生物多样性与濒危物种杂志

A total samples of 858 of Cardisoma armatum and Cardisom aguanhumi) collected from the Lagos Lagoon mangrove area of the University of Lagos were studied for his or her frequency, distribution, growth and sex ratio and a comparative analysis was done on both crabs. Investigation into their length-weight relationships, growth pattern, condition factor, food and feeding habits were administered . The calculated Chi-square (Ù?ا2 ) test showed that male crabs of Cardisoma armatum and Cardisoma guanhumi were significantly (p
Crabs belong to the brachyuran infra order family comprising quite 6,793 species peculiarly known for his or her ten legged creature (decapod) Hosseini et al. [1]. Crabs have flourished to be a predominant icon within the invertebrate fauna due to its ubiquitoes existence in most a part of the planet oceans including freshwater, marine even on land [2]. Crabs are least exploited amongst other crustacean and crabs have been commonly found in West Africa. The Gecarcinidae currently consists of 20 species and has been recognized to incorporate 4 [3] or 6 genera [4,5]. The eggs of crabs have to hatch in the sea, where the larvae undergo typical planktonic development [3]. The mass migration of reproductive individuals to the surf for larval release has been reported for several crab species [6]. The aims of this research was to supply baseline data on condition factor, feeding pattern and sex ratio and to form comparison of populational differences supported morphological analyses of the 2 crabs species: Cardiosoma armatum [7] and Cardiosoma guanhumi [7].

Materials and Methods

Description of study site

The study was administered within the coast/Mangrove area of University of Lagos Lagoon front which is found opposite the Lagos Lagoon on the geographical platform of 6°26’N and 6°39’N and longitude 3°29’E and 3°50’E (Figure 1). The lagoon is that the largest of the four lagoon systems of Gulf of Guinea and is found at South Western Nigeria. The mangrove swamp connects to the Lagos Lagoon by tidal creek.

Collection of specimens

Specimens were collected at the mangrove part of the Lagos Lagoon of the University of Lagos. They were caught with hand at the same time and place between 7 pm-11 pm to allow for precise readings and analysis of the samples. The collection was done randomly and was collected over a period of six months on weekly bases between February and July, 2012. The crabs were collected in 2 different stations within the mangrove swamp. A total of 300 crabs were collected from the location and were preserved immediately during a deep-freeze within the laboratory before examination

Laboratory procedure

The crabs were removed from the freezer and allowed to thaw. Excess water was faraway from the specimens using paper

Condition factor

This is the condition of general well-being of a crab. It was studied in relationship to size. The equation for condition factor as follows:

K=100W/L3
Where K=condition factor
W=weight of the crab (g)
L=length of the crab (cm)
It is defined as a condition representing how lean or fat the crab.

Food analysis

The crabs were dissected and therefore the stomachs removed for food analysis. Each stomach was studied as a unit so as to supply information on individual variation. The stomach is greenish in color, located underneath the carapace and it is divided into four parts. The stomach contents were examined and scored with regards to whether they were empty, one-quarter full (¼), half full (½), three-quarter full (¾) or full stomach (4/4). The methods of food analysis used were the numerical method and frequency of occurrence method.

Numerical method: 
the amount of people of every food items in each stomach was counted. They were summed up to give totals for each kind of item in the whole sample. Then a grand total of all food items were obtained and every food item was expressed as a percentage of the entire number of food found altogether crabs examined.

Frequency of occurrence method: during this method, stomach content was examined and individual food organisms sorted and identified. The number of stomachs during which each item occur was recorded and expressed as a percentage of the entire number of stomach with food. The method gives information only on the organisms fed on. Its main disadvantage is that it does give information on quantities or numbers;

Reproductive biology

Sex ratio: The crabs were sorted out and sexed using gonopod (a thin abdominal segment) and therefore the gonophores (a broad abdominal segment). These structures were used to identify the male and female respectively. In the male, the abdominal segment is present only on the primary and second abdominal somites and is modified to make copulatory organs. The female differs by having all the somites freely moveable and there is one pair of appendages on each of the 2nd, 3rd, 4th and 5th somites, these form the swimmerets to which the eggs are attached in ovigenous crabs.

Fecundity: this is often defined because the number of ripe eggs within the female before subsequent spawning [7]. The egg mass was carefully faraway from the pleopods using tweezers and washed in running water. The eggs were placed in a 50 ml beaker and filled with seawater. Egg diameter decided using an ocular micrometer before the eggs were separated.

Results

418 and 440 specimens of Cardiosoma armatum (Plate 1) and Cardiosoma guanhumi (Plate 2) were studied respectively making a complete of 858 species of crabs collected and studied. The specimens were studied for the length and width frequency distributions between the months of February to July, 2012.

Condition factor of Cardiosoma Armatum and Cardiosoma Guahunmi

The condition factor (CF) or coefficient of condition is mentioned because the K factor which indicates the state or overall wellbeing of the Cardiosoma armatum and Cardiosoma guanhumi was calculated for the 418 C. armatum (combined sex) and 440 C. guanhumi (combined sex) in relation to size. The K values for the Cardiosoma armatum ranged from 3.3 in size group 8.5-9.4 and 30.7 in size group 2.5-3.4. For the Cardiosoma guanhumi the K value ranged from 3.1 in size group 8.5-9.4 and 28.6 in size group 2.5-3.4.

