The Effects of 3-D Geophysical Exploration on the Relative Abundance of Phytoplankton and Fish Species in Surface Water Resources of North Western Imo State, Nigeria

International Research Journal of Applied Sciences, Engineering and Technology Vol.5, No.5; May-2019; ISSN (1573-1405); p –ISSN 0920-5691 Impact factor: 3.57

THE EFFECTS OF 3-D GEOPHYSICAL EXPLORATION ON THE RELATIVE ABUNDANCE OF PHYTOPLANKTON AND FISH SPECIES IN SURFACE WATER RESOURCES OF NORTH WESTERN IMO STATE, NIGERIA

Chukwu Kevin E. Ph.D. Dept. Of Geography and Meteorology Enugu State University of Science and Technology, Enugu. Abstract: This work examines the effects of three-dimensional seismic exploration on the relative abundance of phyto-plankton community and fish species in Oguta Lake and Njaba River in Imo State. The 3D seismic activity utilizes the Brickwall technique comprising surveying, drilling and recording of seismic waves from dynamite detonation to evaluate the hydro-carbon potential of the sub-surface. A 4cm mesh plankton and a taxonomic guide are used for classification and identification. Fish species are observed from the catch by local fishermen. Three algae classes (Chlorophy Ceae, Cyanophy Ceae and bacillariophy Ceae) are discovered in Oguta Lake. The 3D seismic activity has little effect on phytoplankton diversity in Oguta Lake. Twenty-six species of plankton belonging to four classes (bacillariophy Ceae, Dinophy Ceae Cyanophy Ceae and Chlorophy Ceae) are found in the Njaba River with a low diversity ranging from 5.390 to 8380 cells per little due to the 3D seismic activity. Forty-eight species of fish belonging to 17 families are identified in Oguta lake. 19 species of fish belonging to 8 families are observed in Njaba River. Active fishing is absent due to dynamite effects. The authors therefore recommend environmental awareness campaigns for Geophysical company staff coupled with mitigative measures for adverse impacts on aquatic life species to ensure the sustainability of such wetland land resources. Keywords: Geophyiscal, Seismic, exploration, brickwall Imo State.

1.0 INTRODUCTION: 158 environmental studies have been conducted in the upstream Severe damage to wetland has been occurring worldwide in sector in the following categories: Australia, Canada, USA, and Nigeria. In Nigeria the E1A (Environmental Impact Assessment) 76. 20,000sq.krn Niger Delta threatened wetland covering many EER (Environmental Evaluation Report) 63. ecological zones houses her most important oil mineral Ewurum (2001) and Ekop (2004) have pointed out that some producing states (Ajadike, 2004; Ukpong and Akpabio, 2003). companies still do not carry out any form of study inspite of the Concern for the environmental effects of oil mineral activities in fact that the Environmental Guidelines and Standards have the oil producing areas of Niger Delta wetland started gaining prescribed this since 1991. Majority of such companies are considerable attention in the 1980s (Ekop, 2004; Ukpong and found within the geophysical seismic industries where the Akpabio, 2003; Ewurum, 2001). Some oil companies started number of E.I.A. reports has been very few, about six since 1991 also evolving and implementing policies aimed at protecting the (Ifeadi and Orubima, 1996). In fact Essaghah (1999) has environment of their operational areas. observed that the situation in the down stream sector has been Ifeadi and Orubirna (1996) and Ewurum (2001) conducted a very poor and that only the NNPC oil refining company at Port detailed investigation on EIA studies in the Nigerian petroleum Harcourt has conducted three studies, one in 1994, another in industry between 1991 and 1995. They discovered that a total of 1995 and the third in 1996.

