In 1995, the so-called “turbot war” between Spain and Canada was pivotal for Iberian fisheries. The main objective of this research is to revisit the turbot war to reflect on the issue of governing fisheries on the high seas, the cause behind the war, and how it was resolved. This paper provides guidelines for future research on the management of high seas fisheries.
{"title":"Lessons from the “turbot war”: the future of high seas governance","authors":"M. Coelho, Rui J. Lopes, André Estrela Pires","doi":"10.1051/alr/2020009","DOIUrl":"https://doi.org/10.1051/alr/2020009","url":null,"abstract":"In 1995, the so-called “turbot war” between Spain and Canada was pivotal for Iberian fisheries. The main objective of this research is to revisit the turbot war to reflect on the issue of governing fisheries on the high seas, the cause behind the war, and how it was resolved. This paper provides guidelines for future research on the management of high seas fisheries.","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57823939","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}
Selecting an appropriate growth pattern for individual fish is a meaningful but complex topic in fishery research. We model four growth functions − the commonly used von Bertalanffy growth model (VBGM), and the Gompertz growth model (GGM), Schnute–Richards growth model (SRGM), and generalized VBGM (G-VBGM) − to examine possible growth patterns. Mean total length-at-age fish datasets for five commercial fish species (yellow perch Perca flavescens, walleye Sander vitreus, northern pike Esox lucius, largemouth bass Micropterus salmoides and lake herring Coregonus artedi) from North American freshwater ecosystems, were analyzed. Using a Markov chain Monte Carlo (MCMC) algorithm, we structured four models combining informative priors of model parameters. It is the first time that deviance information criterion (DIC) and leave-one-out cross-validation (LOOCV) were combined to select the best growth model. During the model-selection process, the smooth LOOCV error successfully followed the trend of the LOOCV error, although there were difference in the curve shapes. Values of scale reduction factor (SRF) for all four models indicated convergence, ranging 1.02–1.06, below the 1.2 threshold. The GGM was selected for C. artedi, and the G-VBGM for the other four species. Our approach provided a robust process in model-selection uncertainty analysis, with the G-VBGM having the best prediction ability among our datasets.
{"title":"Model selection for fish growth patterns based on a Bayesian approach: A case study of five freshwater fish species","authors":"Kui Zhang, Jun Zhang, Jiajun Li, B. Liao","doi":"10.1051/alr/2020019","DOIUrl":"https://doi.org/10.1051/alr/2020019","url":null,"abstract":"Selecting an appropriate growth pattern for individual fish is a meaningful but complex topic in fishery research. We model four growth functions − the commonly used von Bertalanffy growth model (VBGM), and the Gompertz growth model (GGM), Schnute–Richards growth model (SRGM), and generalized VBGM (G-VBGM) − to examine possible growth patterns. Mean total length-at-age fish datasets for five commercial fish species (yellow perch Perca flavescens, walleye Sander vitreus, northern pike Esox lucius, largemouth bass Micropterus salmoides and lake herring Coregonus artedi) from North American freshwater ecosystems, were analyzed. Using a Markov chain Monte Carlo (MCMC) algorithm, we structured four models combining informative priors of model parameters. It is the first time that deviance information criterion (DIC) and leave-one-out cross-validation (LOOCV) were combined to select the best growth model. During the model-selection process, the smooth LOOCV error successfully followed the trend of the LOOCV error, although there were difference in the curve shapes. Values of scale reduction factor (SRF) for all four models indicated convergence, ranging 1.02–1.06, below the 1.2 threshold. The GGM was selected for C. artedi, and the G-VBGM for the other four species. Our approach provided a robust process in model-selection uncertainty analysis, with the G-VBGM having the best prediction ability among our datasets.","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57823696","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}
Margaux Mathieu‐Resuge, F. Le Grand, G. Schaal, E. Kraffe, A. Lorrain, Y. Letourneur, Hugues Lemonnier, J. Benoit, Sébastien Hochard
Deposit-feeding sea cucumbers are efficient nutrient recyclers and have the potential to contribute to the limitation of organic matter load in polyculture or integrated aquaculture systems. Assessing how they assimilate organic matter originating from other farmed species is therefore important for the development of such multi-species farming systems. Here, a coupled stable isotope − fatty acid approach was used to characterize the assimilation of organic matter from shrimp (Penaeus stylirostris) farming by Holothuria scabra in an experimental culture system. H. scabra were reared in mesocosms on shrimp farming-originating sediment with and without additional food sources (maize and fish meals). Although fatty acid results did indicate that shrimp-farming sediment was assimilated by holothurids, we found no evidence of maize waste and fish meal contribution to H. scabra organic carbon (no effect on δ13C, no accumulation of meal-specific fatty acids). However, a strong effect of fish meal on H. scabra δ15N was observed, suggesting that this additional food source could represent an alternative source of nitrogen for holothurids. Finally, this study supports the culture of H. scabra as a perspective to reduce sedimentary organic matter excess associated with shrimp farms, and suggest that the addition of selected food sources might contribute to increasing the content in some nitrogen organic compounds in holothurid tissues.