Discussion and Conclusions
In studies of population dynamics, high condition factor values shows favorable environmental conditions like habitat and prey availability Moradinasab et al. [8] this assertion shows relevance to the present research work, the condition factor for the Cardiosoma armatum and Cardiosoma guanhumi features a higher k values of 28.60 and 30.75 for both crabs respectively, though Cardiosoma guanhumi had a better condition factor k than Cardiosoma armatum, this is often obviously associated with the relative difference in habitat condition and adequate prey inclusion. This is also supported by the works of Lawal-Are and Nwankwo [9] with k-values of Sersema huzadii from a tropical estuarine lagoon.
The stomach content analysis administered on Cardiosoma armatum and Cardiosoma guanhumi from the Lagos Lagoon, Unilag Water front, indicated that the share empty stomach of Cardiosoma armatum and Cardiosoma guanhumi were 66(5.79%) and 53(2.05%) respectively. The result was in conformity with Lawal-Are and Bilewu [10] for Portunis validus off Lagos‘s coast Nigeria, the share empty stomach content was lowest in March and April for both C. armatum and C. guanhumi, this is often thanks to the low condition at the amount of collection.
 

The Eastern Oyster, Crassostrea virginica, is a keystone species and abundant populations of Eastern oysters provide ecological, environmental, and commercial values to the surrounding area. Ecosystem services provided by oysters have been well studied, including such services are oyster production, water filtration and benthic-pelagic coupling, habitat creation for other species, carbon sequestering, stabilizing of benthic and intertidal habitat, mitigation of fisheries, increasing of landscape diversity, and increasing aquatic species abundance and diversity. With the ever-increasing development along our coastlines, the dramatic decline of oyster population in the Mid-Atlantic and along the Gulf Coast of the United States since the late 1800s has been well documented as results of overharvesting, habitat degradation, reduced water quality, and increased mortality from Dermo and MSX diseases. This causes a cascading effect on the local estuarineenvironment when these ecosystem services are lost. Oyster reefs provide important habitat for fish and mobile crustaceans. The culture of the Eastern oyster in containment gear has become a viable component of restoration programs in many states on the East coasts of the United States and these aquaculture operations provide many of the same ecological services as natural or restored reefs. Oysters grown in aquaculture gears are restoring habitat for a variety of species before they are planted for restoration in the bays.This presentation provides progression of oysters’ life from spat in the remote set tank, to juvenile oysters in floating aquaculture gear, to adult oysters planted throughout the bays using various aquaculture techniques. The use of community volunteers to help rear oysters for restoration has become common practice throughout the Mid-Atlantic region. In response to the detrimental decline, conservation organizations developed community involvement programs commonly referred to as “oyster gardening” to help restore the oyster population, while instilling within the community a strong sense of stewardship for their bays. As enhancement and restoration efforts of this species move forward, it is important to understand the contributions and impacts of oyster aquaculture. Research focusing on the ecological effects of oysters raised with commercial aquaculture equipment is becoming more prolific as the industry moves away from a wild harvest fishery to a cultivated product. Previous studies show positive correlation between oyster aquaculture and increase macro-faunal activities. Clearly, oyster aquaculture supports additional populations of ecologically and economically important macro-fauna. Previous research resulted in 49 species of fishes and invertebrates and 8 species of macro-algae collected from floating oyster aquaculture floats including 9 commercial or recreational fishery species, many of which are likely habitat limited. Of the 17 species found in the cages only 8 of these were also found on the artificial reef, confirming outcomes of earlier studies, species richness is greater in oyster cages than in a sea bed and on an area of open seafloor. Off-bottom oyster aquaculture operations in the mid-Atlantic United States seem to be beneficial addition to host estuaries and associated natural communities.

Aim of the project:
The United Nations "Earth Summit" on the environment, held in Rio de Janeiro in 1992, marked a turning point in the history of mankind. The nations of the world agreed that the future of our planet lies in "sustainable development"; that is, in improving the quality of life whilst respecting the environmental equilibrium. In order to reach this objective, a fundamental concept has been underlined: "as a complex ecosystem capable of providing fundamental economic, social and environmental benefits, the forest has a vital impact on the stability of the biosphere, the maintenance of biodiversity and the process of global sustainable development". In the process of mankind's civilisation, the Mediterranean area has had a determining and prominent role. In the same area, though, man's presence has produced the vastest and most systematic deforestation that has occurred in history. The International Institute for the Study of Man in Florence has sustained a study group which dealt with an ambitious project promoting reforestation of the mountains which mark the outer limits of the western Mediterranean ecosystem. This ecosystem stretches to the north, from the Appenines to the Sierra Nevada; in the south, it is marked by the relief of the Atlas mountains, which extend from Morocco, through Algeria, to Tunisia.The project is based on three fundamental presumptions:

I. The countries of the European Union are committed to reducing the quantity of CO, produced by the combustion of industrial, and released by heating systems and cars: According to international agreements, combustion levels should, by the year 2000, be down to 1990 levels. 

