Most cited articles
1 Development status of world cephalopod fisheries and suggestions for squid jigging fishery in China
2019, 28(3):321-330.
DOI: 10.12024/jsou.20181102445
Abstract:
The cephalopods are one of the most potential fishing species in the world and have become an important component of the world's marine fishing industry. The world cephalopod fisheries and their composition were analysed using the grey association method based on the world cephalopod production statistics from 1970 to 2016. According to the development status of China's pelagic squid fishery, the problems are pointed out and the development countermeasures are put forward. The analysis found that the world's cephalopod fishing production in the period from 1970 to 2016 generally showed a relatively stable growth trend, with an annual growth rate of 3.68%, which is much higher than the growth rate of world marine fishing production in the same period, and reached its highest level ever in 2014. Between 2010 and 2016, the proportion of cephalopods in world fishing production stabilized between 4.5% and 6.0%. The composition and proportion of the production for different families have varied from one generation to another, and the production of main countries and areas has changed greatly. In the 2010s, the proportion of each family was Ommastrephidae (58.41%), Loliginidae (11.98%), Octopodidae (8.92%), and Sepiidae (8.40%). Asia has played the important role in the cephalopod fishery in the world for more than 40 years. Japanese cephalopod production fell from 1st in the 1970s to 5th in the 1990s and 2010s, and China rose from 5th in the 1970s to 1st in the 2000s and 2010s. The lack of knowing, developing and controlling abilities over pelagic squid resources is a major constraint on the sustainable development of pelagic squid fisheries in China. Therefore, a global information service system should be developed on the fishing conditions of pelagic squid fisheries, a system for the standardization of fishing gear and equipment with independent property rights, the catch quality control technologies and traceability systems should be developed, information-based construction of ocean-going fisheries should be carried out based on Internet of Things projects, and the cephalopod fishery resources assessment system should be established.
The cephalopods are one of the most potential fishing species in the world and have become an important component of the world's marine fishing industry. The world cephalopod fisheries and their composition were analysed using the grey association method based on the world cephalopod production statistics from 1970 to 2016. According to the development status of China's pelagic squid fishery, the problems are pointed out and the development countermeasures are put forward. The analysis found that the world's cephalopod fishing production in the period from 1970 to 2016 generally showed a relatively stable growth trend, with an annual growth rate of 3.68%, which is much higher than the growth rate of world marine fishing production in the same period, and reached its highest level ever in 2014. Between 2010 and 2016, the proportion of cephalopods in world fishing production stabilized between 4.5% and 6.0%. The composition and proportion of the production for different families have varied from one generation to another, and the production of main countries and areas has changed greatly. In the 2010s, the proportion of each family was Ommastrephidae (58.41%), Loliginidae (11.98%), Octopodidae (8.92%), and Sepiidae (8.40%). Asia has played the important role in the cephalopod fishery in the world for more than 40 years. Japanese cephalopod production fell from 1st in the 1970s to 5th in the 1990s and 2010s, and China rose from 5th in the 1970s to 1st in the 2000s and 2010s. The lack of knowing, developing and controlling abilities over pelagic squid resources is a major constraint on the sustainable development of pelagic squid fisheries in China. Therefore, a global information service system should be developed on the fishing conditions of pelagic squid fisheries, a system for the standardization of fishing gear and equipment with independent property rights, the catch quality control technologies and traceability systems should be developed, information-based construction of ocean-going fisheries should be carried out based on Internet of Things projects, and the cephalopod fishery resources assessment system should be established.
2018, 27(4):573-583.
DOI: 10.12024/jsou.20171102171
Abstract:
Ommastrephes bartramii is a commercially important cephalopod in the northwest Pacific Ocean, and as ecological opportunist, the spatial distribution of its stock is determined by marine environment. Using the relationship between the spatio-temporal variation of the migratory path and the oceanic environment to predict the spatial distribution of the squid resources is the research emphasis of fishery resources. It has great significance to practical production. According to the fishing production data from Chinese fishing fleet, combined with sea surface temperature (SST), sea surface salinity (SSS), chlorophyll-a concentration (chl-a) and Trans-Niño index (TNI) in the northwest Pacific Ocean during August to November in 2004 to 2015, We used hierarchical cluster analysis and neural network to analyze the relationship between the spatio-temporal variation of the migratory path and the oceanic environment to predict the change of the migratory path of the squid under the influence of the oceanic environment.The results showed that the proportion of production of the migratory gravity of the squid is significantly negatively correlated with the dispersion degree in October and November. There is a significant positive correlation between the change of the migratory gravity in the latitude and the TNI, which does not appear in the longitude.The model of predicting the spatio-temporal variation of the migratory path of the squid was established by using the neural network combined with sea surface temperature, salinity and chlorophyll concentration. The results of forecasting showed that during August to November, the migration gravity of squid shows the change trend of south-north-south in the latitude, and the change trend of west-east-west in the longitude.In August and September, the estimated proportion of production of the migratory gravity area was 64% and 68% respectively. In October and November, the prediction accuracy rate has obviously improved, and the estimated proportion of production of the migratory gravity area was 83% and 89% respectively.
