Pub Date : 2022-03-30DOI: 10.33997/j.afs.2022.35.1.007
P. Purwanto, E. Franklin, Ses Rini Mardiani, Alan T. White
This study presents updated stock assessments and risk analyses of overexploitation for the aggregate small pelagic fish complex and the dominant genus of the complex, Decapterus, for improving the management of the small pelagic fishery in Fisheries Management Area (FMA) 715. The analyses herein used non-equilibrium biomass dynamics models with available data on annual catch and catch per unit effort for 2005 to 2016. Fishing effort was standardised into the number of 20-meter length overall purse-seine vessels. The analyses show that the maximum sustainable yield (MSY) of the aggregate fish was about 121,600 tonnes, caught by 876 purse-seiners, while the MSY of the mackerel scad, Decapterus macarellus (Cuvier, 1833), was about 67,900 tonnes, caught by 805 purse-seiners. Since the mackerel scad and the aggregate fish stocks have been overexploited, a rebuilding strategy would be necessary to restore the stocks to a level capable of producing MSY (BMSY). After achieving the BMSY, it is recommended that a target reference point be implemented for the catch level with the maximum overexploitation risk level of 50 % in 10 years. The catch level meeting this requirement for mackerel scad would equal 80 % of its MSY, which could be achieved by controlling fishing effort at 427 purse-seiners. At this effort level, the fishery would produce 95,800 tonnes of aggregate fish catch with 54,300 tonnes of mackerel scad. These reductions in fishing efforts will be needed to maintain the future sustainability of the fish stocks in FMA 715.
{"title":"Stock Assessment and Overexploitation Risk of Small Pelagic Fish in Fisheries Management Area 715 of Indonesia","authors":"P. Purwanto, E. Franklin, Ses Rini Mardiani, Alan T. White","doi":"10.33997/j.afs.2022.35.1.007","DOIUrl":"https://doi.org/10.33997/j.afs.2022.35.1.007","url":null,"abstract":"This study presents updated stock assessments and risk analyses of overexploitation for the aggregate small pelagic fish complex and the dominant genus of the complex, Decapterus, for improving the management of the small pelagic fishery in Fisheries Management Area (FMA) 715. The analyses herein used non-equilibrium biomass dynamics models with available data on annual catch and catch per unit effort for 2005 to 2016. Fishing effort was standardised into the number of 20-meter length overall purse-seine vessels. The analyses show that the maximum sustainable yield (MSY) of the aggregate fish was about 121,600 tonnes, caught by 876 purse-seiners, while the MSY of the mackerel scad, Decapterus macarellus (Cuvier, 1833), was about 67,900 tonnes, caught by 805 purse-seiners. Since the mackerel scad and the aggregate fish stocks have been overexploited, a rebuilding strategy would be necessary to restore the stocks to a level capable of producing MSY (BMSY). After achieving the BMSY, it is recommended that a target reference point be implemented for the catch level with the maximum overexploitation risk level of 50 % in 10 years. The catch level meeting this requirement for mackerel scad would equal 80 % of its MSY, which could be achieved by controlling fishing effort at 427 purse-seiners. At this effort level, the fishery would produce 95,800 tonnes of aggregate fish catch with 54,300 tonnes of mackerel scad. These reductions in fishing efforts will be needed to maintain the future sustainability of the fish stocks in FMA 715.","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46100119","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 : 2022-03-30DOI: 10.33997/j.afs.2022.35.1.009
I. Halid, Harfika Sari Baso
The traditional fixed stake trap made typically of wooden poles and thinly interwoven bamboos walls have been used for generations as fishing gear in coastal regions of South Sulawesi Province, Indonesia. In the 1980s, bamboo slats were replaced with nets of various mesh sizes as they became readily available, and currently, in the research area, no bamboo is used. Each unit of the wooden structure is made of around 300 poles that must be replaced three to four times annually and is becoming difficult due to the scarcity of wood and the high cost. Thus, this research aims to provide a feasible solution using PVC pipes and a suitable size mesh net for sustainable fisheries management of white-spotted spinefoot, Siganus canaliculatus (Park, 1797). The study was done in Karang-karangan village located on the coast of Luwu Regency where white-spotted spinefoot is the main fishing livelihood activity of fishers. The mesh size of the net used was 2.60 cm, and the results showed that the newly designed fixed stake trap unit made of PVC has been durable for the last 2.2 years and is expected to last at least 5 years. Compared to the traditional wood structure, there are no barnacles attached to the PVC pipes. The net size used allows smaller fish below 8.6 cm in length to escape, thus making white-spotted spinefoot fisheries sustainable. The estimated cost of using wood for 5 years is IDR60 million (USD4200), while PVC only requires around IDR15 million (USD1050).