2.0 THE RESEARCH PROBLEM: researchers have decided to carry out this investigation on the Aggressive geophysical seismic exploration has led to the effects of three dimensional geoseismic exploration on the discovery of new oil fields in rivers, Akwa Ibom, Cross Rivers, relative abundance of phytoplankton and fish species in surface Edo, Delta and Imo States since the past 50 years with their water resources of north western part of Imo State in order to associated environmental effects. Between 1996 and 1997, close the research gap. It is against this background that the aims Nigeria recorded 5334 oil spill incidents with severe ecological and objectives of our investigation are defined. damages. 3.0 AIMS AND OBJECTIVES: Oniawa (1995) and Ewurum (2001), Ukpong and Akpabio The main aim of this work is to evaluate the effects of three (2003) have noted that the environmental guidelines and dimensional geophysical seismic exploration on the relative standards for the petroleum industry in Nigeria stipulate E.l.A abundance of phytoplankton and fish species in surface water for the following five activities. resources of north western Imo state. i. Drilling operations (exploration, appraisal, and To achieve this goal, the specific objectives of our investigation development of oil wells) for onshore and near shore areas. are designed: ii. Construction of crude oil production tank farm and (i) To find out the activities involved in the 3D terminal activities. geophysical seismic exploration of oil in the northwestern part of iii. Laying of crude oil and gas delivery line, flow-ine and Irno State. pipeline in excess of 50km in length. (ii) To examine the effect of 3D seismic activity on the iv. Hydrocarbon processing facilities. diversity and relative abundance of the phytoplankton v. Construction of product depot with combined capacity community of Oguta lake and Njaba river in the study area of 80,000bbls and located within 3km of any commercial or (iii) To investigate the impact of 3D seismic exploration on residential area. the composition of fish species in the surface water resources of Environmental impact Assessment (E.l.A) was first adopted in the study area. The achievement of these objectives will enable the U.S.A. in 1969 due to the problems from two incidents us evolve suitable mitigative measures for adverse impact on which caused large spillages resulting in unprecedented damage aquatic life species to ensure the sustainability of such wetland to aquatic and marine life species (Urneh and Uchegbu, 1997). resources. The National Environmental policy Act of U.S.A became 4.0 THE STUDY AREA effective in January 1, 1970. Consequently, many countries 4.1 LOCATION: started to formulate their E.l.A. policies to suit their legislative, The study area lies within the northwestern part of Imo State. It political and institutional frame works. in Nigeria, the E.I.A. is located approximately between latitudes 05° 36’ 44” and 05° decree of No. 86 of 1992 was promulgated solely to provide 45’ 10” north of the equator and longitudes 06° 44’ 03” and 06° legal muscle for the enforcement of the policies relating to the 37’ 37” east of the Greenwich meridian. need for studies on the environmental impacts of both public and The study area comprises four local government area Oguta, Oru private sector projects during the planning stages of such East, Oru West and Mbaitolu — in Imo State (See fig 1). The projects. Ewurum ( 2001) noted that the overall aim is to seismic geophysical block of the study area covers about improve the suitability of the project within its proposed 200km2. environment and lead to a more efficient use of resources than if 4.2 CLIMATE AND VEGETATION: remedial measures were to be introduced in an already impacted The climate of the study area is the sub-equatorial type which

environment. may be classified in the Koppen’s Af tropical wet climate. The Unfortunately, not much investigation has been conducted on the annual rainfall is over 2000mm most of which is convective environmental impact of geophysical seismic exploration type. There is no month without rainfall. The driest month does activities in Nigeria. This research gap explains why the not register rainfall amount below 25.0mm. There are two

