Maria Hayden-Hughes, Philippa Bayford, Jonathan W. King, D. Smyth
The history of the European native oyster has been documented for numerous countries within its natural range. However, the history of Ostrea edulis in Wales remains conspicuously absent from current UK and European peer-reviewed publications. It was therefore deemed necessary to address this and as a result in-depth research of archival data was conducted including local trade directories, decennial census returns, collections from the National Museum Wales, annual government fisheries reports and grey literature from local historical societies. These historical reviews resulted in the construction of a timeline which documents all the significant historical dates related to O. edulis in Wales from the early 1500 s to present day. Fisheries statistics for England and Wales were also analysed for the western regional oyster fisheries in an attempt to understand the contribution which the Welsh landings made to the region. The review revealed that the Welsh fishery was the primary contributor of regional landings from the early 1600 s with maximum landings reported 1894, with the oyster beds at Mumbles producing more oysters than any other port until the fishery closed in 1937. A commercial native oyster fishery no longer exists in Wales but there remains a small native oyster population in South Wales. It is hoped that the historical accounts of bountiful catches, overexploitation, and restoration of O. edulis over the centuries in Wales may offer current conservation practitioners an insight into failures and mistakes of the past which could benefit the future of the European flat oyster in Wales.
{"title":"The European native oyster, Ostrea edulis, in Wales, a historical account of a forgotten fishery","authors":"Maria Hayden-Hughes, Philippa Bayford, Jonathan W. King, D. Smyth","doi":"10.1051/alr/2022024","DOIUrl":"https://doi.org/10.1051/alr/2022024","url":null,"abstract":"The history of the European native oyster has been documented for numerous countries within its natural range. However, the history of Ostrea edulis in Wales remains conspicuously absent from current UK and European peer-reviewed publications. It was therefore deemed necessary to address this and as a result in-depth research of archival data was conducted including local trade directories, decennial census returns, collections from the National Museum Wales, annual government fisheries reports and grey literature from local historical societies. These historical reviews resulted in the construction of a timeline which documents all the significant historical dates related to O. edulis in Wales from the early 1500 s to present day. Fisheries statistics for England and Wales were also analysed for the western regional oyster fisheries in an attempt to understand the contribution which the Welsh landings made to the region. The review revealed that the Welsh fishery was the primary contributor of regional landings from the early 1600 s with maximum landings reported 1894, with the oyster beds at Mumbles producing more oysters than any other port until the fishery closed in 1937. A commercial native oyster fishery no longer exists in Wales but there remains a small native oyster population in South Wales. It is hoped that the historical accounts of bountiful catches, overexploitation, and restoration of O. edulis over the centuries in Wales may offer current conservation practitioners an insight into failures and mistakes of the past which could benefit the future of the European flat oyster in Wales.","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. ter Hofstede, Gregory Williams, M. van Koningsveld
Incorporation of ecology and ecosystem services into marine infrastructural developments has gained interest over the last decades. Growing attention is given to combine the massive roll-out of offshore wind farms in the North Sea with reinstating the once rich but nowadays nearly extinct European flat oyster (Ostrea edulis). However, the practical upscaling of these pilots is hindered by the absence of clear management objectives and the lack of quantitative knowledge on the effect of technical interventions that could stimulate oyster reef development. Consequently, it is unclear what scale of intervention would actually be required to achieve overall management objectives. This paper presents a stepwise procedure designed in particular to guide the selection of appropriate measures and their required scale for pro-actively facilitating flat oyster reef development in offshore wind farms, in order to reach a desired state for oyster reef inclusive wind farms. The stepwise procedure addresses the historical and current situation of the physical system and social environment, provides options for intervention that stimulate oyster reef development at a range of scales, from micro-scale (materials used) to mega-scale (connectivity between wind farms), and quantitatively assesses the potential effect of applying these interventions. Assumptions have been made in quantifying the effort required for developing oyster reefs in offshore wind farms, and refinement is obviously needed. However, this is a first attempt to make such estimates. The outcomes provide direction in identifying research needs to fill knowledge gaps, as well as in decision-making during the design process for inducing oyster reef development in offshore wind farms. Herewith, application of the stepwise procedure supports authorities in restoration management for the successful reinstatement of flat oyster reefs in the southern North Sea.