{"title":"Improved Design Fixed Stake Trap With PVC Poles and Suitable Mesh Size Net Enables Sustainable White-Spotted Spinefoot, Siganus canaliculatus (Park, 1797) Fisheries in Luwu District, South Sulawesi","authors":"I. Halid, Harfika Sari Baso","doi":"10.33997/j.afs.2022.35.1.009","DOIUrl":"https://doi.org/10.33997/j.afs.2022.35.1.009","url":null,"abstract":"The traditional fixed stake trap made typically of wooden poles and thinly interwoven bamboos walls have been used for generations as fishing gear in coastal regions of South Sulawesi Province, Indonesia. In the 1980s, bamboo slats were replaced with nets of various mesh sizes as they became readily available, and currently, in the research area, no bamboo is used. Each unit of the wooden structure is made of around 300 poles that must be replaced three to four times annually and is becoming difficult due to the scarcity of wood and the high cost. Thus, this research aims to provide a feasible solution using PVC pipes and a suitable size mesh net for sustainable fisheries management of white-spotted spinefoot, Siganus canaliculatus (Park, 1797). The study was done in Karang-karangan village located on the coast of Luwu Regency where white-spotted spinefoot is the main fishing livelihood activity of fishers. The mesh size of the net used was 2.60 cm, and the results showed that the newly designed fixed stake trap unit made of PVC has been durable for the last 2.2 years and is expected to last at least 5 years. Compared to the traditional wood structure, there are no barnacles attached to the PVC pipes. The net size used allows smaller fish below 8.6 cm in length to escape, thus making white-spotted spinefoot fisheries sustainable. The estimated cost of using wood for 5 years is IDR60 million (USD4200), while PVC only requires around IDR15 million (USD1050).","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43897956","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 : 2022-03-30DOI: 10.33997/j.afs.2022.35.1.008
P. Tu, Albert. V. Manuel, Giang Truong Huynh, N. Tsutsui, T. Yoshimatsu
The increased frequency and intensity of extreme rainfall events attributed to global climate change could lead to changes in salinity and turbidity levels in coastal waters which may negatively impact the survival of organisms, particularly during the early developmental stages. In this study, the influences of salinity and turbidity on the early life stage of Japanese sea cucumber, Apostichopus japonicus (Selenka, 1867), were studied in a series of small-scale laboratory experiments. During the first half of the experiments, A. japonicus fertilised eggs were exposed to various levels of salinity stresses (34: control, 30, 26, 22, 18, 14 PSU) for a single period of 3 h. In the second half of the experiments, following the same duration as the first experiment, fertilised eggs were exposed to different levels of turbidity, 0 (control), 100, 300, 500, and 700 NTU. The results showed that the hatching and survival rates significantly decreased as salinity dropped. As for turbidity, there were significant adverse effects on hatching and survival rates of A. japonicus. This study shows that short-term low salinity and high turbidity influenced events could potentially reduce larvae survival of A. japonicas. These factors could affect the robustness of future adult populations.