International Research Journal of Applied Sciences, Engineering and Technology Official Publication of Center for International Research Development Double Blind Peer and Editorial Review International Referred Journal; Globally index Available www.cird.online/IRJASET: E-mail: [email protected] pg. 34 International Research Journal of Applied Sciences, Engineering and Technology Vol.5, No.5; May-2019; ISSN (1573-1405); p –ISSN 0920-5691 Impact factor: 3.57 periods of maximum rainfall in June/July and September/ The stratigraphic succession of the drainage basin is presented in October. A little dry season (usually known as August break) is Table 1. experienced during the wet season between the last week of July TABLE 1: STRATIGRAPHIC SUCCESSION OF THE and third week of August. Wet season commences from early BASIN: March to early part of November. The onset and ceasation of the S/N FORMATION AGE wet season in the study area is related to the shifting position of 1 Deltaic formation Late Pleistocene— the Inter — tropical Discontinuity (l.T.D.) determined by the Holocene two prevailing air masses blowing over Nigeria as a whole. 2 Benin formation (or coastal Oligocene — These air masses are the tropical continental air mass, Tc plains sands) Pleistocene (blowing from northeast during the dry season) and the tropical 3 Ogwashi—Asaba formation Oligocene — Miocene maritime air mass, Tm (blowing from the southwest and 4 Ameke formation Eocene originating from the Atlantic ocean) during wet season. 5 Imo shale Paleocene The Harmattan, a dusty dry wind, is prevalent in the area in (Source: C.G.G. (Nig.) Ltd. Owerri, 2000) December and January and it is ushered in by the north easterly The Benin formation (coastal plain sands) outcrops on the Tc air mass. The relative humidity of the area ranges from about general ground surface of the study area. Underneath the 70 to 90 percent during the rainy season and from 50 to 70% formation of the basins are the petroleum bearing Deltaic during the dry season (between mid November and March). Agbada and Predeltaic Akata formations. Benin, Agbada and The mean temperature in the study area is about 27°C. Monthly Akata lithologic formations comprise regressive tertiary age maximum temperature ranges from about 32°C in sediments (Ofoegbu, 1988; Ewururn, 2001). The northwestern February/March between the onset of the rainy season to about part of Imo State is part of the upper delta plain deposits, which 28°C in July/August. The monthly minimum temperatures is made up of levees. The wetland areas of the study area have ranges from 23°C to about 22°C. The annual temperature range the least elevation of 15m and they include the swamp areas of is therefore about 8°C. The low temperatures in the rainy season Oguta and Urashi catchment systems. are as a result of the cooling effects of the rains and curtailing of The Imo River and its tributaries drain the area in a dendritic the amount of insolation by the cloud cover. (Ojo, Ojo and Oni; pattern and so complement the subsurface geology. The four 2001). major tributaries in the study area include the Urashi, Otamiri, These peculiar climatic characteristics give rise to the evergreen Orarniri — Ukwa and the Ogocha rivers (See Fig 1). In the wet tropical rainforest type similar to the equatorial type of season, when the River Niger increases in volume of runoff, an vegetation. It consists of tall trees (about 36m high) with extensive part of the land between these rivers is flooded and the undergrowth of lianas and other climbing plants. Niger discharges some of its runoff into the Urashi mostly via Scattered species of economic trees such as Iroko, mahogany, the Ndoni and Osmari Creeks. and walnut are found in the study area. However, because of The Urashi River flows more or less to the southeast through high demand for farmland in the area, the original rain forest has area of petroleum exploration — the Oguta and Ossu fields (up- been greatly replaced by the oil palm bush. Areas with the river), the Ebocha, Mbede and Obaji fields (mid river) and the climatic climax (high rain forest vegetation) are now restricted to Enwhe fields. The dominant unconfined aquiferous layer in the the forest reserves and some river banks in the study area. area is the Benin formation. The Urashi stream is the main river 4.3 GEOLOGY, REIJEF AND DRAINAGE: found in the study area and it takes its source from Dikenafia in The study area has gently undulating lowlands and plains (about the Oru region (east of the study area) and passes through Oguta 70m above mean sea level) and it is part of the Imo River lake, a major inland drainage in the study area where the catchment system. Awbana and Njaba river join it.