{"title":"The potential impact of human interventions at different scales in offshore wind farms to promote flat oyster (Ostrea edulis) reef development in the southern North Sea","authors":"R. ter Hofstede, Gregory Williams, M. van Koningsveld","doi":"10.1051/alr/2023001","DOIUrl":"https://doi.org/10.1051/alr/2023001","url":null,"abstract":"Incorporation of ecology and ecosystem services into marine infrastructural developments has gained interest over the last decades. Growing attention is given to combine the massive roll-out of offshore wind farms in the North Sea with reinstating the once rich but nowadays nearly extinct European flat oyster (Ostrea edulis). However, the practical upscaling of these pilots is hindered by the absence of clear management objectives and the lack of quantitative knowledge on the effect of technical interventions that could stimulate oyster reef development. Consequently, it is unclear what scale of intervention would actually be required to achieve overall management objectives. This paper presents a stepwise procedure designed in particular to guide the selection of appropriate measures and their required scale for pro-actively facilitating flat oyster reef development in offshore wind farms, in order to reach a desired state for oyster reef inclusive wind farms. The stepwise procedure addresses the historical and current situation of the physical system and social environment, provides options for intervention that stimulate oyster reef development at a range of scales, from micro-scale (materials used) to mega-scale (connectivity between wind farms), and quantitatively assesses the potential effect of applying these interventions. Assumptions have been made in quantifying the effort required for developing oyster reefs in offshore wind farms, and refinement is obviously needed. However, this is a first attempt to make such estimates. The outcomes provide direction in identifying research needs to fill knowledge gaps, as well as in decision-making during the design process for inducing oyster reef development in offshore wind farms. Herewith, application of the stepwise procedure supports authorities in restoration management for the successful reinstatement of flat oyster reefs in the southern North Sea.","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The present study was simultaneously conducted in two distantly located areas to assess the impacts of COVID-19 on farming processes, instantaneous financial impacts and mitigation strategies adopted by the farmers in the small scale freshwater carp farming and coastal brackish water shrimp farming sectors in India. Primary data were collected through interview of the farmers with the help of pre-tested structured interview schedules. Though the initial impact in both the sectors were substantial, freshwater carp farmers mitigated the crises comparatively well because of wider option in alternative livelihood, low cost locally available inputs, mobilization of local market, direct door to door vending of live fish and mobilization of women work force from the family in the farming sector. Untapped resource in the form of women's' participation in the freshwater farming practices was noteworthy during the pandemic period which increased polynomially (y = –1.0714x2 + 7.5286x − 2.2; R2 = 0.9648). As the shrimp farming sector was dependent upon external markets and burdened with high cost inputs primarily supplied by the input dealers on credit basis, the sector has to bear the burden most. Garret's Rank analysis revealed that integration with other production sectors ranked first as mitigation perception to the freshwater carp farmers, whereas, to the coastal shrimp farmers, the highest rank was with the perception that everything will be normalized within 2–3 months naturally. Garret's Rank analysis also revealed that in both the sectors, the farmers most important need was credit from the Govt. source in mitigating COVID-19 like crisis in future.
