Analysis of Nanoplastics and Microplastics in Food, 2020
The majority of consumer products used today is composed of some form of plastic. Worldwide, almo... more The majority of consumer products used today is composed of some form of plastic. Worldwide, almost 280 million tons of plastic materials are produced annually, much of which end up in landfill or the oceans. Plastics are produced by the conversion of natural products or by synthesis from primary chemicals, generally from oil, natural gas or coal. In contemporary society, plastic has attained a pivotal status, with extensive commercial, industrial, medicinal and municipal applications. It affects at least 267 species worldwide, including 86% of all sea turtle species, 44% of all seabird species, and 43% of all marine mammal species. Marine animals are harmed mostly through ingestion, entanglement and subsequently strangulation. Ingested plastics debris has been found to reduce stomach capacity, hinder growth, cause internal injuries and create intestinal blockage. Plastics entanglement with nets or other materials can result in strangulation, reduction of feeding efficiency, and even drowning. Plastics pollution facilitates the transport of species to other regions, alien species hitchhike on floating debris and invade new ecosystem thereby causing a shift in species composition or even extinction of other species. Legislation, prohibiting the disposal of plastics in the sea, introducing of biodegradable plastics, recycling of plastics and public awareness campaigns to discourage littering are various ways in which this problem can be minimized. Other remedial measures include enforcing environmental laws, development of indigenous and homegrown knowledge for plastic waste management and development and implementation of quality standards for all plastic recycled products.
The aim of good pond management is to increase fish production and one way through which producti... more The aim of good pond management is to increase fish production and one way through which production can be maximized is liming. Liming increases the pH of bottom mud and thereby increasing the availability of phosphorus added in fertilizer. Liming increases benthic production in fertilized ponds, apparently through increased nutrient availability and also increases microbial activity in mud through a favorable increase in pH. The unavailability of liming materials to fish farmers have posed a serious setback to fish farming as the lack of it in a pond may adversely affect the total productivity. In an attempt to overcome the problem of scarcity and high cost of limestone or hydrated lime, this book was put forward to examine the possibility of utilizing calcium carbide lime in raising catfish in earthen ponds thereby ameliorating production cost problems in culturing catfish. Aside from the control ponds, fish in ponds treated with calcium carbide lime had better growth parameters t...
Background: The desire of a fish farmer is to produce table-sized fish within the shortest possib... more Background: The desire of a fish farmer is to produce table-sized fish within the shortest possible period. This can be achieved by providing a good feed since the growth of a fish is influenced by its feed utilization and the feed utilization is a function of the balanced nutrient composition of the feed. Haematological studies have been employed in aquaculture and are usually associated with the feed input because blood parameters have been proved to be valuable tools in determining the health status of the fish in response to the dietary manipulations. Objective: This study investigated haematological indices and growth performance of Clarias gariepinus fingerlings fed locally formulated (sinking) and commercial (floating) pelleted diets in tarpaulin tanks. Materials and methods: Ninety fingerlings of initial mean weight (4.87 g) were observed for an 8 weeks feeding trial with three replicates at a stocking density of 15 fish/m. The fish were fed three times daily at 5% biomass. ...
World Journal of Advanced Research and Reviews, 2021
Delonix regia is commonly called Flamboyant or flame of the forest. The seeds were fermented, boi... more Delonix regia is commonly called Flamboyant or flame of the forest. The seeds were fermented, boiled, sundried and then ground into powdered meal. 40% crude protein based test diets containing Delonix regia seed meal D0 = 0%; D15 = 15%; D20 = 20% and D25 = 25% inclusion levels respectively were prepared. Red tilapia (Oreochromis niloticus) fingerlings of 6 weeks old were acclimatized for two weeks and then stocked in 12 hapas at 15 fish per hapa measuring 0.6 m × 1.2 m × 0.7 m placed in a concrete tank. Each diet was assigned to fish in a separate hapa in triplicate and administered at 3% fish body weight per day for 16 weeks. Fish weight and length were taken initially, biweekly and terminally. Water quality was monitored weekly. Number of fish at the end was recorded and survival rate, growth, feed utilization, fillet yield and blood parameters were determined. The data were subjected to the analysis of variance and mean separation (P= 0.05). Survival rate was highest in fish raised on D20 and least in D25 without any significant difference across the range. Mean growth performances, feed utilization indices and fillet yield were generally congruent between D20 and D25 with varying degrees of significant difference to other feeds. Results of blood assay did not depict harmful effects of the test diets indicating that the fish enjoyed some good measures of health. The gross performance of fish on D20 was optimal. It was therefore concluded that 20% dietary inclusion level of fermented, cooked and dried flamboyant seed was the best for the red tilapia (Oreochromis niloticus) post fingerlings.
In fish farming, feeding rate is an important factor affecting the growth of fish, and thus deter... more In fish farming, feeding rate is an important factor affecting the growth of fish, and thus determining the optimal feeding rate is important to the success of any aquaculture operation. This study which lasted for 99 days investigated the effect of varying feeding rates on the growth response of African catfish, Clarias gariepinus fingerlings. One hundred and eighty fingerlings were randomly distributed into nine experimental tanks giving 20 fingerlings per tank with an initial weight of 5.92±0.006 g. Three feeding rates were employed as treatments-3%, 5%, and 7% of fresh body weight, with three replicates per treatment. The fishes were fed three times daily with commercial feed (Aller-aqua) of 42% crude protein. Growth and water quality parameters were measured fortnightly and feed ration adjusted according to the biomass in each tank. Results show that Final Mean Weight, Mean Weight Gain, Specific Growth Rate, Performance Index and Protein Efficiency Ratio were significantly higher (p<0.05) in fish fed 7%. However, Feed Conversion Ratio were better at 3% body weight (p<0.05). Based on the growth performance and feed efficiency data obtained, the study suggests the optimum feeding rate of 5% bw/day for African catfish, C. gariepinus fingerlings.
South Asian Research Journal of Agriculture and Fisheries , 2020
Background: As other animals, fish needs essential nutrients to enable metabolic activities inclu... more Background: As other animals, fish needs essential nutrients to enable metabolic activities including growth, reproduction, repairs, etc. In fish culture practices, studies on the quantity and rate of feeding are aimed at identifying the optimum level/ration. Objective: This study evaluated growth performance, feed utilization and survival of Clarias gariepinus fingerlings fed varying feeding levels diets in tarpaulin tanks for 14 weeks (August-November, 2019). Methodology: The experiment was carried out at Fulfillment Fish Farm in Uyo Metropolis, Nigeria using 9 tarpaulin tanks of 1M 3. Three (3) feeding levels were chosen as treatments with triplicates. These were 2%, 4% and 6% fresh body weight of the fish and were designated as 2FL, 4FL and 6FL respectively. Twenty-five fingerlings each was randomly stocked in the tanks (25fish/m 2) and starved for 24 hours before the commencement of the feeding trial and the initial mean weight (3.69±0.01 g) was measured. The fish was fed twice daily (08:00 hrs and 16:00 hrs) at 2%, 4% and 6% respectively with Alaqua feed at 42% crude protein. The feeding rate was adjusted fortnightly with increase in body weight. Results: Results showed significance (p<0.05) in mean final weight, mean weight gain, specific growth rate, percentage weight gain, performance index, feed conversion ratio and protein efficiency ratio across the feeding trials with 6FL having highest growth response and 2FL having better feed utilization. Survival rate and mortality rate were non significant (p>0.05) across treatments. Conclusion: On the basis of growth response, feeding African catfish (C. gariepinus) at 6% body weight per day is recommended for raising African catfish at reduced cost of production.
The food and feeding habits of fish community of Qua Iboe River in Akwa Ibom State, Nigeria was s... more The food and feeding habits of fish community of Qua Iboe River in Akwa Ibom State, Nigeria was studied for eight mouths (January-August, 2009). The total number of fish examined was two hundred and twenty-one (221) out of which one hundred and seventy-seven (80.1%) had food while forty-four (19.9%) specimens were empty stomach. A total of 51 (23.1%) individuals had full stomachs while 72 (32.6%), 33 (14.9%) and 21 (9.5%) were ¾, ½ and ¼ full respectively. The data shows that, the food items consumed by these fish species covered a wide feeding range. Analysis of the stomach contents reveal algae, macrophytes (plants), shrimps, insects, fish, fish parts, sand, mud, unidentified plant matter, unidentified animal matter, nematodes and worms as the main food categories selectively eaten by fishes of Qua Iboe River. These fishes exhibited benthopelogic exploitation and grazing tendency. It is shown that, notopterids consumed a wide range of food resources available. The characids: B. leuciscus, A. spilopterus and A. baramose also fed on a wide variety of food resources (algae, insects, shrimps, crabs, fish parts and unidentified matter). The bagriids: C macropogon and C. nigrodigitatus fed on a wide variety of fish and other benthic invertebrates. Clariids and Malapterurus minjiriya feed on unidentified animal materials. H odoe and P obscura fed mostly on fish and other animal materials. The family cichlidae had the highest number of eight fish species, feeding on planktonic organisms and occasionally on feed on mud and other sediments. C. kingsleyae fed largely on plant materials. L falcipinnis fed also on plant materials. Lutjanus endecacantus and Pomadasys jubelini fed on shrimps, fish scales and unidentified animal matter. However, the dominant food items in the stomachs of many fish species were unidentified organic matter and detritus. It is shown here that, fishes of this area were non-selective, utilizing varieties of food items.