{"title":"Assimilation of shrimp farm sediment by Holothuria scabra: a coupled fatty acid and stable isotope approach","authors":"Margaux Mathieu‐Resuge, F. Le Grand, G. Schaal, E. Kraffe, A. Lorrain, Y. Letourneur, Hugues Lemonnier, J. Benoit, Sébastien Hochard","doi":"10.1051/alr/2020004","DOIUrl":"https://doi.org/10.1051/alr/2020004","url":null,"abstract":"Deposit-feeding sea cucumbers are efficient nutrient recyclers and have the potential to contribute to the limitation of organic matter load in polyculture or integrated aquaculture systems. Assessing how they assimilate organic matter originating from other farmed species is therefore important for the development of such multi-species farming systems. Here, a coupled stable isotope − fatty acid approach was used to characterize the assimilation of organic matter from shrimp (Penaeus stylirostris) farming by Holothuria scabra in an experimental culture system. H. scabra were reared in mesocosms on shrimp farming-originating sediment with and without additional food sources (maize and fish meals). Although fatty acid results did indicate that shrimp-farming sediment was assimilated by holothurids, we found no evidence of maize waste and fish meal contribution to H. scabra organic carbon (no effect on δ13C, no accumulation of meal-specific fatty acids). However, a strong effect of fish meal on H. scabra δ15N was observed, suggesting that this additional food source could represent an alternative source of nitrogen for holothurids. Finally, this study supports the culture of H. scabra as a perspective to reduce sedimentary organic matter excess associated with shrimp farms, and suggest that the addition of selected food sources might contribute to increasing the content in some nitrogen organic compounds in holothurid tissues.","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/alr/2020004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57823863","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}
S. G. Akmal, Brigitta P. D. Zámečníková-Wanma, R. E. Prabowo, Aulia M. Khatami, Jindřich Novák, M. Petrtýl, L. Kalous, J. Patoka
Trade with marine species as ornamentals is an important sector of the international pet trade. The vast majority of these species are collected from the wild and one of the top supplying countries is Indonesia. Detailed evidence on trade with marine resources in Indonesia is lacking or it is hardly accessible. Moreover, the exploitation of ornamental species seems to be mostly uncontrolled. This study presents detailed characteristics of such trade for Indonesia, including the offered species, their sizes, prices, and conservation status, based on data and information obtained from wholesalers in 2018. The main provinces of marine wildlife collecting are also identified. In total, 777 marine vertebrate and invertebrate species were traded, belonging to 174 families including two species classified as endangered: Banggai cardinal fish (Pterapogon kauderni) and zebra shark (Stegostoma fasciatum). Commonly traded was red lionfish (Pterois volitans), known to be a successful invader. The volume of ornamental marine fish exported from Indonesia in period 2015–2019 was 3 353 983 kgs sold for 33 123 218 USD. The province of Bali was identified as the main exporter of ornamental marine fish within Indonesia. These findings should help to establish sustainable exploitation of marine resources in relation to conservation and wildlife management.
