Papers by KOUADIO Atto Delphin
African Journal of Biology and Medical Research
Wetlands of the city of Bamenda are characterized by intense agricultural activities. The resulti... more Wetlands of the city of Bamenda are characterized by intense agricultural activities. The resulting consequences are aquatic pollution. The management of these wetlands requires the study of the animal and plant communities found there. Diatoms are known to be good markers of environmental change. The aim of the study was to determine the influence of some abiotic parameters on the diatom densities of the Mezam river. The study was conducted from January to December 2022. Some physicochemical parameters were measured in situ. Water samples were collected and transported to the laboratory for the measurement of nitrates, total phosphorus, carbon dioxide and biological oxygen demand. The diatoms were sampled and analyzed in the laboratory. Factorial axis 2 (0.47%) of correspondence factor analysis opposed the positive variables (conductivity, total dissolved solids and salinity) to the negative variables (water temperature, pH, nitrates, total phosphorus, oxidability, carbon dioxide a...
International journal of biological and chemical sciences, Feb 22, 2024
Le maintien de la qualité optimale de l'eau pour la production de poissons dans les étangs rizipi... more Le maintien de la qualité optimale de l'eau pour la production de poissons dans les étangs rizipiscicoles constituent un défi majeur pour les pisciculteurs ivoiriens. L'étude visait à caractériser les paramètres physicochimiques et la biomasse algale des eaux des étangs rizipiscicoles d'une ferme utilisant des sous-produits agricoles. Pour ce faire, les paramètres physico-chimiques et la biomasse algale ont été collectés mensuellement dans un barrage et dans quatre étangs rizipiscicoles de grossissement de Oreochromis niloticus. Les résultats ont montré que les eaux des étangs rizipiscicoles étaient faiblement oxygénées et moins transparentes avec une forte conductivité et de matières dissoutes. Ces eaux étaient fortement ou très polluées, mais avaient une bonne aptitude à l'aquaculture. Les moyennes du pH (5,05 à 6,4), de la conductivité (133,98 à 225,58 µS/cm) et de l'oxygène dissous (3,26 à 4,03 mg/l) de l'eau des étangs rizipiscicoles étaient comprises dans les fourchettes favorables pour une meilleure croissance du tilapia. Les teneurs en nitrate et en ammonium étaient significativement plus élevées dans les étangs rizipiscicoles que dans le barrage. La biomasse algale (8408,5 à 56313,5 µg/cl) et la demande biochimique en oxygène (10 à 24,15 mg/l) étaient significativement plus élevées dans l'Etang-4. Ces résultats démontrent l'enrichissement des eaux des étangs rizipiscicoles en sels nutritifs et en microalgues par l'usage sous-produits agricoles, ce qui optimiserait la productivité du poisson et du riz.
International Journal of Development Research, 2024
The trials involved 60,132 GBEBI rice (Oryza glaberrima) seedlings and 4,703 tilapia juveniles wi... more The trials involved 60,132 GBEBI rice (Oryza glaberrima) seedlings and 4,703 tilapia juveniles with an average weight of 38 ±9.16 g fed with two complementary diets: (AC), (ASF) and a natural food (AN). Stocking density was 1.5 fish/m2. Nine ponds were used, 3 of which were randomly allocated to each feeding treatment to assess fish growth and rice production. Daily rations of 3% of the reared fish biomass were distributed in two meals (9 am and 3 pm). Rice seedlings were transplanted at a spacing of 25 cm x 20 cm. After 180 days of testing, for the complementary ASF and AC diets, the best nutrient quotients (Qn) (2.74 ±0.75) and daily growth (3.47 ±0.88 g/day) were obtained with AC. On the other hand, the highest Qn (4.56 ±1.15) and the lowest daily growth (2.36 ±0.56 g/day) were recorded with ASF.Comparison of all batches showed that fish fed only natural feed (AN) had the lowest daily growth (1.27 ±0.64 g/day). Rice yields where the supplementary feeds ASF (3.04 ± 0.04 t/ha) and AC (3.91 ± 0.40 t/ha) were fed were better than those of AN (control) (2.59 ±0.54 t/ha). This study shows that it is possible to improve the production of O. niloticus merchantable tilapia and the yield of GBEBI rice (Oryza glaberrima) with the use of supplementary feeds in the rice-fish system.