{"title":"Impacts of COVID-19 on small-scale freshwater carp and coastal brackish water shrimp farming in India","authors":"Debesh Hait, M. Vignesh, S. Das","doi":"10.1051/alr/2022020","DOIUrl":"https://doi.org/10.1051/alr/2022020","url":null,"abstract":"The present study was simultaneously conducted in two distantly located areas to assess the impacts of COVID-19 on farming processes, instantaneous financial impacts and mitigation strategies adopted by the farmers in the small scale freshwater carp farming and coastal brackish water shrimp farming sectors in India. Primary data were collected through interview of the farmers with the help of pre-tested structured interview schedules. Though the initial impact in both the sectors were substantial, freshwater carp farmers mitigated the crises comparatively well because of wider option in alternative livelihood, low cost locally available inputs, mobilization of local market, direct door to door vending of live fish and mobilization of women work force from the family in the farming sector. Untapped resource in the form of women's' participation in the freshwater farming practices was noteworthy during the pandemic period which increased polynomially (y = –1.0714x2 + 7.5286x − 2.2; R2 = 0.9648). As the shrimp farming sector was dependent upon external markets and burdened with high cost inputs primarily supplied by the input dealers on credit basis, the sector has to bear the burden most. Garret's Rank analysis revealed that integration with other production sectors ranked first as mitigation perception to the freshwater carp farmers, whereas, to the coastal shrimp farmers, the highest rank was with the perception that everything will be normalized within 2–3 months naturally. Garret's Rank analysis also revealed that in both the sectors, the farmers most important need was credit from the Govt. source in mitigating COVID-19 like crisis in future.","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Caruso, A. Lusiastuti, S. Pouil, R. Samsudin, O. Z. Arifin, J. Slembrouck
Using Azolla filiculoides, a candidate macrophyte species for ecological intensification, in small-scale aquaculture requires the investigation of the potential effects of fresh plant material not only on fish growth but also on physiological status and responses to disease and stress. In this study, juveniles of giant gourami Osphronemus goramy reared into cages placed in an outdoor pond were fed for six weeks with different proportions of fresh Azolla in replacement of commercial pellets (A: 100%, B: 56%, C:26% and D: 0% of the feeding events). The condition factor (KFulton) somatic and immunological indicators were measured. Effects of Azolla on transport stress and bacterial infection with Aeromonas hydrophila were also assessed. Results showed that KFulton decreased with increasing proportions of Azolla in the diet (p < 0.001). Total protein, albumin and globulin in fish from treatment A were significantly lower than in the other treatments. A decrease in lymphocytes was observed in treatments A and B (p < 0.001) and fish from these treatments had higher levels of monocytes (p < 0.001). Neutrophils were higher in treatment A only (p = 0.012). Plasma lysozyme levels and serum bactericidal activity increased with Azolla in the diet (both p < 0.001). Before transport stress, glycaemia was lower in fish from treatment A (p < 0.001) while after transport, glycaemia increased in all treatments excepted treatment A (p < 0.001) where survival was the highest after 15 days post transport. One week after infection the survival of fish was higher in fish from treatments A and B (p < 0.001). Azolla had positive effects on immunological indicators, and resistance to stress and disease but decreased growth. These findings suggest using Azolla at reasonable rate (i.e. <30% of the diet) to reduce pellets inputs while maintaining growth and providing other benefits to fish.
{"title":"Can Azolla filiculoides be a complementary feed resource for ecological intensification in small-scale fish farming? Biological effects on giant gourami (Osphronemus goramy)","authors":"D. Caruso, A. Lusiastuti, S. Pouil, R. Samsudin, O. Z. Arifin, J. Slembrouck","doi":"10.1051/alr/2023007","DOIUrl":"https://doi.org/10.1051/alr/2023007","url":null,"abstract":"Using Azolla filiculoides, a candidate macrophyte species for ecological intensification, in small-scale aquaculture requires the investigation of the potential effects of fresh plant material not only on fish growth but also on physiological status and responses to disease and stress. In this study, juveniles of giant gourami Osphronemus goramy reared into cages placed in an outdoor pond were fed for six weeks with different proportions of fresh Azolla in replacement of commercial pellets (A: 100%, B: 56%, C:26% and D: 0% of the feeding events). The condition factor (KFulton) somatic and immunological indicators were measured. Effects of Azolla on transport stress and bacterial infection with Aeromonas hydrophila were also assessed. Results showed that KFulton decreased with increasing proportions of Azolla in the diet (p < 