{"title":"Impact of Short-Term Salinity and Turbidity Changes on Hatching and Survival Rates of Japanese Sea Cucumber, Apostichopus japonicus (Selenka, 1867), Eggs","authors":"P. Tu, Albert. V. Manuel, Giang Truong Huynh, N. Tsutsui, T. Yoshimatsu","doi":"10.33997/j.afs.2022.35.1.008","DOIUrl":"https://doi.org/10.33997/j.afs.2022.35.1.008","url":null,"abstract":"The increased frequency and intensity of extreme rainfall events attributed to global climate change could lead to changes in salinity and turbidity levels in coastal waters which may negatively impact the survival of organisms, particularly during the early developmental stages. In this study, the influences of salinity and turbidity on the early life stage of Japanese sea cucumber, Apostichopus japonicus (Selenka, 1867), were studied in a series of small-scale laboratory experiments. During the first half of the experiments, A. japonicus fertilised eggs were exposed to various levels of salinity stresses (34: control, 30, 26, 22, 18, 14 PSU) for a single period of 3 h. In the second half of the experiments, following the same duration as the first experiment, fertilised eggs were exposed to different levels of turbidity, 0 (control), 100, 300, 500, and 700 NTU. The results showed that the hatching and survival rates significantly decreased as salinity dropped. As for turbidity, there were significant adverse effects on hatching and survival rates of A. japonicus. This study shows that short-term low salinity and high turbidity influenced events could potentially reduce larvae survival of A. japonicas. These factors could affect the robustness of future adult populations.","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42787987","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 : 2022-03-24DOI: 10.33997/j.afs.2022.35.1.006
S. Ferosekhan, S. K. Sahoo, K. Radhakrishnan, M. Gokulakrishnan, S. S. Giri, B. Pillai
Clarias magur (Hamilton, 1822) is a highly priced commercially important species targeted for aquaculture diversification in India and South-East Asian countries. Weaning from live to formulated feed during larval rearing is critical for successful seed production. Hence, the present study aimed to standardise the effective weaning age to achieve high growth and survival of C. magur. The 4 days post-hatch (dph) larvae with mean initial length and weight of 7.4 ± 0.83 mm and 4.97 ± 0.35 mg, respectively, were selected, and 2100 larvae were randomly stocked into 21 plastic tubs (100 larvae per tub) for six weaning treatments (W4, W7, W9, W11, W13 and W15 dph) and the control in triplicates. The study was conducted for 21 days and 4 to 24 dph. All larvae in the treatments groups were fed Artemia nauplii ad libitum and a weaning diet fed to apparent satiation according to W4 to W15 schedules. The control group larvae were fed with Artemia nauplii alone. Results revealed that final length and weight, weight gain per cent, daily weight gain and specific growth rate were significantly (P < 0.05) higher in the Artemia nauplii fed control group followed by W15 dph larval group. The survival rate was significantly (P < 0.05) higher for W15 larvae, followed by the control group. The present study indicates that the ideal protocol for C. magur larval fed with Artemia nauplii from 4 dph for weaning to formulated diet was at 15 dph until 24 dph for good growth and survival rates.