2. The Atlas' mountain chain, which concerns Morocco, Algeria and Tunisia, is subject to an ever-increasing process of deforestation due to a perpetually growing demographic pressure. 

3. The Atlas regions are sustaining a strong migratory pressure on Europe. These elements of disequilibrium can be fused together to give birth to a large sustainable development project regarding the western Mediterranean basin: the"Atlas Project". This project deals with a) creating some wells in the Atlas region to absorb CO, from the excess European greenhouse gasses; b) balancing the demographic transitions of the North African countries with the decreases already occurring in the European Union; c) creating new regions of technical and economic exchange between the innovative abilities of Europe and the manufacturing potential of North Africa; d) regenerating the common current of civilisation of Mediterranean shores.

The practical effects expected are the following:

a. Climatic and environmental reequilibrium in the western Mediterranean and a reduction in the greenhouse effect; 
b. The creation of new employment vacancies in North Africa and the reduction of the migratory flow towards Europe; 
c. The production of foodstuffs, of wood for industrial production and of renewable energy sources for the Atlas countries and the related induced business and commerce, including turistic trade; 
d. A greater economic and socio-environmental equilibrium in the Mediterranean countries.

The Atlas project concerns a vast eco-system which extends itself over two continents, from Europe to Africa. So far, no similar large-scale project has ever been carried out. As a result, an ad hoc decision-making process needs to be carried out. This process can be articulated on three different levels: 
A. The International Level: The project can be classified as one of the first of a series of global projects as it needs to organize the involvement of institutions which already operate on a global basis starting when the United Nations and the World Bank. 
B. The National Level: Various European and African Nations are involved. The national programming procedures need to be used, as far as possible, integrating them into the nature of project objective. 
C. The Local Level: The project will have its most direct impact on several specific areas; in these areas the process of participation in the decision-making process needs to filter down to the level of each individual citizen.

Thus, the decision-making process will require a great commitment, as many aspects of the project, starting from its vast territorial involvement through to its global objective, are completely original and therefore it is not possible to draw any lesson from previous experience. 
If we consider that the European Union will be the organization most concerned with the realization of this project, and that the European directives on the "Appraisal of Environmental Effects" are amongst the most advanced, the constitution of a specific European community for the elaboration of proposal regarding the decision-making process is suggested. Such proposals then, need the agreement both on a higher level together with international organizations and on a lower level, regarding the nations concerned.

The Atlas Project is based on three fundamental assumptions:

a. There is a need to build CO2 sinks, which would become important sources of energy and income for the region. European Community member states are currently unable to absorb the quantity of CO2 produced by industrial combustion, heating systems and cars
b. A regular stream of air from Northern Europe discharges its humidity over the Atlas Mountains, before it re-ascends over Europe. This stream of air is a natural conveyer of CO2 produced by the industrial regions of Europe, which could then be immobilized by fixing it to the additional trees planted on the Atlas Mountains, before this stream re-ascends once more over the European continent
c. These areas, Morocco and North Africa, are the source of a large numbers of immigrants who move to Europe in search of work as a result of high population pressures and the lack of employment
 

The examination of natural carbon cycle is very important for better understanding of evolution of Life and Climate Changes on the Earth as well as for the analysis of the trends in development of the planet itself. These problems are tightly bound. Carbon cycle combining various processes in lithosphere, atmosphere, hydrosphere and biosphere enables to obtain the entire picture of the whole interactions on the Earth. As early as in 1926 famous Russian geochemist V.I. Vernadsky suggests a thought on interconditionality of the biosphere and Earth crust processes. The present work develops his thought. In this context it sounds as follows. Development of photosynthesis, which is a basis for the Life on the Earth, occurred under impact of the movement of lithospheric plates that cover the entire Earth surface and are in permanent motion. The effect of lithospheric plates is realized by means of periodic CO2 injections, arising during plates’ collisions. The plates’ movement is a firmly established experimental fact though the reason for that is still arbitrary. According to a wide spread point of view this motion is caused by convection of magma in the asthenosphere. Some researchers assert that magma convection is under the impact of celestial bodies in the course of the Earth's motion around the Sun.

The existing views on the natural carbon turnover consider it as a trivial transfer of carbon through geospheres to biosphere, and back. We regard it as a transfer of the element, under an impact of the redox state of carbon. According to new definition, carbon cycle is considered as a conversion of carbon from the oxidized state, presented by CO2, bicarbonate and carbonate species in the “atmosphere – hydrosphere” system, into the reduced state, presented by different biogenic forms, produced in photosynthesis and in the following transformations. The reverse transition is realized via respiration of living organisms and via microbial and chemical oxidations, accompanying transformations of “living” matter after burial. Among them is the oxidation of the buried organic carbon, the key contributor of CO2, by means of thermochemical sulfate reduction in the subduction zone, where lithospheric plates collide. We called this cycle “natural redox cycle of biospheric carbon. Formally the global redox carbon cycle can be presented as a closed loop consisting of the two branches – oxidative and reductive. It has two remarkable points, one among which is photosynthesis, where the oxidized carbon species become the reduced state; another point provides the reverse transition. A new presentation on global carbon cycle is given. Cycle is considered a turnover of this element from oxidizing state presented by CO2 , bicarbonate and carbonate forms, into reducing state presented by various sorts of biogenic carbon and back. The transition of carbon from oxidizing into reducing state occurs by means of photosynthesis. The transition of the carbon from reducing into oxidizing form is fulfilled by means of sulfate reduction in subduction zones where lithospheric plates collide. The global carbon cycle mechanism is predicated on the concept of tectonics which of orogenic cycles. A new interpretation of ecological compensation point concept is given. The presentations on global carbon cycle are substantiated by various arguments from different sources (by carbon isotope data on sedimentary organic matter and oils, by model reconstructions of climate, by paleontological data, including data on biodiversity, and others).
 