Ommastrephes bartramii is a commercially important cephalopod in the northwest Pacific Ocean, and as ecological opportunist, the spatial distribution of its stock is determined by marine environment. Using the relationship between the spatio-temporal variation of the migratory path and the oceanic environment to predict the spatial distribution of the squid resources is the research emphasis of fishery resources. It has great significance to practical production. According to the fishing production data from Chinese fishing fleet, combined with sea surface temperature (SST), sea surface salinity (SSS), chlorophyll-a concentration (chl-a) and Trans-Niño index (TNI) in the northwest Pacific Ocean during August to November in 2004 to 2015, We used hierarchical cluster analysis and neural network to analyze the relationship between the spatio-temporal variation of the migratory path and the oceanic environment to predict the change of the migratory path of the squid under the influence of the oceanic environment.The results showed that the proportion of production of the migratory gravity of the squid is significantly negatively correlated with the dispersion degree in October and November. There is a significant positive correlation between the change of the migratory gravity in the latitude and the TNI, which does not appear in the longitude.The model of predicting the spatio-temporal variation of the migratory path of the squid was established by using the neural network combined with sea surface temperature, salinity and chlorophyll concentration. The results of forecasting showed that during August to November, the migration gravity of squid shows the change trend of south-north-south in the latitude, and the change trend of west-east-west in the longitude.In August and September, the estimated proportion of production of the migratory gravity area was 64% and 68% respectively. In October and November, the prediction accuracy rate has obviously improved, and the estimated proportion of production of the migratory gravity area was 83% and 89% respectively.
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.
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.
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.
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...
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.
2017, 26(1):75-84.
DOI: 10.12024/jsou.20160501776
Abstract:
Planktonic algae were investigated and researched monthly from January 2014 to December 2015 in Qingcaosha Reservoir, an important water source in Shanghai. There were 25 dominant species in 2014, and only 12 dominant species in 2015. Microcystis incerta, Pseudoanabaena sp., Cyclotella sp., Ankistrodesmus falcatus var. mirabilis and Klebsormidium scopulinum were common dominant species arising in two years. Compared with the data of 2014, the dominant species were substantially reduced in 2015, and the seasonal variation of dominant species was less obvious than in 2014. As a whole, the dominant species were more in summer and autumn than in winter and spring. The majority of dominant species groups was Cyanophyta and Chlorophyta. Dominant species groups showed the characteristics of more Cyanophyta in summer, autumn and more Chlorophyta in spring, summer. Algae of Bacillariophyta and Xanthophyta became dominant species more likely in spring and summer. Redundancy Analysis showed that water temperature, dissolved oxygen, total nitrogen, total phosphorus were the main environmental variables affecting most dominant species density. As for Microcystis incerta, the important dominant species, its density was positively related with water temperature. As for Tribonema sp. and Cyclotella sp., their density had negative correlation with water temperature.
Planktonic algae were investigated and researched monthly from January 2014 to December 2015 in Qingcaosha Reservoir, an important water source in Shanghai. There were 25 dominant species in 2014, and only 12 dominant species in 2015. Microcystis incerta, Pseudoanabaena sp., Cyclotella sp., Ankistrodesmus falcatus var. mirabilis and Klebsormidium scopulinum were common dominant species arising in two years. Compared with the data of 2014, the dominant species were substantially reduced in 2015, and the seasonal variation of dominant species was less obvious than in 2014. As a whole, the dominant species were more in summer and autumn than in winter and spring. The majority of dominant species groups was Cyanophyta and Chlorophyta. Dominant species groups showed the characteristics of more Cyanophyta in summer, autumn and more Chlorophyta in spring, summer. Algae of Bacillariophyta and Xanthophyta became dominant species more likely in spring and summer. Redundancy Analysis showed that water temperature, dissolved oxygen, total nitrogen, total phosphorus were the main environmental variables affecting most dominant species density. As for Microcystis incerta, the important dominant species, its density was positively related with water temperature. As for Tribonema sp. and Cyclotella sp., their density had negative correlation with water temperature.
