Kappaphycus spp. and Eucheuma denticulatum are commercially farmed in the world, notably in tropical countries such as Indonesia, Philippines, and Malaysia. Diseases and pests, particularly ice-ice disease, are the major hurdles in the sustainability of eucheumatoid seaweed culture. In this study, ice-ice disease prevalence in Kappaphycus and Eucheuma farms in Sibutu, Tawi-Tawi, Philippines, was assessed and compared according to species, farm depth, and time. Results revealed that in deep water farms, ice-ice disease prevalence was significantly lower in K. striatus (4.29±0.97%) than in K. alvarezii (10.53±2.64%) in July. In shallow water farms, E. denticulatum had the highest ice-ice prevalence (21.97±1.73%) significantly among the assessed seaweed species during August, and K. alvarezii had the lowest ice-ice disease occurrence (5.43±1.98%) significantly during September. In terms of depth water farm and time comparison, ice-ice disease prevalence (7.41±1.50% - 27.04±4.66%) in deep water (exceeding 2.47±0.16 m during low tide) did not differ significantly from that prevalence (11.35±1.69% - 12.91±1.93%) in shallow water farms (0.61±0.29 m during low tide) across time. This study suggests that ice-ice disease is still a prevalent and persistent problem in eucheumatoid seaweed farming.
{"title":"Prevalence of Ice-Ice Disease in Kappaphycus spp. and Eucheuma denticulatum Farms in Sibutu, Tawi-Tawi, Philippines","authors":"Albaris B. Tahiluddin, Samiya U. Damsik","doi":"10.4194/aquast1137","DOIUrl":"https://doi.org/10.4194/aquast1137","url":null,"abstract":"Kappaphycus spp. and Eucheuma denticulatum are commercially farmed in the world, notably in tropical countries such as Indonesia, Philippines, and Malaysia. Diseases and pests, particularly ice-ice disease, are the major hurdles in the sustainability of eucheumatoid seaweed culture. In this study, ice-ice disease prevalence in Kappaphycus and Eucheuma farms in Sibutu, Tawi-Tawi, Philippines, was assessed and compared according to species, farm depth, and time. Results revealed that in deep water farms, ice-ice disease prevalence was significantly lower in K. striatus (4.29±0.97%) than in K. alvarezii (10.53±2.64%) in July. In shallow water farms, E. denticulatum had the highest ice-ice prevalence (21.97±1.73%) significantly among the assessed seaweed species during August, and K. alvarezii had the lowest ice-ice disease occurrence (5.43±1.98%) significantly during September. In terms of depth water farm and time comparison, ice-ice disease prevalence (7.41±1.50% - 27.04±4.66%) in deep water (exceeding 2.47±0.16 m during low tide) did not differ significantly from that prevalence (11.35±1.69% - 12.91±1.93%) in shallow water farms (0.61±0.29 m during low tide) across time. This study suggests that ice-ice disease is still a prevalent and persistent problem in eucheumatoid seaweed farming.","PeriodicalId":36343,"journal":{"name":"Aquaculture Studies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44733774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The optimizing stocking density for biofloc technology is essential for improving fish growth and profitability of aquaculture. The treatments consisted of different stocking density of 125, 250, 375, and 500 common carp (Cyprinus carpio) fish/m3. Fish with an initial average weight of 17.10±0.3 g were fed three times per day in triplicates for 40 days with a commercial diet (25% crude protein), and the ratio of carbon to nitrogen 20 in each treatment. The water nitrogen substances enhanced by increased stocking density (P<0.05). The final growth (-19.75%), whole-body protein (-2.84%), lipid content (-7.27%) significantly decreased, and food conversion ratio (+67.29%) increased in the treatment of 500 fish/m3 compared to the treatment of 250 fish/m3 (P<0.05). Serum glucose (-11.09%), triglycerides (-11.24%), high-density lipoprotein (-26.16%), and low-density lipoprotein (-31.98%) levels significantly reduced, but serum cortisol concentrations (+13.08%) and, liver enzymes increased in the treatment of 500 fish/m3 compared to the treatment of 250 fish/m3 (P<0.05). Total protein (-9.01%), globulin (-12.80%), ACH50 (-4.97%), and lysozyme activity (-9.21%) significantly reduced in the treatment of 500 fish/m3 compared to the treatment of 250 fish/m3 (P<0.05). The best performance of fish was observed at stocking density up to 250 fish/m3 in the biofloc system.
