Most cited articles
2011, 20(2):260-269.
Abstract:
Habitat suitability index (HSI) has been widely used in fishery resources exploitation, management, assessment and protection since it was found in the early 1980s, and it has become one of the most important tools in fishery science research. In this article, outlining the studies in the world, the theory and methods of HSI, and the advance applications and exist problems have been summarized. Some advice should be considered sufficiently in the application of HSI, i.e., (1) study on target species’ life history and biological characteristics and its habitats; (2) suitable environment factors should be selected according to different growth stages; (3) research on spatialtempral scales of data and rule set on data; (4) selecting logical weights upon different factors based on literature and expert knowledge; (5) selecting preparatory HSI models be propitious to the various goals, such as protection area, fishing ground and biomass evaluation; (6) selecting suitable HSI models by comparison of models and related analysis; (7) modifying models using insitu or recent data in order to improve precision of model.
Habitat suitability index (HSI) has been widely used in fishery resources exploitation, management, assessment and protection since it was found in the early 1980s, and it has become one of the most important tools in fishery science research. In this article, outlining the studies in the world, the theory and methods of HSI, and the advance applications and exist problems have been summarized. Some advice should be considered sufficiently in the application of HSI, i.e., (1) study on target species’ life history and biological characteristics and its habitats; (2) suitable environment factors should be selected according to different growth stages; (3) research on spatialtempral scales of data and rule set on data; (4) selecting logical weights upon different factors based on literature and expert knowledge; (5) selecting preparatory HSI models be propitious to the various goals, such as protection area, fishing ground and biomass evaluation; (6) selecting suitable HSI models by comparison of models and related analysis; (7) modifying models using insitu or recent data in order to improve precision of model.
CAO Jie
,
CHEN Xin-jun
,
,
LIU Bi-lin
,
TIAN Si-quan
,
QIAN Wei-guo
,
(.College of Marine Sciences
,
Shanghai Ocean University
,
Shanghai
,
China
,
.Key Laboratory of Shanghai Education Commission for Oceanic Fisheries Resources Exploitation
,
.Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources
,
Ministry of Education
,
China)
2010(2).
Abstract:
Over the past decades,with the decline of economic finfish stocks around the world,the short-life cycle squid has become one of important fishing targets and its total catches keep on increasing.Becasue the short-life cycle squid is sensitive responding to environmental changes with great abundence fluctuations,which sometimes reduces the recruitment to the stocks,the assessment and management do not work well based on traditional population dynamic models.In this paper,we review the development of methods ...
Over the past decades,with the decline of economic finfish stocks around the world,the short-life cycle squid has become one of important fishing targets and its total catches keep on increasing.Becasue the short-life cycle squid is sensitive responding to environmental changes with great abundence fluctuations,which sometimes reduces the recruitment to the stocks,the assessment and management do not work well based on traditional population dynamic models.In this paper,we review the development of methods ...
2012, 21(5):831-840.
Abstract:
The oceanic Ommastrephidae is an important cephalopod resource. The main species which have been exploited at the large scale commercial development included 〖WTBX〗Todarodes pacificus, Illex argentinus, Dosidicus gigas, Nototodarus sloani and Symplectoteuthis oualaniensis. According to the data statistics during 1992 to 2010, the Ommastrephidae production accounted for 51.15%-62.19% of cephalopods in the world, with an average of 55.40%. In this paper, the current exploitation and resources conditions of Todarodes pacificus, Illex argentinus, Dosidicus gigas and other squids are described in details. Meanwhile, according to the biological characteristics of short life cycle and fast growth, four major scientific issues which are to be resolved have been put forward. The four scientific issues are: (1) a completely comprehensive understanding of the ecological status and role of Ommastrephidae; (2) fully mastering the effect of environment including global climate change on the recruitment of Ommastrephidae; (3) further study of assessment model for Ommastrephidae based on the short life cycle; and (4) developing the ecosystem based resource management approaches for Ommastrephidae.
The oceanic Ommastrephidae is an important cephalopod resource. The main species which have been exploited at the large scale commercial development included 〖WTBX〗Todarodes pacificus, Illex argentinus, Dosidicus gigas, Nototodarus sloani and Symplectoteuthis oualaniensis. According to the data statistics during 1992 to 2010, the Ommastrephidae production accounted for 51.15%-62.19% of cephalopods in the world, with an average of 55.40%. In this paper, the current exploitation and resources conditions of Todarodes pacificus, Illex argentinus, Dosidicus gigas and other squids are described in details. Meanwhile, according to the biological characteristics of short life cycle and fast growth, four major scientific issues which are to be resolved have been put forward. The four scientific issues are: (1) a completely comprehensive understanding of the ecological status and role of Ommastrephidae; (2) fully mastering the effect of environment including global climate change on the recruitment of Ommastrephidae; (3) further study of assessment model for Ommastrephidae based on the short life cycle; and (4) developing the ecosystem based resource management approaches for Ommastrephidae.
2015, 24(1):60-67.