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 ...
2011, 20(4):534-540.
Abstract:
To investigate the effect of different doses of compound Chinese herbal immunostimulant in feed on the growth and immune function of grass carp, which was fed with the diets including the compound Chinese herbal immunostimulant, a kind of mixture of five Chinese herbs is proportionally composed of Astragalus membranaceus, Allium sativum, Dendranthema morifolium，Frutellaria crataegi and Isatis indigotica. Grass carp individuals, the average weight of which was (27.84?1.57) g, were fed with 1%, 2%, 4% and 8% compound Chinese herbal immunostimulant in feed for 30 days, respectively. Results showed that weight gain rate（WGR）and specific growth rate（SGR）in Groups 1, 2 and 3 (especially Group 3) increased significantly compared with those of the control group(P<0.05), and phagocytic activities of phagocytes of all test groups increased significantly (P<0.05), while serum lysozyme（LSZ）activities and serum superoxide dismutase (SOD) activities of all test groups increased very significantly (P<0.01). Relative percentage survivals of test groups were very significantly higher than that of the control group (P<0.01), when the grass carps were injected with Aeromonas hydrophila, and the highest one reached 70.28%?6.26% in Group 3. Therefore, 4% Chinese herbal immunostimulant in feed was the fittest for the growth and immunity increment, and resistance of grass carp against the bacterial pathogen, Aeromonas hydrophila.
To investigate the effect of different doses of compound Chinese herbal immunostimulant in feed on the growth and immune function of grass carp, which was fed with the diets including the compound Chinese herbal immunostimulant, a kind of mixture of five Chinese herbs is proportionally composed of Astragalus membranaceus, Allium sativum, Dendranthema morifolium，Frutellaria crataegi and Isatis indigotica. Grass carp individuals, the average weight of which was (27.84?1.57) g, were fed with 1%, 2%, 4% and 8% compound Chinese herbal immunostimulant in feed for 30 days, respectively. Results showed that weight gain rate（WGR）and specific growth rate（SGR）in Groups 1, 2 and 3 (especially Group 3) increased significantly compared with those of the control group(P<0.05), and phagocytic activities of phagocytes of all test groups increased significantly (P<0.05), while serum lysozyme（LSZ）activities and serum superoxide dismutase (SOD) activities of all test groups increased very significantly (P<0.01). Relative percentage survivals of test groups were very significantly higher than that of the control group (P<0.01), when the grass carps were injected with Aeromonas hydrophila, and the highest one reached 70.28%?6.26% in Group 3. Therefore, 4% Chinese herbal immunostimulant in feed was the fittest for the growth and immunity increment, and resistance of grass carp against the bacterial pathogen, Aeromonas hydrophila.
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.
2017, 26(4):490-500.
DOI: 10.12024/jsou.20161101909
Abstract:
This study tries to gradually reduce the addition of carbon source to zero,and to explore the effect of domesticating nitrifying bio-flocs on water quality,bacterial community dynamics of bio-floc and the growth performance of shrimp in high-intensive culture system. Experiment was carried out in three runway aquaculture systems at stocking density of 685 shrimp/m3.Water quality results showed that daily addition of glucose at 100%-150% of feed,which can decrease the concentration of TAN,but the concentration of NO2--N was not decreased obviously.When the addition of glucose dropped to zero,TAN can be maintained at lower level,and the NO2--N concentration decreased significantly.The bacterial community structure was analyzed by using high throughput sequencing technology.At the phylum level,experiment results showed that both the main advantage microflora of heterotrophic bioflocs and nitrifying bioflocs are Proteobacteria and Bacteroidetes.At the class level,dominant microflora of heterotrophic biofloc is Alphaproteobacteria,and dominant microflora of nitrifying bioflocs are Alphaproteobacteria,Flavobacteria and Gammaproteobacteria.After 65 d,study found that without adding carbon source,nitrifying bio-flocs can limit the abundance of heterotrophic bacteria,nitrospira was rising,and developing into dominant bacteria.At the end of the experiment, glucose which is 41.03%±7.86% of feed was added throughout the culture period.The survival rate and harvest of Litopenaeus vannamei respectively were 43.35%±7.57% and (3.03±0.59) kg/m3.The domestication of nitrifying bio-flocs not only saved cost, but also effectively optimized the structure of bacterial communities, and contributed to better water environment which results in the higher growth and survival of shrimp.