Journal of Aquatic Science and Marine Biology , 2019
This study investigated the effects of sand mining on the physico-chemical parameters of Ikot Ekp... more This study investigated the effects of sand mining on the physico-chemical parameters of Ikot Ekpan River. Four sampling stations were selected. Station one, was a partially dredged section of the river, station 2 and 4; fully dredged portions while station 3, (under the bridge) was not dredged. Temperature, DO, pH, electrical conductivity, total dissolved solids, turbidity, salinity, acidity, BOD, transparency, depth, nitrate, nitrite, sulphate, phosphate and ammonium were measured using standard methods. There were no spatial significant variations (p>0.05) in eleven (temperature, pH, EC, salinity, TDS, BOD, acidity, sulphate, transparency, nitrate and nitrite) of the sixteen parameters measured. However, temperature, EC, salinity, turbidity, sulphate, ammonium, nitrate and nitrite showed significant seasonal variations (p<0.05). The remaining parameters did not show significant seasonal variations (p>0.05). No parameters exceeded WHO standards except for turbidity, thus indicating water quality to be good. Keywords: Sand mining, physico-chemical parameters, stations, DO, Ikot Ekpan River.
Journal of Aquatic Science and Marine Biology , 2019
Fish is a rich source of nutrients, however, its nutritional value may be affected by the environ... more Fish is a rich source of nutrients, however, its nutritional value may be affected by the environment in which it exists. The threat of toxic and trace metals in the environment is more serious than those of other pollutants due to their non-biodegradable nature. This is coupled with their bio-accumulative and biomagnification potentials. Within the aquatic habitat fish cannot escape from the detrimental effects of these pollutants. Heavy metal toxicity as a result of fish consumption can result in damage or reduced mental and central nervous system function, lower energy levels, and damage to blood composition, lungs, kidneys, bones, liver and other vital organs. Long term exposure may result in slowly progressing physical, muscular, and Alzheimer’s disease, Parkinson’s disease, muscular dystrophy, and multiple sclerosis. Allergies are not uncommon and repeated long term contact with some metals or their compounds may even cause cancer. Heavy metal toxicity is a chemically significant condition when it does occur. If unrecognized or inappropriately treated, toxicity can result in significant illness and reduced quality of life which can ultimately result in death. Recommended strategies to combat this menace involves environmental legislation, holistic planning, technological measures to improve the quality of waste discharges and environmental monitoring programs. Keywords: Heavy metals, fish, human health, contamination.
The food and feeding habits of fish community of Qua Iboe River in Akwa Ibom State, Nigeria was s... more The food and feeding habits of fish community of Qua Iboe River in Akwa Ibom State, Nigeria was studied for eight mouths (January-August, 2009). The total number of fish examined was two hundred and twenty-one (221) out of which one hundred and seventy-seven (80.1%) had food while forty-four (19.9%) specimens were empty stomach. A total of 51 (23.1%) individuals had full stomachs while 72 (32.6%), 33 (14.9%) and 21 (9.5%) were ¾, ½ and ¼ full respectively. The data shows that, the food items consumed by these fish species covered a wide feeding range. Analysis of the stomach contents reveal algae, macrophytes (plants), shrimps, insects, fish, fish parts, sand, mud, unidentified plant matter, unidentified animal matter, nematodes and worms as the main food categories selectively eaten by fishes of Qua Iboe River. These fishes exhibited benthopelogic exploitation and grazing tendency. It is shown that, notopterids consumed a wide range of food resources available. The characids: B. leuciscus, A. spilopterus and A. baramose also fed on a wide variety of food resources (algae, insects, shrimps, crabs, fish parts and unidentified matter). The bagriids: C macropogon and C. nigrodigitatus fed on a wide variety of fish and other benthic invertebrates. Clariids and Malapterurus minjiriya feed on unidentified animal materials. H odoe and P obscura fed mostly on fish and other animal materials. The family cichlidae had the highest number of eight fish species, feeding on planktonic organisms and occasionally on feed on mud and other sediments. C. kingsleyae fed largely on plant materials. L falcipinnis fed also on plant materials. Lutjanus endecacantus and Pomadasys jubelini fed on shrimps, fish scales and unidentified animal matter. However, the dominant food items in the stomachs of many fish species were unidentified organic matter and detritus. It is shown here that, fishes of this area were non-selective, utilizing varieties of food items.
Background and Objective: Sustainability of the consistent expansion of aquacultural industry dep... more Background and Objective: Sustainability of the consistent expansion of aquacultural industry depends on development of fish culture techniques in order to obtain the most efficient, safe and cost effective methods for producing aqua products. The study evaluated the Heterobranchus bidorsalis fed varying levels of flamboyant (Delonix regia) growth performance and feed utilization of African catfish seed meal as replacement for wheat offal for 14 weeks. Materials and Methods: The experiment was conducted for 14 weeks (98 days) from May 6th to August 12th, 2017. Four experimental feeds (Diets 1, 2, 3 and 4) each with about 40% crude protein content were Delonix regia seed meal formulated at diet 1 = 0%, diet 2 = 15%, diet 3 = 20% and diet 4 = 25% inclusion levels of fermented and boiled (FSM). Post 2 weeks of acclimation, 15 fish were stocked in a happa pen sized 0.432 m for each feed with 3 replicates. The initial mean weight of fish was (33.70±0.78 g). Fish were fed at 3% body weight daily and adjusted accordingly every fortnight. Water quality parameters were noted morning and evening weekly. Results: Survival rate ranged from 79.99-86.66% randomly without significant difference. Treatments which contained 15% FSM gave the highest nominal performance with respect to mean weight gain, percentage mean weight gain, mean growth rate, specific growth rate and performance index, though there was no clear superiority over other feeds (p>0.05). The feed utilization indices were generally fair across all treatments, with best nominal performance in the treatment containing 25% FSM. Conclusion: The results revealed that the fish were able to utilize all the feed types well for growth, particularly at 15% inclusion level of flamboyant seed meal as basal feed stuff. Key words: Growth performance, feed utilization, Heterobranchus bidorsalis, Delonix regia
Background and Objective: Fish haematology is gaining increasing importance in fish culture becau... more Background and Objective: Fish haematology is gaining increasing importance in fish culture because of its importance in monitoring the health status of fish. The present study compared different stocking densities and its effect on the blood parameters of hybrid catfish (Heteroclarias) when they are fed at 1 and 2% body weight, respectively. Materials and Methods: The experiment lasted 12 months using 30 tarpaulin tanks of 1 m volume. The study was designed to have five different stocking densities, T = 100 fish/m , T = 75 fish/m , T = 38 fish/m , T = 18 fish/m and T = 9 fish/m and two feeding levels, 1 and 2% body weight as treatments. These were replicated 3 times. The fish was fed three times daily using commercial feed at 1.0 and 2.0% body weight, respectively. The feed was adjusted monthly with increase in body weight. Blood profile was determined using 5-part differential Haematology Auto-analyzer (Mindray BC 5300 model). Results: At 1.0%, white blood cells count, haemoglobin concentration, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration were insignificant (p>0.05) for T -T . Red blood cells count and packed cell volume however showed significant variation (p<0.05) across treatments. At 2.0%, there was significance (p>0.05) in only mean corpuscular haemoglobin, all other blood parameters showed no significance (p>0.05) across treatments. Conclusion: Heteroclarias easily adapts to high stocking densities without any serious effect on the health status if adequate measures are put in place during management. Key words: Hybrid catfish, Heteroclarias, stocking density, feeding level, haematology, blood profile