0.001). Total protein, albumin and globulin in fish from treatment A were significantly lower than in the other treatments. A decrease in lymphocytes was observed in treatments A and B (p < 0.001) and fish from these treatments had higher levels of monocytes (p < 0.001). Neutrophils were higher in treatment A only (p = 0.012). Plasma lysozyme levels and serum bactericidal activity increased with Azolla in the diet (both p < 0.001). Before transport stress, glycaemia was lower in fish from treatment A (p < 0.001) while after transport, glycaemia increased in all treatments excepted treatment A (p < 0.001) where survival was the highest after 15 days post transport. One week after infection the survival of fish was higher in fish from treatments A and B (p < 0.001). Azolla had positive effects on immunological indicators, and resistance to stress and disease but decreased growth. These findings suggest using Azolla at reasonable rate (i.e. <30% of the diet) to reduce pellets inputs while maintaining growth and providing other benefits to fish.","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57825096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kilian Heutte, F. Daurès, Sterenn Lucas, S. Girard, Frédérique Alban, Pascal Le Floc’h
In terms of food consumption, sustainability dimensions are often conflicting with purchasing power and practical purchases. France lands, farms, imports, and consumes large quantities of fisheries and aquaculture products (FAPs). The pandemic affected both domestic and foreign FAP supply through restrictions on trade and fishing conditions. Numerous sale points offering FAPs were closed during the pandemic. This general context has likely questioned the role of consumers on environmental, economic, and social matters. The aim of the paper is to assess whether the Covid-19 crisis has been an opportunity for French consumers to align their consumption at-home with the environmental issues by favouring domestic producers, short channels, or eco-friendly products. Quantitative data on at-home ordinary household purchases in metropolitan France from 2017 to 2021 was used along with t-test methods. It seems that fresh FAPs consumption did not truly adapt to the domestic fish production in defiance of import restrictions and available surpluses. While fresh shellfish at-home consumption did not change significantly in 2020, salmon and cod are still widely favoured by French consumers at-home, although their French production is virtually non-existent. On the contrary, domestically produced fish species remains poorly consumed at-home. The abundant supply of fresh salmon initially intended for other markets has permitted to consolidate the dominant position of this species on the French at-home consumption market. Initiated by supermarkets and hypermarkets and followed up by consumers, the trend of purchasing pre-packaged fresh fish has been substantially amplified by the pandemic and seems to persist over time.
{"title":"Fisheries and aquaculture products consumption in France: when the Covid-19 crisis did not lead to more sustainable purchases","authors":"Kilian Heutte, F. Daurès, Sterenn Lucas, S. Girard, Frédérique Alban, Pascal Le Floc’h","doi":"10.1051/alr/2023004","DOIUrl":"https://doi.org/10.1051/alr/2023004","url":null,"abstract":"In terms of food consumption, sustainability dimensions are often conflicting with purchasing power and practical purchases. France lands, farms, imports, and consumes large quantities of fisheries and aquaculture products (FAPs). The pandemic affected both domestic and foreign FAP supply through restrictions on trade and fishing conditions. Numerous sale points offering FAPs were closed during the pandemic. This general context has likely questioned the role of consumers on environmental, economic, and social matters. The aim of the paper is to assess whether the Covid-19 crisis has been an opportunity for French consumers to align their consumption at-home with the environmental issues by favouring domestic producers, short channels, or eco-friendly products. Quantitative data on at-home ordinary household purchases in metropolitan France from 2017 to 2021 was used along with t-test methods. It seems that fresh FAPs consumption did not truly adapt to the domestic fish production in defiance of import restrictions and available surpluses. While fresh shellfish at-home consumption did not change significantly in 2020, salmon and cod are still widely favoured by French consumers at-home, although their French production is virtually non-existent. On the contrary, domestically produced fish species remains poorly consumed at-home. The abundant supply of fresh salmon initially intended for other markets has permitted to consolidate the dominant position of this species on the French at-home consumption market. Initiated by supermarkets and hypermarkets and followed up by consumers, the trend of purchasing pre-packaged fresh fish has been substantially amplified by the pandemic and seems to persist over time.","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Kamermans, Ainhoa Blanco, P. van Dalen, M. Engelsma, Nienke Bakker, P. Jacobs, M. Dubbeldam, Inés M. Sambade, M. Vera, P. Martínez