Community perception has its contribution in the flood disaster management process. This research aimed at producing the flood event map according to the community perception. The collected data is based on a participatory approach. The sampling methods applied in this study were purposive sampling and stratified sampling. The flood data was obtained through interview with 60 respondents based on research questionnaire and Focus Group Discussion (FGD). The results of interview from respondents and FGD have shown similar flood data on flood frequency, flood extent and water depth. The frequency of flooding occurred from 1939, 1959, 1975, 1979 and 1999 until 2012. Every time flood hits the study area, all sites were inundated. While, the average duration of inundation in the study areas (Lasaen, Umatoos and Fafoe) was started from 24 hours (1day) it’s minimum and up to three weeks or up to 1 month evenly it’s maximum. The water depth of three villages varies between 60 cm and 300 cm. Thus, possess a direct impact on people daily needs with losses reaching more than Rp. 1,000,000,00 and Rp. 200,000,00 it’s less minimum.

Flood is known as one of disasters that annually or eventually occurred in the world. Floods are one of the most disastrous phenomena occurring all over the world (Kinosita, 1983). As added by APFM (2008) divides four types of flood and the second type of flood is river flood which occurs as the impact of river run-off volume exceeds local flow capacities. This paper is going to discuss the river flood which has been impacted by the flood event due to the overflow of Benanain River which is located in Belu. The evidence of flood disaster has affected the livelihood of people life, live and economic damages of the people in Belu Regency, East Nusa Tenggara Province (da Costa, 2013). Andriyani et.,al (2010) describes the floods represent the part of environmental problems of physical on the surface of earth resulting loss and can be interpreted an situation where irrigate river abundance, suffusing area of around it until certain deepness till generate loss. As asserted by IFRC (2010) that the impact of flooding can include destruction of housing, crops, cattle and people. Flooding causes few deaths, instead, widespread and long-lasting detrimental effects include mass homelessness, disruption of communications and health care systems, and heavy loss of business, livestock, crops, and grain, particularly in densely-populated, low lying areas (Medscape, 2005). Floods can lead to the loss of human life and other (non-lethal) human health effects (Ohl and Tapsell, 2000; WHO, 2002; Hajat et al., 2003) in (Ezemonye and Emeribe, 2011). The indirect impact of flooding is on the health infrastructures and all lifeline systems can be massive and can result in food shortages and the interruption of basic public health services (WHO, 2013). According to Medscape (2005), Global statistics show that floods are the most frequently recorded destructive events, accounting for about 30 percent of the world's disasters each year where the frequency of floods is increasing faster than in any other type of disaster. The greatest damage of flood disaster worldwide affected the greatest number of people. Flood hazard index in each city / country of Indonesia has 3 different scores and class, particularly rural flood as happened in the study area. As supposed by BNPB (2011), From 23 Provinces/Regions of the index of prone single hazard that vulnerable to floods by 2011, Belu Regency gets a high class of flood’s hazard with it’s score 54, and sits 21 of the national ranking. To obtain this, the discussion was done through flood characteristics, namely; flood frequency, flood distributions, flood duration and waterdepth. This paper is going to discuss two sub objectives of flood event as the first objective of the study that is (1). To produce flood event map by identifying flood characteristics, i.e., Flood frequency, Flood extent, flood duration and waterdepth and; (2). To identify the flood impact and the flood consequence.

The flood frequency in the study area has similar time period that occurred in 1939, 1959, 1975, and 1999 and until 2012 the present year. All sites in the study area are inundated or flooded as the consequences of flood. The flood characteristics i.e., flood frequency, flood extent and waterdepth data gathered by interview are similar with FGD’s result. The duration of inundation in Lasaen and Fafoe Villages based on FGD are similar while Umatoos Village is not. The duration of inundation in these villages are from minimum (0-7 days) until (14-21 days) it’s maximum. While, the duration of inundation in Fafoe Village is started from 1 week and lasted at 1 month maximum. Whereas, based on Interview, the flood duration in three villages are similar which started from (0-7 days) until more than (>15days). For waterdepth in Lasaen and Umatoos Villages have same zone depth variation which ranged from the lowest (0-50cm) until the deepest (251-300cm). The impact of flood in three Villages (i.e., Lasaen, Umatoos and Fafoe) is on economy in term of income and consequences of floods. On economy, the respondent's income started with the lowest, medium and the highest levels.
 