This study tries to gradually reduce the addition of carbon source to zero,and to explore the effect of domesticating nitrifying bio-flocs on water quality,bacterial community dynamics of bio-floc and the growth performance of shrimp in high-intensive culture system. Experiment was carried out in three runway aquaculture systems at stocking density of 685 shrimp/m3.Water quality results showed that daily addition of glucose at 100%-150% of feed,which can decrease the concentration of TAN,but the concentration of NO2--N was not decreased obviously.When the addition of glucose dropped to zero,TAN can be maintained at lower level,and the NO2--N concentration decreased significantly.The bacterial community structure was analyzed by using high throughput sequencing technology.At the phylum level,experiment results showed that both the main advantage microflora of heterotrophic bioflocs and nitrifying bioflocs are Proteobacteria and Bacteroidetes.At the class level,dominant microflora of heterotrophic biofloc is Alphaproteobacteria,and dominant microflora of nitrifying bioflocs are Alphaproteobacteria,Flavobacteria and Gammaproteobacteria.After 65 d,study found that without adding carbon source,nitrifying bio-flocs can limit the abundance of heterotrophic bacteria,nitrospira was rising,and developing into dominant bacteria.At the end of the experiment, glucose which is 41.03%±7.86% of feed was added throughout the culture period.The survival rate and harvest of Litopenaeus vannamei respectively were 43.35%±7.57% and (3.03±0.59) kg/m3.The domestication of nitrifying bio-flocs not only saved cost, but also effectively optimized the structure of bacterial communities, and contributed to better water environment which results in the higher growth and survival of shrimp.
2013, 22(5):734-743.
Abstract:
The most of fish species have the schooling behavior, due to the different causes and mechanism of schooling, which are presented by varied definitions of different words, such as shoal, cluster or aggregation, even swam or flock, etc. This article describes and analyses the definitions and classification based on their characteristics, and recommends the word “schooling” is mostly reflecting the phenomenon of fish migration in group. The way to explore the mechanism of schooling, the factors having impact on their behavior, and the methods used in the varied studies are reviewed. And the characteristics of the structure of fish school, sub groups, the phenomena of self organization, etc. are summarized. It is recommended that the mathematics model and simulation technique are effective methods to explore the mechanism of fish self organization phenomenon. This is a way to understand nature by “linkage by phenomena only”, based on observation data, experience and phenomena observed, building mathematics model for predicating and forecasting the fish behavior and schooling structure, and the results of simulation will again be compared with the actual observation records. It might speculate or determine the dominant factors affecting the schooling phenomenon or mechanism. Meanwhile, computer technology provides support for the creation of complex models using simulation technology as an effective tool to study fish schooling behavior in recent years.
The most of fish species have the schooling behavior, due to the different causes and mechanism of schooling, which are presented by varied definitions of different words, such as shoal, cluster or aggregation, even swam or flock, etc. This article describes and analyses the definitions and classification based on their characteristics, and recommends the word “schooling” is mostly reflecting the phenomenon of fish migration in group. The way to explore the mechanism of schooling, the factors having impact on their behavior, and the methods used in the varied studies are reviewed. And the characteristics of the structure of fish school, sub groups, the phenomena of self organization, etc. are summarized. It is recommended that the mathematics model and simulation technique are effective methods to explore the mechanism of fish self organization phenomenon. This is a way to understand nature by “linkage by phenomena only”, based on observation data, experience and phenomena observed, building mathematics model for predicating and forecasting the fish behavior and schooling structure, and the results of simulation will again be compared with the actual observation records. It might speculate or determine the dominant factors affecting the schooling phenomenon or mechanism. Meanwhile, computer technology provides support for the creation of complex models using simulation technology as an effective tool to study fish schooling behavior in recent years.
2013, 22(5).
Abstract:
The most of fish species have the schooling behavior, due to the different causes and mechanism of schooling, which presented by varied definition of different words, such as shoal, cluster or aggregation even swam or flock etc. This article describes and analyses the definitions and classification based on their characteristics, and recommend the word “schooling” is mostly reflecting the phenomenon of fish migration in group. The way to explore the mechanism of schooling, the factors having impact on their behavior, and the methods used in the varied studies ?are reviewed. And the characteristic of the structure of fish school, sub-groups, the phenomena of self-organization etc are summarized. It is recommended that the mathematics model and simulation technical is an effective method to explore the mechanism of fish self-organization phenomenon. This is a way to understand nature by "linkage by phenomena only", based on observation data, experience and phenomena observed, building mathematics model for predicating and forecasting the fish behavior and schooling structure, the results of simulation will again be compared with the actual observation records, it might speculate or determine the dominant factors which effecting the schooling phenomenon or mechanism. Meanwhile, Computer technology provides support for the creation of complex models using simulation technology as an effective tool to study fish schooling behavior in recent years.
