hydrogen ion (PH) 65
4.1.2 Temperature 65
4.1.3 Electrical conductivity 70
4.1.4 Total dissolved solids 70
4.1.5 Dissolved oxygen 71
4.1.6 Chloride as salinity 71
4.1.7 Turbidity 71
4.1.8 Total suspended solid 78
4.1.9 Bicarbonate 78
4.1.10 Total alkalinity 81
4.1.11 Biological oxygen demand 81
4.1.12 Chemical oxygen demand 81
4.1.13 Total hydrocarbon 82
4.1.14 Total organic carbon 82
4.1.15 Nitrate 89
4.1.16 Phosphate 89
4.1.17 Sulphate 92
4.1.18 Ammonia 92
4.1.19 Silica 92
4.2 Correlation Matrise and Hierarchical
Cluster Dendrogam based on Physico-chemical Parameters (Wet
season) 95
4.3 Correlation Matrix and Hierarchical
Cluster Dendrogam based on Physico-chemical Parameter (Dry
season) 98
4.4 Heavy Metals in Sediment samples 105
4.4.1 Cadmium 105
4.4.2 Chromium 105
4.4.3 Vanadium 106
4.4.4 Arsenic 110
4.4.5 Copper 110
4.4.6 Iron 110
4.4.7 Lead 111
4.4.8 Cobalt 111
4.4.9 Zinc 111
4.4.10 Total hydrocarbon 118
4.4.11 Total organic carbon 114
4.5 Correlation Matrix and Hierarchical
Cluster Dendron based on Heavy Metals in Sediment (Wet
season) 118
4.6 Correlation Matrix and Hierarchical Cluster
Dendron based on Heavy Metals in Sediment (Dry
season) 119
4.7 Ordination of Contaminants and
Physico-chemical Parameters for Wet and Dry Season in QIRE 119
4.7.1 Ordination of contaminants and
physico-chemical parameters of Study area (wet season) 119
4.7.2 Ordination of contaminants and
physico-chemical parameters (dry season) 128
4.8 Heavy Metals in Tympanotonus fuscatus (Benthic Species) 130
4.8.1 Cadmium 136
4.8.2 Chromium 136
4.8.3 Vanadium 136
4.8.4 Arsenic 136
4.8.5 Copper 136
4.8. Iron 137
4.8.7 Lead 137
4.8.8 Cobalt 137
4.8.9 Zinc 137
4.9 Heavy Metals in Callinectes aminicola 138
4.9.1 Cadmium 138
4.9.2 Chromium 138
4.9.3 Vanaduim 138
4.9.4 Arsenic 138
4.9.5 Copper 140
4.9.6 Iron 140
4.9.7 Lead 140
4.9.8 Cobalt 140
4.9.9 Zinc 141
4.10 Transfer Factor for
Macro benthic Organism 141
4.10.1 Typmpanotonus fuscatus 141
4.10.2 Callinectes
amnicola 142
4.11 Discussion 142
4.11.1 Season and spatial variation in
physico-chemical parameters in water samples 153
4.11.2 Seasonal and spatial
variation in contaminant concentrations in sediments 153
4.11.3 Multivariate analysis,
nutrient distribution and source apportionment 155
4.11.4 Heavy metal concentration in the tissue of Tympanotonus fuscatus and Callinectes
amincola 157
4.11.5 Accumulation factor (transfer factor) 158
CHAPTER 5: CONCLUSION AND
RECOMMENDATIONS
5.1 Conclusion 161
5.2 Recommendations 164
References 165
Appendices 177
LIST OF TABLES
4.1 Seasonal
range, Mean Variation, Standard Error of Physico-
chemical Parameters Measured in Qua Iboe River Estuary for
Wet and Dry Season 67
4.2 Pearson’s
Correlation Matrix of Physico-chemical Parameters in
Water from QIRE (Wet Season) 98
4.3 Pearson’s
Correlation Matrix of Physico-chemical Parameters in
Water from QIRE (Dry Season) 103
4.4 Seasonal
Range, Mean Variation, Standard Error of Contaminants
in Sediment of QIRE for Wet and Dry Seasons 106
4.5 Pearson’s
Correlation Matrix of Trace Metals in Sediment from
QIRE (Wet Season) 112
4.6 Pearson’s
Correlation Matrix of Trace Metals in Sediment
from QIRE (Dry
Season) 124
4.7 Size,
Percentage Total Variation and Cumulative Percentage of
Correlation Matrix of Three Components in QIRE 124
4.8 Rotated
Component Matrix of Contaminant and Physico-chemical
Parameters of QIRE
(Wet Season) 127
4.9 Size,
Percentage Total Variation and Cumulative Percentage of
Correlation Matrix of Three Components in the Original Data Set of
Contaminants of Physico-chemical Parameters of QIRE 132
4.10 Rotated
Component Matrix of Contaminant and Physio-chemical
Parameters of QIRE
(Dry Season) 133
4.11 Seasonal Range, Mean Variation, Standard
Error of Heavy Metal
Concentrations