Abstract:
Although the wild Yangtze Eriocheir sinensis juveniles (coin-sized seed) have the better culture performance than the artifically pond-reared juveniles during the adult crab breeding stage, the culture performance of wild-caught megalopae was largely unclear. Therefore, this study was designed to compare the growth, gonadal development, survival, crab yield, feed conversion rate (FCR), final mean body weight and size distribution between wild population (WP) and artificial breeding population (AP) of E. sinensis megalopae for the Yangtze population during the adult crab culture stage. The results show that: despite of males or females, the mean body weight of WP was significantly higher than that of AP during the mid-late culture stage. It was the evidence that the males of WP had the significantly higher body weight gain rate (WGR) and specific growth rate (SGR) than those of AP duiring the periods of May-July and July-August, while the females of WP had the significantly higher WGR and SGR than those of AP duiring the period of August-September (P<0.05). Although WP had the significantly higher final mean body weight than AP, the AP had a slightly higher survival than WP, leading to the similar crab yeilds between two populations. As for the size distribution of adult crabs, WP had the higher percentage of large size crabs (male ≥175 g; female ≥125 g), but the lower proportion of middle size crabs (male: 125-174.9 g; female: 100-124.9 g) than AP for both males and females. In conclusion, wild -caught megalopae of Yangtze E. sinensis had the better culture performance than the artificial breeding population, and the selective breeding program of Yangtze E. sinensis could be based on the wild populations by the exploitation and enhancement of their excellent germplasm resources.
Although the wild Yangtze Eriocheir sinensis juveniles (coin-sized seed) have the better culture performance than the artifically pond-reared juveniles during the adult crab breeding stage, the culture performance of wild-caught megalopae was largely unclear. Therefore, this study was designed to compare the growth, gonadal development, survival, crab yield, feed conversion rate (FCR), final mean body weight and size distribution between wild population (WP) and artificial breeding population (AP) of E. sinensis megalopae for the Yangtze population during the adult crab culture stage. The results show that: despite of males or females, the mean body weight of WP was significantly higher than that of AP during the mid-late culture stage. It was the evidence that the males of WP had the significantly higher body weight gain rate (WGR) and specific growth rate (SGR) than those of AP duiring the periods of May-July and July-August, while the females of WP had the significantly higher WGR and SGR than those of AP duiring the period of August-September (P<0.05). Although WP had the significantly higher final mean body weight than AP, the AP had a slightly higher survival than WP, leading to the similar crab yeilds between two populations. As for the size distribution of adult crabs, WP had the higher percentage of large size crabs (male ≥175 g; female ≥125 g), but the lower proportion of middle size crabs (male: 125-174.9 g; female: 100-124.9 g) than AP for both males and females. In conclusion, wild -caught megalopae of Yangtze E. sinensis had the better culture performance than the artificial breeding population, and the selective breeding program of Yangtze E. sinensis could be based on the wild populations by the exploitation and enhancement of their excellent germplasm resources.
2012, 21(3):431-438.
Abstract:
Illex argentinus is an important target species for Chinese squid jigging fleets in the southwest Atlantic,and the accurate forecasting of fishing ground can provide better scientific guidance for fishing activities. In this study, according to the Chinese squid fishing production data during the main fishing season (January to May) from 2000 to 2005, combined with sea surface temperature (SST) and chl.a accordingly, the percentage of fishing times and daily catch (CPUE) will be considered as the suitability index (SI). Using arithmetic mean model (AM) to establish the integrated habitat suitability index (HSI) based on SST and chl.a from 2000 to 2004, and the fishing and environmental data were used to test the established HSI model from January to May in 2005. The results indicated that AM model is fitted well. According to the data from January to May in 2005, we found that the main fishing ground is distributed in the waters with HSI more than 0.6 from the AM HSI model, and its percentage of fishing times reached more than 76 percent and its average CPUE were above 7.6 t/d. The results showed that the AM HSI model based on SST and chl.a can better predict the fishing grounds of squid in the southwest Atlantic and the accuracy rate of forecasting fishing ground reaches more than 70%.
Illex argentinus is an important target species for Chinese squid jigging fleets in the southwest Atlantic,and the accurate forecasting of fishing ground can provide better scientific guidance for fishing activities. In this study, according to the Chinese squid fishing production data during the main fishing season (January to May) from 2000 to 2005, combined with sea surface temperature (SST) and chl.a accordingly, the percentage of fishing times and daily catch (CPUE) will be considered as the suitability index (SI). Using arithmetic mean model (AM) to establish the integrated habitat suitability index (HSI) based on SST and chl.a from 2000 to 2004, and the fishing and environmental data were used to test the established HSI model from January to May in 2005. The results indicated that AM model is fitted well. According to the data from January to May in 2005, we found that the main fishing ground is distributed in the waters with HSI more than 0.6 from the AM HSI model, and its percentage of fishing times reached more than 76 percent and its average CPUE were above 7.6 t/d. The results showed that the AM HSI model based on SST and chl.a can better predict the fishing grounds of squid in the southwest Atlantic and the accuracy rate of forecasting fishing ground reaches more than 70%.
2012, 21(5):841-847.