Native (flat) oyster (Ostrea edulis) beds, once a major component of the North Sea, largely disappeared from the region in the late 19th century. Flat oyster restoration is taking place at a number of locations in the North Sea. When flat oyster beds are restored in areas where O. edulis is functionally extinct it is advised to treat these as disease-free areas. Adult oysters were collected in the Dutch Delta area which is infected with the pathogenic parasite Bonamia ostreae. The aim of this research was to obtain Bonamia-free seed from parents collected in a Bonamia-infected area. In addition, the oysters were analysed to identify candidate genomic regions related to bonamiosis tolerance and exposed to Bonamia in the field to assess survival compared to a naïve control group. With the aid of a non-destructive screening method, Bonamia-free broodstock were selected. These oysters produced Bonamia-free larvae and seed. For comparison, broodstock oysters were collected in the Dutch Wadden Sea, an area free of Bonamia. These oysters also produced Bonamia-free larvae and seed. To study if the Delta area oysters had developed a degree of resistance to the disease, while the naïve Wadden Sea oysters had not, seed of both groups was challenged in Lake Grevelingen where Bonamia occurs. Survival of the pre-selected Bonamia-free oysters was significantly higher than the naïve group. Samples of seed were analysed for association of candidate genetic markers related to bonamiosis tolerance. A higher percentage of individuals with tolerance-associated marker genotypes was found in the screened group compared to the naïve one. However, mortality of the naïve group could not be related to Bonamia presence. Further challenge tests are needed before firm conclusions regarding the genetic markers can be made. The results show that hatchery production of Bonamia-free and potentially Bonamia-tolerant flat oysters is possible.
{"title":"Bonamia-free flat oyster (Ostrea edulis L.) seed for restoration projects: non-destructive screening of broodstock, hatchery production and test for Bonamia-tolerance","authors":"P. Kamermans, Ainhoa Blanco, P. van Dalen, M. Engelsma, Nienke Bakker, P. Jacobs, M. Dubbeldam, Inés M. Sambade, M. Vera, P. Martínez","doi":"10.1051/alr/2023005","DOIUrl":"https://doi.org/10.1051/alr/2023005","url":null,"abstract":"Native (flat) oyster (Ostrea edulis) beds, once a major component of the North Sea, largely disappeared from the region in the late 19th century. Flat oyster restoration is taking place at a number of locations in the North Sea. When flat oyster beds are restored in areas where O. edulis is functionally extinct it is advised to treat these as disease-free areas. Adult oysters were collected in the Dutch Delta area which is infected with the pathogenic parasite Bonamia ostreae. The aim of this research was to obtain Bonamia-free seed from parents collected in a Bonamia-infected area. In addition, the oysters were analysed to identify candidate genomic regions related to bonamiosis tolerance and exposed to Bonamia in the field to assess survival compared to a naïve control group. With the aid of a non-destructive screening method, Bonamia-free broodstock were selected. These oysters produced Bonamia-free larvae and seed. For comparison, broodstock oysters were collected in the Dutch Wadden Sea, an area free of Bonamia. These oysters also produced Bonamia-free larvae and seed. To study if the Delta area oysters had developed a degree of resistance to the disease, while the naïve Wadden Sea oysters had not, seed of both groups was challenged in Lake Grevelingen where Bonamia occurs. Survival of the pre-selected Bonamia-free oysters was significantly higher than the naïve group. Samples of seed were analysed for association of candidate genetic markers related to bonamiosis tolerance. A higher percentage of individuals with tolerance-associated marker genotypes was found in the screened group compared to the naïve one. However, mortality of the naïve group could not be related to Bonamia presence. Further challenge tests are needed before firm conclusions regarding the genetic markers can be made. The results show that hatchery production of Bonamia-free and potentially Bonamia-tolerant flat oysters is possible.","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Patricia A. Herinirina, L. Bigot, P. Frouin, Huguette T.E Volandrae, R. M. Randriatsara, Faustinato Behivoke, Lanto Ranivoarivelo, M. Léopold