(mg/kg) in Tympanotonus fuscutus in QIRE 135
4.12 Seasonal Range, Mean Variation, Standard
Error of Heavy Metal
Concentrations in Callinectes amnicola in QIRE 139
LIST OF FIGURES
3.1 Map of the study area
showing sampling stations in Qua Iboe River 42
4.1 Monthly spatial variation
in pH concentration 68
4.2 Monthly spatial
variation of temperature 69
4.3 Monthly spatial
variation of electrical conductivity 73
4.4 Monthly spatial
variation of total dissolved solids 74
4.5 Monthly spatial
variation of dissolved oxygen 75
4.6 Monthly spatial
variation in pH concentration of chloride 76
4.7 Monthly spatial
variation of turbidity 77
4.8 Monthly spatial
variation of total suspended solids 79
4.9 Monthly spatial
variation of bicarbonate 80
4.10 Monthly spatial
variation of total alkalinity 84
4.11 Monthly spatial
variation of biological oxygen demand 85
4.12 Monthly spatial
variation of chemical oxygen demand 86
4.13 Monthly spatial
variation of total hydrocarbon 87
4.14 Monthly spatial
variation of total organic carbon 88
4.15 Monthly spatial
variation of nitrate 90
4.16 Monthly spatial
variation of phosphate 91
4.17 Monthly spatial
variation of sulphate 93
4.18 Monthly spatial
variation in ammonia concentration 94
4.19 Dendrogram showing spatial distribution of
physico-chemical
parameters in water (wet season) 99
4.20 Dendrogram showing spatial distribution of
physico-chemical
parameter in water (dry season) 104
4.21 Monthly spatial variation in the
concentration of cadmium in
sediment of QIRE 108
4.22 Monthly spatial variation in the
concentration of chromium
in sediment of
QIRE 109
4.23 Monthly spatial variation in the
concentration of Copper
in sediment 113
4.24 Monthly spatial variation in the
concentration of Iron
in sediment 114
4.25 Monthly spatial variation in the
concentration of lead
in sediment 115
4.26 Monthly spatial variation in the
concentration of zinc
in sediment 116
4.27 Monthly spatial variation in the
concentration of total
hydrogen in sediment 117
4.28 Monthly spatial variation in the
concentration of total organic
carbon in sediment 118
4.29 Dendrogram showing source apportionment in
sediment
(wet season) 122
4.30 Dendrogram showing spatial distribution of
contaminants in
sediment (wet season) 123
4.31 Dendrogram showing source apportionment in
sediment
(dry season) 125
4.32 Dendrogram showing spatial distribution of
contaminants in
sediment (dry season) 126
4.33 Principal component analysis plot of
contaminants and
physico-chemical Parameters (wet season) 131
4.34 Principal component analysis plot of
contaminants and
physico-chemical parameters (dry season) 134
LISTS OF PLATES
1 Station one (I woukpom) showing linear
settlement by the bank
of the estuary 47
2 Station two
(Mkpanak) showing the platform where offloading
of finished
Petroleum products from ship is done 48
3 Station three (Iwuochang) showing
linear settlement by the bank
of the Estuary and
evidence of fishing activities 49
4 Station four (Eketai) showing evidence
of lumbering activities,
dredging) 50
5 Station five
(Atabong) showing evidence of less coastal impacts 51
CHAPTER 1
INTRODUCTION
1.1 BACKGROUND OF STUDY
The ecological integrity of most coastal aquatic ecosystems in the
world has been widely threatened and degraded by unprecedented levels of chemicals
ranging from trace metals, petroleum hydrocarbon, pesticides, industrial
effluents, sewage, etc. arising mainly from human activities. Varying
quantities of chemicals and organic pollutants have been discharged directly
into coastal systems as byproducts of many commercial and industrial processes,
land and municipal sewage runoff, agricultural and domestic wastewater,
effluents, and atmospheric fall outs (Huang et
al., 2013; Gao et al., 2014).