Abstract:
Retrospective problem (RR) was defined as systematic biases in successive estimations of fishery parameters (typically stock biomass and fishing mortality) with additional years of data added in stock assessment. RP arising in many fishery stock assessments can potentially result in large uncertainty in fish stock biomass estimates, which will lead to over exploit or under exploit fish populations. RP is one of hot and hard topics in fishery stock assessment at present. The MOHN ρ was used mainly as the metric of RP and the cause of RP was reduced to errors in data or in assumption of models or both. At present, there were diverse methods for diagnoses of RP, but these methods were generally valid only in some specific case. The researchers working on fisheries stock assessment provided some methods to fix or avoid RP according to their specific study, but there was still a lack of general methods or means to correct or avoid RP. If RP occurred in a stock assessment, there must be some errors in data or assumption of the model. Therefore, Retrospective analysis was effective means to assess the quality of the data and check the consistency of assumption between data and the model.
Retrospective problem (RR) was defined as systematic biases in successive estimations of fishery parameters (typically stock biomass and fishing mortality) with additional years of data added in stock assessment. RP arising in many fishery stock assessments can potentially result in large uncertainty in fish stock biomass estimates, which will lead to over exploit or under exploit fish populations. RP is one of hot and hard topics in fishery stock assessment at present. The MOHN ρ was used mainly as the metric of RP and the cause of RP was reduced to errors in data or in assumption of models or both. At present, there were diverse methods for diagnoses of RP, but these methods were generally valid only in some specific case. The researchers working on fisheries stock assessment provided some methods to fix or avoid RP according to their specific study, but there was still a lack of general methods or means to correct or avoid RP. If RP occurred in a stock assessment, there must be some errors in data or assumption of the model. Therefore, Retrospective analysis was effective means to assess the quality of the data and check the consistency of assumption between data and the model.
WANG Wei
,
CHEN Jun
,
LIU Huang
,
HE Ya-ping (.Fishery Machinery
,
Instrument Reserch Institute of Chinece Academy of Fishery Scinces
,
Shanghai
,
China
,
.Key Laboratory of Fishery Equipment
,
Engineering
,
Ministry of Agriculture
,
China)
2010(1).
Abstract:
Aquaculture water purification technology is one part of modern aquaculture engineering.Taking water body as object of study,its aim is to solve the problems of aquatic products safety,fish diseases and resource environment,by using controllable artificial measures,and physical,chemical and biological methods to improve the aquaculture water environment.The current aquaculture water purification technology in China mainly includes physical filtration,ultraviolet & ozone disinfection,water aeration,artificia...
Aquaculture water purification technology is one part of modern aquaculture engineering.Taking water body as object of study,its aim is to solve the problems of aquatic products safety,fish diseases and resource environment,by using controllable artificial measures,and physical,chemical and biological methods to improve the aquaculture water environment.The current aquaculture water purification technology in China mainly includes physical filtration,ultraviolet & ozone disinfection,water aeration,artificia...
ZHAO Jing
,
ZHANG Shou-yu
,
XU Min(Marine Ecosystem & Environmental Laboratory
,
College of Marine Sciences
,
Shanghai Ocean University
,
Shanghai
,
China)
2010(1).
Abstract:
The kelp bed is a typical offshore ecosystem,with especial ecosystem structure and abundance aquicolous resources,which made it have a complex energy structure and obvious character.By using Ecopath with Ecosim(EWE) software,a mass-balanced ecopath model of the kelp bed ecosystem in Gouqi was constructed.Through the analysis of the trophic level,energy flowing,and the ecosystem characters etc.also combining the function of kelp bed,the state of the kelp bed was estimated,and the causes were discussed here.T...
The kelp bed is a typical offshore ecosystem,with especial ecosystem structure and abundance aquicolous resources,which made it have a complex energy structure and obvious character.By using Ecopath with Ecosim(EWE) software,a mass-balanced ecopath model of the kelp bed ecosystem in Gouqi was constructed.Through the analysis of the trophic level,energy flowing,and the ecosystem characters etc.also combining the function of kelp bed,the state of the kelp bed was estimated,and the causes were discussed here.T...
CHENG Fang
,
LING Qu-fei
,
XU Hai-jun
,
LIN Jian-hua
,
WU Lin-kun
,
JIA Wen-fang (.School of Life Sciences
,
Soochow University
,
Suzhou
,
China
,
.Taihu Lake Fisheries Administration Committee of Jiangsu Province
,
Suzhou
,
China)
2010(1).
Abstract:
The analysis samples of water chemistry and aquatic biology were collected quarterly in Taihu Lake from November 2007 to August 2008.We evaluate the actual condition of water quality and the main pollution sources of Taihu Lake by ways of water pollution index and comprehensive analysis of eutrophication.Evaluation of water pollution index analysis revealed that the main pollutants in Taihu Lake were nitrogen(N),phosphorus(P) and organic oxygen consumption(COD Mn).Total phosphorus(TP) shared the largest pol...
The analysis samples of water chemistry and aquatic biology were collected quarterly in Taihu Lake from November 2007 to August 2008.We evaluate the actual condition of water quality and the main pollution sources of Taihu Lake by ways of water pollution index and comprehensive analysis of eutrophication.Evaluation of water pollution index analysis revealed that the main pollutants in Taihu Lake were nitrogen(N),phosphorus(P) and organic oxygen consumption(COD Mn).Total phosphorus(TP) shared the largest pol...
ZHANG Hua-wei
,
MA Jia-hai
,
HU Xiang
,
YANG Jian-qiang
,
ZHANG Tian-fu
,
CHEN Bin-bin
,
XU Ren
,
YE Shu-feng
2011, 20(4):600-606.