The use of mosquito nets, primarily for targeting small and/or juvenile fish, has rapidly increased in Western Indian Ocean shallow seagrass beds and coral reefs over the last 20 years. However, to date, invertebrate by-catch by locally-made fishing gear has not been reported. We studied the mosquito net trawl fishery in seagrass areas in the Bay of Toliara, Southwest Madagascar through the GPS tracking of fishers from August 2018 to February 2019. Catches were monitored through monthly landing surveys to characterize spatial temporal patterns in the abundance and diversity of macroinvertebrates in the seagrass beds. Fishing was carried out at low tide, mostly at night, by fishers pulling a hand-made trawl net of varying dimensions. Overall, 43 macroinvertebrate taxa were identified out of 217,080 individuals collected from 109 catch samples. Catches were generally composed of crustaceans (mainly Portunidae, Processidae, Penaeidae, and Alpheidae). The crab Thalamita mitsiensis largely dominated the abundance and biomass of the macroinvertebrate assemblage (from 6% to 100% and from 5 to 100% of the overall density and biomass, respectively). Macroinvertebrates composed 1.5% to 100% of the total catch per trip (i.e., 4–55 kg trip−1). They were sold for human consumption or animal feed, which provided additional income to fishers (USD 1–24 trip−1 and 1–72% of catch income per trip). This study revealed that macroinvertebrate resources provide valuable by-catch to small-scale fishers in Southwest Madagascar. This bycatch generates income that further encourages the use of mosquito net trawls and exacerbates their negative effects on coastal seagrass ecosystems and fisheries.
{"title":"Seagrass macroinvertebrate bycatches support mosquito net trawl fishery in Madagascar","authors":"Patricia A. Herinirina, L. Bigot, P. Frouin, Huguette T.E Volandrae, R. M. Randriatsara, Faustinato Behivoke, Lanto Ranivoarivelo, M. Léopold","doi":"10.1051/alr/2023014","DOIUrl":"https://doi.org/10.1051/alr/2023014","url":null,"abstract":"The use of mosquito nets, primarily for targeting small and/or juvenile fish, has rapidly increased in Western Indian Ocean shallow seagrass beds and coral reefs over the last 20 years. However, to date, invertebrate by-catch by locally-made fishing gear has not been reported. We studied the mosquito net trawl fishery in seagrass areas in the Bay of Toliara, Southwest Madagascar through the GPS tracking of fishers from August 2018 to February 2019. Catches were monitored through monthly landing surveys to characterize spatial temporal patterns in the abundance and diversity of macroinvertebrates in the seagrass beds. Fishing was carried out at low tide, mostly at night, by fishers pulling a hand-made trawl net of varying dimensions. Overall, 43 macroinvertebrate taxa were identified out of 217,080 individuals collected from 109 catch samples. Catches were generally composed of crustaceans (mainly Portunidae, Processidae, Penaeidae, and Alpheidae). The crab Thalamita mitsiensis largely dominated the abundance and biomass of the macroinvertebrate assemblage (from 6% to 100% and from 5 to 100% of the overall density and biomass, respectively). Macroinvertebrates composed 1.5% to 100% of the total catch per trip (i.e., 4–55 kg trip−1). They were sold for human consumption or animal feed, which provided additional income to fishers (USD 1–24 trip−1 and 1–72% of catch income per trip). This study revealed that macroinvertebrate resources provide valuable by-catch to small-scale fishers in Southwest Madagascar. This bycatch generates income that further encourages the use of mosquito net trawls and exacerbates their negative effects on coastal seagrass ecosystems and fisheries.","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57825328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Cameron, Russel Smart, Alice E. Lown, A. Baker, R. Korda
Fishing gear-based landings or survey methods are often used to make assessments of species stock abundance. In order to convert catch into abundance values, estimates or assumptions are made on the catch efficiency of the gear-based method. This is the case in areas where flat oysters, Ostrea edulis, are surveyed for fisheries and conservation objectives in a range of projects across Europe. Flat oyster dredge efficiency assumptions vary widely from 5–30% in published studies and uncertainty in what is an appropriate efficiency estimate has led some survey teams to switch to Catch-per-unit-effort (CPUE), where CPUE is also of concern should catch efficiency change with shellfish density, ground type or some other unmeasured variable such as shellfish distribution. We undertook an experimental approach to estimate dredge efficiency in a standard ladder dredge used to harvest and survey adult flat oysters in the UK and Ireland. The dredge efficiency trials assessed how efficiency was influenced by oyster density (between 1 and 2.2 oysters m2), distribution (clumped vs uniform) and ground types across a gradient of more hard to more soft surface sediments. Dredge efficiency was significantly affected by oyster distribution, but also density and ground hardness as well as their interactions. While a median value between 7 and 10% seems an appropriate universal ladder dredge efficiency to adopt, ground type and distribution had such an effect that local conditions may effect this considerably. Catch efficiency was negatively density-dependent, this makes CPUE methods challenging where oyster densities are likely to vary. Practitioners, regulators and researchers conducting surveys can improve CPUE approaches through standard techniques and knowledge of how catch efficiency varies as we have presented here.