Previous investigations on intertidal estuarine and associated aquatic
ecosystems in this part of the world have revealed that different
human-mediated activities arising from crude oil spillage (Benson et. al., 2007a; Essien et al., 2008 and Essien et al., 2009) can adversely alter the
ecological integrity of these fragile aquatic ecosystems, leading to bioaccumulation
of pollutants by biota (Benson et al.,
2007b; Essien et al., 2008 and Essien
et al., 2009), and heavy metals
enrichment in sediment (Goher et al.,
2014 and Benson et al., 2008).
However, the transport, mobilization and pollution of trace metals
in aquatic ecosystems especially intertidal coastal water bodies have become an
important problem due to their toxic effects, accumulation and bio-concentration
through the food chain. Metal toxicity
mainly depends on the metal speciation and bioavailability, as well as the
means of uptake, accumulation and excretion rates of the organisms (Benson et al., 2013). Body levels of some
crustacean (crab) are capable of regulating essential trace metals such as Zn,
Cu, Mn, Fe and Cr at concentrations below threshold level. These metals play a
vital role in many physiological processes, but have a toxic effect when
present at high concentrations in the surrounding medium. On the contrary, body
levels of nonessential metals such as Cd and Pb are not regulated by crustacean
and are toxic even at trace concentrations. This could result in adverse
effects such as disruption of reproductive potential, and endocrine disruption
for higher trophic level organisms.
The bioavailability/remobilization of trace metals onto aquatic
substrates such as sediment, surface water, aquatic organisms and
microorganisms is dependent on their physicochemical forms (Benson et al., 2013). Several studies have
indicated that phytoplankton and other aquatic organisms can remove bio-accumulate
and transfer bio-concentrated trace metals from lower to higher trophic levels
in food webs (Benson et al., 2007).
These biological systems could be used in environmental studies as bio-indicators
or bio-monitors (Song and Sun, 2014 and Conti et al., 2015). To date,
there are scarce data pertaining to bioaccumulation and integrated risk
assessment of trace metals and other chemical stressors in aquatic organisms of
this important estuary.
Despite the increasing environmental and health concerns posed crude
oil pollution to aquatic ecosystems in Niger Delta, the state or degree of
contamination by chemicals and associated human health risk through dietary
exposure have not been duly assessed to date. Most previous studies on the
occurrence of trace metals were mainly focused on quantifying hydrocarbons and
heavy metals levels in water, zoo-benthos, and sediment (Benson et al., 2007a; Benson et al., 2007b; Essien et al., 2008 and Essien et al., 2009). Studies have indicated
enhanced levels of trace metals in soil, surface water, sediments and biota
from aquatic ecosystems in the area (Benson et
al., 2007b; Essien et al., 2008;
Benson et al., 2008; Essien et al., 2009 and Benson et al., 2016). Many tropical ecosystems
in the Niger Delta serve as primary recipients of petroleum
exploration-exploitation wastes, domestic and industrial wastes generated by
multinational oil companies that are found in the region.
1.1.1
Industrial discharges
and oil spills
Research carried out in majority of the cities in Nigeria had
discovered that industrial effluent is one of the key sources of surface water
pollution in Nigeria (Ekiye and Zejiao, 2010). Industrial effluents when
discharged directly into the rivers devoid of prior treatment have ability of
escalating water quality parameters. Dada (1997) indicated that less than 10 %
of industries in Nigeria treat their effluents before predisposing into the
rivers. This has led to elevated load of inorganic metals in most of the water
bodies (Wakawa et al. 2008). The
consequential effects of this will be on the receiving streams and rivers. The
impacts might include water quality mutilation, reduction in fish abundance and
effect on water-usage for recreation, industrial and domestic purposes.