{"title":"Optimizing Stocking Density in Biofloc Culture of Juvenile Common Carp (Cyprinus carpio) Using Growth and Immune-biochemical Indices as Indicators","authors":"S. Nazarpour, H. Mohammadiazarm","doi":"10.4194/aquast1223","DOIUrl":"https://doi.org/10.4194/aquast1223","url":null,"abstract":"The optimizing stocking density for biofloc technology is essential for improving fish growth and profitability of aquaculture. The treatments consisted of different stocking density of 125, 250, 375, and 500 common carp (Cyprinus carpio) fish/m3. Fish with an initial average weight of 17.10±0.3 g were fed three times per day in triplicates for 40 days with a commercial diet (25% crude protein), and the ratio of carbon to nitrogen 20 in each treatment. The water nitrogen substances enhanced by increased stocking density (P<0.05). The final growth (-19.75%), whole-body protein (-2.84%), lipid content (-7.27%) significantly decreased, and food conversion ratio (+67.29%) increased in the treatment of 500 fish/m3 compared to the treatment of 250 fish/m3 (P<0.05). Serum glucose (-11.09%), triglycerides (-11.24%), high-density lipoprotein (-26.16%), and low-density lipoprotein (-31.98%) levels significantly reduced, but serum cortisol concentrations (+13.08%) and, liver enzymes increased in the treatment of 500 fish/m3 compared to the treatment of 250 fish/m3 (P<0.05). Total protein (-9.01%), globulin (-12.80%), ACH50 (-4.97%), and lysozyme activity (-9.21%) significantly reduced in the treatment of 500 fish/m3 compared to the treatment of 250 fish/m3 (P<0.05). The best performance of fish was observed at stocking density up to 250 fish/m3 in the biofloc system.","PeriodicalId":36343,"journal":{"name":"Aquaculture Studies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45987632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-15DOI: 10.4194/sofas_book_of_proceedings_2022
{"title":"International Symposium on Fisheries and Aquatic Sciences - Book of Proceedings 2022","authors":"","doi":"10.4194/sofas_book_of_proceedings_2022","DOIUrl":"https://doi.org/10.4194/sofas_book_of_proceedings_2022","url":null,"abstract":"","PeriodicalId":36343,"journal":{"name":"Aquaculture Studies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44901024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Benard Maranga, R. Kagali, K. Mbogo, P. Orina, J. Munguti, E. Ogello
Cost of fish production can be reduced by replacement of high-priced fishmeal (FM) with insects sourced ingredients. Four months feed experiment was conducted at a fish farm in Baringo County, Kenya to investigate effects of substituting fishmeal (FM) with black soldier fly larvae meal (BSFLM) on survival and growth performance of C. gariepinus under aquaponic system. Three test diets 35% crude protein content (CP) in which FM was substituted by BSFLM at 25%, 50% and 75% were formulated and experimented with commercial diet of 35% CP. Four weeks old C. gariepinus were stocked in 12 tanks at a density of 50 fish/tank and subjected to the diets. Fish were sampled every three weeks; water parameters were sampled weekly and mortality recorded on occurrence. Diet with 50% BSFLM obtained better FCR for formulated diets with no significance (P<0.05) for FCR and survival. Weight gain of control diet (97.07 g) was significant (P<0.05) compared to formulated diets 64.09g, 69.78g and 67.77g for 75%, 50% and 25% of BSFL replacement respectively. Growth performance and survival demonstrated that BSFLM has potential to substitute FM up to 75%. The fish productivity can be improved and feed cost reduced by incorporating fully defatted BSFLM with CP higher than 25.3% used for the diets.