{"title":"Standardisation of Weaning Protocol for Larvae of Clarias magur (Hamilton, 1822)","authors":"S. Ferosekhan, S. K. Sahoo, K. Radhakrishnan, M. Gokulakrishnan, S. S. Giri, B. Pillai","doi":"10.33997/j.afs.2022.35.1.006","DOIUrl":"https://doi.org/10.33997/j.afs.2022.35.1.006","url":null,"abstract":"Clarias magur (Hamilton, 1822) is a highly priced commercially important species targeted for aquaculture diversification in India and South-East Asian countries. Weaning from live to formulated feed during larval rearing is critical for successful seed production. Hence, the present study aimed to standardise the effective weaning age to achieve high growth and survival of C. magur. The 4 days post-hatch (dph) larvae with mean initial length and weight of 7.4 ± 0.83 mm and 4.97 ± 0.35 mg, respectively, were selected, and 2100 larvae were randomly stocked into 21 plastic tubs (100 larvae per tub) for six weaning treatments (W4, W7, W9, W11, W13 and W15 dph) and the control in triplicates. The study was conducted for 21 days and 4 to 24 dph. All larvae in the treatments groups were fed Artemia nauplii ad libitum and a weaning diet fed to apparent satiation according to W4 to W15 schedules. The control group larvae were fed with Artemia nauplii alone. Results revealed that final length and weight, weight gain per cent, daily weight gain and specific growth rate were significantly (P < 0.05) higher in the Artemia nauplii fed control group followed by W15 dph larval group. The survival rate was significantly (P < 0.05) higher for W15 larvae, followed by the control group. The present study indicates that the ideal protocol for C. magur larval fed with Artemia nauplii from 4 dph for weaning to formulated diet was at 15 dph until 24 dph for good growth and survival rates.","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49201120","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 : 2022-03-24DOI: 10.33997/j.afs.2022.35.1.005
Maila V. Pan, R. Traifalgar
The present study evaluated the potential of squid by-product hydrolysate as fishmeal replacement in the plant-based diet of juvenile black tiger shrimp, Penaeus monodon Fabricius, 1798. Five experimental plant protein-based diets were formulated containing squid by-product hydrolysate to replace fishmeal at 0, 25, 50, 75 and 100 %. These experimental diets were fed to triplicate groups of P. monodon for 8 weeks. Results revealed that 25 % fishmeal replacement with squid by-product hydrolysate resulted in growth enhancement, attributable to increased feed intake and gut lactic acid bacteria proliferation. The shrimp fed with 100 % replacement level exhibited a similar growth response with the control group. Protein retention was not affected by the fishmeal replacement levels, but lipid retention was found higher in all treatments with squid by-product hydrolysate than the control. Digestive protease activity decreased with increasing levels of hydrolysate while α-amylase and lipase activities were not affected. Hepatopancreas histology showed thatB-cells dominated the control group while R-cells proliferated with increasing inclusion of dietary squid by-product hydrolysate. These results collectively indicate that fishmeal could be totally replaced with squid by-product hydrolysate and 25 % fishmeal replacement could promote the growth of juvenile P. monodon.
{"title":"Growth Enhancing Effects of Squid By-Product Hydrolysate in Plant Protein-Based Diet Fed to Black Tiger Shrimp, Penaeus monodon Fabricius, 1798","authors":"Maila V. Pan, R. Traifalgar","doi":"10.33997/j.afs.2022.35.1.005","DOIUrl":"https://doi.org/10.33997/j.afs.2022.35.1.005","url":null,"abstract":"The present study evaluated the potential of squid by-product hydrolysate as fishmeal replacement in the plant-based diet of juvenile black tiger shrimp, Penaeus monodon Fabricius, 1798. Five experimental plant protein-based diets were formulated containing squid by-product hydrolysate to replace fishmeal at 0, 25, 50, 75 and 100 %. These experimental diets were fed to triplicate groups of P. monodon for 8 weeks. Results revealed that 25 % fishmeal replacement with squid by-product hydrolysate resulted in growth enhancement, attributable to increased feed intake and gut lactic acid bacteria proliferation. The shrimp fed with 100 % replacement level exhibited a similar growth response with the control group. Protein retention was not affected by the fishmeal replacement levels, but lipid retention was found higher in all treatments with squid by-product hydrolysate than the control. Digestive protease activity decreased with increasing levels of hydrolysate while α-amylase and lipase activities were not affected. Hepatopancreas histology showed thatB-cells dominated the control group while R-cells proliferated with increasing inclusion of dietary squid by-product hydrolysate. These results collectively indicate that fishmeal could be totally replaced with squid by-product hydrolysate and 25 % fishmeal replacement could promote the growth of juvenile P. monodon.","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46124743","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 : 2022-03-04DOI: 10.33997/j.afs.2022.35.1.004