5.0 THE RESEARCH DESIGN AND METHODS: identified using keys provided by Food and Agricultural In this section, we discuss the problem of constructing unbiased Organization (FAQ) (1990) and the Nigeria institute for Marine research design and methodology for our investigation. We Research and Oceanography. therefore confront some fundamental methodological questions, 5.3 DATA ANALYSIS which are solved out successfully. These include: The analyses of all associated impacts of the 3D geophysical (i) Sources of data collection. seismic exploration on the hydrobiology of the study area are (ii) Methods of sampling performed utilizing the International Standards Organization (iii) Methods of data analysis. (ISO) 14001 approach. 5.1 SOURCES OF DATA COLLECTION: Five impact analysis criteria are employed here, viz. Secondary and primary data are utilized in the investigation. For (i) Legal/Regulatory Requirement (L) instance apart from desk top research, maps aerial photographs (ii) Risk and satellite imageries are collected from the survey department (R) of C.G.G. (Nig.) Ltd. Crew 088, Owerri and the Ministry of (iii) Impact frequency (F) Lands, Survey and Urban planning, Owerri, Imo State. (iv) Important Primary data are sourced from field investigation and interviews. (I) Field trips are made to the surface water resources and the (v) Public interest/perception (p) various communities in the study area to investigate the status Each of these five criteria is qualitatively sub divided into three and ecological integrity of the lake and rivers in the wetland area parts 0/1, 3 and 5 corresponding to “low”, “intermediate” and of northwestern Imo State. The stakeholders, (environmental “High” impacts respectively. experts and representatives of host communities) are also The algorithm system alluded to by Nwadiaro and Ogidi (1988) interviewed on issues relating to the impact of 3D— geophysical and Ewurum (2001) for describing the relative abundance of the seismic exploration on the hydrobiology of surface water fish species closely resemble the iSO impact rating approach. resources in the study area. Gaps in environmental baseline The method uses a set of five algorithms. Due to its clarity and information of the study area are identified and field simplicity, it has also been adopted here thus: investigation is carried out them. (i) very High abundance ----- 4 5.2 SAMPLING STRATEGIES: (ii) High abundance ------3 A plankton mesh of 40mmmesh size is used for the study of the (iii) Moderate abundance ----- 2 phytoplankton community. At each sample station a composite (iv) Low abundance ------1 network of vertical and horizontal hauls constitute the mesh for (v) Rare ------0 such station. it is therefore, necessary to throw a little light on the result of our Samples are stored in 4.0% formation in glass vials and work beginning with 3D geophysical seismic exploration transported to the laboratory. lml of homogenized sample is because it is one of the first activities in crude oil prospecting, introduced into a plankton counting chamber called sedqevick exploration and exploitation in the wet land areas of Niger Delta. rafter and examined under a light microscope at a magnification 6.0 RESULTS AND DISCUSSION OF RESEARCH of 100. The average of three examinations is taken. A taxonornic FINDINGS guide recommended by Jeje and Fernando, (1986) and Ewururn 6A 3D GEOPHYSICAL SEISMIC EXPLORATION: (2001) is used for identification and classification. The 3D geophysical seismic exploration is an advanced A survey of the species of the fish fauna is achieved by technology in which the environmental and earth scientists observing the catch of the local artisan fishermen in the Oguta utilize computer technology to locate commercially viable lake and surface streams in the area. Samples of fish species that hydrocarbon reserves and traps. It is a Brick wall pattern of are not identified instantly are taken to the laboratory and

seismic acquisition project that involves no physical construction coordinates for the entire geophysical block of the study area are (Fig. 2). presented in Table 2. TABLE 2: POLYGON CO-ORDINATE OF THE STUDY The Drilling aspect involves 4m depth drilling pattern of ten AREA: holes between two receiver lines of one shot. Thumping and SURFACE FOLD CO- SUB-SURFACE FOLD CO- flushing are two drilling techniques used in 3D seismic operation ORDINATE (M) ODINATE(M) in the northwestern part of Imo State. Thumping is the application of a 4rn steel casing pipe with a diameter of 9.5cm to X(M) Y(M)9 X(M) Y (M) (EASTHINGS) NORTHINGS) (EASTHING) (NORTHINGS) drill a hole to a required dept of 360cm. Flushing is the utility of 476,800.000 189,677.000 477,500.000 188,200.000 a drilling stem of 150cm length and a diameter of 3.8cm. Sixteen pieces of the stem were used in flushing to a dept of 24m or in 480,080.000 89,677.000 480,796.000 1 88,204.000 the case of up holes drilling, 60m. Flushing with a pumping 480,080.000 193,837.00 480,796.000 192,359.000 machine involves a yanmar semi trash pump model YDP 20 ST 484,093.000 186,836.000 483,803.000 192,359.000 E. For up hole drilling, a mixing machine was used for mixing E3entonite and greasy — mud, water being the drilling fluid. 498,530.000 178,600.000 498,008.000 184,981.000 Samples of geological materials (from 63rn depth) are described 492,610.000 178,847.000 498,008.000 181,719.000 based on structural and textural properties on Wenthworth scale 492,610.000 180,197.000 493,258.000 183,161.000 of classification. The formations encountered during the drilling activities are shown on Table 3. 485,170.000 180,197.000 485,112.000 183,160.000 TABLE 3: GEOLOGICAL FORMAT1ONS IN THE 485,170.000 180,197.000 485,112.000 184,1700.000 NORTHWESTERN PART OF IMO STATE UP TO 63rn 482,970.000 180,297.000 483,100.000 182,300.000 DEPTH: 483,430.000 180,290.000 477,500.000 188,200.000 S/N DEPTH FORMATION TEXTURE (M) 476,800.000 186,507.000 477,500.000 188,200.000 1 0 — 20 Mud Red, find grain 2 20 – 34 Gravel Gravelly —clay NB: Nigeria Reference origin for the local Geodetic parameters (mixed media) is Minna. 3 34 – 42 Gravel Medium grain sub Source: C.G.G (Nig.) Crew 09, Imo State, 2000, involved in 3D angular seismic exploration are surveying, drilling and recording. 4 42 – 63 Sand White, coarse grain In the survey aspect, the global positioning system (G.P.S) is (Source: C.G.G. (Mg. Ltd Owerri, 2000,) used first to define the area to be surveyed by means of satellite The seismic Gelit 20 (400g stick) was the explosive type used in imageries obtained from spot imageries in France. the recording activity. The total quantity of explosive used is These satellite imageries provide bases for the establishment of 1203.kg. stored in a 15 tone isolated magazine. access line control points to acquire possible commencement The explosives are located in drilled holes and licensed operators points within the area of the project specification. This program carry out shooting with necessary precautions. At the point of consists of a set of grid lines cut over the geological area of taking the shot, a seismic signal of waves is generated by the interest. The receiver lines parallel and source lines are 300m explosion of dynamites in the deep hole. The sound energy apart (see fig 3). Intervals of 50m for receiver points and 100m generated travels underground and is reflected in the subsurface for source points with a tolerance of ±2.5m to offset lines from strata where it is picked up again by geo phones (detectors) at obstacles. The number of the entire survey crews is 20 each the surface where the reflected sound energy is converted by a using 11 — 13 men with the field surveyors. The polygon computer system into electrical impulses recorded on magnetic