Abstract:
In the last three years, vast green tides occurred repeatedly in the Yellow Sea area every summer. The biomass of floating green tide algae increased fast in a few months, moreover, the area covered by floating green tide algae expanded sharply. The material of this study is the dominant species Ulva prolifera in green tide. The reproductive characteristics study of the floating green algae showed that every square centimeter of the thalli produced about 5.35×106 spores or 1.07×107 gametes; during May to August, 25% surface area of the mature thalli produced about 1.15×107 spores or 2.31×107gametes. Parthenogenesis and asexual reproduction are the main reproductive modes of the floating green algae. Gametes showed intensive positive phototaxis, after syngamy, motile zygotes showed negative phototaxis. The spores and gametes could grow to new thalli independently, and the same to motile zygotes. As a result, the strong reproductive capacity of floating green tide algae Ulva prolifera might be the main reason of green tide occurrence.
In the last three years, vast green tides occurred repeatedly in the Yellow Sea area every summer. The biomass of floating green tide algae increased fast in a few months, moreover, the area covered by floating green tide algae expanded sharply. The material of this study is the dominant species Ulva prolifera in green tide. The reproductive characteristics study of the floating green algae showed that every square centimeter of the thalli produced about 5.35×106 spores or 1.07×107 gametes; during May to August, 25% surface area of the mature thalli produced about 1.15×107 spores or 2.31×107gametes. Parthenogenesis and asexual reproduction are the main reproductive modes of the floating green algae. Gametes showed intensive positive phototaxis, after syngamy, motile zygotes showed negative phototaxis. The spores and gametes could grow to new thalli independently, and the same to motile zygotes. As a result, the strong reproductive capacity of floating green tide algae Ulva prolifera might be the main reason of green tide occurrence.
2017, 26(3):450-457.
DOI: 10.12024/jsou.20160501781
Abstract:
Squid is one of the important economic species in the northwestern Pacific. Using Catch per Unit Effort and V% as the target of central fishing ground and adopting BP artificial neural network, we forecast fishing ground in the northwest Pacific Ocean. The study was based on the data of squid fishing and relevant marine environment factors, including longitude, latitude, SST and SSHA from July to November from 1995 to 2001.The input factor is marine environment factor, the output factors are CPUE and V% and 4-3-1 and 4-2-1 model total 4 kinds models were used to compare which is the best suitable model for fishery forecast. The minimum fitting residual of model is the best one. Result shows that 4-3-1 is the best suitable model for each month, but the best suitable model for July and August is 4-3-1 with output V% and best suitable model for September, October and November is 4-3-1 with output CPUE, the minimum overall average error is 4-3-1 model output V%. Research suggests that there are differences as a center of fishery forecast targets by CPUE and V%, and the 4-3-1 model output V% can be used as forecasting model of squid fishing ground.
Squid is one of the important economic species in the northwestern Pacific. Using Catch per Unit Effort and V% as the target of central fishing ground and adopting BP artificial neural network, we forecast fishing ground in the northwest Pacific Ocean. The study was based on the data of squid fishing and relevant marine environment factors, including longitude, latitude, SST and SSHA from July to November from 1995 to 2001.The input factor is marine environment factor, the output factors are CPUE and V% and 4-3-1 and 4-2-1 model total 4 kinds models were used to compare which is the best suitable model for fishery forecast. The minimum fitting residual of model is the best one. Result shows that 4-3-1 is the best suitable model for each month, but the best suitable model for July and August is 4-3-1 with output V% and best suitable model for September, October and November is 4-3-1 with output CPUE, the minimum overall average error is 4-3-1 model output V%. Research suggests that there are differences as a center of fishery forecast targets by CPUE and V%, and the 4-3-1 model output V% can be used as forecasting model of squid fishing ground.
12 Review on the early life history of neon flying squid Ommastrephes bartramii in the North Pacific
2013, 22(5):755-762.
Abstract:
Ommastrephes bartramii is a kind of short life cycle species which has the characteristics of dying immediately after spawning, and the stock size entirely depends on the recruitment, while the recruitment mainly depends on its mortality in the early life stage.Ommastrephes bartramii is an important economic cephalopod, and is widely distribute in the North Pacific Ocean, therefore understanding the progress of the early life history of Ommastrephes bartramii thoroughly can play an important role in predicting the changes of recruitment in the next year. For this purpose, this paper mainly reviews and discusses the distribution of paralarvae and juveniles of Ommastrephes bartramii, feeding, age and growth, natural mortality, and also the correlation between the environment and recruitment. This paper also gives a brief introduction to the progress of embryonic development and morphological changes of larvae. The early life history which is from spawning to hatching and embryonic development to grow to be larvae is a very important and least understood stage. Future research should focus on this stage by studying the growth and death of the larvae and the influence of environment changes on the squid hatching success, as well as the stock recruitment.