This paper follows FAO model of suitability analysis. Influential factors affecting extensive grazing are determined and converted into a model. 6 different regions with different climate and features in Iran were examined for common types of grazing animals and advantages and limitations were elicited. All range ecosystems’ components affect range suitability but due to the time and money restrictions, the most important and feasible elements were investigated. From which three sub models including water accessibility, forage production and erosion sensitivity were considered. Suitable areas in four levels of suitability were calculated using GIS. This suitability modeling approach was adopted due to its simplicity and the minimal time that is required for transforming and analyzing the datasets. Managers could be benefited from the model to devise the measures more wisely to cope with the limitations and enhance the rangelands health and condition.

Rangelands have different functions like forage and by-products supply, wildlife habitat function, regulative function, recreation, non-use / Intangible values including preservation of endangered species and anthropological sites. These different types of land-use are often mentioned as multiple-use (Heady &Dennis Child, 1994). Meanwhile, allocation of limited rangeland resources to various land uses, lack of sufficient environmental policies for sustainable use of rangelands as well as degradation of these areas have caused increasing concern among managers and revealed the importance of land suitability analysis (Jafari & Zaredar, 2010).Combining land and land use in a land evaluation procedure gives land suitability, defined as the fitness of a land unit for a land use type which is assessed by comparing land use requirements of each land utilization type with land(FAO, 1991). Land suitability analysis is one of the most important tools in making locational and siting decisions as a part of planning studies (Ricketts et al., 2004). Broadly defined, land-use suitability analysis aims at identifying the most appropriate spatial pattern for future land uses according to specify requirements, preferences, or predictors of some activities.

In this study, rangeland suitability for extensive grazing was considered as one of the most rampant uses of rangelands. Assessing suitability for grazing not only decreases the risk of degradation but also could open a space for debating other usages of rangeland for range managers. In most of the cases studied, the criteria for rangeland suitability assumed for livestock grazing are categorized into 3 sub-models of forage production, water (accessibility, quantity and quality) and soil erosion vulnerability (Arzaniet al., 2006; Javadi et al., 2008; Amiri, 2008, 2009). Ayoubi and Alizadeh (2006) evaluated range suitability for livestock grazing qualitatively (plant access to moisture, saltiness and the amount of sodium, physical hampersagainst root expansion, range accessibility and water accessibility) and found that slope, moisture accessibility, outcrops and water accessibility were the limiting factors. Dvaran et al. (2009) analyzed goat production suitability in Turkey and explain that erosion, destruction of shoots and branches and forest degradation are the most important limiting factors. Javadi et al. (2008) assessed rangeland suitability for camel grazing and found that water accessibility, severe erosion and low forage production as the most effective factors on suitability. Arzani et al. (2006) studied sheep grazing suitability in four regions and found that slope, water accessibility and erosion mostly affected range suitability within these regions. Oberlie and Bishop (2009) presented a model for cattle grazing suitability, including slope and water remoteness as the important factors.

This study is about to define influential factors on rangeland suitability for extensive grazing, proposing a model, and classifying rangelands suitability and finally define declining and limiting factors for extensive grazing. In this study which covers a wide climatic area, topographic and geographic conditions, a model for range suitability assessment for extensive grazing of sheep as dominated grazing animal in Iran was elicited. Three limiting conditions for extensive grazing according to FAO (1991) have been taken into account as pointed out. In this study different limitations and opportunities for extensive grazing were examined. Meanwhile, we represented a comprehensive attitude towards extensive grazing, but one should know that grazing is one of the uses readily available for rangelands. As FAO (1991) argues, different land units have different qualities for certain utilizations. As might be understood, rangelands' utilizations comprise certain qualities and criteria that the model prepared to assess suitability, must consider. Moreover, multiple uses could be substituted with single utilization in order to gain sustainability in resources and gain ultimate but sustainable benefit.
 

Environmental pollution due to oil and gas exploration and production (O&G E&P) wastes disposal and oil spills following several decades of irresponsible practices and neglects by the operating companies and over-dependence of government on the oil sector remains the major problem in the oil-producing communities in Nigeria. Studies to ascertain the ecological status of a remote Aviation fuel-contaminated sediment of a lentic ecosystem in Ibeno, Nigeria, have been have been carried out using standard microbiological culture - dependent methods which captures only <1% of all microorganisms present in a sample. The results from these studies were therefore inaccurate and grossly misleading. In this study, sediment samples from this lentic ecosystem in Ibeno, Nigeria previously polluted by Aviation fuel in 2001 (about 14 years ago) were collected and analyzed to assess its microbial diversity using standard microbiological culture - dependent techniques as well as the use of metagenomic techniques involving community DNA extraction, sequencing and bioinformatics analyses. Standard microbiological culture - dependent techniques revealed the presence of only six (6) genera of bacteria and four (4) genera of fungi. The results of metagenomics studies of same sample revealed that the ecosystem harbors complex microbial consortia as shown by the phylogenetic dendrogram to include members of the bacterial, archaeal and eukarya genera. These results corroborate the ‘great plate count anomaly’ principle and demonstrate that the use of metagenomic techniques will redefine the actual ecological status of the environment.