300 (m) phytoplankton species in Nigeria by Nwadiaro and Ogidi, (1988), the relative abundance is low in Oguta lake. These show that the geophysical seismic exploration activity does affect the relative abundance of phytoplankton in Oguata Lake adversely. A checklist of the phytoplankton diversity of Njaba River is 300 (m) presented in Table 5. The result shows that there are twenty-six species of plankton that inhabit the river. These belong to the four different classes viz, Bacillariophy Ceae, Dinophy Ceae, Cyanophy Ceae and chlorophyceae. The bacillariophy Ceae is the dominant class of phytoplankton in both diversity and

abundance (see Table 5) Plankton diversity rages from 5,390 to

8,380 cells per liter. The diversity of phytoplankton of Njaba FIG. 2 BRICK WALL SEISMIC PARTTERN River compares favourably with literature reports of Source: C. G.G (Nig) Ltd. Crew 09 Owerri phytoplankton in Niger Delta by Nwadiaro and Ogidi, (1988) Survey Depth (2000). but the abundance in the study area is relatively low. The reason LEGEND for this low relative abundance of phytoplankton may be Source Line E W accounted for by relatively high level of silt suspended in the Receiver Line N water column, which is a result of disturbances within the water S column due to cable laying across the river during the activity. The 3D seismic exploration is conducted by compagnie geophysical seismic exploration activities. Silt is capable of Generale de Geophysique (Nigeria) Limited (C.G.G) for Addax absorbing light that would have otherwise been used for

phytoplankton production.

6.3: The impact of 3D Seismic Exploration on Fishing and with dugout wooden canoes using long set lines, seire nets and Fish Species in the Study Area. cast nets. Young men in the age bracket of 15- 45 years largely do engage in fishing in Oguta Lake. This category of fishermen operates

Table 4: Diversity and Relative Abundance (X10/l) of Phytoplankton of Oguta Lake Samples Station