{"title":"Growth Performance of African Catfish (Clarias Gariepinus) Fed on Diets Containing Black Soldier Fly (Hermetia Illucens) Larvae Under Aquaponic System","authors":"Benard Maranga, R. Kagali, K. Mbogo, P. Orina, J. Munguti, E. Ogello","doi":"10.4194/aquast910","DOIUrl":"https://doi.org/10.4194/aquast910","url":null,"abstract":"Cost of fish production can be reduced by replacement of high-priced fishmeal (FM) with insects sourced ingredients. Four months feed experiment was conducted at a fish farm in Baringo County, Kenya to investigate effects of substituting fishmeal (FM) with black soldier fly larvae meal (BSFLM) on survival and growth performance of C. gariepinus under aquaponic system. Three test diets 35% crude protein content (CP) in which FM was substituted by BSFLM at 25%, 50% and 75% were formulated and experimented with commercial diet of 35% CP. Four weeks old C. gariepinus were stocked in 12 tanks at a density of 50 fish/tank and subjected to the diets. Fish were sampled every three weeks; water parameters were sampled weekly and mortality recorded on occurrence. Diet with 50% BSFLM obtained better FCR for formulated diets with no significance (P<0.05) for FCR and survival. Weight gain of control diet (97.07 g) was significant (P<0.05) compared to formulated diets 64.09g, 69.78g and 67.77g for 75%, 50% and 25% of BSFL replacement respectively. Growth performance and survival demonstrated that BSFLM has potential to substitute FM up to 75%. The fish productivity can be improved and feed cost reduced by incorporating fully defatted BSFLM with CP higher than 25.3% used for the diets.","PeriodicalId":36343,"journal":{"name":"Aquaculture Studies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42427460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Ajadi, T. Jarikre, Afusat Jagun Jibril, B. Emikpe
The present study was carried out to determine the protective effects of two dietary plants and the associated pathology in African catfish exposed to A. hydrophila. Four hundred and twenty fish with average weight of 20.53±0.15 g were distributed equally (in triplicates) into seven experimental groups (six treatment groups and a control group) with 20 juvenile African catfish in each aquarium. Fish were fed for 84 days with control and six other experimental diets containing different percentages of Alstonia boonei (0.5%,1.0% and 1.5%) and Mitracarpus scaber (0.5%,1.0% and 1.5%) of the basal diets. At the end of 12th week, the fish were challenged with A. hydrophila and clinical signs and mortality rate were observed for fourteen days, post challenge. Blood and tissue samples were collected for analysis. All the groups fed with plant supplemented feed had 100% survival rate except A. boonei (0.5%) with 85% and control had 70% survival rate. The dietary plants also improved the haematological parameters and reduced the histopathological lesions associated with A. hydrophila exposure, compared to the control. These findings have demonstrated the protective potentials of A. boonei and M. scaber inculcated in feed against A. hydrophila infection in African catfish.