Manel Gharsalli, T. Kitakado
The common spiny lobster, Palinurus elephas (Fabricius, 1787), fishery in Tunisia has been overexploited. This species is currently managed by temporal closures, minimum legal sizes of landings, and the prohibition of catching berried females. This study aims to develop management procedures (MPs) based on the surplus production model to set total allowable catch (TAC) as a management action for the common spiny lobster. Ten MPs ranging from conservative to more relaxed management procedures were evaluated within a management strategy evaluation (MSE) framework. Several scenarios of the operating model were considered to account for uncertainties. Five performance measures were used to evaluate MPs to identify the management strategies that can achieve the prespecified management objective of recovering the stock size as a priority and ensuring high and stable catches. The results of the MSE showed that the conservative management strategies with the highest control points performed well in terms of management objectives with a probability of biomass exceeding the reference point of higher than 90 % but yielded in the lowest catches. On the other hand, relaxed threshold-based management strategies failed in achieving management objectives with 20 % probability of being below the limit reference point. These MSE results also highlighted the trade-off between conservation and catch performance objectives and showed that some moderate management strategies balanced these objectives efficiently.
{"title":"Management Strategy Evaluation for the Common Spiny Lobster, Palinurus elephas (Fabricius, 1787), Stock in Tunisia","authors":"Manel Gharsalli, T. Kitakado","doi":"10.33997/j.afs.2022.35.1.004","DOIUrl":"https://doi.org/10.33997/j.afs.2022.35.1.004","url":null,"abstract":"The common spiny lobster, Palinurus elephas (Fabricius, 1787), fishery in Tunisia has been overexploited. This species is currently managed by temporal closures, minimum legal sizes of landings, and the prohibition of catching berried females. This study aims to develop management procedures (MPs) based on the surplus production model to set total allowable catch (TAC) as a management action for the common spiny lobster. Ten MPs ranging from conservative to more relaxed management procedures were evaluated within a management strategy evaluation (MSE) framework. Several scenarios of the operating model were considered to account for uncertainties. Five performance measures were used to evaluate MPs to identify the management strategies that can achieve the prespecified management objective of recovering the stock size as a priority and ensuring high and stable catches. The results of the MSE showed that the conservative management strategies with the highest control points performed well in terms of management objectives with a probability of biomass exceeding the reference point of higher than 90 % but yielded in the lowest catches. On the other hand, relaxed threshold-based management strategies failed in achieving management objectives with 20 % probability of being below the limit reference point. These MSE results also highlighted the trade-off between conservation and catch performance objectives and showed that some moderate management strategies balanced these objectives efficiently.","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41366272","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 : 2022-03-03DOI: 10.33997/j.afs.2022.35.1.003
Sanny David P. Lumayno, K. Ohta, A. Yamaguchi, M. Matsuyama
The gonadotropin-releasing hormone (GnRH) is an important gene involved in fish reproduction and its action is mediated by GnRH receptor (GnRHR). Numerous GnRH-GnRHR studies have already been published in many teleost orders but information on reproduction-related genes for Clupeiformes is limited. To acquire a better understanding on the reproduction of Clupeiform fish species, GnRH isoforms and GnRHR paralogues of Japanese sardine, Sardinops sagax melanostictus (Temminck & Schlegel, 1846) were sequenced. Three GnRH isoforms (named as jsGnRH1, jsGnRH2, and jsGnRH3) and two GnRHR paralogues (named as jsGnRHR1 and jsGnRHR2) were isolated in the brain and pituitary of Japanese sardine. Based on phylogenetic analysis, jsGnRH1, jsGnRH2, and jsGnRH3 grouped into GnRH1, GnRH2, and GnRH3 forms, respectively, while jsGnRHR1 and jsGnRHR2 clustered into Type 2b and Type 1c receptors, correspondingly. The reporter gene assay showed high binding affinity of jsGnRHR1 to all three GnRH synthetic decapeptides, whereas jsGnRHR2 responded best to jsGnRH2 only. Clustering of jsGnRH1and jsGnRHR1 to other teleost GnRH1 and GnRHR2b, respectively, and activating the calcineurin/NFAT signalling pathway, suggests that these two genes are likely involved in fish reproduction.