{"title":"Experimental estimation of ladder dredge efficiency for capture of European flat oysters over mixed sediment","authors":"T. Cameron, Russel Smart, Alice E. Lown, A. Baker, R. Korda","doi":"10.1051/alr/2023021","DOIUrl":"https://doi.org/10.1051/alr/2023021","url":null,"abstract":"Fishing gear-based landings or survey methods are often used to make assessments of species stock abundance. In order to convert catch into abundance values, estimates or assumptions are made on the catch efficiency of the gear-based method. This is the case in areas where flat oysters, Ostrea edulis, are surveyed for fisheries and conservation objectives in a range of projects across Europe. Flat oyster dredge efficiency assumptions vary widely from 5–30% in published studies and uncertainty in what is an appropriate efficiency estimate has led some survey teams to switch to Catch-per-unit-effort (CPUE), where CPUE is also of concern should catch efficiency change with shellfish density, ground type or some other unmeasured variable such as shellfish distribution. We undertook an experimental approach to estimate dredge efficiency in a standard ladder dredge used to harvest and survey adult flat oysters in the UK and Ireland. The dredge efficiency trials assessed how efficiency was influenced by oyster density (between 1 and 2.2 oysters m2), distribution (clumped vs uniform) and ground types across a gradient of more hard to more soft surface sediments. Dredge efficiency was significantly affected by oyster distribution, but also density and ground hardness as well as their interactions. While a median value between 7 and 10% seems an appropriate universal ladder dredge efficiency to adopt, ground type and distribution had such an effect that local conditions may effect this considerably. Catch efficiency was negatively density-dependent, this makes CPUE methods challenging where oyster densities are likely to vary. Practitioners, regulators and researchers conducting surveys can improve CPUE approaches through standard techniques and knowledge of how catch efficiency varies as we have presented here.","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57825003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Larochelle, Declan Burton, Jamie C. Madden, Sascha Clark Danylchuk, S. Cooke, A. Danylchuk
There is a growing body of research focused on how angled fish respond to catch-and-release (C&R). However, most of those studies do not span a wide range of body sizes for the targeted species. Physical injury and physiological responses to C&R can be size-dependent, and methods used for landing fish of different sizes vary. As such, studying the response to C&R across a range of fish sizes may help inform best practices that improve outcomes for released fish. Northern Pike (Esox lucius) widely ranges in body size. Anglers may land them by hand, cradle, or net, and they are often released voluntarily or to comply with regulations. We angled 25 Northern Pike (total length 620–1030 mm) from one population and recorded fight, handling, and unhooking times across landing methods (i.e., hand, cradle, net). Prior to release, a pop-off biologging package was temporarily affixed to each fish to monitor locomotor activity, depth, and water temperature during a 12-h period post-release to understand how the interaction of landing method and body size influenced post-release behaviour and short-term fate. Fight and handling time increased with increasing body size. Northern Pike landed with a cradle or net had shorter fight times but longer handling times, compared to fish landed by hand. Post-release locomotor activity was greater for larger fish and those landed with a net. Fish <775mm and landed by hand had greater locomotor activity than fish landed with a net or cradle, while fish >775mm landed by hand had reduced locomotor activity compared to fish landed with a net. There was no post-release mortality observed. Collectively, anglers should use a net for Northern Pike >775 mm to avoid long fight times and reduce post-release exhaustion, but also attempt to reduce the extent of handling associated with fish landed by net.