Background and Objective: Feeding level depends on the weight of the fish as well as being influe... more Background and Objective: Feeding level depends on the weight of the fish as well as being influenced by variables such as temperature of the water, dissolved oxygen, time of day, season and other physico-chemical parameters. The growth response, survival and feed utilization of hybrid catfish (Heteroclarias) under different feeding levels were evaluated for 12 months. Methodology: The experiment was carried out at the Department of Fisheries and Aquatic Environmental Management, University of Uyo, Nigeria using 9 tarpaulin tanks of 1 M3 volume. The study employed completely block design with three feeding levels (FL), 1.0% Fresh Body Weight (FBW) of fish (FL1), 1.5% FBW (FL2) and 2.0% FBW (FL3) as treatments. These were replicated three times at a stocking density of 75 fish mG2. The feeding rate was adjusted monthly with increase in body weight. Sampling of fish was done monthly by draining whole water from all tarpaulin tanks. Results: Result shows that, there was no significant difference (p>0.05) for mean final weight, mean weight gain, specific growth rate and daily weight gain for FL1, FL2 and FL3, respectively. Feed conversion ratio at FL1 was significantly different (p<0.05) from FL2 and FL3. However, protein efficiency ratio showed no significant (p>0.05) difference among the feeding levels. Survival rate showed significant difference (p<0.05) among the feeding levels and the values increased with increasing feeding levels. Conclusion: On the basis of growth response and nutrient utilization data obtained, feeding hybrid catfish (Heteroclarias) at 1.5% body weight per day is recommended for raising catfish at reduced cost of production. Key words: Heteroclarias, hybrid catfish, feeding level, growth performance, nutrient utilization, survival
Journal of Aquatic Science and Marine Biology , 2019
Environmental concerns of aquatic ecosystems have become emerging issues in Nigeria. Study of the... more Environmental concerns of aquatic ecosystems have become emerging issues in Nigeria. Study of the benthic macro-invertebrates of Douglas creek, south-eastern Nigeria was carried out from September 2011 –August 2013. Benthic macro-invertebrates from six classes, nine families and ten species were encountered. Maxillopoda class had the highest abundance of 47.37 %. The others were Bivalvia (18.95 %), Clitellata (15.79 %), Insecta (13.68 %), while the least were Malacostraca and Oligohaeta with 2.11 % each. Again, only Maxillopoda showed a significant seasonal variation (p<0.05). Gammarus lacustris was the most frequent and abundant species; occurring in 16 of the 24 months. This was followed by Tubifex tubifex and Anodonta grandis. Iphigenia laevigata, I. rostrata and Pisidium casertanum were the least frequent; each occurring just once throughout the study period. Gammarus lacustris, Tubifex tubifex and Hexacylloepus sp. occurred in all the stations while Iphigenia laevigata, I. rostrata and Pisidium casertanum each occurred in only one station. Margalelf species diversity and Shannon-wiener index were generally low with highest values of 1.924 and 1.591 respectively. The low diversity of benthic macro- invertebrates in Douglas creek is an indication of high anthropogenic perturbation. The presence of T. tubifex in all the stations suggests organic pollution from anthropogenic source. This study thus recommends that private and government agencies operating in this environment implement ecological surveillance and mitigation measures that will prevent further environmental degradation. Keywords: Benthos, distribution, abundance, Douglas creek, Maxillopoda, Gammarus lacustris
Journal of Aquatic Science and Marine Biology , 2019
The comparative effect of stocking densities (SD) and feeding levels (FL) on growth response of C... more The comparative effect of stocking densities (SD) and feeding levels (FL) on growth response of Clarias gariepinus was examined for 12 months in collapsible tarpaulin tanks. Two hundred and forty (240) fingerlings spawned at the hatchery complex of Fisheries and Aquatic Environmental Management were used in a factorial experimental design consisting of five (5) different stocking densities (SD) and three (3) feeding levels (FL). SD were 100 fish/0.25 m 3 , 75 fish/0.25 m 3 , 38 fish/0.25 m 3 , 18 fish/0.25 m 3 , and 9 fish/0.25 m 3 . Similarly, the three feeding levels established were: 1% Fresh Body Weight (FBW), 1.5% FBW and 2% FBW fed thrice daily. Each treatment was triplicated. Results show that SD at 100 fish/0.25 m 3 had the highest monthly Mean Weight Gain (MWG) (1165.8 g) while SD 18 fish/0.25 m 3 showed the least MWG (604.2 g) for FL 1%. At FL 1.5%, the trend was more uniform in progression with SD 75 fish/0.25 m 3 having the highest MWG and SD 38 fish/0.25 m 3 as the least in MWG (896.8 g and 709.8 g) respectively. FL 2% had MWG values from SD 75 fish/0.25 m 3 and SD 38 fish/0.25 m 3 as highest and lowest respectively (837.1 g and 836.3 g). For Specific Growth Rate (SGR) at 1% FL across all SD, there was a sharp increase in month May and a gradual decline through to the end. Specific Growth Rate at FL 1.5%and FL 2% followed a similar trend as in SGR of FL 1%. The values were notably higher in May and declined progressively to the end. Generally, SD 75 fish/0.25 m 3 and FL 1.5% gave the best MWG; hence fish for intensive culture can be carried out using tarpaulin tanks at high stocking density 75 fish/0.25 m 3 for maximum performances in growth. Keywords: Stocking density, feeding level, heteroclarias, hybrid catfish, specific growth rate
From the discovery of the first commercially viable oil wells in Oloibiri, in the Niger Delta, Ni... more From the discovery of the first commercially viable oil wells in Oloibiri, in the Niger Delta, Nigeria, in 1956 to the present day, the issue of oil production and its effect on the aquatic environment has been the source of constant friction between oil companies and their host communities. These oil-related activities have affected fishing activities in the host communities, the major economic preoccupation in these areas. As at 2016, daily production of crude oil stood at 1,999,855 barrels per day making Nigeria the largest oil producer in Africa, the seventh largest under OPEC and thirteenth largest in the world. The main sources of oil spill in the Niger Delta are: vandalization of the oil pipelines by the local inhabitants, ageing of the pipelines, oil blow outs from the flow stations, cleaning of oil tankers on the high sea, disposal of used oil into the drains by the road side mechanics, tanker accidents, ballast water discharge, etc. The harmful effects of oil spill on living aquatic resources cannot be overemphasized. Oil kills plants and animals in the estuarine zone. Oil settles on beaches and kills organisms that live there; it also settles on ocean floor and kills benthic (bottom-dwelling) organisms such as crabs. Oil poisons algae, disrupts major food chains and decreases the yield of edible crustaceans. It also coats birds, impairing their flight or reducing the insulative property of their feathers, thus making the birds more vulnerable to cold. It affects the essential organs of aquatic mammals, reptiles and amphibians. Oil endangers fish hatcheries in coastal waters and contaminates the flesh of commercially valuable fish. Regulations should be put in place to maintain oil spill free exploration and exploitation. Recommendations have been given, however, to make the region to be habitable.
Journal of Aquatic Science and Marine Biology , 2018
The effect of different stocking densities of hybrid catfish (Heteroclarias) on plankton abundanc... more The effect of different stocking densities of hybrid catfish (Heteroclarias) on plankton abundance in tarpaulin tanks was studied for a period of six (6) months (January – June 2016). The study employed Complete Randomized Design (CRD) experimental design. Five different stocking densities (treatments) were employed (T1 = 100fish/m2, T2 = 75fish/m2, T3 = 38fish/m2, T4 = 18fish/m2and T5 = 9fish/m2). These were replicated three times. Filtration technique was employed. Mesh size plankton net (25µm) was used to filter 10L depth integrated water samples. The water samples (net content) were emptied into a wide mouth plastic container and preserved in 5% formalin solution after proper labeling. The samples were then taken to the laboratory and were allowed to stand for at least 24hrs in the laboratory for the plankton to settle. The samples were pipetted (1ml sample) with sample pipette. The content was placed in a Sedgewick-Rafter plankton-counting chamber and examined under a magnification of 500× and 1000×. The plankton were identified, enumerated and total number of species were also recorded using keys and check lists. For phytoplankton, a total of eighty-three (83) species belonging to six (6) taxonomic groups were observed in the experimental tanks. Bacillariophyceae occurred highest and was represented by thirty-six (36) species. Chrysophyceae and xanthophyceae occurred least with one (1) species respectively. For zooplankton, a total of twenty (20) species belonging to four (4) taxa were identified during the study. Cladocera occurred highest with nine (9) species, while protozoa occurred least with two (2) species. T5 (9fish/m2) had the highest abundance of phytoplankton and zooplankton. T1 (100fish/m2) had the least abundance of phytoplankton and T2 (75fish/m2) had the lowest abundance of zooplankton. Therefore, a stocking density of 9fish/m2 of heteroclarias is optimal and is recommended in order to maintain better plankton presence and good environmental condition.