{"title":"Marine ornamental trade in Indonesia","authors":"S. G. Akmal, Brigitta P. D. Zámečníková-Wanma, R. E. Prabowo, Aulia M. Khatami, Jindřich Novák, M. Petrtýl, L. Kalous, J. Patoka","doi":"10.1051/alr/2020026","DOIUrl":"https://doi.org/10.1051/alr/2020026","url":null,"abstract":"Trade with marine species as ornamentals is an important sector of the international pet trade. The vast majority of these species are collected from the wild and one of the top supplying countries is Indonesia. Detailed evidence on trade with marine resources in Indonesia is lacking or it is hardly accessible. Moreover, the exploitation of ornamental species seems to be mostly uncontrolled. This study presents detailed characteristics of such trade for Indonesia, including the offered species, their sizes, prices, and conservation status, based on data and information obtained from wholesalers in 2018. The main provinces of marine wildlife collecting are also identified. In total, 777 marine vertebrate and invertebrate species were traded, belonging to 174 families including two species classified as endangered: Banggai cardinal fish (Pterapogon kauderni) and zebra shark (Stegostoma fasciatum). Commonly traded was red lionfish (Pterois volitans), known to be a successful invader. The volume of ornamental marine fish exported from Indonesia in period 2015–2019 was 3 353 983 kgs sold for 33 123 218 USD. The province of Bali was identified as the main exporter of ornamental marine fish within Indonesia. These findings should help to establish sustainable exploitation of marine resources in relation to conservation and wildlife management.","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824019","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 intense exploitation since 1972 of the formerly only slightly exploited protogynous hermaphroditic fish Pagrus pagrus (L.) in southern Brazil has led in less than a decade to the collapse of the fishery, with no recovery four decades later. In this study we analized the age structure, growth, reproduction and mortality of the species were studied based on samples collected from 1976 to 1985 to provide a baseline before the onset of overexploitation. Maximum estimated ages were 21 and 26 years based on scale and otolith readings, respectively. Mean total length (TL) at age did not differ between males and females, while hermaphrodites were smaller. The von Bertalanffy growth coefficients for all fish (immature, females, hermaphrodites and males) were L∞ = 447 mm, k = 0.204 and t0 = −1.134 yr. Change in growth was observed during the study period. Females were dominant at all sizes, hermaphrodites were only present up to intermediate sizes, and males, despite being infrequent at small sizes, made up over 40% among the larger specimen (TL > 400 mm). Spawning took place mainly in late spring and condition factors were lower after spawning. Natural mortality was estimated as M = 0.173 yr−1 based on the von Bertalanffy growth parameters. Total mortality (Z) and exploitation rate (E) estimated from catch curves of fully recruited red porgies aged five to ten years increased from 0.24 yr−1 and 28% before 1973 to 0.49 yr−1 and 63% in the following years. Two distinct scale and otolith patterns, one with well-marked annuli and another with faint or absent annuli, suggested that the red porgy stock off southern Brazil might not be homogeneous and may include subpopulations that do not fully mix.