The Nigerian economy relies heavily on the revenue derived from the oil sector, as they supply 70% of state revenue and about 95% of exchange earnings . The nonchalant attitude of the oil operating companies in their improper ways of oily wastes disposal, intermittent oil spillages , relatively underdeveloped technology for spill prevention and response measures, and insufficient local capacity and political will power of state to stem the spate of incessant oil spill incidents in Nigeria, all end in increased risks of oil pollution and environmental degradation. Oil and gas reserves in Nigeria are concentrated within the Niger Delta region of the country, and have attracted the presence of multinational oil companies to the world. The Niger Delta region consists of nine states with Akwa Ibom State because the highest oil-producing state and thus attracts the very best financial allocation from the federal. Ibeno government Area hosts the operational base of Mobil Producing Nigeria Unlimited (MPNU), a subsidiary of Exxon Mobil and Qua Iboe Terminal (QIT). Thousands of barrels of oil are spilt into the environment through oil pipelines bursts and oiler accidents within the country since the inception of oil activities, partly as a results of lack of normal maintenance of the oil installations e.g., pipelines replacements after they out-lived their installed lifespan and partly due to sabotage and other causes like oiler accidents. Notably, a number of these facilities are in use for many years without replacement . for instance , in 2004, an abandoned oiler at Oloibiri, Bayelsa State released about 20,000 barrels of oil into the environment and evidence proved that the well had been leaking for several years without response from the operating company . In January 1998, 40,000 barrels of petroleum from Idoho production platform of Exxon Mobil was spilt into the environment and caused severe damage to the whole Nigerian coastline . Between 1997 and 2001, about 2,097 oil spill incidents were recorded in Nigeria . Oil spill cases occur daily and in most cases quite once during a day within the Niger Delta region of Nigeria. On 8th August 2001, Exxon Mobil’s aviation fuel pipeline ruptured releasing about 1000 barrels of aviation fuel into a lentic ecosystem in Inua Eyet Ikot village, Ibeno, Akwa Ibom State. Dispersant was used because the only remedial measure to contain the spill. Microbial diversity of the spill site is monitored using the culture-dependent methods which is understood to reveal only <1% of the microbial population . These results are unrealistic and therefore do not present the true ecological status of the site. Fourteen years after the spill, the ecological integrity of the site is questionable and appropriate remediation action can not be carried out. In conclusion, as low as six species of bacteria with no archaeal representative were detected from the conventional culture-dependent techniques while the 16S metagenomic analysis detected a total of 718 microbial species comprising both bacterial and archaeal diversity. Comparing the efficiency of both approaches adopted, this study confirms and thus supports the “great plate count anomaly” as well as support the adoption of the 16S metagenomic and other complimentary OMICS tools to investigate the true ecological integrity of any investigated environment.
 

The simplest kind of bioremediation is natural bioattenuation, during which the indigenous microbial populations degrade recalcitrants or xenobiotics supported their natural, nonengineered metabolic processes. According to the Environmental Protection Agency in the United States NA or intrinsic bioremediation processes include a variety of physical, chemical, and biological processes that act to reduce the mass, toxicity, mobility, volume, or concentration of contaminants. These processes include aerobic and anaerobic biodegradation, dispersion, dilution, sorption, volatilization, decay , and chemical or biological stabilization, transformation, or destruction of contaminants.

Natural attenuation as a tool at this moment is now renewed to develop criteria and methods to follow the process of intrinsic bioremediation and to make this process more predictable and therefore more suitable as a bioremediation tool. In the situation of this study, plants in interaction with microorganisms are now employed. Plant roots release an honest kind of materials to their surrounding soil; these include various alcohols, ethylene, sugars, anion and organic acids, vitamins, nucleotides, polysaccharides and enzymes. Microorganisms within the rhizosphere react to the various metabolites released by plant roots. They (rhizosphere microbes) and their products also interact with plant roots during a sort of positive, negative and neutral ways. Such interactions can influence plant growth and development, change nutrient dynamics, and alter the plant susceptibility to disease and abiotic stress. On the opposite hand, they function liable sources of nutrients for other organisms, thus creating a soil microbial loop additionally to playing critical roles in organic matter synthesis and degradation. A wide range of bacteria within the rhizosphere can however, promote plant growth. The living beings speak with the plant utilizing complex substance signals. These concoction signal mixes incorporate auxins, gibberellins, glycolipids and cytokinins.

Furthermore, plants do accumulate non-essential and/or toxic mineral elements like lead, sodium, within the ir ionic form once they're present within the soil solution. Their growth, on the opposite hand, may therefore be limited by the supply of essential elements, also as by the presence of those toxic elements. However, the interactions between plant roots and organisms within their rhizosphere help them to accumulate essential mineral nutrients and stop the buildup of toxic elements. Since all the minerals that a plant requires must come from the ground/soil, and because the activity of microbes within the soil are central to the efficient solubilization of these mineral elements, it's not surprising that a series of generalized and specific plant-microbe associations exist to perform this function [8,9]. This study therefore was designed to elucidate the effect of interaction between plant and indigenous micro- organisms on the degradation of n-alkanes in petroleum contaminated agricultural soil.