International Journal of Agriculture, Environment and Bioresearch , Oct 2017
Proximate composition of cultured and wild samples of catfish Clarias gariepinus were studied usi... more Proximate composition of cultured and wild samples of catfish Clarias gariepinus were studied using standard methods. Five (5) samples each of table-sized cultured and wild C. gariepinus were used for determining proximate composition. The cultured C. gariepinus was higher than the wild sample (P<0.05) in crude protein, carbohydrate and energy, while crude fibre, fat, ash and moisture content was higher in the wild samples. There was no significant difference (P>0.05) in the carbohydrate content between wild and cultured C. gariepinus, however other proximate parameters showed significant variation (P<0.05) between cultured and wild C. gariepinus. The species is recommended as a good source of minerals.
The majority of consumer products used today is composed of some form of plastic. Worldwide, almo... more The majority of consumer products used today is composed of some form of plastic. Worldwide, almost 280 million tons of plastic materials are produced annually, much of which end up in landfill or the oceans. Plastics are produced by the conversion of natural products or by synthesis from primary chemicals, generally from oil, natural gas or coal. In contemporary society, plastic has attained a pivotal status, with extensive commercial, industrial, medicinal and municipal applications. It affects at least 267 species worldwide, including 86% of all sea turtle species, 44% of all seabird species, and 43% of all marine mammal species. Marine animals are harmed mostly through ingestion, entanglement and subsequently strangulation. Ingested plastics debris has been found to reduce stomach capacity, hinder growth, cause internal injuries and create intestinal blockage. Plastics entanglement with nets or other materials can result in strangulation, reduction of feeding efficiency, and even drowning. Plastics pollution facilitates the transport of species to other regions, alien species hitchhike on floating debris and invade new ecosystem thereby causing a shift in species composition or even extinction of other species. Legislation, prohibiting the disposal of plastics in the sea, introducing of biodegradable plastics, recycling of plastics and public awareness campaigns to discourage littering are various ways in which this problem can be minimized. Other remedial measures include enforcing environmental laws, development of indigenous and homegrown knowledge for plastic waste management and development and implementation of quality standards for all plastic recycled products.
Analysis of Nanoplastics and Microplastics in Food, 2020
The majority of consumer products used today is composed of some form of plastic. Worldwide, almo... more The majority of consumer products used today is composed of some form of plastic. Worldwide, almost 280 million tons of plastic materials are produced annually, much of which end up in landfill or the oceans. Plastics are produced by the conversion of natural products or by synthesis from primary chemicals, generally from oil, natural gas or coal. In contemporary society, plastic has attained a pivotal status, with extensive commercial, industrial, medicinal and municipal applications. It affects at least 267 species worldwide, including 86% of all sea turtle species, 44% of all seabird species, and 43% of all marine mammal species. Marine animals are harmed mostly through ingestion, entanglement and subsequently strangulation. Ingested plastics debris has been found to reduce stomach capacity, hinder growth, cause internal injuries and create intestinal blockage. Plastics entanglement with nets or other materials can result in strangulation, reduction of feeding efficiency, and even drowning. Plastics pollution facilitates the transport of species to other regions, alien species hitchhike on floating debris and invade new ecosystem thereby causing a shift in species composition or even extinction of other species. Legislation, prohibiting the disposal of plastics in the sea, introducing of biodegradable plastics, recycling of plastics and public awareness campaigns to discourage littering are various ways in which this problem can be minimized. Other remedial measures include enforcing environmental laws, development of indigenous and homegrown knowledge for plastic waste management and development and implementation of quality standards for all plastic recycled products.
The aim of good pond management is to increase fish production and one way through which producti... more The aim of good pond management is to increase fish production and one way through which production can be maximized is liming. Liming increases the pH of bottom mud and thereby increasing the availability of phosphorus added in fertilizer. Liming increases benthic production in fertilized ponds, apparently through increased nutrient availability and also increases microbial activity in mud through a favorable increase in pH. The unavailability of liming materials to fish farmers have posed a serious setback to fish farming as the lack of it in a pond may adversely affect the total productivity. In an attempt to overcome the problem of scarcity and high cost of limestone or hydrated lime, this book was put forward to examine the possibility of utilizing calcium carbide lime in raising catfish in earthen ponds thereby ameliorating production cost problems in culturing catfish. Aside from the control ponds, fish in ponds treated with calcium carbide lime had better growth parameters t...
Background: The desire of a fish farmer is to produce table-sized fish within the shortest possib... more Background: The desire of a fish farmer is to produce table-sized fish within the shortest possible period. This can be achieved by providing a good feed since the growth of a fish is influenced by its feed utilization and the feed utilization is a function of the balanced nutrient composition of the feed. Haematological studies have been employed in aquaculture and are usually associated with the feed input because blood parameters have been proved to be valuable tools in determining the health status of the fish in response to the dietary manipulations. Objective: This study investigated haematological indices and growth performance of Clarias gariepinus fingerlings fed locally formulated (sinking) and commercial (floating) pelleted diets in tarpaulin tanks. Materials and methods: Ninety fingerlings of initial mean weight (4.87 g) were observed for an 8 weeks feeding trial with three replicates at a stocking density of 15 fish/m. The fish were fed three times daily at 5% biomass. ...
World Journal of Advanced Research and Reviews, 2021
Delonix regia is commonly called Flamboyant or flame of the forest. The seeds were fermented, boi... more Delonix regia is commonly called Flamboyant or flame of the forest. The seeds were fermented, boiled, sundried and then ground into powdered meal. 40% crude protein based test diets containing Delonix regia seed meal D0 = 0%; D15 = 15%; D20 = 20% and D25 = 25% inclusion levels respectively were prepared. Red tilapia (Oreochromis niloticus) fingerlings of 6 weeks old were acclimatized for two weeks and then stocked in 12 hapas at 15 fish per hapa measuring 0.6 m × 1.2 m × 0.7 m placed in a concrete tank. Each diet was assigned to fish in a separate hapa in triplicate and administered at 3% fish body weight per day for 16 weeks. Fish weight and length were taken initially, biweekly and terminally. Water quality was monitored weekly. Number of fish at the end was recorded and survival rate, growth, feed utilization, fillet yield and blood parameters were determined. The data were subjected to the analysis of variance and mean separation (P= 0.05). Survival rate was highest in fish raised on D20 and least in D25 without any significant difference across the range. Mean growth performances, feed utilization indices and fillet yield were generally congruent between D20 and D25 with varying degrees of significant difference to other feeds. Results of blood assay did not depict harmful effects of the test diets indicating that the fish enjoyed some good measures of health. The gross performance of fish on D20 was optimal. It was therefore concluded that 20% dietary inclusion level of fermented, cooked and dried flamboyant seed was the best for the red tilapia (Oreochromis niloticus) post fingerlings.
In fish farming, feeding rate is an important factor affecting the growth of fish, and thus deter... more In fish farming, feeding rate is an important factor affecting the growth of fish, and thus determining the optimal feeding rate is important to the success of any aquaculture operation. This study which lasted for 99 days investigated the effect of varying feeding rates on the growth response of African catfish, Clarias gariepinus fingerlings. One hundred and eighty fingerlings were randomly distributed into nine experimental tanks giving 20 fingerlings per tank with an initial weight of 5.92±0.006 g. Three feeding rates were employed as treatments-3%, 5%, and 7% of fresh body weight, with three replicates per treatment. The fishes were fed three times daily with commercial feed (Aller-aqua) of 42% crude protein. Growth and water quality parameters were measured fortnightly and feed ration adjusted according to the biomass in each tank. Results show that Final Mean Weight, Mean Weight Gain, Specific Growth Rate, Performance Index and Protein Efficiency Ratio were significantly higher (p<0.05) in fish fed 7%. However, Feed Conversion Ratio were better at 3% body weight (p<0.05). Based on the growth performance and feed efficiency data obtained, the study suggests the optimum feeding rate of 5% bw/day for African catfish, C. gariepinus fingerlings.