自1972年以来，巴西南部对原本只有少量开发的雌雄同体鱼Pagrus Pagrus (L.)的大量开发导致了渔业在不到十年的时间里崩溃，四十年后没有恢复。本研究以1976年至1985年收集的样本为基础，对该物种的年龄结构、生长、繁殖和死亡率进行了分析，以提供过度开发发生前的基线。根据体表和耳石读数，最大估计年龄分别为21岁和26岁。年龄平均总长度(TL)雌雄间无差异，雌雄同体较小。所有鱼(未成熟、雌性、雌雄同体和雄性)的von Bertalanffy生长系数为L∞= 447 mm, k = 0.204, t0 = - 1.134 yr。雌性在所有尺寸中均占优势，雌雄同体仅在中等尺寸中存在，而雄性尽管在小尺寸中很少出现，但在较大的标本(TL bb0 400 mm)中占40%以上。产卵主要发生在晚春，产卵后的条件因子较低。根据von Bertalanffy生长参数估计自然死亡率M = 0.173 yr - 1。5 ~ 10岁全捕红鳉鱼的总死亡率(Z)和捕捞率(E)由1973年以前的0.24年和28%增加到1973年以后的0.49年和63%。两种不同的鳞片和耳石模式，一种有明显的环空，另一种有微弱或不存在环空，表明巴西南部的红色porgy种群可能不是同质的，可能包括没有完全混合的亚种群。
{"title":"The population dynamics of the red porgy Pagrus pagrus along southern Brazil, before its fishery collapse in the 1980s: a baseline study","authors":"M. Haimovici, E. Kikuchi, L. Cardoso, R. Moralles","doi":"10.1051/alr/2020010","DOIUrl":"https://doi.org/10.1051/alr/2020010","url":null,"abstract":"The intense exploitation since 1972 of the formerly only slightly exploited protogynous hermaphroditic fish Pagrus pagrus (L.) in southern Brazil has led in less than a decade to the collapse of the fishery, with no recovery four decades later. In this study we analized the age structure, growth, reproduction and mortality of the species were studied based on samples collected from 1976 to 1985 to provide a baseline before the onset of overexploitation. Maximum estimated ages were 21 and 26 years based on scale and otolith readings, respectively. Mean total length (TL) at age did not differ between males and females, while hermaphrodites were smaller. The von Bertalanffy growth coefficients for all fish (immature, females, hermaphrodites and males) were L∞ = 447 mm, k = 0.204 and t0 = −1.134 yr. Change in growth was observed during the study period. Females were dominant at all sizes, hermaphrodites were only present up to intermediate sizes, and males, despite being infrequent at small sizes, made up over 40% among the larger specimen (TL > 400 mm). Spawning took place mainly in late spring and condition factors were lower after spawning. Natural mortality was estimated as M = 0.173 yr−1 based on the von Bertalanffy growth parameters. Total mortality (Z) and exploitation rate (E) estimated from catch curves of fully recruited red porgies aged five to ten years increased from 0.24 yr−1 and 28% before 1973 to 0.49 yr−1 and 63% in the following years. Two distinct scale and otolith patterns, one with well-marked annuli and another with faint or absent annuli, suggested that the red porgy stock off southern Brazil might not be homogeneous and may include subpopulations that do not fully mix.","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57823506","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}
Omir Abdalwahhab, A. Galal-Khallaf, Samy Abd El-Latif Saber, Alaa Osman, K. Mohammed-Geba
The Red Sea is one of the key areas of biodiversity in the world. It is a hotspot for speciation and biological invasions. In the current work, a pilot, random sampling trial was carried out to characterize some species in the landings reaching the fish market in Suez city, which is one of the largest fish markets in the Northern Red Sea. Samples of different fish species were subjected to the standard procedures of DNA barcoding, applying the sequencing of the cytochrome oxidase subunit 1 mitochondrial gene (COI). DNA barcoding could successfully identify all the targeted fishes to the species-level (>98%). The results exhibited a taxonomically-versatile commercial trends in this market, being the collected species belonging to 7 different fish families and 3 orders. These species were Coris aygula, Papilloculiceps longiceps, Priacanthus sagittarious, Gerres longirostris, Alepes djedaba, Psettodes erumei Cheilinus trilobatus, Calotomus viridescens, and Pardachirus marmoratus. Haplotype diversities in the first six species were moderate. However, their nucleotide diversities were low. This may have resulted from fishing from bottlenecked populations, or from areas that do not hinder the genetic flow. Also, possible cryptic speciation could be detected in P. sagittarius, P. erumei and G. longirostris. Applying the DNA barcoding for species identification in Suez city fish market could then detect various aspects of fish species diversity. More works using the applied analyses can be strongly recommended to aid proper conservation and management of economic fisheries in the Red Sea.