Elevated phosphate concentrations in these effluents could result into nutrient
enrichment of the receiving water bodies thus leading to ecological tragedy. Metal
pollution of Warri River by industrial discharges has been reported by Ayenimo et al. (2005). The river was monitored
for heavy metals such as Fe, Cu, Ba, Pb, Cd, Cr, Ni and Co. Results showed
elevated values of these metals at sampling point situated in the vicinity of
an industry. Correlation analysis of the metals suggested similar source. Other
water quality parameters showed elevated values signifying pollution in close
proximity to the industry. The nefarious activities of the oil industries in the
Niger-Delta region of Nigeria have impacted negatively on the surface water
quality of the area. This has led to water shortage, interference of
socio-economic activities and poor aesthetic value of most of the water bodies
tainted by oil spills (Egborge, 1994). The majority of the rivers around the
Niger-Delta province of the Country could not be abstracted for management for
drinking purpose because of contamination by crude oil. The impact of oil
activities in these areas had done much destruction to the environment of this
region in particular on the water resources, sediment and fishes.
1.1.2
Municipal and agricultural
wastes
Waste management is a key dilemma in most emergent nations of the
world including Nigeria (Taiwo, 2010 and Taiwo, 2011). Indiscriminate dumping
of community wastes remains a key hazard to surface water contamination in
Nigeria. Generally, sewage and waste water from homes are routed into the
rivers and streams. Jaji et al.
(2007) found elevated water quality parameters in some sampling stations of
Ogun River. These were partially credited to the activities of abattoir sited
close to the river at an outstanding market in Abeokuta metropolis. The work of
Arimoro et al. (2007) on the impact
of sawmill activities on the water quality of River Benin reported elevated BOD
and low DO values at the discharge point of the wastes into the river. The
impact of point source pollution from sewage treatment oxidation pond on a
receiving stream was reported by Ogunfowokan et al. (2005). The authors observed momentous elevation of
water indices such as pH, BOD, nitrate, phosphate and TSS. It is well known
that oxygen diminution in water bodies might lead to fish casualty while
increase in BOD signifies elevated load of organic matter. Also, organic matter
disintegration in surface water produced inorganic nutrients such as ammonia,
nitrate and phosphorus with consequential effects of eutrophication and other
severe ecological problems associated with organic matter degradation
(Ogunfowokan et al., 2005). Taiwo
(2010) has also observed elevated water quality parameters of a stream in
Abeokuta owing to direct release of poultry wastes into the stream. The use of
pesticides and fertilizer for abundant food production is a well-known strategy
of several Governments all over the world. However, agriculture remains the
chief source of nitrate and phosphate contamination of surface water. Nitrate
in drinking water is harmful to toddler health owing to the disease known as
methemoglobineamia (Taiwo, 2010).
1.1.3
Urban run-off
Urbanization in the majority of Nigerian cities has resulted in the
concentration of huge inhabitants in some areas living beneath poor sanitation
conditions (Olade, 1987). This habitually has led to huge waste generations
with tons of waste all over the place. During rainfall, some of these wastes
are washed into the poor drainage systems and consequently, into close by
rivers (Taiwo et. al., 2011). Lack of
town planning ideology and strategies in Nigeria’s cities and towns has
motivated the risks of urban run-off with consequential effect on surface
water. The poorly managed drainage system in the country had caused the surface
water mutilation due to erosions during rainfall. Surface runoff carries all
sorts of pollutants from houses, industries, farmland and dumping sites.
Research has revealed that some water quality parameters such as turbidity,
total dissolved solids and anionic species are often influenced during rainfall
with high values owing to surface runoff (Jaji et al. 2007 and Taiwo, 2010). The consequence of urban run-off has
been reported by Izonfuo and Bariweni (2001) on Epie Creek in the Niger Delta.
The adverse impact of anthropogenic activities around the Creek was felt on the
water body as low DO values were observed during the wet season owing to urban
run-off. Run-off from agricultural field owing to the use of fertilizer and
pesticides is also a major contributing source of organic pollution to water
bodies in Nigeria. The work of Mustapha (2008) had established a linked between
run-off of phosphate fertilizers from nearby farms in addition to cow dung
washing from the watershed into the Reservoir as a key source of eutrophication
observed in Oyun Reservior in Offa, Kwara State.