South Asian Research Journal of Agriculture and Fisheries , 2020
Background: As other animals, fish needs essential nutrients to enable metabolic activities inclu... more Background: As other animals, fish needs essential nutrients to enable metabolic activities including growth, reproduction, repairs, etc. In fish culture practices, studies on the quantity and rate of feeding are aimed at identifying the optimum level/ration. Objective: This study evaluated growth performance, feed utilization and survival of Clarias gariepinus fingerlings fed varying feeding levels diets in tarpaulin tanks for 14 weeks (August-November, 2019). Methodology: The experiment was carried out at Fulfillment Fish Farm in Uyo Metropolis, Nigeria using 9 tarpaulin tanks of 1M 3. Three (3) feeding levels were chosen as treatments with triplicates. These were 2%, 4% and 6% fresh body weight of the fish and were designated as 2FL, 4FL and 6FL respectively. Twenty-five fingerlings each was randomly stocked in the tanks (25fish/m 2) and starved for 24 hours before the commencement of the feeding trial and the initial mean weight (3.69±0.01 g) was measured. The fish was fed twice daily (08:00 hrs and 16:00 hrs) at 2%, 4% and 6% respectively with Alaqua feed at 42% crude protein. The feeding rate was adjusted fortnightly with increase in body weight. Results: Results showed significance (p<0.05) in mean final weight, mean weight gain, specific growth rate, percentage weight gain, performance index, feed conversion ratio and protein efficiency ratio across the feeding trials with 6FL having highest growth response and 2FL having better feed utilization. Survival rate and mortality rate were non significant (p>0.05) across treatments. Conclusion: On the basis of growth response, feeding African catfish (C. gariepinus) at 6% body weight per day is recommended for raising African catfish at reduced cost of production.
The food and feeding habits of fish community of Qua Iboe River in Akwa Ibom State, Nigeria was s... more The food and feeding habits of fish community of Qua Iboe River in Akwa Ibom State, Nigeria was studied for eight mouths (January-August, 2009). The total number of fish examined was two hundred and twenty-one (221) out of which one hundred and seventy-seven (80.1%) had food while forty-four (19.9%) specimens were empty stomach. A total of 51 (23.1%) individuals had full stomachs while 72 (32.6%), 33 (14.9%) and 21 (9.5%) were ¾, ½ and ¼ full respectively. The data shows that, the food items consumed by these fish species covered a wide feeding range. Analysis of the stomach contents reveal algae, macrophytes (plants), shrimps, insects, fish, fish parts, sand, mud, unidentified plant matter, unidentified animal matter, nematodes and worms as the main food categories selectively eaten by fishes of Qua Iboe River. These fishes exhibited benthopelogic exploitation and grazing tendency. It is shown that, notopterids consumed a wide range of food resources available. The characids: B. leuciscus, A. spilopterus and A. baramose also fed on a wide variety of food resources (algae, insects, shrimps, crabs, fish parts and unidentified matter). The bagriids: C macropogon and C. nigrodigitatus fed on a wide variety of fish and other benthic invertebrates. Clariids and Malapterurus minjiriya feed on unidentified animal materials. H odoe and P obscura fed mostly on fish and other animal materials. The family cichlidae had the highest number of eight fish species, feeding on planktonic organisms and occasionally on feed on mud and other sediments. C. kingsleyae fed largely on plant materials. L falcipinnis fed also on plant materials. Lutjanus endecacantus and Pomadasys jubelini fed on shrimps, fish scales and unidentified animal matter. However, the dominant food items in the stomachs of many fish species were unidentified organic matter and detritus. It is shown here that, fishes of this area were non-selective, utilizing varieties of food items.
Journal of Aquatic Science and Marine Biology , 2019
This study investigated the effects of sand mining on the physico-chemical parameters of Ikot Ekp... more This study investigated the effects of sand mining on the physico-chemical parameters of Ikot Ekpan River. Four sampling stations were selected. Station one, was a partially dredged section of the river, station 2 and 4; fully dredged portions while station 3, (under the bridge) was not dredged. Temperature, DO, pH, electrical conductivity, total dissolved solids, turbidity, salinity, acidity, BOD, transparency, depth, nitrate, nitrite, sulphate, phosphate and ammonium were measured using standard methods. There were no spatial significant variations (p>0.05) in eleven (temperature, pH, EC, salinity, TDS, BOD, acidity, sulphate, transparency, nitrate and nitrite) of the sixteen parameters measured. However, temperature, EC, salinity, turbidity, sulphate, ammonium, nitrate and nitrite showed significant seasonal variations (p<0.05). The remaining parameters did not show significant seasonal variations (p>0.05). No parameters exceeded WHO standards except for turbidity, thus indicating water quality to be good. Keywords: Sand mining, physico-chemical parameters, stations, DO, Ikot Ekpan River.
Journal of Aquatic Science and Marine Biology , 2019
Fish is a rich source of nutrients, however, its nutritional value may be affected by the environ... more Fish is a rich source of nutrients, however, its nutritional value may be affected by the environment in which it exists. The threat of toxic and trace metals in the environment is more serious than those of other pollutants due to their non-biodegradable nature. This is coupled with their bio-accumulative and biomagnification potentials. Within the aquatic habitat fish cannot escape from the detrimental effects of these pollutants. Heavy metal toxicity as a result of fish consumption can result in damage or reduced mental and central nervous system function, lower energy levels, and damage to blood composition, lungs, kidneys, bones, liver and other vital organs. Long term exposure may result in slowly progressing physical, muscular, and Alzheimer’s disease, Parkinson’s disease, muscular dystrophy, and multiple sclerosis. Allergies are not uncommon and repeated long term contact with some metals or their compounds may even cause cancer. Heavy metal toxicity is a chemically significant condition when it does occur. If unrecognized or inappropriately treated, toxicity can result in significant illness and reduced quality of life which can ultimately result in death. Recommended strategies to combat this menace involves environmental legislation, holistic planning, technological measures to improve the quality of waste discharges and environmental monitoring programs. Keywords: Heavy metals, fish, human health, contamination.
The food and feeding habits of fish community of Qua Iboe River in Akwa Ibom State, Nigeria was s... more The food and feeding habits of fish community of Qua Iboe River in Akwa Ibom State, Nigeria was studied for eight mouths (January-August, 2009). The total number of fish examined was two hundred and twenty-one (221) out of which one hundred and seventy-seven (80.1%) had food while forty-four (19.9%) specimens were empty stomach. A total of 51 (23.1%) individuals had full stomachs while 72 (32.6%), 33 (14.9%) and 21 (9.5%) were ¾, ½ and ¼ full respectively. The data shows that, the food items consumed by these fish species covered a wide feeding range. Analysis of the stomach contents reveal algae, macrophytes (plants), shrimps, insects, fish, fish parts, sand, mud, unidentified plant matter, unidentified animal matter, nematodes and worms as the main food categories selectively eaten by fishes of Qua Iboe River. These fishes exhibited benthopelogic exploitation and grazing tendency. It is shown that, notopterids consumed a wide range of food resources available. The characids: B. leuciscus, A. spilopterus and A. baramose also fed on a wide variety of food resources (algae, insects, shrimps, crabs, fish parts and unidentified matter). The bagriids: C macropogon and C. nigrodigitatus fed on a wide variety of fish and other benthic invertebrates. Clariids and Malapterurus minjiriya feed on unidentified animal materials. H odoe and P obscura fed mostly on fish and other animal materials. The family cichlidae had the highest number of eight fish species, feeding on planktonic organisms and occasionally on feed on mud and other sediments. C. kingsleyae fed largely on plant materials. L falcipinnis fed also on plant materials. Lutjanus endecacantus and Pomadasys jubelini fed on shrimps, fish scales and unidentified animal matter. However, the dominant food items in the stomachs of many fish species were unidentified organic matter and detritus. It is shown here that, fishes of this area were non-selective, utilizing varieties of food items.