{"title":"A case study for application of DNA barcoding in identifying species and genetic diversity of fish from the Suez city market, Egypt","authors":"Omir Abdalwahhab, A. Galal-Khallaf, Samy Abd El-Latif Saber, Alaa Osman, K. Mohammed-Geba","doi":"10.1051/alr/2020012","DOIUrl":"https://doi.org/10.1051/alr/2020012","url":null,"abstract":"The Red Sea is one of the key areas of biodiversity in the world. It is a hotspot for speciation and biological invasions. In the current work, a pilot, random sampling trial was carried out to characterize some species in the landings reaching the fish market in Suez city, which is one of the largest fish markets in the Northern Red Sea. Samples of different fish species were subjected to the standard procedures of DNA barcoding, applying the sequencing of the cytochrome oxidase subunit 1 mitochondrial gene (COI). DNA barcoding could successfully identify all the targeted fishes to the species-level (>98%). The results exhibited a taxonomically-versatile commercial trends in this market, being the collected species belonging to 7 different fish families and 3 orders. These species were Coris aygula, Papilloculiceps longiceps, Priacanthus sagittarious, Gerres longirostris, Alepes djedaba, Psettodes erumei Cheilinus trilobatus, Calotomus viridescens, and Pardachirus marmoratus. Haplotype diversities in the first six species were moderate. However, their nucleotide diversities were low. This may have resulted from fishing from bottlenecked populations, or from areas that do not hinder the genetic flow. Also, possible cryptic speciation could be detected in P. sagittarius, P. erumei and G. longirostris. Applying the DNA barcoding for species identification in Suez city fish market could then detect various aspects of fish species diversity. More works using the applied analyses can be strongly recommended to aid proper conservation and management of economic fisheries in the Red Sea.","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57823561","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}
M. Toba, J. Kakino, K. Tada, Yutaka Kobayashi, Hideharu Tsuchie
In Tokyo Bay, the harvestable quantity of asari (Manila) clams Ruditapes philippinarum has been decreasing since the late 1990s. We conducted a field investigation on clam density in the Banzu culture area from April 1988 to December 2014 and collected records spanning January 1986 to September 2017 from relevant fisheries cooperative associations to clarify the relationship between the temporal variation in stock abundance and the production activities of fishermen. The yearly variation in clam abundance over the study period was marked by larger decreases in the numbers of larger clams. A large quantity of juvenile clams, beyond the biological productivity of the culture area, may have been introduced as seed stock in the late 1980s despite the high level of harvestable stock. The declines in harvested quantity began in the late 1990s and may have been caused by decreases in harvestable stock despite the continuous addition of seed stock clams. The harvested quantity is likely to be significantly dependent upon the wild clam population, even within the culture area, as the harvestable quantity was not correlated with the quantity of seed stock introduced during the study period. These declines in harvested quantity may have resulted from a decreasing number of operating harvesters due to the low level of harvestable stock and consequently reduced profitability. Two findings were emphasized. A certain management style, based on predictions of the contributions of wild and introduced clams to future stock biomass, is essential for economically-feasible culturing. In areas with less harvestable stock, actions should be taken to maintain the incomes of harvesters while avoiding overexploitation, even if the total harvest quantity decreases.