1 2 3 4 5 6 Total % Genera/species CLASS: CHLOROPHY CEAE Chosterium sp 42 . 58 63 21 30 214 4.79 Pandorina 60 24 32 - 28 36 180 4.03 Sceredesmus 21 6 43 42 41 45 198 4.44 Chladophora 103 70 82 23 56 2 335 7.51 Cosmarium 42 81 - - - 50 173 3.87 Chlorella 30 11 7 59 2 3 112 2.51 SUB-TOTAL 298 198 222 187 148 165 1212 27.17 CLASS: CYANOPHY CEAE Oscillatoria Lacutris 54 48 24 15 81 72 294 6.59 Oscillatoria Lacutis 15 28 56 82 65 - 246 5.51 Anabaena Spirodes - 50 83 81 65 48 327 7.33 SUB-TOTAL 60 126 163 178 211 120 867 19.4 CLASS: BACCILAROPHY CEAE Nitzschia Gracillis 15 28 41 - - - 84 7.88 Melosira 36 28 - 36 48 3 151 3.38 Fragilaria 51 - 48 37 - 4 140 3.14 Cyclotella striata 23 - - 62 52 - 137 3.07 Synedra 124 - 36 - 63 - 223 50 Stephamodiscus - 34 - 45 - 15 94 2.11 Asterionella 11 36 58 - 41 28 174 3.90 Amphora 7 - - 32 32 11 82 1.83 Compilodiscus - - 71 15 - - 86 1.92 Cyrobello 62 48 46 28 113 6 303 6.79 Novicula - - 33 20 - 13 66 1.47 SUB-TOTAL 376 232 333 275 364 109 1689 37.83 Source: Field Work Laboratory Analysis at Summit Laboratory Test Port Harcourt. Table 5: Phytoplankton at Njaba River (X10/l) Station Samples

1 2 3 4 5 Total % Genera/species Total BACILLARIOPHY CEAE Conscinodiscuys Rudofi 40 26 46 38 6 156 5.58 Closterira 45 18 13 17 - 93 3.46 Melosiro Ganulata - 21 - 49 - 70 2.61 Bidlphia Donicum 15 28 31 36 - 110 4.09 B. Rhombus 4 11 15 22 - 52 1.93 Pinnularia major 18 - 24 - - 42 1.56 Synedra sp - 61 23 - - 84 3.13 Suriella linearis 52 15 - - 2 69 2.43 Asterionella sp 11 18 16 - - 45 1.67 Bacillaria paradoxa 6 2 - 3 3 14 0.40 Nitzshia Gracilis 27 26 34 22 21 130 4.5 Naricu sp 28 18 36 41 89 212 5.69 SUB-TOTAL 246 244 238 228 121 956 DINOPHY CEAE Ceratuim lineatum 15 28 31 11 45 77 2.86 Clongispina - - 62 51 10 123 4.50 Bacteria scintilans 11 - 2 72 85 173 5.86 Pecidinuim sp 42 15 42 31 - 130 4.83 SUB-TOTAL 68 35 137 165 140 405 18.05 CYANOPHY CEAE Anabana spirioides 30 32 41 - 10 113 4.03 Oscillatoria boryana 20 - 28 62 - 110 4.09 Oscillatoria platensis 10 51 - 28 6 95 3.51 Nostoc Piscinate - - 36 43 3 82 2.95

TABLE 5: CONTINUE Station Samples

1 2 3 4 5 Total % Genera/species Total Spirulina 11 41 42 11 15 120 4.50 Sub-total 71 124 147 144 34 486 19.08 Chlorophy ceae Scenedemus - - - 18 18 36 1.20 Eudorina 41 - 32 - 23 96 3.01 Pandorina - - 40 51 7 98 3.39 Spirogyra 32 - 1 4 13 50 1.83

Chladophora - 15 10 11 13 49 1.89 SUB-TOTAL 73 15 83 84 74 329 11.28 Source: Field work Laboratory Analysis at Summit laboratory Test, Port Harcourt. Table 6: Composition of Fish Species in Njaba River S/N Family/species Abundance 1 0 2 3 3 0 4 2 5 2 6 2 7 3 8 2 9 2 10 2 11 2 12 1 13 1 14 0 15 1 16 1 17 1 18 0 19 1 20 1 21 0 22 1 23 0 24 2 25 0 26 1 Source: Field Work Laboratory analysis at Summit Laboratory Test Port Harcourt

Small lake like Oguta Lake where the catch rate of 2.27kg of total of 19 species belonging to 8 families are from the local fish per boat per unit effort has been estimated. catch. The mode of harvest is by the use of gillnets, traps, A total of 48 species of fish belonging to 17 families are baskets and rotenone. The taxonomic composition of fish (Table identified in the catch of an experimental gillnet and those of 6) in the river is higher compared to the observed of 19 spp fishermen operating in the lake. People of Awo-omamma. figure Nwadiaro and Ogidi (1988). This might be connected to Ndeogu. Mgbele and Nkwesi communities who live along the the impact of dynamite explosion around the Njaba River during bank of Njaba River do not engage in active fishing practice any the geophysical seismic exploration activities. The taxonomic longer. Consequently fishing practice in this area is very low. A composition of the 26 fish species in the river is presented in

