The Role of Abiotic Factors in Diurnal Vertical Distribution of Zooplankton in Awba Dam, Ibadan, Nigeria (original) (raw)
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Notulae Scientia Biologicae
The present study investigated the ecological status of Opa reservoir, Obafemi Awolowo University, Ile Ife, Nigeria, based on the spatial and temporal variations in abundance and distribution of zooplankton. 72 samples were collected monthly with a quantitative net zooplankton from both the surface and bottom levels in three stations established at the dam site (Lacustrine), mid-lake (Transition) and inflow (Riverine) over a period of an annual cycle. A total of fifty-four (54) species were recorded from the reservoir comprising Rotifera (57.41%) > Arthropoda (33.33%) > Protozoa (5.56%) > Ciliophora (1.85%) = Cnidaria (1.85%), in the order of abundance. The least number of species (47) was recorded at the Transition station, while the highest number of species (49) occurred at the Lacustrine zone. Of all the zooplankton recorded, four species had significant spatial variation, while nine displayed seasonal variations during the study period (p ≤ 0.05). The highest species r...
Abundance and Distribution of Zooplankton in Pindiga Lake, Gombe State, Nigeria
2019
Zooplankton abundance and distribution of Pindiga Lake, Gombe State were evaluated. Four sampling sites (A, B, C, and D) with distance of 500 meters were selected. Physico-chemical characteristic were measured in situ and zooplanktons sampled fortnightly for three months. Zooplanktons collected were identified using taxonomic keys. Simpson’s and Margalef richness indices were employed for analyses. The results showed a total of 524 individual species of zooplankton in 26 genera among the three zooplankton taxa of Cladocera, Copepoda and Rotifera. The genera abundance of Pindiga Lake arranged in lessening trend as Copepoda > Rotifera > Cladocera, with respective total zooplankton values of 47.3%, 30.0%, and 22.7%. The number of individual zooplanktons and their genera for the respective sites were: A, 150 individuals in 26 genera; B, 127 individual in 22 genera; C, 123 individuals in 22 genera; and D, 124 individuals in 24 genera. The Simpson’s species diversity index for the...
Zooplankton Composition and Abundance In Goronyo Reservoir, Sokoto State, Nigeria
IOSR Journals , 2019
Anthropogenic activities affect water quality and biological resources such as zooplankton community. A survey on the taxonomic composition and relative abundance of zooplankton groups was conducted in goronyo reservoir between the periods of May and August 2013. A total of 20 and 17 zooplankton species in May and August belonging to three (3) major taxonomic groups namely; cladoceran, copepods and rotifers were identified from goronyo reservoir. These include three(3) species of copepods, four(4) species of cladoceran and thirteen (13) species of rotifers were recorded in May, while three(3) species of copepods, three (3) species of cladoceran and eleven (11) species of rotifers were identified in August. Species present in May but Absent in August include Bosmina Sp, Trichocera Elongata, Branchinous falcatus, Branchinous Angularis and Keratella Cochlearis. While those present in August but absent in May include brachinous patulus and Ptyra Melicerta. The percentage relative abundance of Zooplankton in Goronyo Reservoir for both sampling months indicates that the rotifers has the highest dominant species with (39.7% and 59.3%) for both season, followed by the copepods (39.5% and 24.7%) and the least dominated are the cladoceran(20.8% and 16.0%).
The distribution, relative abundance and species diversity of some zooplanktons and the changes in nutrients composition and concentrations was studied for the period of three months in Wasai reservoir Kano, Nigeria. Protozoa, Rotifera, Cladocera and Copepoda were identified. Protozoan number was dominant over the other zooplankton group throughout the period of sampling and in all the sampling points; then followed by Rotifera, Cladocera and Copepoda was represented by few species. Total individuals of Rotifera and Cladocera observed were 236 and one hundred and thirty six respectively. Highest and least occurred Rotifera Cladocera and Rotifera were observed have 79 species and twenty-nine, while Cladocera has fifty and twenty species respectively. The reservoir was within small range of pH 7.8 to 8.5 of mild alkaline condition, PH values decrease from the sampling point I down the sampling point V. Surface water temperature variations recorded was minimal. Maximum temperature observed was 23℃, and the least was 16℃. These slight variations resulted in a weak relationship (r =0.398) with zooplankton Physical parameters (e.g. transparency) in this research work was fairly uniform, ranges from 0.30m to 0.35m at all the sampling points, and throughout the period of this research there was no rainfall which might increase the level of reservoir water and its transparency. This slight variation in the water transparency among the sampling points when correlated with zooplankton counts were found to have a weak relationship (r=0.382). It has no influence on the distribution and abundance of zooplankton. The value of dissolved oxygen (DO) was observed to be increasing gently from sampling point I to V (3.7 mg/l to 4.4 mg/L), although there was sharp rise in sampling point III (4.6 mg/L). While Biochemical Oxygen Demand (BOD) decreases from sampling point I to V (2.7 to 2.4 mg/L), unlike DO, there was sharp decline in sampling point III (2.1 mg/L). The increase in dissolved oxygen and decreased in biochemical oxygen demand along the sampling point II, III, IV, V), and (I was due to nutrient enrichment from the continuous influx of sewage from the Jakara River. It revealed that highest phosphate ion concentration recorded was in sampling point I. This might be because of incoming domestic wastewater from Jakara River 1.Introduction Distribution and abundance of zooplankton communities may be a reflection of three major environmental pressures, physical or chemical, food resources, and vertebrate predation (Brooks & Dodson, 1965 and Post, 2002). On the other hand, it is evident that