1.1.4
Future management
strategy for surface water quality monitoring in Nigeria
At the moment, the monitoring of surface and ground water in Nigeria
is carried out generally by individual researchers in the tertiary institutions,
Research consortium, Non-Government Agencies and some other private firms. The
monitoring is slapdash, short term and based on individual curiosity and the
reagents and equipment accessible to the Scientist. The monitoring is not
appropriately synchronized and quality assurance programme is not integrated in
the majority of these studies. Consequently, comprehensive data on the water
quality of key rivers in Nigeria is not accessible. Recalling that water
quality monitoring is a systematically planned arrangement of long-term which
involved standardized measurement, systematic observation, evaluation and
reporting of water quality in order to define status and / or trends. The call
for improving the monitoring of Nigerian surface water cannot be overemphasized
(Taiwo et al. 2012).
According to Whitfield (1988), the goals for water quality
monitoring ought to be geared towards expansive information needs,
determination of compliance within aim and standard framework, evaluation of
environmental trend and effects, mass transport assessment and routine
surveillance. It is fundamental to set up monitoring goals, which ought to be
approved with appropriate sampling plan, where composed statistics may possibly
be occasionally reviewed (Whitfield, 1988). All these measures are missing in
the framework of water quality in Nigeria.
The Federal Ministry of Water Resources and Rural Development were
established in 1984 to sustain the water resource of the nation through
sporadic monitoring. The Federal Environmental Protection Agency – FEPA
(established in 1988) which presently is transformed to the Federal Ministry of
Environment also had the consent of monitoring the environment of the country.
The functions of FEPA also integrated guideline of effluents discharge by
industries and numerous other Institutions. Constitutional power was given to
the Agency to arraign any offender. The essence of this is to guard the water
resource of Nigeria from contamination (Taiwo et al., 2012).
Adewolu et al. (2009) and Ekiye and Zejiao (2010) during their
studies observed that most cities in Nigeria such as Lagos, Rivers, Kano and
Kaduna where most of the country’s industries are located have impacted
negatively on the water quality with consequent effects on public health and
economic growth. This call for the protection of water bodies in Nigeria as
millions of the general public depend on it on a daily basis. The Federal
Ministry of Environment has to reinforce the current environmental laws with
the intention of prosecuting the polluters of water bodies in Nigeria.
Industrial and agricultural sectors should also be bound to treat their wastes
prior to being discharged into the water bodies. Radical measures ought to be
taken by all establishment concern to curtail children morbidity and mortality
owing to poor sanitation and water quality problems (Taiwo et al., 2012).
There is a pressing need for the establishment of a National Water
Monitoring Programme (NWMP) with the intention of monitoring the surface water
of Nigeria. Quality Assurance Monitoring Plan (QAMP), which addresses quality
control issues in detail, has to be incorporated in the monitoring programme.
The water quality data that will be obtained from such a programme will be used
to differentiate waters, discover trends over time, discover up-and-coming
problems, find out whether pollution control programs are working, help direct
pollution control efforts to where they are most wanted, react to emergencies
such as floods and spills and also make available baseline data to the regulatory
community which will be used to enforce environmental law (Taiwo et al., 2012).
In developed countries, skilled volunteers are monitoring the state
of their neighboring streams, lakes, estuaries and wetlands. Environmental
Pollution organization encourages the general public to study in relation to
their water resources and supports volunteer monitoring because of its numerous
benefits. Volunteer water monitors build community consciousness of pollution
problems, help discover and reinstate problem sites, turn out to be advocates
for their watersheds and complement the existing information on water quality
in their country database. A related move toward protection of surface water in
Nigeria can be adopted. For instance, a Directory of Environmental Monitoring
Volunteers should be introduced via the National Youth Service Corps (NYSC)
members (‘Youth Corpers’).
The youthful Science graduates that spend one year serving the
country ought to be trained as Water Quality Monitoring Officers during their
Orientation Programme. In addition, a special scheme to employ young graduates
as Water Quality Monitoring Officers should be initiated. The outcome of a
comprehensive monitoring of our surface water on a weekly, monthly and
quarterly basis will then be uploaded on a website. If the programme is
adopted, quality data on our rivers and estuaries will be available (Taiwo et al., 2012). Considering the benefits
of protecting our aquatic ecosystem, there is an urgent need for an evaluation
of existing environmental laws in the country. The establishment of an
organization / Agency or a component under the Federal Ministry of Environment
with the intention to enforce the laws and prosecute offenders cannot be
overemphasized.