International Research Journal of Applied Sciences, Engineering and Technology Official Publication of Center for International Research Development Double Blind Peer and Editorial Review International Referred Journal; Globally index Available www.cird.online/IRJASET: E-mail: [email protected] pg. 41 International Research Journal of Applied Sciences, Engineering and Technology Vol.5, No.5; May-2019; ISSN (1573-1405); p –ISSN 0920-5691 Impact factor: 3.57 table 6. The rating of the relative abundance of the fish species Although the 3D seismic exploration has little impact on of Njaba. phytoplankton diversity in Oguta Lake. The low diversity of phytoplankton community in the Njaba river is as a result of the Table 7 adverse effect of 3 D seismic activity. RATING OF THE RELATIVE ABUNDANCE OF FISH We also discovered that forty species of fish belonging to 17 SPECIES families are identified in Oguta Lake while 19 species of fish S/N DESCRIPTION RATING belonging to 8 families are observed in Njaba River. Active 1 High abundance >4 — fishing is absent in the study area due to the adverse impact of 2 Very abundance -4 detonation of dynamite on fish species. The preceding conclusions show that the effect of 3D geoseismic 3 Moderate abundance 3 activity on surface water resources of our study area poses a 4 Low abundance -1 serious threat to the diversity and relative abundance of aquatic 5 Rare -0 life species and even on the ecological integrity of Oguta Lake Source: Adapted from Ewurum, 2000. and Njaba River. The researchers therefore consider it necessary to make the following policy recommendations to ensure the It is important to point out here that the abundance of the aquatic sustainability of the fragile ecosystem of the wetland areas of the life species of the northwestern part of Imo state is not known Niger Delta. precisely. What is known however, is that most of what existed (i) Enforcement of relevant laws and regulations: as aquatic life of this area has fallen from being widely Contrary to the widely held opinion that Nigeria has very few distributed on viable population species to becoming classified environmental laws, it must be emphasized here that there exist as vulnerable, threatened and endangered. sufficient relevant environmental laws in Nigeria and 7.0 CONCLUSIONS AND RECOMMENDATIONS international conventions endorsed also by Nigeria designed to The 3D geophysical seismic exploration gives a firm indication prohibit and control the pollution of aquatic and marine and the best resolution of the hydrocarbon reserve in undrilled ecosystems especially by petroleum activities in the wetland block of subterranean rocks. areas of Niger delta. Tables 9 and 10 illustrate these national In this paper the authors have shown that in the 3D seismic laws and relevant international conventions. Both the federal and project, which employs the Brick wall method, the overall state ministries of environment should be mandated to utilize activities involved are surveying (involving massive cutting of these instruments (see Tables 9 and 10) with their provisions to receiver and source lines), drilling and recording. We have regulate and control oil mineral operations adversely affecting established that the 3D seismic activity has significant impact on the aquatic ecological integrity of the Niger Delta wetland as a diversity and relative abundance of species in the surface water whole. These provisions also prescribe sanctions in the forms of resources (especially in Oguta lake and Njaba river) of fines, imprisonment or damages to be enforced against the northwestern Imo state. A 4cm mesh plankton and taxonomic persons or companies who flout the provisions. guide are used for classification and identification. Fish species (ii) Environmental awareness campaigns and education for are observed from the catch by local fishermen. Three alga geophysical company staff and the public. classes of phytoplankton community discovered in Oguta Lake The appropriate environmental agencies should go beyond the include Chlorophy Ceae, Cyanophy Ceae and Bacillariophy present “war against Urban refuse waste”. In this aspect, the Ceae. Thirty- five species of plankton belonging to four classes( agencies are strongly advised to organize awareness creation Dinophy Ceae, Cyonophy Ceae Bacillariphy Ceae and workshops to enlighten the members of staff of geophysical Chiorophy Ceae) are found in the Njaba River with a low companies. The school curriculum of all oil producing states in diversity which ranges from 5.390 to 8.380 cells per liter. the Niger delta should be reorganized in order to enlighten the