African Journal of Biology and Medical Research, 2023
Wetlands of the city of Bamenda are characterized by intense agricultural activities. The resulti... more Wetlands of the city of Bamenda are characterized by intense agricultural activities. The resulting consequences are aquatic pollution. The management of these wetlands requires the study of the animal and plant communities found there. Diatoms are known to be good markers of environmental change. The study aimed to determine the influence of some abiotic parameters on the diatom densities of the Mezam river. The study was conducted from January to December 2022. Some physicochemical parameters were measured in situ. Water samples were collected and transported to the laboratory for the measurement of nitrates, total phosphorus, carbon dioxide and biological oxygen demand. The diatoms were sampled and analyzed in the laboratory. Factorial axis 2 (0.47%) of correspondence factor analysis opposed the positive variables (conductivity, total dissolved solids and salinity) to the negative variables (water temperature, pH, nitrates, total phosphorus, oxidability, carbon dioxide and alkalinity). Study sites showed a mineralization gradient going from upstream (Site 1) to downstream (Site 3). Total species richness amounted to 4 classes divided in 18 families, 21 genera and 43 species. The most dominating family was Naviculaceae with 10 species. Multiple component analysis showed, in different study sites, the correlation between chemical parameters and density of different genera. The more the site was polluted, the more the density of Navicula, Tabellaria, Melosira and Coscinodiscus increased. On the contrary, the less the site was polluted, the more the density of Cyclotella, Gomphonema, Cocconeis, Gyrosigma, Synedra increased. These results showed that the distribution of diatoms in the different study sites was influenced by a set of conditions related to physicochemical parameters, but more on their densities.
International Journal of Biological and Chemical Sciences, 2023
Le maintien de la qualité optimale de l'eau pour la production de poissons dans les étangs rizipi... more Le maintien de la qualité optimale de l'eau pour la production de poissons dans les étangs rizipiscicoles constitue un défi majeur pour les pisciculteurs ivoiriens. L'étude visait à caractériser les paramètres physicochimiques et la biomasse algale des eaux des étangs rizipiscicoles d'une ferme utilisant des sous-produits agricoles. Pour ce faire, les paramètres physico-chimiques et la biomasse algale ont été collectés mensuellement dans un barrage et dans quatre étangs rizipiscicoles de grossissement de Oreochromis niloticus. Les résultats ont montré que les eaux des étangs rizipiscicoles étaient faiblement oxygénées et moins transparentes avec une forte conductivité et de matières dissoutes. Ces eaux étaient fortement ou très polluées, mais avaient une bonne aptitude à l'aquaculture. Les moyennes du pH (5,05 à 6,4), de la conductivité (133,98 à 225,58 µS/cm) et de l'oxygène dissous (3,26 à 4,03 mg/l) de l'eau des étangs rizipiscicoles étaient comprises dans les fourchettes favorables pour une meilleure croissance du tilapia. Les teneurs en nitrate et en ammonium étaient significativement plus élevées dans les étangs rizipiscicoles que dans le barrage. La biomasse algale (8408,5 à 56313,5 µg/cl) et la demande biochimique en oxygène (10 à 24,15 mg/l) étaient significativement plus élevées dans l'Etang-4. Ces résultats démontrent l'enrichissement des eaux des étangs rizipiscicoles en sels nutritifs et en microalgues par l'usage sous-produits agricoles, ce qui optimiserait la productivité du poisson et du riz.
Le maintien de la qualité optimale de l'eau pour la production de poissons dans les étangs rizipi... more Le maintien de la qualité optimale de l'eau pour la production de poissons dans les étangs rizipiscicoles constituent un défi majeur pour les pisciculteurs ivoiriens. L'étude visait à caractériser les paramètres physicochimiques et la biomasse algale des eaux des étangs rizipiscicoles d'une ferme utilisant des sous-produits agricoles. Pour ce faire, les paramètres physico-chimiques et la biomasse algale ont été collectés mensuellement dans un barrage et dans quatre étangs rizipiscicoles de grossissement de Oreochromis niloticus. Les résultats ont montré que les eaux des étangs rizipiscicoles étaient faiblement oxygénées et moins transparentes avec une forte conductivité et de matières dissoutes. Ces eaux étaient fortement ou très polluées, mais avaient une bonne aptitude à l'aquaculture. Les moyennes du pH (5,05 à 6,4), de la conductivité (133,98 à 225,58 µS/cm) et de l'oxygène dissous (3,26 à 4,03 mg/l) de l'eau des étangs rizipiscicoles étaient comprises dans les fourchettes favorables pour une meilleure croissance du tilapia. Les teneurs en nitrate et en ammonium étaient significativement plus élevées dans les étangs rizipiscicoles que dans le barrage. La biomasse algale (8408,5 à 56313,5 µg/cl) et la demande biochimique en oxygène (10 à 24,15 mg/l) étaient significativement plus élevées dans l'Etang-4. Ces résultats démontrent l'enrichissement des eaux des étangs rizipiscicoles en sels nutritifs et en microalgues par l'usage sous-produits agricoles, ce qui optimiserait la productivité du poisson et du riz.