1.2 JUSTIFICATION OF THE
STUDY
Qua
Iboe River Estuary is one of the areas zoned for industrial development in and
around its environs. Anthropogenic activities in this area among others include
fishing, farming, dredging, oil exploration and seismic activities, gas flaring
and indiscriminate disposal of sewage and domestic wastes. The rate of
urbanization with respect to road construction in and around the Qua Iboe River
Estuary catchment area is intensive in a bid of the government to deliver on
its mandate to the people of the area. Intensive and massive road construction
in this area is of concern to environmentalist due to the impacts associated
with such activities.
Farming
activities within the catchment area is also a source of concern as a result of
the use of inorganic fertilizers and pesticides by these farmers which
eventually gets into the adjoining water bodies and subsequently Qua Iboe River
Estuary through surface run-off, increasing the nutrients load of the system. The
changes in the nutrient concentrations of water may lead to harmful effects to
humans and aquatic life. Fishing
activities is intensive within the area employing the use of large fishing
vessels and also artisanal fishermen who use fishing boat. Fishing may also
have direct or indirect effects on the aquatic system due to accidental fuel
and oil spill from fishing vessel and boat. Dredging is also another major
activity within the Qua Iboe River Estuary which has a direct or indirect
consequence on the aquatic system. Survey around the Qua Iboe River Estuary
catchment area shows that’s domestic waste from homes and markets are
indiscriminately disposed due to lack of proper waste disposal management in
the area. Domestic waste and sewage are of serious concern when the find their
way into aquatic system through surface run-off due to the problems associated
with these waste.
Qua
Iboe River Estuary serve as a source of water for cleaning, construction of
buildings, irrigation of vegetables, drunk by animals and birds, domestic
usage, children use it for recreation and other purposes. The Estuary has been
seriously impacted by anthropogenic activities rendering the water source unfit
for domestic use and other purposes owing
to undesirable taste and odour, consequently leading to failing health
standards and diseases amongst the inhabitants of this area. Also owing to the
extensive use of shorelines and near shore areas by humans, there have been
significant social and economic losses, as tourism and recreation have been
hindered.
The conservation and management of
marine resources in the face of pollution becomes highly imperative. Presently
there is a shift in the global community from green economy (poverty
eradication and sustainable development) to marine economy (sustainable
exploitation, conservation and management of marine resources). Previous
studies on Qua Iboe River Estuary recommend the need for Continuous monitoring due
to the incessant human activities going on in and around the estuary. It is therefore the aim of this study to evaluate the condition of
the environment and examine the linkages between anthropogenic activities and
the observed status of the environment using multivariate statistical tool in
modeling contaminants concentration which will help policy makers in the proper
planning and monitoring in the event of pollution.
1.3 SIGNIFICANCE OF STUDY
Human activities world over is directed towards
sustainable development. A development approach that stipulate that while the
developmental needs and aspirations of the present world are met, the protection
and conservation of the environment must be ensured. That is a process where
exploitation of resources, orientation of technological development and
institutional change are all in harmony and enhances both current and future
potentials of meeting needs and aspirations. This study will provide relevant
information on critical issues relating pollution status of the environment and
the toxicological implication of consuming water and animal products from Qua
Iboe River estuary. It will also highlight the sources that commonly contribute
to increased concentration of these pollutants. Understanding the current
sources of concentration of these pollutants allows policy-makers and local
actors to design programs and policies to improve on the existing practices and
mitigate future problems.
1.4 AIM AND OBJECTIVES OF
THE STUDY
The research main objective is aimed at assessment of chemical
stressors of water quality, sediment and fish of Qua Iboe River Estuary with
the following specific objectives.
- To determine the levels of trace metals
accumulation and distribution in surface water, obtained from Qua Iboe
River Estuary.
- Evaluate the
impacts of human activities on Qua Iboe River Estuary shoreline with
respect to heavy metal levels in the sediments.
- Determine the Spatial and seasonal
variations in physico-chemical parameters of water and sediment including
heavy metals.
- Measure heavy metal levels in the
benthic organisms, Tympanotonus fuscatus and Callinectes
amnicola collected along the Estuary.
- To identify the possible
sources of trace metal pollution and assess their eco-toxicological
significance.
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