1989 Basel convention on the control of trans boundary TABLE 10 movements of hazardous waste and their disposal The Relevant International Conventions Endorsed By 1990 Convention on oil pollution preparedness response Nigeria and co-operation. 1948 Conventional of the inter-governmental maritime 1992 United nations framework convention on consultative organization (IMCO) biological diversity 1954 Convention for the prevention of pollution of the 1992 United nations framework convention on climate sea by oil (not the 1978 protocol) change (plus 1997 Tokyo protocol) 1958 Convention on fishing and conservation of living Source: Federal environment protection agency (1995) resources of the high sea (note, into force 20march (1966) (ïii) Environmental impact assessment (E,l.A) and 1958 Convention of the high sea environmental impact auditing. 1958 Convention of the continental shelf Every geophysical seismic activity should be subjected at both 1958 Convention of the territorial sea and contiguous pre- and post operational state to the process of EJ.A and impact zone auditing respectively. For instance every seismic exploration and 1958 Africa convention on the conservation of nature development! production plans must be accompanied by E. I. A and natural resources. report and must not be subject to undue political considerations. 1969 Convention on civil liability for oil pollution (iv) Institution of comprehensive environmental monitoring damage (not the 1976 and 1992 protocols) programme. 1992 Convention concerning the protection of the world The present surveillance mounted by the petroleum inspectorate cultural and natural heritage department needs to be expanded to protect the diverse species 1972 Convention of the prevention of marine pollution of aquatic life in the wetland areas of lmo state as a whole from by dumping of waste and other matter. pollution. A long- term monitoring and surveillance should be included in the recommended comprehensive environmental 1973 Convention to regulate international trade in monitoring programme and also designed to acquire facilities for endangered species of fauna and flora (cites) comprehensive base line data for 3D seismic activities in the 1974 International convention for the safety of life at operational areas. sea (v) Mitigation measures for 3D seismic impact on aquatic 1979 Convention on conservation of migratory species life: of wild animals Site clearing, cutting of source and receiver lines shall he 1981 Convention for co-operation in the protection and planned to minimize access and impact to protected surface development of the marine and coastal water resources in the study area. The detonation of explosives environment of the west and central Africa by oil companies should be carried out with great precautions regions regarding the time and space dimension of the operational area 1982 Convention for co-operation in the protection and in the Niger delta. These mitigative measures for adverse development of the marine and coastal impacts of seismic activities on aquatic life species will ensure environment of the west and central Africa region the sustainability of such wetland resources in the operational 1985 Vienna convention for the protection of the ozone areas. This very fact makes further work on this area layer Indispensable. The researchers therefore advise future workers to 1987 Vienna convention for the protection of the ozone investigates further the environmental impacts of 3D seismic layer activity on water resources (ground, surface and oceanic) quality

References Federal Environmental Procedural Guidelines for E. I.A. the Presidency, Abuja. ADDAX Petroleum Development (Nigeria) Ltd.(1998): Health, Safety and Environmental Guideline& APDN L Lagos. Food and Agricultural Organization (FAQ) (1990): Keys for Identification of fish species: year Book of food and Ajadike J.G (2004): “The need for sustainable management of agricultural statistics. Vol. 1.2 part 6. Rome. Nigeria’s wetland.” ESUT Journal of Environmental management. Vol. 2(1); pp.16-24 Ifeadi. G. N. and Orubima I. I (1996): Critical review of the implementation of E. 1. A in the Nigeria Petroleum Compagnie Generate de Geophysique (Nig.) Ltd (2000) Oil Industry. 1991- 1995” International Conference, prospecting Lease (OPLI 18). Final Prospect Report Petroleum lndustiy and the Nigeria Environment. October 2001. NNPC. Lagos; 35pp.

Ekop. 0.13 (2004): Aspect of environmental degradation and International Organization for Standards (ISO) (19991: control in Akwa Ibom. Esut Journal of Environmental Environmental Guidelines and Standards JSO- Management. Vol. 2. Nol; pp 92-102. 4001.Federal Mm. of Envt: Abuja.

Ewurum C.O.S. (2001): Environmental Impact of Three- lta EQ and Balogun J. (1983): A Preliminary survey of the Dimensional Geophysical seismic exploration in the fisheries of Oguta Lake. Anarnbra/ Imo River Basin Northwestern part of Imo state. Unpublished M.Sc Development Authority Owerri, lmo State; pp.49-58.