{"title":"Molecular Characterisation and Reporter Gene Assay ofthe Three GnRH Isoforms and Two GnRH Receptors of a Clupeiform Fish, Japanese Sardine, Sardinops sagax melanostictus (Temminck & Schlegel, 1846)","authors":"Sanny David P. Lumayno, K. Ohta, A. Yamaguchi, M. Matsuyama","doi":"10.33997/j.afs.2022.35.1.003","DOIUrl":"https://doi.org/10.33997/j.afs.2022.35.1.003","url":null,"abstract":"The gonadotropin-releasing hormone (GnRH) is an important gene involved in fish reproduction and its action is mediated by GnRH receptor (GnRHR). Numerous GnRH-GnRHR studies have already been published in many teleost orders but information on reproduction-related genes for Clupeiformes is limited. To acquire a better understanding on the reproduction of Clupeiform fish species, GnRH isoforms and GnRHR paralogues of Japanese sardine, Sardinops sagax melanostictus (Temminck & Schlegel, 1846) were sequenced. Three GnRH isoforms (named as jsGnRH1, jsGnRH2, and jsGnRH3) and two GnRHR paralogues (named as jsGnRHR1 and jsGnRHR2) were isolated in the brain and pituitary of Japanese sardine. Based on phylogenetic analysis, jsGnRH1, jsGnRH2, and jsGnRH3 grouped into GnRH1, GnRH2, and GnRH3 forms, respectively, while jsGnRHR1 and jsGnRHR2 clustered into Type 2b and Type 1c receptors, correspondingly. The reporter gene assay showed high binding affinity of jsGnRHR1 to all three GnRH synthetic decapeptides, whereas jsGnRHR2 responded best to jsGnRH2 only. Clustering of jsGnRH1and jsGnRHR1 to other teleost GnRH1 and GnRHR2b, respectively, and activating the calcineurin/NFAT signalling pathway, suggests that these two genes are likely involved in fish reproduction.","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47762154","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 : 2022-02-14DOI: 10.33997/j.afs.2022.35.1.002
Tô Văn Phương, R. Pomeroy
Illegal, unreported and unregulated (IUU) fishing activities have negatively impacted Vietnam fisheries. As a result, the European Commission (EC) issued a yellow card warning in October 2017. This paper examines how Vietnam has responded to the EC’s recommendations to address the yellow card. The analysis used a mix of documents analysis and online group discussion approaches. Although Vietnam has made considerable efforts to halt IUU fishing and clear the yellow card, the results are still insufficient to remove the yellow card. However, the yellow card has brought about positive signals for Vietnamese fisheries management. It is also an opportunity for the national marine fisheries sector and fishers communities to be more responsible in fishing. Institutional and legal regulations have been refined to be in line with international rules and enormously improved the enforcement capacity of the fisheries management system for fishers to end the situation of fishing vessels engaged in illegal fishing in the waters of Vietnam and other countries. Recommended actions to address the yellow card include finalisation of the fisheries guidance decrees in line with obligations to combating IUU fishing, more robust sanctions, strengthening the monitoring, control and surveillance (MCS) system, information dissemination and education of the fisheries law and relevant regulations, and apply an electronic catch documentation and traceability (eCDT) system.