Egyptian Journal of Aquatic Biology and Fisheries
Ivorian aquaculture production reached an estimate of 4500 tons/ year (FAO, 2021a) and that of mi... more Ivorian aquaculture production reached an estimate of 4500 tons/ year (FAO, 2021a) and that of milled rice recorded an average of 1336446 tons/year (FAO, 2021b). These productions remain low to cover the enormous demands of the Ivorian population despite many years of practice and immense natural potentials (FAO, 2014; ONDR, 2020). Notably,
International Journal of Fisheries and Aquatic Studies, 2020
The influence of agricultural by-products inputs to juveniles of Oreochromis niloticus on phytopl... more The influence of agricultural by-products inputs to juveniles of Oreochromis niloticus on phytoplankton composition and density in rice-fish ponds was assessed from water samples collected between April 10 to July 18, 2019. The experiment was carried out in four types of rice-fish ponds, namely, ponds without exogenous food input (RC), ponds with maize bran input (RSM), ponds with rice bran input (RSR) and ponds with various agricultural by-products combined input (RPC). Phytoplankton sampling was carried out by filtering 45 litres of water using a 20 µm plankton net with a 20 µm void and environmental parameters that could influence phytoplankton blooms were determined in situ. A total of 194 taxa divided into five phytoplankton phyla and 51 genera were inventoried. Species richness was higher in the RSM and RPC ponds than in the others with 101 and 92 taxa, respectively. Mean phytoplankton density was significantly higher in rice-fish ponds RPC (60.6 10 6 Individuals/L) and RSM (55.1 10 6 Individuals/L) with a strong dominance of Chlorophyta and Euglenophyta. These high densities were positively correlated with high nutrient concentrations.
Egyptian Journal of Aquatic Biology and Fisheries, 2022
This study aimed to evaluate the influence of agricultural by-products on the
proliferation of p... more This study aimed to evaluate the influence of agricultural by-products on the
proliferation of potentially toxic microalgae in rice-fish farming. For this purpose, an
experiment was carried out in rice-fish culture ponds growing Oreochromis niloticus
with four dietary treatments: corn bran input (RSM), rice bran input (RSR), mixed byproduct input (RPC) and no feed input (RC). Phytotoxic Dinoflagellata and
Cyanobacteria from these ponds were collected monthly for six months. Sampling of
these microalgae was done by water filtration and scraping of the algal biofilm
attached to the submerged parts of the rice stems. In addition, the physico-chemical
parameters of the water in these ponds were measured. The analyses recorded a total of
44 phytotoxic microalgal taxa, including 33 Cyanobacteria and 11 Dinoflagellata with
eight taxa constant in the ponds. The majority of these taxa are likely to produce
hepatotoxins and neurotoxins in the ponds. The absolute density of potentially toxic
pelagic microalgae was significantly higher in RPC (15339 to 24450 Individuals/L)
than that in RC (5586 to13078 Individuals/L). Moreover, the density of potentially
toxic microalgae epiphytic on submerged rice stems was higher in RPC (113.5 to 160.5
Individuals/cm2) than that in RC (85.5 to 115.96 Individuals/cm2). In contrast to other
ponds. Anabaena affinis, Microcystis aeruginosa, Peridinium cinctum and
Protoperidinium sp. were the most abundant. The use of rice bran and its combination
with other agricultural by-products in rice-fish farming results in the proliferation of
toxic Cyanobacteria that would be harmful to fish health.
International Journal of Fisheries and Aquatic Studies, 2020
The influence of agricultural by-products inputs to juveniles of Oreochromis niloticus on phytopl... more The influence of agricultural by-products inputs to juveniles of Oreochromis niloticus on phytoplankton composition and density in rice-fish ponds was assessed from water samples collected between April 10 to July 18, 2019. The experiment was carried out in four types of rice-fish ponds, namely, ponds without exogenous food input (RC), ponds with maize bran input (RSM), ponds with rice bran input (RSR) and ponds with various agricultural by-products combined input (RPC). Phytoplankton sampling was carried out by filtering 45 litres of water using a 20 µm plankton net with a 20 µm void and environmental parameters that could influence phytoplankton blooms were determined in situ. A total of 194 taxa divided into five phytoplankton phyla and 51 genera were inventoried. Species richness was higher in the RSM and RPC ponds than in the others with 101 and 92 taxa, respectively. Mean phytoplankton density was significantly higher in rice-fish ponds RPC (60.6 10 6 Individuals/L) and RSM (55.1 10 6 Individuals/L) with a strong dominance of Chlorophyta and Euglenophyta. These high densities were positively correlated with high nutrient concentrations.