Ommastrephes bartramii is a kind of short life cycle species which has the characteristics of dying immediately after spawning, and the stock size entirely depends on the recruitment, while the recruitment mainly depends on its mortality in the early life stage.Ommastrephes bartramii is an important economic cephalopod, and is widely distribute in the North Pacific Ocean, therefore understanding the progress of the early life history of Ommastrephes bartramii thoroughly can play an important role in predicting the changes of recruitment in the next year. For this purpose, this paper mainly reviews and discusses the distribution of paralarvae and juveniles of Ommastrephes bartramii, feeding, age and growth, natural mortality, and also the correlation between the environment and recruitment. This paper also gives a brief introduction to the progress of embryonic development and morphological changes of larvae. The early life history which is from spawning to hatching and embryonic development to grow to be larvae is a very important and least understood stage. Future research should focus on this stage by studying the growth and death of the larvae and the influence of environment changes on the squid hatching success, as well as the stock recruitment.
2013, 22(5).
Abstract:
The oceanic squid is a kind of short life cycle species which has the characteristics of being dead immediately after spawning, and the stock size entirely depends on the recruitment, while the recruitment mainly depends on the mortality of the oceanic squid in the early life stages. Ommastrephes bartramii is an important economic cephalopod, and widely distribute in the North Pacific Ocean, therefore understanding the progress of the early life history of Ommastrephes bartramii thoroughly can play an important role on predicting the changes of recruitment in the next year. For this purpose, this paper mainly reviews and discusses the distribution of paralarval and juvenile of Ommastrephes bartramii, feeding, age and growth, natural mortality, also the correlation between the environment and recruitment. This passage also gives a brief introduction of the progress of embryonic development and morphological changes of larvae. The early life history which is from spawning to hatching and embryonic development to grow to be larvae is a very important and least understood stage. Future research should focus on this stage by studying the growth and death of the larvae and the influents of environment changes on the squid hatching success, as well as the stock recruitment.
The oceanic squid is a kind of short life cycle species which has the characteristics of being dead immediately after spawning, and the stock size entirely depends on the recruitment, while the recruitment mainly depends on the mortality of the oceanic squid in the early life stages. Ommastrephes bartramii is an important economic cephalopod, and widely distribute in the North Pacific Ocean, therefore understanding the progress of the early life history of Ommastrephes bartramii thoroughly can play an important role on predicting the changes of recruitment in the next year. For this purpose, this paper mainly reviews and discusses the distribution of paralarval and juvenile of Ommastrephes bartramii, feeding, age and growth, natural mortality, also the correlation between the environment and recruitment. This passage also gives a brief introduction of the progress of embryonic development and morphological changes of larvae. The early life history which is from spawning to hatching and embryonic development to grow to be larvae is a very important and least understood stage. Future research should focus on this stage by studying the growth and death of the larvae and the influents of environment changes on the squid hatching success, as well as the stock recruitment.
2014, 23(1):123-130.
Abstract:
CPUE (catch per unit effort) standardization is an essential task in fisheries stock assessment and GLM (generalized linear model) which has been used as a standardized method in the CPUE standardization. Before using GLM, the error structure, independent variables, and interaction between variables in the model had to be assigned and it would cause a great error if the assumption was wrong. Moreover, GLM could not be used to handle missing values automatically and to detect and extract complex interactions from the CPUE data. Outliers also had a great impact on the results estimated by using GLM. In contrast to GLM, regression trees may do a great job to deal with the above situations. In this paper, based on simulation data and chub mackerel (Scomber japonicus) catch and effort data from Chinese lighting-purse seine fishery in the East China Sea and Yellow Sea, we compared the performance of the regression tree and GLM in the CPUE standardization and the results showed that both models could do a good job if there were no outliers in the data and nonlinear relationships between nominal CPUE and abundance. Because the regression tree was characterized by a step function, the GLM was better in standardizing CPUE in this situation. However, if there were outliers and nonlinear relationships, the regression tree would harvest less root mean square errors and explain more deviations with fewer variables than GLM. The regression tree also could detect the complex relationships between independent variables and response variables by visualization which was ideally suited to explore and analyze the catch and effort data from fisheries.
CPUE (catch per unit effort) standardization is an essential task in fisheries stock assessment and GLM (generalized linear model) which has been used as a standardized method in the CPUE standardization. Before using GLM, the error structure, independent variables, and interaction between variables in the model had to be assigned and it would cause a great error if the assumption was wrong. Moreover, GLM could not be used to handle missing values automatically and to detect and extract complex interactions from the CPUE data. Outliers also had a great impact on the results estimated by using GLM. In contrast to GLM, regression trees may do a great job to deal with the above situations. In this paper, based on simulation data and chub mackerel (Scomber japonicus) catch and effort data from Chinese lighting-purse seine fishery in the East China Sea and Yellow Sea, we compared the performance of the regression tree and GLM in the CPUE standardization and the results showed that both models could do a good job if there were no outliers in the data and nonlinear relationships between nominal CPUE and abundance. Because the regression tree was characterized by a step function, the GLM was better in standardizing CPUE in this situation. However, if there were outliers and nonlinear relationships, the regression tree would harvest less root mean square errors and explain more deviations with fewer variables than GLM. The regression tree also could detect the complex relationships between independent variables and response variables by visualization which was ideally suited to explore and analyze the catch and effort data from fisheries.
2011, 20(1):102-107.