{"title":"Combating Illegal, Unreported and Unregulated (IUU) Fishing and Removing Yellow Card From European Commission (EC): Vietnam's Determined Actions","authors":"Tô Văn Phương, R. Pomeroy","doi":"10.33997/j.afs.2022.35.1.002","DOIUrl":"https://doi.org/10.33997/j.afs.2022.35.1.002","url":null,"abstract":"Illegal, unreported and unregulated (IUU) fishing activities have negatively impacted Vietnam fisheries. As a result, the European Commission (EC) issued a yellow card warning in October 2017. This paper examines how Vietnam has responded to the EC’s recommendations to address the yellow card. The analysis used a mix of documents analysis and online group discussion approaches. Although Vietnam has made considerable efforts to halt IUU fishing and clear the yellow card, the results are still insufficient to remove the yellow card. However, the yellow card has brought about positive signals for Vietnamese fisheries management. It is also an opportunity for the national marine fisheries sector and fishers communities to be more responsible in fishing. Institutional and legal regulations have been refined to be in line with international rules and enormously improved the enforcement capacity of the fisheries management system for fishers to end the situation of fishing vessels engaged in illegal fishing in the waters of Vietnam and other countries. Recommended actions to address the yellow card include finalisation of the fisheries guidance decrees in line with obligations to combating IUU fishing, more robust sanctions, strengthening the monitoring, control and surveillance (MCS) system, information dissemination and education of the fisheries law and relevant regulations, and apply an electronic catch documentation and traceability (eCDT) system.","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46616275","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 : 2022-02-12DOI: 10.33997/j.afs.2022.35.1.001
Shaharah Mohd Idris, Wan Norhana Md. Noordin, Fatin Osman Manah, A. Hamzah
Asian sea bass, Lates calcarifer (Bloch, 1790), is one of the most farmed marine fish in Malaysia since the 1970s and is predominantly cultured at present. Although it has been farmed for some time, there is no systematic breeding programme in place. Local hatcheries rely heavily on wild and imported broodstock. However, imported stocks do not guarantee improved quality and even increase the chances of introducing pathogens into the country. Availability of superior breeding stocks, efficient dissemination and control of seed production could greatly assist in increasing Asian sea bass production. This paper presents the status of Asian sea bass production, its culture history in Malaysia and the current broodstock development programme implemented by the Fisheries Research Institute, particularly in the 11th Malaysia Plan from 2015 to 2020. In brief, broodstock from Malaysia, Thailand and Indonesia were used as base population and were mated using full diallel method to produce cohorts. Three pairs of the selected broodstock were used for each cross and spawning performance was evaluated. The growth performances of the first generation (F1) offsprings were assessed in different culture systems. Physico-chemical water quality parameters such as dissolved oxygen, temperature, pH and salinity were maintained at optimal levels during all stages of the experiment. Results indicate that the growth performance of F1 improved by more than 60 % in terms of weight gain compared with the base population. The project demonstrated the benefits of using selective breeding to enhance the production of Asian sea bass.