{"title":"Protective Evaluation of Feed Fortified with Alstonia Boonei and Mitracarpus Scaber in African Catfish Exposed to Aeromonas Hydrophila: Clinicopathology and Immunohistochemistry","authors":"A. Ajadi, T. Jarikre, Afusat Jagun Jibril, B. Emikpe","doi":"10.4194/aquast1007","DOIUrl":"https://doi.org/10.4194/aquast1007","url":null,"abstract":"The present study was carried out to determine the protective effects of two dietary plants and the associated pathology in African catfish exposed to A. hydrophila. Four hundred and twenty fish with average weight of 20.53±0.15 g were distributed equally (in triplicates) into seven experimental groups (six treatment groups and a control group) with 20 juvenile African catfish in each aquarium. Fish were fed for 84 days with control and six other experimental diets containing different percentages of Alstonia boonei (0.5%,1.0% and 1.5%) and Mitracarpus scaber (0.5%,1.0% and 1.5%) of the basal diets. At the end of 12th week, the fish were challenged with A. hydrophila and clinical signs and mortality rate were observed for fourteen days, post challenge. Blood and tissue samples were collected for analysis. All the groups fed with plant supplemented feed had 100% survival rate except A. boonei (0.5%) with 85% and control had 70% survival rate. The dietary plants also improved the haematological parameters and reduced the histopathological lesions associated with A. hydrophila exposure, compared to the control. These findings have demonstrated the protective potentials of A. boonei and M. scaber inculcated in feed against A. hydrophila infection in African catfish.","PeriodicalId":36343,"journal":{"name":"Aquaculture Studies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44765564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Jara, L. Freites, M. Gregori, A. Márquez, D. Rodríguez‐Pesantes, J. Villon, L. Troccoli, C. Lodeiros
This study evaluated the performance of P. sterna under suspended culture at three depths (2, 6, and 10 m). Juveniles (dorso-ventral length 42.6±0.94 mm) were placed in enclosures suspended on a long line in Palmar (Ecuador) from October 2018 to October 2019. The antero-posterior axis of the shells, the shell, softs tissues, and biofouling masses, and the survival rate, were determined during one year of culture. Chlorophyll-a, total particulate matter (TPM), particulate organic matter (POM), salinity and temperature were studied at each depth. At the end of the cultivation period, growth and survival rates did not show significant differences between water depths, with all oysters attaining dorso-ventral lengths of 102-106 mm. Principal components analysis (PCA) revealed a direct and significant relationship between the variance of soft tissue dry mass growth and chlorophyll a concentration, salinity, particulate organic matter (POM) concentration, and temperature, during the culture period evaluated. Thus, the results obtained indicate that the suspended culture of the winged oyster P. sterna in Ecuador can be carried out effectively within the range of 2 and 10 m of depth, obtaining relatively high yields (growth-survival).
{"title":"Performance of the Winged Pearl Oyster Pteria sterna (Gould, 1851), Maintained in Hanging Culture at Three Depths, in the Eastern Equatorial Pacific","authors":"F. Jara, L. Freites, M. Gregori, A. Márquez, D. Rodríguez‐Pesantes, J. Villon, L. Troccoli, C. Lodeiros","doi":"10.4194/aquast926","DOIUrl":"https://doi.org/10.4194/aquast926","url":null,"abstract":"This study evaluated the performance of P. sterna under suspended culture at three depths (2, 6, and 10 m). Juveniles (dorso-ventral length 42.6±0.94 mm) were placed in enclosures suspended on a long line in Palmar (Ecuador) from October 2018 to October 2019. The antero-posterior axis of the shells, the shell, softs tissues, and biofouling masses, and the survival rate, were determined during one year of culture. Chlorophyll-a, total particulate matter (TPM), particulate organic matter (POM), salinity and temperature were studied at each depth. At the end of the cultivation period, growth and survival rates did not show significant differences between water depths, with all oysters attaining dorso-ventral lengths of 102-106 mm. Principal components analysis (PCA) revealed a direct and significant relationship between the variance of soft tissue dry mass growth and chlorophyll a concentration, salinity, particulate organic matter (POM) concentration, and temperature, during the culture period evaluated. Thus, the results obtained indicate that the suspended culture of the winged oyster P. sterna in Ecuador can be carried out effectively within the range of 2 and 10 m of depth, obtaining relatively high yields (growth-survival).","PeriodicalId":36343,"journal":{"name":"Aquaculture Studies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43257366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Abdullahi, J. Auta, S. Abdullahi, Paul Ibukun-Olu Bolorunduro, H. U. Onimisi
This study evaluated the effect of replacing Glycine max with processed Lemna paucicostata on haematological parameters and enzyme activity of Oreochromis niloticus. The processing methods employed were blanching and sun-drying. Nine diets (D1-D9) were formulated using the least cost feed formulation software. Soybean meal was replaced by blanched and sun-dried L. paucicostata at 25%, 50%, 75% and 100% each. 27 nets measuring 1m2 each were used in outdoor concrete ponds of 5m x 3.5m (l × b) and depth of 1.5m each. Ten fingerlings of O. niloticus were stocked per Hapa and fed three times daily at 5% body weight. The fish fed 75% blanched L. paucicostata obtained the best concentration of the packed cell volume (32.01%) in the blood while a poor concentration of 27.01% was observed in the fish fed 100% blanched L. paucicostata. The fish fed 75% blanched L. paucicostata and 50% blanched L. paucicostata gave higher total enzyme activities of 4,675.13(TU) and 4,648.06(TU), respectively. While the fish fed 100% blanched L. paucicostata gave the lowest value of 3,558.33(TU). The digestive enzyme activities were observed to be the main factors that helped the experimental fish to digest the blanched and sun-dried Lemna paucicostata efficiently.