Abstract:
Based on the catch and fishing effort data from small scale traditional light seining fisheries of Zhejiang Province and abundance data estimated by Fisheries Agency of Japan, the influence of the sea surface temperature (SST) from East China Sea and sea surface temperature anomaly (SSTA) from Niňo 3.4 area on the stock size of chub mackerel in East China Sea was analyzed. The results showed that there were significant positive relation (P<0.05) between SST and CPUE derived from small scale traditional light seining fisheries of Zhejiang Province and significant negative relation (P<0.05) between SST and abundance from Japan. The averaged SSTA of Niňo 3.4 from January to March can be considered as an index which roughly reflected abundance levels. When the averaged SSTA was negative, there was a great chance in lean year for chub mackerel stock, and vice versa. The opposite relationships between SST and abundance from different areas may be attributed to the influence of SST on migration of chub mackerel. La Niňa event would have a negative impact on the resource in the whole East China Sea, but the reason needs to be investigated in the future. The results indicated that the temporal and spatial dynamics of the stock should be included in the stock assessment for chub mackerel.
Based on the catch and fishing effort data from small scale traditional light seining fisheries of Zhejiang Province and abundance data estimated by Fisheries Agency of Japan, the influence of the sea surface temperature (SST) from East China Sea and sea surface temperature anomaly (SSTA) from Niňo 3.4 area on the stock size of chub mackerel in East China Sea was analyzed. The results showed that there were significant positive relation (P<0.05) between SST and CPUE derived from small scale traditional light seining fisheries of Zhejiang Province and significant negative relation (P<0.05) between SST and abundance from Japan. The averaged SSTA of Niňo 3.4 from January to March can be considered as an index which roughly reflected abundance levels. When the averaged SSTA was negative, there was a great chance in lean year for chub mackerel stock, and vice versa. The opposite relationships between SST and abundance from different areas may be attributed to the influence of SST on migration of chub mackerel. La Niňa event would have a negative impact on the resource in the whole East China Sea, but the reason needs to be investigated in the future. The results indicated that the temporal and spatial dynamics of the stock should be included in the stock assessment for chub mackerel.
2011, 20(1):108-113.
Abstract:
Sea water temperature (SST) is one of the important factors that impact growth, reproduction and recruitment of chub mackerel. According to the catch and standardized CPUE data of purse seine fishery with lights (PSFL) and monthly sea surface temperature of the spawning ground in February from 1998 to 2006, the author developed a surplus production model for chub mackerel based on SST, and analyzed the impact of SST on the chub mackerel stock and its sustainable yield. The result indicates the relationship between sustainable yield and SST, can be expressed as Yt=1 080.97 ft-0.006f2t+114.51SSTt ft-2.91SST2tft. Variations of chub mackerel stock biomass and sustainable yield are controlled mainly by SST in the spawning ground and fishing effort. The optimal SST range for chub mackerel spawning is 18.5- 20.6℃. It is suggested that the maximum sustainable yield may be estimated based on the annual different environmental conditions, and the fishery management measures should be adjusted in realtime.
Sea water temperature (SST) is one of the important factors that impact growth, reproduction and recruitment of chub mackerel. According to the catch and standardized CPUE data of purse seine fishery with lights (PSFL) and monthly sea surface temperature of the spawning ground in February from 1998 to 2006, the author developed a surplus production model for chub mackerel based on SST, and analyzed the impact of SST on the chub mackerel stock and its sustainable yield. The result indicates the relationship between sustainable yield and SST, can be expressed as Yt=1 080.97 ft-0.006f2t+114.51SSTt ft-2.91SST2tft. Variations of chub mackerel stock biomass and sustainable yield are controlled mainly by SST in the spawning ground and fishing effort. The optimal SST range for chub mackerel spawning is 18.5- 20.6℃. It is suggested that the maximum sustainable yield may be estimated based on the annual different environmental conditions, and the fishery management measures should be adjusted in realtime.
2012, 21(6):955-964.
Abstract:
From May to September in 2010, water quality parameters such as water temperature, total dissolved salt, dissolved oxygen, pH, transparency, nitrite nitrogen, ammonia nitrogen, nitrate nitrogen, total nitrogen, reactive phosphorus, total phosphorus, chlorophyll a and biochemical oxygen demand were analyzed in 22 Litopenaeus vannamei ponds with different culturing methods in Fengxian District, Shanghai. Water used for Farm No.1 was natural fresh water which had been precipitated before being introduced to the ponds. Mixed salt were added to the fresh water for culturing shrimp in Farm No.2. Results were as follows: water temperature, dissolved oxygen and pH didn’t change dramatically and could match the demand of Litopenaeus vannamei. The proportion of nitrate nitrogen in ponds to TIN was the highest, the ratio of ammonia nitrogen to TIN increased with time extension, and that of nitrite nitrogen to TIN increased obviously in the later period of culture cycle. Contents of reactive phosphorus decreased gradually while the total phosphorus increased in the whole process of culture. Biochemical oxygen demand and chlorophyll a also increased gradually with the shrimp growing up. Muscle nutritional quality of Litopenaeus vannamei from the two farms were analyzed and the results were as follows: contents of crude protein and crude fat of shrimp muscle in Farm No.1 were 16.30% and 1.42% respectively, lower than those in shrimp muscle from Farm No.2 which were 18.30% and 1.61%. Content of total amino acids in shrimp from Farm No.1was 23.27%, and the essential amino acid was 9.09%. While those in shrimp from Farm No.2 were 27.52% and 10.74%. Contents of flavor amino acids in shrimp from Farms No.1 and 2 were 8.52% and 10.16% respectively.