{"title":"Toward Systematic Breeding of Asian Sea Bass, Lates calcarifer (Bloch, 1790), in Malaysia: Status, Challenges and Prospects for Future Development","authors":"Shaharah Mohd Idris, Wan Norhana Md. Noordin, Fatin Osman Manah, A. Hamzah","doi":"10.33997/j.afs.2022.35.1.001","DOIUrl":"https://doi.org/10.33997/j.afs.2022.35.1.001","url":null,"abstract":"Asian sea bass, Lates calcarifer (Bloch, 1790), is one of the most farmed marine fish in Malaysia since the 1970s and is predominantly cultured at present. Although it has been farmed for some time, there is no systematic breeding programme in place. Local hatcheries rely heavily on wild and imported broodstock. However, imported stocks do not guarantee improved quality and even increase the chances of introducing pathogens into the country. Availability of superior breeding stocks, efficient dissemination and control of seed production could greatly assist in increasing Asian sea bass production. This paper presents the status of Asian sea bass production, its culture history in Malaysia and the current broodstock development programme implemented by the Fisheries Research Institute, particularly in the 11th Malaysia Plan from 2015 to 2020. In brief, broodstock from Malaysia, Thailand and Indonesia were used as base population and were mated using full diallel method to produce cohorts. Three pairs of the selected broodstock were used for each cross and spawning performance was evaluated. The growth performances of the first generation (F1) offsprings were assessed in different culture systems. Physico-chemical water quality parameters such as dissolved oxygen, temperature, pH and salinity were maintained at optimal levels during all stages of the experiment. Results indicate that the growth performance of F1 improved by more than 60 % in terms of weight gain compared with the base population. The project demonstrated the benefits of using selective breeding to enhance the production of Asian sea bass.","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46946220","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 : 2022-01-09DOI: 10.33997/j.afs.2021.34.4.012
Nguyen Thi Anh Quyen, Tran Thi Hoang Yen, Anna Karia Lerøy Riple
The increasing demand by international customers for high-quality shrimp products has led to the introduction of various certificates of traceability intended to validate quality products in Vietnam. The Vietnamese good agricultural practices (VietGAP), better known in aquaculture as the Vietnamese good aquaculture practices, has emerged as a reliable certificate for small-scale farmers and a prerequisite for international certification. This study investigates factors affecting applications for VietGAP by small-scale shrimp farmers in Vietnam. Cost-benefit analysis and binary logistic regression approaches were used to categorise shrimp farms with and without VietGAP certification. Findings indicated that while the adoption of VietGAP raised production costs by 14.5 %, it could increase net profit by up to 22 %. The increase in net profit is from increased productivity and antibiotics and chemical-free products in shrimp farming, helped fetch better prices. The results also revealed three factors that positively influenced the farmers’ decision to acquire VietGAP; education, farm size, and production system. Shrimp farmers with longer schooling years, larger farms, and those who possess cooperative/farming cluster membership are more likely to acquire VietGAP certification. The results imply that the VietGAP certification should be better promoted to cooperative production forms of farming, by strengthening the schooling year of farmers and increasing awareness of VietGAP certification to farmers who operate shrimp farms of 5,000–9,000 m2.
{"title":"Adoption of Vietnamese Good Agricultural Practices (VietGAP) in Aquaculture: Evidence From Small-Scale Shrimp Farming","authors":"Nguyen Thi Anh Quyen, Tran Thi Hoang Yen, Anna Karia Lerøy Riple","doi":"10.33997/j.afs.2021.34.4.012","DOIUrl":"https://doi.org/10.33997/j.afs.2021.34.4.012","url":null,"abstract":"The increasing demand by international customers for high-quality shrimp products has led to the introduction of various certificates of traceability intended to validate quality products in Vietnam. The Vietnamese good agricultural practices (VietGAP), better known in aquaculture as the Vietnamese good aquaculture practices, has emerged as a reliable certificate for small-scale farmers and a prerequisite for international certification. This study investigates factors affecting applications for VietGAP by small-scale shrimp farmers in Vietnam. Cost-benefit analysis and binary logistic regression approaches were used to categorise shrimp farms with and without VietGAP certification. Findings indicated that while the adoption of VietGAP raised production costs by 14.5 %, it could increase net profit by up to 22 %. The increase in net profit is from increased productivity and antibiotics and chemical-free products in shrimp farming, helped fetch better prices. The results also revealed three factors that positively influenced the farmers’ decision to acquire VietGAP; education, farm size, and production system. Shrimp farmers with longer schooling years, larger farms, and those who possess cooperative/farming cluster membership are more likely to acquire VietGAP certification. The results imply that the VietGAP certification should be better promoted to cooperative production forms of farming, by strengthening the schooling year of farmers and increasing awareness of VietGAP certification to farmers who operate shrimp farms of 5,000–9,000 m2.","PeriodicalId":37296,"journal":{"name":"Asian Fisheries Science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45104217","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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