{"title":"Blood Chemistry and Enzyme Activity of Oreochromis niloticus (Linnaeus, 1758) Fed Dietary Processed Lemna paucicostata (Hegelm) as a Replacement for Soybean Meal","authors":"A. Abdullahi, J. Auta, S. Abdullahi, Paul Ibukun-Olu Bolorunduro, H. U. Onimisi","doi":"10.4194/aquast1128","DOIUrl":"https://doi.org/10.4194/aquast1128","url":null,"abstract":"This study evaluated the effect of replacing Glycine max with processed Lemna paucicostata on haematological parameters and enzyme activity of Oreochromis niloticus. The processing methods employed were blanching and sun-drying. Nine diets (D1-D9) were formulated using the least cost feed formulation software. Soybean meal was replaced by blanched and sun-dried L. paucicostata at 25%, 50%, 75% and 100% each. 27 nets measuring 1m2 each were used in outdoor concrete ponds of 5m x 3.5m (l × b) and depth of 1.5m each. Ten fingerlings of O. niloticus were stocked per Hapa and fed three times daily at 5% body weight. The fish fed 75% blanched L. paucicostata obtained the best concentration of the packed cell volume (32.01%) in the blood while a poor concentration of 27.01% was observed in the fish fed 100% blanched L. paucicostata. The fish fed 75% blanched L. paucicostata and 50% blanched L. paucicostata gave higher total enzyme activities of 4,675.13(TU) and 4,648.06(TU), respectively. While the fish fed 100% blanched L. paucicostata gave the lowest value of 3,558.33(TU). The digestive enzyme activities were observed to be the main factors that helped the experimental fish to digest the blanched and sun-dried Lemna paucicostata efficiently.","PeriodicalId":36343,"journal":{"name":"Aquaculture Studies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45708166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fish mortality has a significant impact on fish production by lowering fish productivity, causing an economic loss to the farmers, and also has a cost in terms of reduced fish health, thereby limiting the growth of the enterprise. A cross-sectional study was carried out to determine the impact of biosecurity measures and risk factors on the mortality of fish from fish farms. A structured questionnaire that focused on socioeconomic information, management practice, health, disease, and biosecurity measures was administered to fish farmers. A total of eighty fish farmers were involved in this study. Most of the fish farmers were male (70.00%), had tertiary education qualifications (60.00%), and were between the ages of 41 and 50 (37.50%). They had been engaged in fish farming for about 1-3 years (48.75%) and they combined it with poultry production. Varying mortality rates were recorded on the farm and the recorded mortality was associated with management practices, disease, health, and biosecurity measures and they differed significantly at P≤0.05. Fish farmers' practices were generally not in accordance with biosecurity principles. Therefore, it is crucial to create and implement biosecurity measures to prevent, manage, and eliminate the mortality of fish in fish farms.