From May to September in 2010, water quality parameters such as water temperature, total dissolved salt, dissolved oxygen, pH, transparency, nitrite nitrogen, ammonia nitrogen, nitrate nitrogen, total nitrogen, reactive phosphorus, total phosphorus, chlorophyll a and biochemical oxygen demand were analyzed in 22 Litopenaeus vannamei ponds with different culturing methods in Fengxian District, Shanghai. Water used for Farm No.1 was natural fresh water which had been precipitated before being introduced to the ponds. Mixed salt were added to the fresh water for culturing shrimp in Farm No.2. Results were as follows: water temperature, dissolved oxygen and pH didn’t change dramatically and could match the demand of Litopenaeus vannamei. The proportion of nitrate nitrogen in ponds to TIN was the highest, the ratio of ammonia nitrogen to TIN increased with time extension, and that of nitrite nitrogen to TIN increased obviously in the later period of culture cycle. Contents of reactive phosphorus decreased gradually while the total phosphorus increased in the whole process of culture. Biochemical oxygen demand and chlorophyll a also increased gradually with the shrimp growing up. Muscle nutritional quality of Litopenaeus vannamei from the two farms were analyzed and the results were as follows: contents of crude protein and crude fat of shrimp muscle in Farm No.1 were 16.30% and 1.42% respectively, lower than those in shrimp muscle from Farm No.2 which were 18.30% and 1.61%. Content of total amino acids in shrimp from Farm No.1was 23.27%, and the essential amino acid was 9.09%. While those in shrimp from Farm No.2 were 27.52% and 10.74%. Contents of flavor amino acids in shrimp from Farms No.1 and 2 were 8.52% and 10.16% respectively.
2018, 27(4):531-542.
DOI: 10.12024/jsou.20171002156
Abstract:
In order to study the effect of composite vertical subsurface flow constructed wetlands on the removal of heavy metals in pond aquaculture water, the correlation between different plant roots and their substrates near roots on heavy metal enrichment effect, different environmental factors and heavy metal enrichment rate were analyzed by measuring water quality index and heavy metal. The results showed that the removal efficiencies of Pb and Cu in constructed wetlands were 77.20% and 41.70%, respectively. Compared with other types of wetlands, the composite vertical subsurface flow constructed wetlands had some advantages for the removal of Pb and Cu; the As was released in wetland with an average release rate of 8.40%. The roots of Polygonum hydropiper and Thalia dealbata Fraser have enrichment effect on Cr, As, Pb and Cu, and the roots of Pontederia cordata L. have only enrichment of Cr and As. The substrates near the roots of Polygonum hydropiper, Pontederia cordata L., and Thalia dealbata Fraser have a good enrichment effect on chromium, and among them, the maximum rate of the concentration of Pontederia cordata L. to chromium is 0.987mg/(kg·d). The enrichment rate of Pb and Cu in Polygonum hydropiper root was negatively correlated with temperature and the enrichment rate of Cr and Cu was negatively correlated with pH; the enrichment rate of Cr and As in Pontederia cordata L. root was negatively correlated with temperature; the enrichment rate of Pb in Thalia dealbata Fraser root was negatively correlated with temperature and pH, the enrichment rate of Cu was negatively correlated with temperature. The results of this study provide a theoretical basis and reference for the application of composite vertical subsurface flow constructed wetlands and the selection of wetland plants from the perspective of heavy metal removal.
In order to study the effect of composite vertical subsurface flow constructed wetlands on the removal of heavy metals in pond aquaculture water, the correlation between different plant roots and their substrates near roots on heavy metal enrichment effect, different environmental factors and heavy metal enrichment rate were analyzed by measuring water quality index and heavy metal. The results showed that the removal efficiencies of Pb and Cu in constructed wetlands were 77.20% and 41.70%, respectively. Compared with other types of wetlands, the composite vertical subsurface flow constructed wetlands had some advantages for the removal of Pb and Cu; the As was released in wetland with an average release rate of 8.40%. The roots of Polygonum hydropiper and Thalia dealbata Fraser have enrichment effect on Cr, As, Pb and Cu, and the roots of Pontederia cordata L. have only enrichment of Cr and As. The substrates near the roots of Polygonum hydropiper, Pontederia cordata L., and Thalia dealbata Fraser have a good enrichment effect on chromium, and among them, the maximum rate of the concentration of Pontederia cordata L. to chromium is 0.987mg/(kg·d). The enrichment rate of Pb and Cu in Polygonum hydropiper root was negatively correlated with temperature and the enrichment rate of Cr and Cu was negatively correlated with pH; the enrichment rate of Cr and As in Pontederia cordata L. root was negatively correlated with temperature; the enrichment rate of Pb in Thalia dealbata Fraser root was negatively correlated with temperature and pH, the enrichment rate of Cu was negatively correlated with temperature. The results of this study provide a theoretical basis and reference for the application of composite vertical subsurface flow constructed wetlands and the selection of wetland plants from the perspective of heavy metal removal.
2013, 22(2):219-224.