individual size, aggregation in clusters, deil vertical migration, filtration rate, birth rate of the zooplanktons, size and density of the algae, predation and distribution pattern of the temperature and oxygen concentration with depth are among the most important factor influencing the structure of the zooplankton association. Decrease of the diversity of zooplankton is commonly attributed to decrease in pH value resulting from increase in chemical pollutants or extreme environmental condition. Chemical pollutants significantly influence aquatic community structure and functions. For example Odum (1985), Marmorek and Korman, (1991) predicted the following trends in chemically stress communities; decreased efficiency of resource use, a decline in average body size and a decrease in the length of food chain. Chemicals acidification and pesticides contamination affects structure of fresh water zooplankton (Havens and Hanazato, 1993). Pollutants from insecticides stress decreases the average size of the organism, reduces energy flow, transfer efficiency and reduces food web complexity shortening the length of the food chain, and sometimes decreases species richness (Hanazato, 1998) It has been recognized (Matsumura-Tundisi, 1991) that the composition, abundance, and diversity of zooplankton can be modified slowly over time by continuous or increased artificial Eutrophication of aquatic ecosystem. Consequently, many of these organisms have been found useful and reliable as biological indicators of the quality of the water and its sediments (Marmorek and Korman, 1991). Accordingly, zooplankton revealed early warning indicators that give a number of advantages over benthos organisms and fish. First, they are easy to collect, relatively homogeneously distributed in lakes, live in the water column where they are exposed to changing water chemistry, and have a generation time that would allow changes in recruitment success to rapidly be manifested as changes in population size and community structure. Second, they are easy to culture; hence, toxicity data are not too difficult to assemble. Third, sample processing for bio-monitoring studies is relatively
Bayero Journal of Pure and Applied Sciences, 2020
A study of spatio-temporal distribution of zooplanktonic community in relation to physico-chemical water condition of Wasai Reservoir was carried out between March and October, 2018. Three sampling sites selected for the purpose of this study were based on different human activities taking place in the areas like fishing, sand collection, washing etc. Nine physico-chemical and biological parameters were determined on fortnight basis 8:00 to 10:00am using standard methods. The result revealed that temperature, pH, Electrical conductivity, Total dissolved solids, Dissolved oxygen, Biochemical oxygen demand, transparency, nitrate and phosphate ranged from 24.4 to 29.1°C, 6.4 to 8.4, 353.3 to 846.6µS/cm, 264.3 to 602.8mg/L, 6.7 to 10.9mg/L, 2.8 to6.8mg/L, 5.6 to 12.3cm, 0.12 to 0.55mg/L and 0.08 to 0.22mg/L respectively. A total of thirteen (13) species of zooplankton were identified from the reservoir out of which three (3) belong to the class copepoda with a highest mean value of 37.6...
Composition, Abundance and Diversity Indices of Zooplankton in Lake Alau, Borno State Nigeria
Arid Zone Journal of Basic and Applied Research, 2022
The occurrence and abundance of zooplankton in lake Alau were documented during the rainy and dry seasons (July, 2012 to April, 2013) in station A, B, C, D and E respectively. The sampling was done in the morning before 8:00am on monthly basis. Pour-through method was used to collect the samples and analysed. A total of ten species belonging to four families were identified. The research reveals that seasonal population abundance and species composition of zooplankton envisaged Brachionidae (59.52%) as the dominant specie, followed by Asplanchidae (22.22%) Cladocera (10.76%) and Copepoda (7.50%). Throughout the study period, five species of rotifers, three species of Cladocera and two species of Copepoda were identified. Not all of the identified species were found in all the five stations, thus indicating that depth play a vital role in their vertical migration. Shannon-Weiner index showed that station A (2.021) and B (2.016) have high species diversity index compared to station C, D, and E (1.888, 1.894 and 1.875) respectively. Equitability index revealed that all the stations were within 0.908 to 0.963 ranged. Simpson's index shows that station C (0.170) has the highest diversity index while station A and B had the same value of 0.151 as the least. Lake Alau is fairly rich in terms of zooplankton population and abundance. The presence of typical zooplankton species, notwithstanding other limnological features strongly suggests that the water body is maintaining an Oligo-mesotrophic status. More intensive study of the zooplankton species in West African arid region lakes will lead to the documentation of other species and wider distribution of many others than those that were recorded in the current study. This will lead to greater understanding of the factor that controls the distribution of these species.
UMYU Journal of Microbiology Research (UJMR)
Studies on the physico-chemical parameters and Zooplankton composition of Ajiwa reservoir, Katsina State, Nigeria was conducted from May 2012 to April 2013. Three sampling stations were selected; the physico-chemical and biological parameters were determined using standard methods and procedures. The result showed that; Water temperature (23.8 ± 0.8 °C), pH (6.8 ± 0.1), Turbidity (99.3 ± 3.6 NTU), Conductivity (129.9 ± 4.1µS/cm), Total Dissolved Solids (17.8 ± 0.3 mg/L), Nitrate-nitrogen (6.01 ± 0.3 mg/L), Water hardness (88.8 ±1.4 mg/LCaCO3), Dissolved Oxygen (6.6 ± 0.3 mg/L), Biochemical Oxygen Demand (3.2 ± 0.4 mg/L), Phosphate- phosphorus (6.4 ± 0.2 mg/L) and Water depth (5.4±0.3 m) varied with months and seasons. Analysis of variance indicated significant difference between seasons (P<0.05); but there was no significant difference in zooplankton distribution and abundance between the three stations (P>0.05). The result indicated Zooplankton percentage composition as follo...