Agricultural soil samples from mapped out areas for the study were aseptically collected with sterile plastic sample containers and microbiologically analyzed to isolate autochthonous microbial flora. After pollution though, soil samples were also collected to understand the persisting isolate the polluted soil. These were administered using spread plate method of Cheesbrough on agar (Oxoid), MacConkey agar (Oxoid), Mineral salt agar (Lab-M) and Saboraud dextrose agar (Oxoid. The microorganisms isolated were characterized morphologically and biochemically using standard microbiological methods; whereas identification was as described in Berger’s Manual of Determinative Bacteriology. Seeds of 4 annual crops including cowpea var unguiculata, Mucuna pruriens, corn and T. occidentalis used were planted on the test soil and polluted with Bonny light petroleum twenty eight (28) days after plant growth. Thirty days after pollution, soil samples were collected within the rhizosphere of the test plants and examined microbiologically to isolate persisting microorganisms within the polluted soil. The variation in degradation of n-alkanes was ascertained using Gas chromatographic analysis on test soil samples and compared with the control. The pre microbial lab analysis of the soil under study revealed culturally, the presence of Penicillum sp., Aspergillus fumigatus , Aspergillus niger, Candida sp., Pseudomonas fluorescence, Acinetobacter baumanni, Bacillus mycoides, Klebsiella sp., Staphylococcus aureus and Escherichia coli whereas the absence of the last two isolates was observed during post microbial analyses. The results of the GC analysis on comparison to the control sample depict that plants kept within the green house were ready to degrade alkanes within the range of C7 to C12 and C32 to C40 while samples in the field degraded alkanes within the range C7 to C15 and C36 to C40. M. pruriens degraded C13 in addition. This study might be a promising tool in conversion of petroleum in contaminated agricultural soil to less toxic substances for enhanced remediation.
 

Water is one of the most important available substances on the earth. The survival of and quality of human life depends on the availability of fresh water. The aquatic animal’s life directly or indirectly depends on the water quality status. Water quality study provides current information about suitability of water designated uses. Most of the aquatic ecosystem receives million liters of municipal sewage, industrial and agricultural runoff. Planktonic organisms are important components in the productivity of inland waters. They are distributed among the waters in the bottom (benthic), open water (pellagic) and at the littoral zones (vegetative sides). Planktons are the small and microscopic organisms (phyto and zoo plankton) due to their size, feebleness or immobile nature float or drift at the mercy of water current to maintain a constant position against the water tides. An understanding of their ecology and distribution contribute significantly to the use and management of aquatic ecosystems. Both plankton and macro invertebrates are useful in aquatic food web, with higher trophic levels, such as fish and whales, depending nutritionally on them. They provide a crucial source of food to many large aquatic organisms in both marine and freshwater ecosystem &#40;Lalli and Parsons, 1993&#41;. Besides food chain supports in commercial fisheries, plankton ecosystems play a major role in the biogeochemical cycles of many important chemical elements (carbon, oxygen, nitrogen, phosphorus cycles) (Falkowski, 1994). According to Emiliani (1991), plankton are primarily divided into broad functional (trophic levels) groups. Plankton composition, distribution pattern and succession vary among lakes, streams and rivers, because each aquatic ecosystem has its physio-chemical and biological properties emanated from both the surrounding land mass, geological formation of the water, the local climate, human activities in water and drainage conditions through which run-off is received (White et al., 2008). In addition to its intrinsic biological importance, planktonic organisms are used in the evaluation of the productive capacity of water bodies (Umeham and Ogbonnaya, 1993). Plankton typically flow with water current while some forms are capable of independent movement and can swim hundreds of meters vertical in a single day (diel vertical migration), their horizontal position is determined primarily by the surrounding current, contrary to newton which can swim with the ambient flow and still maintain their position (Aumont and Bopp, 2006). 