{"title":"Using a novel biologging approach to assess how different handling practices influence the post-release behaviour of Northern Pike across a wide range of body sizes","authors":"L. Larochelle, Declan Burton, Jamie C. Madden, Sascha Clark Danylchuk, S. Cooke, A. Danylchuk","doi":"10.1051/alr/2023019","DOIUrl":"https://doi.org/10.1051/alr/2023019","url":null,"abstract":"There is a growing body of research focused on how angled fish respond to catch-and-release (C&R). However, most of those studies do not span a wide range of body sizes for the targeted species. Physical injury and physiological responses to C&R can be size-dependent, and methods used for landing fish of different sizes vary. As such, studying the response to C&R across a range of fish sizes may help inform best practices that improve outcomes for released fish. Northern Pike (Esox lucius) widely ranges in body size. Anglers may land them by hand, cradle, or net, and they are often released voluntarily or to comply with regulations. We angled 25 Northern Pike (total length 620–1030 mm) from one population and recorded fight, handling, and unhooking times across landing methods (i.e., hand, cradle, net). Prior to release, a pop-off biologging package was temporarily affixed to each fish to monitor locomotor activity, depth, and water temperature during a 12-h period post-release to understand how the interaction of landing method and body size influenced post-release behaviour and short-term fate. Fight and handling time increased with increasing body size. Northern Pike landed with a cradle or net had shorter fight times but longer handling times, compared to fish landed by hand. Post-release locomotor activity was greater for larger fish and those landed with a net. Fish <775mm and landed by hand had greater locomotor activity than fish landed with a net or cradle, while fish >775mm landed by hand had reduced locomotor activity compared to fish landed with a net. There was no post-release mortality observed. Collectively, anglers should use a net for Northern Pike >775 mm to avoid long fight times and reduce post-release exhaustion, but also attempt to reduce the extent of handling associated with fish landed by net.","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kenn Papadopoulo, D. Villegas‐Ríos, G. Mucientes, A. Hillinger, A. Alonso‐Fernández
This is an O Regarding the article [Papadopoulo K, Villegas-Ríos D, Mucientes G, Hillinger A, Alonso-Fernández A. 2023. Drivers of the spatial behaviour of the threatened thornback skate (Raja clavata). Aquat. Living Resour. 36: 21], published on July 25, 2023, This erratum corrects a mistake happened during the process of generating final proof of the paper. Indeed, in Table 1, the term “Probability of Presence” appearing twice in the first column of the second and the tenth lines are incorrect. It should be “Parametric coefficients”.
这是一个O关于文章[Papadopoulo K, Villegas-Ríos D, Mucientes G, Hillinger A, Alonso-Fernández A. 2023]。受威胁的刺背鳐空间行为的驱动因素(拉贾克拉瓦塔)。Aquat。《生活资源》，36:21]，发表于2023年7月25日，此勘误表纠正了在生成论文最终证明过程中发生的错误。的确，在表1中，术语“存在概率”在第二行和第十行第一列中出现两次是不正确的。应该是“参数系数”。
{"title":"Erratum to: Drivers of the spatial behaviour of the threatened thornback skate (Raja clavata)","authors":"Kenn Papadopoulo, D. Villegas‐Ríos, G. Mucientes, A. Hillinger, A. Alonso‐Fernández","doi":"10.1051/alr/2023024","DOIUrl":"https://doi.org/10.1051/alr/2023024","url":null,"abstract":"This is an O Regarding the article [Papadopoulo K, Villegas-Ríos D, Mucientes G, Hillinger A, Alonso-Fernández A. 2023. Drivers of the spatial behaviour of the threatened thornback skate (Raja clavata). Aquat. Living Resour. 36: 21], published on July 25, 2023, This erratum corrects a mistake happened during the process of generating final proof of the paper. Indeed, in Table 1, the term “Probability of Presence” appearing twice in the first column of the second and the tenth lines are incorrect. It should be “Parametric coefficients”.","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57825053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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