Background and Objective: Sustainability of the consistent expansion of aquacultural industry dep... more Background and Objective: Sustainability of the consistent expansion of aquacultural industry depends on development of fish culture techniques in order to obtain the most efficient, safe and cost effective methods for producing aqua products. The study evaluated the Heterobranchus bidorsalis fed varying levels of flamboyant (Delonix regia) growth performance and feed utilization of African catfish seed meal as replacement for wheat offal for 14 weeks. Materials and Methods: The experiment was conducted for 14 weeks (98 days) from May 6th to August 12th, 2017. Four experimental feeds (Diets 1, 2, 3 and 4) each with about 40% crude protein content were Delonix regia seed meal formulated at diet 1 = 0%, diet 2 = 15%, diet 3 = 20% and diet 4 = 25% inclusion levels of fermented and boiled (FSM). Post 2 weeks of acclimation, 15 fish were stocked in a happa pen sized 0.432 m for each feed with 3 replicates. The initial mean weight of fish was (33.70±0.78 g). Fish were fed at 3% body weight daily and adjusted accordingly every fortnight. Water quality parameters were noted morning and evening weekly. Results: Survival rate ranged from 79.99-86.66% randomly without significant difference. Treatments which contained 15% FSM gave the highest nominal performance with respect to mean weight gain, percentage mean weight gain, mean growth rate, specific growth rate and performance index, though there was no clear superiority over other feeds (p>0.05). The feed utilization indices were generally fair across all treatments, with best nominal performance in the treatment containing 25% FSM. Conclusion: The results revealed that the fish were able to utilize all the feed types well for growth, particularly at 15% inclusion level of flamboyant seed meal as basal feed stuff. Key words: Growth performance, feed utilization, Heterobranchus bidorsalis, Delonix regia
Background and Objective: Fish haematology is gaining increasing importance in fish culture becau... more Background and Objective: Fish haematology is gaining increasing importance in fish culture because of its importance in monitoring the health status of fish. The present study compared different stocking densities and its effect on the blood parameters of hybrid catfish (Heteroclarias) when they are fed at 1 and 2% body weight, respectively. Materials and Methods: The experiment lasted 12 months using 30 tarpaulin tanks of 1 m volume. The study was designed to have five different stocking densities, T = 100 fish/m , T = 75 fish/m , T = 38 fish/m , T = 18 fish/m and T = 9 fish/m and two feeding levels, 1 and 2% body weight as treatments. These were replicated 3 times. The fish was fed three times daily using commercial feed at 1.0 and 2.0% body weight, respectively. The feed was adjusted monthly with increase in body weight. Blood profile was determined using 5-part differential Haematology Auto-analyzer (Mindray BC 5300 model). Results: At 1.0%, white blood cells count, haemoglobin concentration, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration were insignificant (p>0.05) for T -T . Red blood cells count and packed cell volume however showed significant variation (p<0.05) across treatments. At 2.0%, there was significance (p>0.05) in only mean corpuscular haemoglobin, all other blood parameters showed no significance (p>0.05) across treatments. Conclusion: Heteroclarias easily adapts to high stocking densities without any serious effect on the health status if adequate measures are put in place during management. Key words: Hybrid catfish, Heteroclarias, stocking density, feeding level, haematology, blood profile
Background and Objective: Feeding level depends on the weight of the fish as well as being influe... more Background and Objective: Feeding level depends on the weight of the fish as well as being influenced by variables such as temperature of the water, dissolved oxygen, time of day, season and other physico-chemical parameters. The growth response, survival and feed utilization of hybrid catfish (Heteroclarias) under different feeding levels were evaluated for 12 months. Methodology: The experiment was carried out at the Department of Fisheries and Aquatic Environmental Management, University of Uyo, Nigeria using 9 tarpaulin tanks of 1 M3 volume. The study employed completely block design with three feeding levels (FL), 1.0% Fresh Body Weight (FBW) of fish (FL1), 1.5% FBW (FL2) and 2.0% FBW (FL3) as treatments. These were replicated three times at a stocking density of 75 fish mG2. The feeding rate was adjusted monthly with increase in body weight. Sampling of fish was done monthly by draining whole water from all tarpaulin tanks. Results: Result shows that, there was no significant difference (p>0.05) for mean final weight, mean weight gain, specific growth rate and daily weight gain for FL1, FL2 and FL3, respectively. Feed conversion ratio at FL1 was significantly different (p<0.05) from FL2 and FL3. However, protein efficiency ratio showed no significant (p>0.05) difference among the feeding levels. Survival rate showed significant difference (p<0.05) among the feeding levels and the values increased with increasing feeding levels. Conclusion: On the basis of growth response and nutrient utilization data obtained, feeding hybrid catfish (Heteroclarias) at 1.5% body weight per day is recommended for raising catfish at reduced cost of production. Key words: Heteroclarias, hybrid catfish, feeding level, growth performance, nutrient utilization, survival
Journal of Aquatic Science and Marine Biology , 2019
Environmental concerns of aquatic ecosystems have become emerging issues in Nigeria. Study of the... more Environmental concerns of aquatic ecosystems have become emerging issues in Nigeria. Study of the benthic macro-invertebrates of Douglas creek, south-eastern Nigeria was carried out from September 2011 –August 2013. Benthic macro-invertebrates from six classes, nine families and ten species were encountered. Maxillopoda class had the highest abundance of 47.37 %. The others were Bivalvia (18.95 %), Clitellata (15.79 %), Insecta (13.68 %), while the least were Malacostraca and Oligohaeta with 2.11 % each. Again, only Maxillopoda showed a significant seasonal variation (p<0.05). Gammarus lacustris was the most frequent and abundant species; occurring in 16 of the 24 months. This was followed by Tubifex tubifex and Anodonta grandis. Iphigenia laevigata, I. rostrata and Pisidium casertanum were the least frequent; each occurring just once throughout the study period. Gammarus lacustris, Tubifex tubifex and Hexacylloepus sp. occurred in all the stations while Iphigenia laevigata, I. rostrata and Pisidium casertanum each occurred in only one station. Margalelf species diversity and Shannon-wiener index were generally low with highest values of 1.924 and 1.591 respectively. The low diversity of benthic macro- invertebrates in Douglas creek is an indication of high anthropogenic perturbation. The presence of T. tubifex in all the stations suggests organic pollution from anthropogenic source. This study thus recommends that private and government agencies operating in this environment implement ecological surveillance and mitigation measures that will prevent further environmental degradation. Keywords: Benthos, distribution, abundance, Douglas creek, Maxillopoda, Gammarus lacustris
Journal of Aquatic Science and Marine Biology , 2019
The comparative effect of stocking densities (SD) and feeding levels (FL) on growth response of C... more The comparative effect of stocking densities (SD) and feeding levels (FL) on growth response of Clarias gariepinus was examined for 12 months in collapsible tarpaulin tanks. Two hundred and forty (240) fingerlings spawned at the hatchery complex of Fisheries and Aquatic Environmental Management were used in a factorial experimental design consisting of five (5) different stocking densities (SD) and three (3) feeding levels (FL). SD were 100 fish/0.25 m 3 , 75 fish/0.25 m 3 , 38 fish/0.25 m 3 , 18 fish/0.25 m 3 , and 9 fish/0.25 m 3 . Similarly, the three feeding levels established were: 1% Fresh Body Weight (FBW), 1.5% FBW and 2% FBW fed thrice daily. Each treatment was triplicated. Results show that SD at 100 fish/0.25 m 3 had the highest monthly Mean Weight Gain (MWG) (1165.8 g) while SD 18 fish/0.25 m 3 showed the least MWG (604.2 g) for FL 1%. At FL 1.5%, the trend was more uniform in progression with SD 75 fish/0.25 m 3 having the highest MWG and SD 38 fish/0.25 m 3 as the least in MWG (896.8 g and 709.8 g) respectively. FL 2% had MWG values from SD 75 fish/0.25 m 3 and SD 38 fish/0.25 m 3 as highest and lowest respectively (837.1 g and 836.3 g). For Specific Growth Rate (SGR) at 1% FL across all SD, there was a sharp increase in month May and a gradual decline through to the end. Specific Growth Rate at FL 1.5%and FL 2% followed a similar trend as in SGR of FL 1%. The values were notably higher in May and declined progressively to the end. Generally, SD 75 fish/0.25 m 3 and FL 1.5% gave the best MWG; hence fish for intensive culture can be carried out using tarpaulin tanks at high stocking density 75 fish/0.25 m 3 for maximum performances in growth. Keywords: Stocking density, feeding level, heteroclarias, hybrid catfish, specific growth rate
From the discovery of the first commercially viable oil wells in Oloibiri, in the Niger Delta, Ni... more From the discovery of the first commercially viable oil wells in Oloibiri, in the Niger Delta, Nigeria, in 1956 to the present day, the issue of oil production and its effect on the aquatic environment has been the source of constant friction between oil companies and their host communities. These oil-related activities have affected fishing activities in the host communities, the major economic preoccupation in these areas. As at 2016, daily production of crude oil stood at 1,999,855 barrels per day making Nigeria the largest oil producer in Africa, the seventh largest under OPEC and thirteenth largest in the world. The main sources of oil spill in the Niger Delta are: vandalization of the oil pipelines by the local inhabitants, ageing of the pipelines, oil blow outs from the flow stations, cleaning of oil tankers on the high sea, disposal of used oil into the drains by the road side mechanics, tanker accidents, ballast water discharge, etc. The harmful effects of oil spill on living aquatic resources cannot be overemphasized. Oil kills plants and animals in the estuarine zone. Oil settles on beaches and kills organisms that live there; it also settles on ocean floor and kills benthic (bottom-dwelling) organisms such as crabs. Oil poisons algae, disrupts major food chains and decreases the yield of edible crustaceans. It also coats birds, impairing their flight or reducing the insulative property of their feathers, thus making the birds more vulnerable to cold. It affects the essential organs of aquatic mammals, reptiles and amphibians. Oil endangers fish hatcheries in coastal waters and contaminates the flesh of commercially valuable fish. Regulations should be put in place to maintain oil spill free exploration and exploitation. Recommendations have been given, however, to make the region to be habitable.