{"title":"An Assessment of the Impacts of Biosecurity Measures on Mortality of Fish from Fish Farms","authors":"D. Adah, Lawal Saidu, S. J. Oniye, A. Adah","doi":"10.4194/aquast1060","DOIUrl":"https://doi.org/10.4194/aquast1060","url":null,"abstract":"Fish mortality has a significant impact on fish production by lowering fish productivity, causing an economic loss to the farmers, and also has a cost in terms of reduced fish health, thereby limiting the growth of the enterprise. A cross-sectional study was carried out to determine the impact of biosecurity measures and risk factors on the mortality of fish from fish farms. A structured questionnaire that focused on socioeconomic information, management practice, health, disease, and biosecurity measures was administered to fish farmers. A total of eighty fish farmers were involved in this study. Most of the fish farmers were male (70.00%), had tertiary education qualifications (60.00%), and were between the ages of 41 and 50 (37.50%). They had been engaged in fish farming for about 1-3 years (48.75%) and they combined it with poultry production. Varying mortality rates were recorded on the farm and the recorded mortality was associated with management practices, disease, health, and biosecurity measures and they differed significantly at P≤0.05. Fish farmers' practices were generally not in accordance with biosecurity principles. Therefore, it is crucial to create and implement biosecurity measures to prevent, manage, and eliminate the mortality of fish in fish farms.","PeriodicalId":36343,"journal":{"name":"Aquaculture Studies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48779559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Youssra Imane Aissaoui, Dahbia Mokhbi-Soukane, K. Mezouar, S. Soukane
A methodology for aquaculture site selection is presented using a combined hydrodynamic/nutritional model to predict fish farm wastes and dispersion, using the indirect fish waste estimation method, and the numerical model MIKE 21. This method can be used as a basis for assessment of the environmental impact of fish farms. The models were applied for a virtual inland fish farm to harvest 450 tons of sea bass in the west coast of Algeria. The results show that the fish farm effluents quantities and dispersion depends on the production cycle and size, the hydrodynamic parameters, as well as the food quantity and composition. The suspended waste, nitrogen and phosphorus are respectively the main contributors to the fish farm pollution. The current speed varies from 0.005 to 0.045 m/s, while the nitrogen and phosphorus concentrations reached 2.1 mg/L, and 0.03 mg/L respectively. This study allows the Algerian authorities to decide upon delivering fish farming permissions in the studied area, by identifying the suitability of the area for aquaculture, and predicting potential fish farm pollution. The use of numerical models in aquaculture could help reducing installation, water treatment costs and the environmental impact of fish farms by contributing to the sustainability of the activity.
{"title":"Numerical Investigation of the Impact of Onshore Fish Farming on the Western Coast of Algeria","authors":"Youssra Imane Aissaoui, Dahbia Mokhbi-Soukane, K. Mezouar, S. Soukane","doi":"10.4194/aquast934","DOIUrl":"https://doi.org/10.4194/aquast934","url":null,"abstract":"A methodology for aquaculture site selection is presented using a combined hydrodynamic/nutritional model to predict fish farm wastes and dispersion, using the indirect fish waste estimation method, and the numerical model MIKE 21. This method can be used as a basis for assessment of the environmental impact of fish farms. The models were applied for a virtual inland fish farm to harvest 450 tons of sea bass in the west coast of Algeria. The results show that the fish farm effluents quantities and dispersion depends on the production cycle and size, the hydrodynamic parameters, as well as the food quantity and composition. The suspended waste, nitrogen and phosphorus are respectively the main contributors to the fish farm pollution. The current speed varies from 0.005 to 0.045 m/s, while the nitrogen and phosphorus concentrations reached 2.1 mg/L, and 0.03 mg/L respectively. This study allows the Algerian authorities to decide upon delivering fish farming permissions in the studied area, by identifying the suitability of the area for aquaculture, and predicting potential fish farm pollution. The use of numerical models in aquaculture could help reducing installation, water treatment costs and the environmental impact of fish farms