{"title":"Production of asari (Manila) clams, Ruditapes philippinarum, during the period of harvest decrease in the 2000s in the Banzu tidal area, Tokyo Bay","authors":"M. Toba, J. Kakino, K. Tada, Yutaka Kobayashi, Hideharu Tsuchie","doi":"10.1051/alr/2020016","DOIUrl":"https://doi.org/10.1051/alr/2020016","url":null,"abstract":"In Tokyo Bay, the harvestable quantity of asari (Manila) clams Ruditapes philippinarum has been decreasing since the late 1990s. We conducted a field investigation on clam density in the Banzu culture area from April 1988 to December 2014 and collected records spanning January 1986 to September 2017 from relevant fisheries cooperative associations to clarify the relationship between the temporal variation in stock abundance and the production activities of fishermen. The yearly variation in clam abundance over the study period was marked by larger decreases in the numbers of larger clams. A large quantity of juvenile clams, beyond the biological productivity of the culture area, may have been introduced as seed stock in the late 1980s despite the high level of harvestable stock. The declines in harvested quantity began in the late 1990s and may have been caused by decreases in harvestable stock despite the continuous addition of seed stock clams. The harvested quantity is likely to be significantly dependent upon the wild clam population, even within the culture area, as the harvestable quantity was not correlated with the quantity of seed stock introduced during the study period. These declines in harvested quantity may have resulted from a decreasing number of operating harvesters due to the low level of harvestable stock and consequently reduced profitability. Two findings were emphasized. A certain management style, based on predictions of the contributions of wild and introduced clams to future stock biomass, is essential for economically-feasible culturing. In areas with less harvestable stock, actions should be taken to maintain the incomes of harvesters while avoiding overexploitation, even if the total harvest quantity decreases.","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57823631","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}
M. Girard, C. Goulon, A. Tessier, P. Vonlanthen, J. Guillard
In recent years, due to an increased need for non-intrusive sampling techniques, hydroacoustics has attracted attention in fishery science and management. Efforts to promote standardisation are increasing the accuracy, efficiency, and comparability of this method. The European Water Framework Directive and the Standard Operating Procedures for Fisheries Hydroacoustic Surveys in North American Great Lakes has recommended that surveys be conducted at night. At night, fish usually disperse in the water column, thus allowing for single echo detection and subsequent accurate fish size estimation, while day-time schooling behaviour hampers the estimation of fish size. However, sampling during the day would often be safer and cheaper. This study analyses how fisheries hydroacoustic results differ between day-time and night-time surveys, using data from 14 natural temperate lakes of various size. Data collected during the day and night at two depth layers linked to thermal stratification were compared in terms of acoustic scattering strength, target strength, and biomass estimates. The results showed a significant correlation between day-time and night-time estimates, though biomass in the upper layer was biased for day-time surveys, mainly due to incorrect fish size estimates resulting from rare single echo detections and schooling behaviour. Biomass estimates for the lower depth layer did not significantly differ between the two diel periods. Thus, this study confirms that hydroacoustic sampling in temperate lakes should be performed at night for accurate fish stock biomass estimates.
{"title":"Comparisons of day-time and night-time hydroacoustic surveys in temperate lakes","authors":"M. Girard, C. Goulon, A. Tessier, P. Vonlanthen, J. Guillard","doi":"10.1051/alr/2020011","DOIUrl":"https://doi.org/10.1051/alr/2020011","url":null,"abstract":"In recent years, due to an increased need for non-intrusive sampling techniques, hydroacoustics has attracted attention in fishery science and management. Efforts to promote standardisation are increasing the accuracy, efficiency, and comparability of this method. The European Water Framework Directive and the Standard Operating Procedures for Fisheries Hydroacoustic Surveys in North American Great Lakes has recommended that surveys be conducted at night. At night, fish usually disperse in the water column, thus allowing for single echo detection and subsequent accurate fish size estimation, while day-time schooling behaviour hampers the estimation of fish size. However, sampling during the day would often be safer and cheaper. This study analyses how fisheries hydroacoustic results differ between day-time and night-time surveys, using data from 14 natural temperate lakes of various size. Data collected during the day and night at two depth layers linked to thermal stratification were compared in terms of acoustic scattering strength, target strength, and biomass estimates. The results showed a significant correlation between day-time and night-time estimates, though biomass in the upper layer was biased for day-time surveys, mainly due to incorrect fish size estimates resulting from rare single echo detections and schooling behaviour. Biomass estimates for the lower depth layer did not significantly differ between the two diel periods. Thus, this study confirms that hydroacoustic sampling in temperate lakes should be performed at night for accurate fish stock biomass estimates.","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57823521","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}
Roi Martínez-Escauriaza, C.A. Vieira, L. Gouveia, N. Gouveia, M. Hermida
Data obtained from licenses of spearfishers and surveys conducted in 2004 and 2017 allowed for the analysis, for the first time, of the practice of spearfishing in the Madeira archipelago. Only a small percentage of the population practices spearfishing, mostly local young men. Most of them practice the activity with a partner throughout most of the year and along most of the island's coastal areas, although preferentially along the North and Southeast coast. Results show how, in recent years, despite the population of spearfishers decreasing, the abundance in the annual catch potentially increased, probably due to the higher investment of time in this activity. It has been observed that many fishers complement their catches with manual collecting of invertebrates. Overall, 40 teleost fishes and also 4 crustaceans and 8 molluscs were identified. The most frequently captured fish species were parrotfish and white seabream, while limpets were the most collected invertebrates in both selected periods.