Journal of Aquatic Science and Marine Biology , 2018
The effect of different stocking densities of hybrid catfish (Heteroclarias) on plankton abundanc... more The effect of different stocking densities of hybrid catfish (Heteroclarias) on plankton abundance in tarpaulin tanks was studied for a period of six (6) months (January – June 2016). The study employed Complete Randomized Design (CRD) experimental design. Five different stocking densities (treatments) were employed (T1 = 100fish/m2, T2 = 75fish/m2, T3 = 38fish/m2, T4 = 18fish/m2and T5 = 9fish/m2). These were replicated three times. Filtration technique was employed. Mesh size plankton net (25µm) was used to filter 10L depth integrated water samples. The water samples (net content) were emptied into a wide mouth plastic container and preserved in 5% formalin solution after proper labeling. The samples were then taken to the laboratory and were allowed to stand for at least 24hrs in the laboratory for the plankton to settle. The samples were pipetted (1ml sample) with sample pipette. The content was placed in a Sedgewick-Rafter plankton-counting chamber and examined under a magnification of 500× and 1000×. The plankton were identified, enumerated and total number of species were also recorded using keys and check lists. For phytoplankton, a total of eighty-three (83) species belonging to six (6) taxonomic groups were observed in the experimental tanks. Bacillariophyceae occurred highest and was represented by thirty-six (36) species. Chrysophyceae and xanthophyceae occurred least with one (1) species respectively. For zooplankton, a total of twenty (20) species belonging to four (4) taxa were identified during the study. Cladocera occurred highest with nine (9) species, while protozoa occurred least with two (2) species. T5 (9fish/m2) had the highest abundance of phytoplankton and zooplankton. T1 (100fish/m2) had the least abundance of phytoplankton and T2 (75fish/m2) had the lowest abundance of zooplankton. Therefore, a stocking density of 9fish/m2 of heteroclarias is optimal and is recommended in order to maintain better plankton presence and good environmental condition.
International Journal of Agriculture, Environment and Bioresearch , Oct 2017
Proximate composition of cultured and wild samples of catfish Clarias gariepinus were studied usi... more Proximate composition of cultured and wild samples of catfish Clarias gariepinus were studied using standard methods. Five (5) samples each of table-sized cultured and wild C. gariepinus were used for determining proximate composition. The cultured C. gariepinus was higher than the wild sample (P<0.05) in crude protein, carbohydrate and energy, while crude fibre, fat, ash and moisture content was higher in the wild samples. There was no significant difference (P>0.05) in the carbohydrate content between wild and cultured C. gariepinus, however other proximate parameters showed significant variation (P<0.05) between cultured and wild C. gariepinus. The species is recommended as a good source of minerals.
The majority of consumer products used today is composed of some form of plastic. Worldwide, almo... more The majority of consumer products used today is composed of some form of plastic. Worldwide, almost 280 million tons of plastic materials are produced annually, much of which end up in landfill or the oceans. Plastics are produced by the conversion of natural products or by synthesis from primary chemicals, generally from oil, natural gas or coal. In contemporary society, plastic has attained a pivotal status, with extensive commercial, industrial, medicinal and municipal applications. It affects at least 267 species worldwide, including 86% of all sea turtle species, 44% of all seabird species, and 43% of all marine mammal species. Marine animals are harmed mostly through ingestion, entanglement and subsequently strangulation. Ingested plastics debris has been found to reduce stomach capacity, hinder growth, cause internal injuries and create intestinal blockage. Plastics entanglement with nets or other materials can result in strangulation, reduction of feeding efficiency, and even drowning. Plastics pollution facilitates the transport of species to other regions, alien species hitchhike on floating debris and invade new ecosystem thereby causing a shift in species composition or even extinction of other species. Legislation, prohibiting the disposal of plastics in the sea, introducing of biodegradable plastics, recycling of plastics and public awareness campaigns to discourage littering are various ways in which this problem can be minimized. Other remedial measures include enforcing environmental laws, development of indigenous and homegrown knowledge for plastic waste management and development and implementation of quality standards for all plastic recycled products.
In fish farming, feeding rate is an important factor affecting the growth of fish, and thus deter... more In fish farming, feeding rate is an important factor affecting the growth of fish, and thus determining the optimal feeding rate is important to the success of any aquaculture operation. This study which lasted for 99 days investigated the effect of varying feeding rates on the growth response of African catfish, Clarias gariepinus fingerlings. One hundred and eighty fingerlings were randomly distributed into nine experimental tanks giving 20 fingerlings per tank with an initial weight of 5.92±0.006 g. Three feeding rates were employed as treatments – 3%, 5%, and 7% of fresh body weight, with three replicates per treatment. The fishes were fed three times daily with commercial feed (Aller-aqua) of 42% crude protein. Growth and water quality parameters were measured fortnightly and feed ration adjusted according to the biomass in each tank. Results show that Final Mean Weight, Mean Weight Gain, Specific Growth Rate, Performance Index and Protein Efficiency Ratio were significantly hi...
Analysis of Nanoplastics and Microplastics in Food, 2020
The majority of consumer products used today is composed of some form of plastic. Worldwide, almo... more The majority of consumer products used today is composed of some form of plastic. Worldwide, almost 280 million tons of plastic materials are produced annually, much of which end up in landfill or the oceans. Plastics are produced by the conversion of natural products or by synthesis from primary chemicals, generally from oil, natural gas or coal. In contemporary society, plastic has attained a pivotal status, with extensive commercial, industrial, medicinal and municipal applications. It affects at least 267 species worldwide, including 86% of all sea turtle species, 44% of all seabird species, and 43% of all marine mammal species. Marine animals are harmed mostly through ingestion, entanglement and subsequently strangulation. Ingested plastics debris has been found to reduce stomach capacity, hinder growth, cause internal injuries and create intestinal blockage. Plastics entanglement with nets or other materials can result in strangulation, reduction of feeding efficiency, and even drowning. Plastics pollution facilitates the transport of species to other regions, alien species hitchhike on floating debris and invade new ecosystem thereby causing a shift in species composition or even extinction of other species. Legislation, prohibiting the disposal of plastics in the sea, introducing of biodegradable plastics, recycling of plastics and public awareness campaigns to discourage littering are various ways in which this problem can be minimized. Other remedial measures include enforcing environmental laws, development of indigenous and homegrown knowledge for plastic waste management and development and implementation of quality standards for all plastic recycled products.
World Journal of Advanced Research and Reviews, 2021
Delonix regia is commonly called Flamboyant or flame of the forest. The seeds were fermented, boi... more Delonix regia is commonly called Flamboyant or flame of the forest. The seeds were fermented, boiled, sundried and then ground into powdered meal. 40% crude protein based test diets containing Delonix regia seed meal D0 = 0%; D15 = 15%; D20 = 20% and D25 = 25% inclusion levels respectively were prepared. Red tilapia (Oreochromis niloticus) fingerlings of 6 weeks old were acclimatized for two weeks and then stocked in 12 hapas at 15 fish per hapa measuring 0.6 m × 1.2 m × 0.7 m placed in a concrete tank. Each diet was assigned to fish in a separate hapa in triplicate and administered at 3% fish body weight per day for 16 weeks. Fish weight and length were taken initially, bi-weekly and terminally. Water quality was monitored weekly. Number of fish at the end was recorded and survival rate, growth, feed utilization, fillet yield and blood parameters were determined. The data were subjected to the analysis of variance and mean separation (P= 0.05). Survival rate was highest in fish rai...
Aquaculture is the rearing of fish and other aquatic organisms in man-made ponds, reservoirs, cag... more Aquaculture is the rearing of fish and other aquatic organisms in man-made ponds, reservoirs, cages or other enclosures in lakes and coastal waters[1]. Aquaculture practices in Nigeria have increased drastically as seen in other parts of the world because of the increasing demand on fish protein. FAO[2] report shows that global total fisheries production (excluding aquatic plants) reached 167.2 million tonnes in 2014, with 93.4 (55.86%) million tonnes from capture and 73.8 (44.14%) million tonnes from aquaculture. Nigeria accounted for 0.42% of global aquaculture production in 2014 [2]. In Nigeria, getting fast growing fish seed have been a major problem to farmers targeting high yields. Hybrid catfish production has increased rapidly in the last few years and apparently market demand is still increasing. Among the culturable finfish in Nigeria, catfish is the most sought after fish species, very popular with fish farmers and consumers; it commands very good commercial value in Nige...