by contributing to the sustainability of the activity.","PeriodicalId":36343,"journal":{"name":"Aquaculture Studies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43454120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Plankton is major food item for Nile tilapia and their availability is one of the most important factors affecting its growth performance in an extensive and semi-intensive pond-based culture systems. Thus, this study aimed to examine plankton composition, abundance, and feeding preference by Nile tilapia reared under a semi-intensive pond-based production system. The experiment was carried out using ponds (10mx15mx1.7m size) fertilized with chicken manure at the rate of 100g/m2/week. Nile tilapia with 7.8g average body weight was stocked at a density of 2 fish/m2. Examination of plankton from both pond water and stomach samples of fish was done using qualitative assessment methods. The results showed that a total of 20 phytoplankton groups were identified following standard identification key. These include four types of Blue-green algae (Cyanophyceae), seven types of Green algae (Chlorophyceae), six Diatoms (Bacillariophyceae), one type of Dinophyceae, and two types of Euglenophyceae. Among the phytoplankton groups, Chlorophyceae was the dominant group with 56% followed by Bacillariophyceae (23%), Cyanophyceae (17%), and Euglenophyceae (3%) while the least was Dinophyceae (1%). The most frequently observed algal genus was Scenedesmus. In addition, three Zooplankton groups namely Copepods (43%), Rotifers (31%) and Cladocerans (26%) were also identified. The result indicated that, the most preferred planktonic groups used by Nile tilapia was green algae, particularly Chlorophyceae followed by Copepoda and Rotifers. The level of chlorophyll `a` was 62.3±2.0 μg/l concentration. The different water quality parameters together with the availability of different plankton were optimal for the growth of Nile tilapia which resulted in a 0.45 specific growth rate. In conclusion, Nile tilapia exhibit preference for green algae, blue-green algae from phytoplankton, and Copepods from zooplankton groups than other groups of plankton.
{"title":"Plankton Composition and Abundance in Semi Intensive Aquaculture Pond and their Preference by Nile tilapia","authors":"Teklay Gebru Tikue, K. B. Workagegn","doi":"10.4194/aquast1032","DOIUrl":"https://doi.org/10.4194/aquast1032","url":null,"abstract":"Plankton is major food item for Nile tilapia and their availability is one of the most important factors affecting its growth performance in an extensive and semi-intensive pond-based culture systems. Thus, this study aimed to examine plankton composition, abundance, and feeding preference by Nile tilapia reared under a semi-intensive pond-based production system. The experiment was carried out using ponds (10mx15mx1.7m size) fertilized with chicken manure at the rate of 100g/m2/week. Nile tilapia with 7.8g average body weight was stocked at a density of 2 fish/m2. Examination of plankton from both pond water and stomach samples of fish was done using qualitative assessment methods. The results showed that a total of 20 phytoplankton groups were identified following standard identification key. These include four types of Blue-green algae (Cyanophyceae), seven types of Green algae (Chlorophyceae), six Diatoms (Bacillariophyceae), one type of Dinophyceae, and two types of Euglenophyceae. Among the phytoplankton groups, Chlorophyceae was the dominant group with 56% followed by Bacillariophyceae (23%), Cyanophyceae (17%), and Euglenophyceae (3%) while the least was Dinophyceae (1%). The most frequently observed algal genus was Scenedesmus. In addition, three Zooplankton groups namely Copepods (43%), Rotifers (31%) and Cladocerans (26%) were also identified. The result indicated that, the most preferred planktonic groups used by Nile tilapia was green algae, particularly Chlorophyceae followed by Copepoda and Rotifers. The level of chlorophyll `a` was 62.3±2.0 μg/l concentration. The different water quality parameters together with the availability of different plankton were optimal for the growth of Nile tilapia which resulted in a 0.45 specific growth rate. In conclusion, Nile tilapia exhibit preference for green algae, blue-green algae from phytoplankton, and Copepods from zooplankton groups than other groups of plankton.","PeriodicalId":36343,"journal":{"name":"Aquaculture Studies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43671060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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