The role of plankton in aquatic food web and as an indicator of water quality is well known. The availability, distribution, abundance and population of certain community of plankton is an indication of the water quality of an aquatic ecosystem &#40;Case et al., 2008&#41;. Water pollution by domestic, industrial and other water users as well as in lock constructions for navigation are the major causes of degradation in the water quality. However, such studies are still very limited in scope. The aim of the present study is to investigate the species composition as well as abundance of both plankton and macro invertebrates of Anya Stream. It is envisaged that this will make a remarkable contribution to the few existing checklists of the plankton and macro invertebrate composition of Nigerian waters. The physico-chemical also as Macro invertebrate characteristics of Anya stream in Amaoba community, Abia state was studied over a period of 5 months. The stream was investigated in 3 different outlined stations supported degree of human interaction and therefore the plant community along the length of the stream. The result indicated that human interaction influence to an extent the physico-chemical parameter of the water. The phosphate value recorded was between 0.67±0.22 to 0.77±0.18 mg/l. Total hardness ranged between 7.66±0.06 to 20.33±9.16mg/l while dissolved oxygen recorded 0.73±0.13 to 3.76±0.56 mg/l. The rainfall amount recorded within the amount of study had influence on a number of the parameters. The surface water temperature was lower within the wet months than within the dry ones. The nitrate concentration increased with an increase in the rainfall amount recorded. All parameters assessed apart from the pH and total phosphate fell within the suitable standard of World Health, Organization (WHO), Standard of Nigeria (SON), European Economic Community (EEC), Federal Ministry of Environment (FMENV).There was significant difference within the monthly concentrations of theses chemical parameters when subjected to Duncan and LSD analysis. However when the various stations were analyzed, there was no significant difference. A check list of the planktonic abundance and macro invertebrates revealed a total of five zooplankton species, four phytoplankton and six macro invertebrates. The zooplanktons encountered include Water flea, Branchionus plicatilis, Cyclops sp., calanus hyperboreus and Moina sp. The phytoplanktons included the subsequent species Spirogyra, Euglena, chlorophyte , cyanobacteria while the macroinvertebrates were pond-skater , Dragon flies, Damsel flies, Beetles, Water bugs, immature stages of Mosquitoes (larva, pupa) and the adults respectively. Chlorophycene (spirogyra), had the very best cell density of phytoplankton with a percentage of 100.0% obtained from a complete of 184 cells/ml from four broad groups of phytoplankton, based on the result and following standard criteria, the stream might be said to be suitable for domestic, industrial and agricultural uses, however basic treatment can help improve the portability of water especially for drinking.
 

Modern technology uses heavy metals both in the elemental and combined forms . During recent years serious concern has been voiced about the deteriorating state of fresh water bodies with respect to trace metal pollution. Heavy metals have the potential to be toxic to living organisms, if present at a level above a threshold. The metal concentrations are routinely monitored using biomonitoring species, which accumulate heavy metals in their tissues and may therefore be analyzed as a measure of the bioavaliability of metals in the ambient habitat. Low salinity which is unique to fresh water systems is known to increase the bioavalabilities of metals  and this may increase metal bioavailabilities at sites with low metal concentrations. Changes in pH can induce significant effects on the partitioning of metals between dissolved and particulate phases as well as on their speciation in each of these phases. It is recognized that in freshwater systems trace metals have high pollution potential that could be measured through the use of fish. A number of human activities have been identified through research to impact on biological productivity in fresh water ecosystems either positively or negatively. Some of such activities include dredging, petroleum exploration and production, road and bridge construction, urbanization, indiscriminate use of fertilizers and pesticides on agricultural lands, industrialization, indiscriminate waste dumping and filling of wetlands, amongst others. According to Oribhabor, human activities have great impacts on biodiversity in the Nigerian aquatic ecosystems. His work revealed that the impact can be brought about through persistent threat by heavy metals and eutrophication, amongst others. The work of Moslem and Miebake  on the effect of dredging on plankton community of Orashi River in the Niger delta, Nigeria showed that nutrient levels downstream of the dredger position had higher influence on the plankton community than the dredging induced-increase in turbidity and total suspended solids. 

This present research on the toxicity of heavy metals and effect of their concentrations on biological productivity and diversity in freshwater ecosystem was designed using three heavy metals (Cu, Fe, Pb) separately, to show the effect of these metals on biological productivity in a static simulated study. Toxicity of copper (Cu), iron (Fe) and lead (Pb) to tilapia fish was conducted using the simple arithmetic graphic method. In each experiment, a control (distilled water) and graded concentrations of the test metals were used. Observations for fish mortality and subsequent removal of dead fishes were made hourly for 4 days. Percent mortality was calculated for each of the heavy metals and 96-hr LC50 for Cu, Fe and Pb for tilapia fish were determined to be 0.44 mg/l, 0.96 mg/l and 2.85 mg/l, respectively. Of interest was the result obtained on biological productivity in the Aquaria containing 2.85mg/l of Pb within seven (7) days from the start of the experiment. This was repeated for each of the heavy metals. The test lasted for 96 hrs. From the observations made, it was possible to select four concentrations for the heavy metal toxicity studies. Cu, Fe and Pb heavy metals were used in static simulation studies. Mortality and toxicity studies were each carried out for 96 hours. The period for the toxicity studies was extended to 168 hours (7 days). Test solutions were observed for any effect due to the heavy metals in solution. The test was also extended for 14 days for observed effects to be more obvious. Biological productivity and thus high diversity were observed in the case of Cu and Fe when the period was lengthened to fourteen (14) days. As against scientific believe that Pb is highly toxic to humans, this study showed that Pb pollution in a freshwater ecosystem encourages high rate of biological productivity and thus high diversity; thus confirming that heavy metals have differing effects on biological productivity and diversity in the ecosystem. Lead (Pb), whose response is dictated by the dose which may depend on mobility and bioavailability, was therefore identified by this work as a trigger factor to eutrophication. Heavy metals support biological productivity in fresh water ecosystems and the degree differs from one metal to the other as was evident in the study. Regular bioassay, a test involving living tissues should be conducted in organisms or groups of organisms to determine the potency of any physiologically active substance of unknown activity. These tests have been used to ascertain effects such as toxicity, bioaccumulation, histopathology, growth rate, mutagenicity, embryo toxicity and teratogenicity.