Fish is a vital source of animal protein for many households. World per capita fish consumption h... more Fish is a vital source of animal protein for many households. World per capita fish consumption had risen from 9.9 kg in 1960s, and 14.4 kg in 1990s to 20 kg of animal protein intake in 2014 [1]. The vigorous growth in aquaculture, which according to FAO [1] now provides half of all fish for human consumption, is attributed to improvement in the state of the fish stock and fisheries management. According to the report, aquaculture marginally supplied 7% of fish for human consumption in 1974, which increased to 26% in 1994, and 39% in 2004 but in 2014 the total contribution of aquaculture to total global fish production rose to 44.1% [1].
Cost-effectiveness, food utilization and proximate composition of Clarias gariepinus fingerlings ... more Cost-effectiveness, food utilization and proximate composition of Clarias gariepinus fingerlings fed locally formulated (sinking) and commercial (floating) diets in tarpaulin tanks were observed for 56 days. Ninety (90) C. gariepinus fingerlings with initial mean weight (72.99 g ± 3.09) per treatment were observed during the period with three replicates at a stocking density of 15 fish per m2. The fish were fed 5% body weight three times daily. Results showed that C. gariepinus fingerlings fed floating diet had significantly lower (p<0.05) feed conversion ratio (0.83 ± 0.03) than sinking diet (3.23 ± 0.40). Protein efficiency ratio was significantly (p<0.05) higher in fish fed commercial diet (2.69 ± 0.09) than locally formulated (0.80 ± 0.11). Specific growth rate was significantly (p<0.05) higher in floating (3.29 ± 0.07) than sinking diet (0.97 ± 0.20). Incidence cost was lower (₦1,989.65) in fish fed commercial diet than locally formulated (₦3,819.63). The profit index ...
Growth, feed utilization and survival of African catfish (Clarias gariepinus, Burchell 1822) rear... more Growth, feed utilization and survival of African catfish (Clarias gariepinus, Burchell 1822) reared in earthen ponds using hydrated lime and calcium carbide lime as the liming materials were studied for 24 weeks. Three treatments – hydrated lime ponds, calcium carbide lime ponds and control ponds were used in three replicates. Each pond was stocked with 300 fingerlings at an average weight of 26 g. fish were fed 4% body weight. Growth parameters and feed utilization were estimated. Some water quality parameters – dissolved oxygen, pH, temperature, alkalinity, hardness, nitrate, nitrite and ammonia were monitored bi-weekly using standard analytical procedures. Results show that there was no significant difference (p>0.05) in the levels of ammonia and temperature of the water among the treatments but significant difference (p<0.05) were recorded in the levels of total alkalinity, pH, nitrate, nitrite, and hardness values among treatment ponds. The mean weight gain of the fish were 824 g for the control ponds, 661 g for the calcium carbide lime ponds, while fish in the hydrated lime ponds had the least weight gain value of 551 g. Specific growth rate (SGR) among the treatments were 2.08, 1.93 and 1.85 for control ponds, calcium carbide lime ponds and hydrated lime ponds respectively. Food conversion ratio (FCR) was 3.21 for control ponds, 3.11 for calcium carbide lime pond and 2.49 for the hydrated lime ponds. The survival rate was 92.33%, 89.84% and 78.00% respectively for calcium carbide lime ponds, control ponds and hydrated lime ponds. The heavy metal contents on fresh weight basis among the treatment varied significantly from each other (p<0.05). The poor growth, feed utilization and survival rate obtained in hydrated lime ponds may be attributed to the heavy metal contents of the lime. The best growth and feed utilization values were obtained for fish in control ponds. However, values obtained for fish in the calcium carbide lime ponds were satisfactory. From this study, calcium carbide lime can be recommended for use by fish farmers.
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Papers by Gift S David
Keywords: Sand mining, physico-chemical parameters, stations, DO, Ikot Ekpan River.
bones, liver and other vital organs. Long term exposure may result in slowly progressing physical, muscular, and
Alzheimer’s disease, Parkinson’s disease, muscular dystrophy, and multiple sclerosis. Allergies are not
uncommon and repeated long term contact with some metals or their compounds may even cause cancer. Heavy metal toxicity is a chemically significant condition when it does occur. If unrecognized or inappropriately treated, toxicity can result in significant illness and reduced quality of life which can ultimately result in death. Recommended strategies to combat this menace involves environmental legislation, holistic planning, technological measures to improve the quality of waste discharges and environmental monitoring programs.
Keywords: Heavy metals, fish, human health, contamination.
Key words: Growth performance, feed utilization, Heterobranchus bidorsalis, Delonix regia
Key words: Hybrid catfish, Heteroclarias, stocking density, feeding level, haematology, blood profile
recommended for raising catfish at reduced cost of production.
Key words: Heteroclarias, hybrid catfish, feeding level, growth performance, nutrient utilization, survival
Keywords: Benthos, distribution, abundance, Douglas creek, Maxillopoda, Gammarus lacustris
Keywords: Stocking density, feeding level, heteroclarias, hybrid catfish, specific growth rate
plastic container and preserved in 5% formalin solution after proper labeling. The samples were then taken to the laboratory and were allowed to stand for at least 24hrs in the laboratory for the plankton to settle. The samples were pipetted (1ml sample) with sample pipette. The content was placed in a Sedgewick-Rafter plankton-counting chamber and examined under a magnification of 500× and 1000×.
The plankton were identified, enumerated and total number of species were also recorded using keys and check lists. For phytoplankton, a total of eighty-three (83) species belonging to six (6) taxonomic groups were observed in the experimental tanks. Bacillariophyceae occurred highest and was represented by thirty-six (36) species. Chrysophyceae and xanthophyceae occurred least with one (1) species respectively. For zooplankton, a total of twenty (20) species belonging to four (4) taxa were identified during the study.
Cladocera occurred highest with nine (9) species, while protozoa occurred least with two (2) species. T5 (9fish/m2) had the highest abundance of phytoplankton and zooplankton. T1 (100fish/m2) had the least abundance of phytoplankton and T2 (75fish/m2) had the lowest abundance of zooplankton. Therefore, a stocking density of 9fish/m2 of heteroclarias is optimal and is recommended in order to maintain better plankton presence and good environmental condition.
Keywords: Sand mining, physico-chemical parameters, stations, DO, Ikot Ekpan River.
bones, liver and other vital organs. Long term exposure may result in slowly progressing physical, muscular, and
Alzheimer’s disease, Parkinson’s disease, muscular dystrophy, and multiple sclerosis. Allergies are not
uncommon and repeated long term contact with some metals or their compounds may even cause cancer. Heavy metal toxicity is a chemically significant condition when it does occur. If unrecognized or inappropriately treated, toxicity can result in significant illness and reduced quality of life which can ultimately result in death. Recommended strategies to combat this menace involves environmental legislation, holistic planning, technological measures to improve the quality of waste discharges and environmental monitoring programs.
Keywords: Heavy metals, fish, human health, contamination.
Key words: Growth performance, feed utilization, Heterobranchus bidorsalis, Delonix regia
Key words: Hybrid catfish, Heteroclarias, stocking density, feeding level, haematology, blood profile
recommended for raising catfish at reduced cost of production.
Key words: Heteroclarias, hybrid catfish, feeding level, growth performance, nutrient utilization, survival
Keywords: Benthos, distribution, abundance, Douglas creek, Maxillopoda, Gammarus lacustris
Keywords: Stocking density, feeding level, heteroclarias, hybrid catfish, specific growth rate
plastic container and preserved in 5% formalin solution after proper labeling. The samples were then taken to the laboratory and were allowed to stand for at least 24hrs in the laboratory for the plankton to settle. The samples were pipetted (1ml sample) with sample pipette. The content was placed in a Sedgewick-Rafter plankton-counting chamber and examined under a magnification of 500× and 1000×.
The plankton were identified, enumerated and total number of species were also recorded using keys and check lists. For phytoplankton, a total of eighty-three (83) species belonging to six (6) taxonomic groups were observed in the experimental tanks. Bacillariophyceae occurred highest and was represented by thirty-six (36) species. Chrysophyceae and xanthophyceae occurred least with one (1) species respectively. For zooplankton, a total of twenty (20) species belonging to four (4) taxa were identified during the study.
Cladocera occurred highest with nine (9) species, while protozoa occurred least with two (2) species. T5 (9fish/m2) had the highest abundance of phytoplankton and zooplankton. T1 (100fish/m2) had the least abundance of phytoplankton and T2 (75fish/m2) had the lowest abundance of zooplankton. Therefore, a stocking density of 9fish/m2 of heteroclarias is optimal and is recommended in order to maintain better plankton presence and good environmental condition.