In recent years, Lake Kossou has been subject to heavy human activities, including clandestine go... more In recent years, Lake Kossou has been subject to heavy human activities, including clandestine gold panning and the extensive application of nutrients related to the repetitive fish farming activities of the fish farm in floating cages on the lake. Objectives: This study thus aims to evaluate the influence of fish farming activities on the ecological quality of the waters of Lake Kossou on the basis of physico-chemical parameters. Methodology: The physico-chemical parameters of the waters of the floating fish farm on Lake Kossou were studied on a seasonal basis between 12 May 2017 and 26 February 2018. In-situ measurements and chemical analyses were carried out on water samples taken from 0 to 6 m deep in the lake waters. Results: Analyses show that the waters of Lake Kossou have a low transparency ranging from 0.62 to 1.5 m with high nitrate concentrations ranging from 0.82 to 7.02 mg/l. The two main seasons were characterized by high values of temperature, pH, nitrate and dissolved oxygen content. The stratification of temperature, pH, dissolved oxygen and nitrate content revealed the presence of a metalimnetic layer at a depth of 2 to 3 m in Lake Kossou. Conclusion: Data obtained from nutrient salts and transparency therefore characterize the advanced trophic status of Lake Kossou.
International Journal of Development Research, 2019
The objective of this study is to contribute to the knowledge of the Euglenophyte population of L... more The objective of this study is to contribute to the knowledge of the Euglenophyte population of Lake Kossou. On a seasonal rhythm, physicochemical parameters were measured and Euglenophytes were sampled using a 20 μm mesh plankton net in the water column of five stations of the cage farm. floating from the lake. A total of 54 taxa divided into 2 families and 5 genera was identified. Taxonomic richness was dominated by Trachelomonas genera (44%) and Phacus genera (30%). The Euglenophytes of Lake Kossou are quite diverse with Shannon indices ranging from 1.98 to 3.68 bits cell-1. The total density of Euglenophytes in surface waters and in the water column was higher in the dry season than in the rainy season. The genera Trachelomonas and Phacus contribute to the elevation of this density in the layer from 0 to 2 m deep. Dissolved oxygen, pH, and nitrates strongly influence the distribution of some taxa.
Uploads
Papers by KOUADIO Atto Delphin
proliferation of potentially toxic microalgae in rice-fish farming. For this purpose, an
experiment was carried out in rice-fish culture ponds growing Oreochromis niloticus
with four dietary treatments: corn bran input (RSM), rice bran input (RSR), mixed byproduct input (RPC) and no feed input (RC). Phytotoxic Dinoflagellata and
Cyanobacteria from these ponds were collected monthly for six months. Sampling of
these microalgae was done by water filtration and scraping of the algal biofilm
attached to the submerged parts of the rice stems. In addition, the physico-chemical
parameters of the water in these ponds were measured. The analyses recorded a total of
44 phytotoxic microalgal taxa, including 33 Cyanobacteria and 11 Dinoflagellata with
eight taxa constant in the ponds. The majority of these taxa are likely to produce
hepatotoxins and neurotoxins in the ponds. The absolute density of potentially toxic
pelagic microalgae was significantly higher in RPC (15339 to 24450 Individuals/L)
than that in RC (5586 to13078 Individuals/L). Moreover, the density of potentially
toxic microalgae epiphytic on submerged rice stems was higher in RPC (113.5 to 160.5
Individuals/cm2) than that in RC (85.5 to 115.96 Individuals/cm2). In contrast to other
ponds. Anabaena affinis, Microcystis aeruginosa, Peridinium cinctum and
Protoperidinium sp. were the most abundant. The use of rice bran and its combination
with other agricultural by-products in rice-fish farming results in the proliferation of
toxic Cyanobacteria that would be harmful to fish health.
proliferation of potentially toxic microalgae in rice-fish farming. For this purpose, an
experiment was carried out in rice-fish culture ponds growing Oreochromis niloticus
with four dietary treatments: corn bran input (RSM), rice bran input (RSR), mixed byproduct input (RPC) and no feed input (RC). Phytotoxic Dinoflagellata and
Cyanobacteria from these ponds were collected monthly for six months. Sampling of
these microalgae was done by water filtration and scraping of the algal biofilm
attached to the submerged parts of the rice stems. In addition, the physico-chemical
parameters of the water in these ponds were measured. The analyses recorded a total of
44 phytotoxic microalgal taxa, including 33 Cyanobacteria and 11 Dinoflagellata with
eight taxa constant in the ponds. The majority of these taxa are likely to produce
hepatotoxins and neurotoxins in the ponds. The absolute density of potentially toxic
pelagic microalgae was significantly higher in RPC (15339 to 24450 Individuals/L)
than that in RC (5586 to13078 Individuals/L). Moreover, the density of potentially
toxic microalgae epiphytic on submerged rice stems was higher in RPC (113.5 to 160.5
Individuals/cm2) than that in RC (85.5 to 115.96 Individuals/cm2). In contrast to other
ponds. Anabaena affinis, Microcystis aeruginosa, Peridinium cinctum and
Protoperidinium sp. were the most abundant. The use of rice bran and its combination
with other agricultural by-products in rice-fish farming results in the proliferation of
toxic Cyanobacteria that would be harmful to fish health.