Abstract:
112 Aeromonas strains were isolated from various aquatic animals at different time in Guangdong province. Kirby Bauer disc diffusion method was used to detect the resistance of 112 strains against 20 commonly used antimicrobial agents. Resistance rates were analyzed by WHONET 5.6 software. The overall resistance rates were highest for ampicillin (85.7%) and cephalothin (79.5%) followed by rifampicin (57.1%)，amoxicillin/clavulanic acid (51.8%)，streptomycin (49.1%)，sulfonamides (31.2%)，cefoxitin（28.6%），tetracycline (28.6%) and trimethoprim/sulfamethoxazole (21.4%). Aeromonas isolates were suseptible to most of antimicrobial agents and a low incidence (<10%) of resistance to imipenem (0.9%)，nitrofurantoin (0.9%), ceftriaxone (1.8%)， cefotaxime (2.7%) and amikacin (3.6%) were observed. Although 46.6% of isolates displayed nalidixic acid resistance，majority of isolates were very susceptible to other kinds of fluroquinolones. Compared with the resistance rates of different antimicrobial agents from different origins of aquatic animals, fluroquinolones and cephalosporins resistance was more prevalent in strains from reptiles, amphibians and ornamental fishes than those from farm fishes and shrimps. Our results showed that antimicrobial resistant Aeromonas were widespread in the aquaculture in Guangdong and show various resistant rates to different antimircrobial agents. There is a need to build a national surveillance system of antimicrobial resistance in aquaculture.
112 Aeromonas strains were isolated from various aquatic animals at different time in Guangdong province. Kirby Bauer disc diffusion method was used to detect the resistance of 112 strains against 20 commonly used antimicrobial agents. Resistance rates were analyzed by WHONET 5.6 software. The overall resistance rates were highest for ampicillin (85.7%) and cephalothin (79.5%) followed by rifampicin (57.1%)，amoxicillin/clavulanic acid (51.8%)，streptomycin (49.1%)，sulfonamides (31.2%)，cefoxitin（28.6%），tetracycline (28.6%) and trimethoprim/sulfamethoxazole (21.4%). Aeromonas isolates were suseptible to most of antimicrobial agents and a low incidence (<10%) of resistance to imipenem (0.9%)，nitrofurantoin (0.9%), ceftriaxone (1.8%)， cefotaxime (2.7%) and amikacin (3.6%) were observed. Although 46.6% of isolates displayed nalidixic acid resistance，majority of isolates were very susceptible to other kinds of fluroquinolones. Compared with the resistance rates of different antimicrobial agents from different origins of aquatic animals, fluroquinolones and cephalosporins resistance was more prevalent in strains from reptiles, amphibians and ornamental fishes than those from farm fishes and shrimps. Our results showed that antimicrobial resistant Aeromonas were widespread in the aquaculture in Guangdong and show various resistant rates to different antimircrobial agents. There is a need to build a national surveillance system of antimicrobial resistance in aquaculture.
2011, 20(5):688-696.
Abstract:
From August 2009 to August 2010, larval and juvenile fishes were monthly collected by a seine net(1m×4m，1 mm meshaperture) in the surf zones of south branch of Yangtze River estuary and north coast of Hangzhou Bay. 267 hauls were conducted in the Yangtze River estuary, and a total of 11 066 catches belonging to 43 species from 23 families were collected, the most dominant species was Coilia nasus which comprised 64.44% of the total catches.195 hauls were conducted in Hangzhou Bay, a total of 3 841 catches belonging to 62 species from 23 families were collected, Acentrogobius pflaumii and Eleutheronema rhadinum comprised 61.73% of the total catches. The differences of geography and aquatic environment between two areas affected composition of fish assemblage, while 26 mutual species occurred, the dissimilarity index still rose to 0.927. Developmental stage of fish larvae and juveniles also showed some differences, postflexion and juvenile fish dominated the total catches in Hangzhou Bay, whereas the variation in Yangtze River estuary was not in evidence.Community diversity of Hangzhou Bay is higher than that of the Yangtze River estuary, and the Margalef index, ShannonWierner index and Pielou eveness index were all higher. Kdominance curves revealed that the species richness was higher in Hangzhou Bay.
From August 2009 to August 2010, larval and juvenile fishes were monthly collected by a seine net(1m×4m，1 mm meshaperture) in the surf zones of south branch of Yangtze River estuary and north coast of Hangzhou Bay. 267 hauls were conducted in the Yangtze River estuary, and a total of 11 066 catches belonging to 43 species from 23 families were collected, the most dominant species was Coilia nasus which comprised 64.44% of the total catches.195 hauls were conducted in Hangzhou Bay, a total of 3 841 catches belonging to 62 species from 23 families were collected, Acentrogobius pflaumii and Eleutheronema rhadinum comprised 61.73% of the total catches. The differences of geography and aquatic environment between two areas affected composition of fish assemblage, while 26 mutual species occurred, the dissimilarity index still rose to 0.927. Developmental stage of fish larvae and juveniles also showed some differences, postflexion and juvenile fish dominated the total catches in Hangzhou Bay, whereas the variation in Yangtze River estuary was not in evidence.Community diversity of Hangzhou Bay is higher than that of the Yangtze River estuary, and the Margalef index, ShannonWierner index and Pielou eveness index were all higher. Kdominance curves revealed that the species richness was higher in Hangzhou Bay.