{"title":"Characterization and evolution of spearfishing in Madeira archipelago, Eastern Atlantic","authors":"Roi Martínez-Escauriaza, C.A. Vieira, L. Gouveia, N. Gouveia, M. Hermida","doi":"10.1051/alr/2020015","DOIUrl":"https://doi.org/10.1051/alr/2020015","url":null,"abstract":"Data obtained from licenses of spearfishers and surveys conducted in 2004 and 2017 allowed for the analysis, for the first time, of the practice of spearfishing in the Madeira archipelago. Only a small percentage of the population practices spearfishing, mostly local young men. Most of them practice the activity with a partner throughout most of the year and along most of the island's coastal areas, although preferentially along the North and Southeast coast. Results show how, in recent years, despite the population of spearfishers decreasing, the abundance in the annual catch potentially increased, probably due to the higher investment of time in this activity. It has been observed that many fishers complement their catches with manual collecting of invertebrates. Overall, 40 teleost fishes and also 4 crustaceans and 8 molluscs were identified. The most frequently captured fish species were parrotfish and white seabream, while limpets were the most collected invertebrates in both selected periods.","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57823619","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. Malara, P. Battaglia, P. Consoli, Erika Arcadi, S. Canese, S. Greco, F. Andaloro, T. Romeo
The Strait of Messina is located at the centre of the Mediterranean Sea and is considered a biodiversity hotspot and an obligatory seasonal passage for different pelagic species such as sharks, marine mammals, and billfishes. For the first time, in the Strait of Messina, our research group tagged a Mediterranean spearfish (Tetrapturus belone) using a pop-up satellite archival tag (PSAT). The observation of abiotic parameters (depth, light, and temperature) recorded by the PSAT confirmed that the tagged specimen was predated after about nine hours. The tag was then regurgitated 14 days after the tag deployment date. The analysis of collected data seems to indicate that the predator may be an ectothermic shark, most likely the bluntnose sixgill shark (Hexanchus griseus).
{"title":"Evidence of a predation event on a tagged Mediterranean spearfish (Tetrapturus belone; Pisces, Istiophoridae), inferred from pop-up satellite tagging data","authors":"D. Malara, P. Battaglia, P. Consoli, Erika Arcadi, S. Canese, S. Greco, F. Andaloro, T. Romeo","doi":"10.1051/alr/2020024","DOIUrl":"https://doi.org/10.1051/alr/2020024","url":null,"abstract":"The Strait of Messina is located at the centre of the Mediterranean Sea and is considered a biodiversity hotspot and an obligatory seasonal passage for different pelagic species such as sharks, marine mammals, and billfishes. For the first time, in the Strait of Messina, our research group tagged a Mediterranean spearfish (Tetrapturus belone) using a pop-up satellite archival tag (PSAT). The observation of abiotic parameters (depth, light, and temperature) recorded by the PSAT confirmed that the tagged specimen was predated after about nine hours. The tag was then regurgitated 14 days after the tag deployment date. The analysis of collected data seems to indicate that the predator may be an ectothermic shark, most likely the bluntnose sixgill shark (Hexanchus griseus).","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57823781","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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