The most of fish species have the schooling behavior, due to the different causes and mechanism of schooling, which presented by varied definition of different words, such as shoal, cluster or aggregation even swam or flock etc. This article describes and analyses the definitions and classification based on their characteristics, and recommend the word “schooling” is mostly reflecting the phenomenon of fish migration in group. The way to explore the mechanism of schooling, the factors having impact on their behavior, and the methods used in the varied studies ?are reviewed. And the characteristic of the structure of fish school, sub-groups, the phenomena of self-organization etc are summarized. It is recommended that the mathematics model and simulation technical is an effective method to explore the mechanism of fish self-organization phenomenon. This is a way to understand nature by "linkage by phenomena only", based on observation data, experience and phenomena observed, building mathematics model for predicating and forecasting the fish behavior and schooling structure, the results of simulation will again be compared with the actual observation records, it might speculate or determine the dominant factors which effecting the schooling phenomenon or mechanism. Meanwhile, Computer technology provides support for the creation of complex models using simulation technology as an effective tool to study fish schooling behavior in recent years.
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.
17 Observation on molting and growth of adult Chinese mitten crab reared in the laboratory condition
2014, 23(3):359-365.
Abstract:
In this study, observation on molting and growth of Chinese mitten crab (Eriocheir sinensis) at adult stage (200 days) was carried out under laboratory conditions. The results showed that the average growth rate of body weight at the first to fourth molting stages was 48.7%, 69.1%, 80.1%, 64.8%, respectively; the average carapace length growth rate was 21.3%, 17.0%, 29.5%, 16.7%, respectively; the average carapace width growth rate was 17.4%, 18.3%, 28.2%, 18.1%, respectively. The body weight, carapace length and carapace width of male individuals were higher than those of female individuals at each molting stage, and the significant differences (P<0.05) were found since the third molting time. The average molting period was 37 days, 38 days, 29 days and 41 days for the first to fourth molting stages, respectively. The coefficient of variation of growth was higher at the first two molting stages than that at the latter two molting stages. The initial weight had significant effect (P<0.05) on the weight gained after each molting. There was significant difference (P<0.01) in weight,carapace length and carapace width among each molting stage, and the body weight after the third molting stage had significant correlation (P<0.05) with the weight at other molting stages. This result also showed the carapace length and carapace width had significant correlation(P<0.05) with the culturing temperature, however, the body weight had slightly significant difference (r=0.917-0.923, 0.05<P<0.10) with the culturing temperature. Generally, the present study showed that the growth rate was the highest at the third molting stage, indicating its important effect on the growth and culture practice at this stage. Meanwhile, the results showed that the larger size of juveniles, the larger size of adults would be.
In this study, observation on molting and growth of Chinese mitten crab (Eriocheir sinensis) at adult stage (200 days) was carried out under laboratory conditions. The results showed that the average growth rate of body weight at the first to fourth molting stages was 48.7%, 69.1%, 80.1%, 64.8%, respectively; the average carapace length growth rate was 21.3%, 17.0%, 29.5%, 16.7%, respectively; the average carapace width growth rate was 17.4%, 18.3%, 28.2%, 18.1%, respectively. The body weight, carapace length and carapace width of male individuals were higher than those of female individuals at each molting stage, and the significant differences (P<0.05) were found since the third molting time. The average molting period was 37 days, 38 days, 29 days and 41 days for the first to fourth molting stages, respectively. The coefficient of variation of growth was higher at the first two molting stages than that at the latter two molting stages. The initial weight had significant effect (P<0.05) on the weight gained after each molting. There was significant difference (P<0.01) in weight,carapace length and carapace width among each molting stage, and the body weight after the third molting stage had significant correlation (P<0.05) with the weight at other molting stages. This result also showed the carapace length and carapace width had significant correlation(P<0.05) with the culturing temperature, however, the body weight had slightly significant difference (r=0.917-0.923, 0.05<P<0.10) with the culturing temperature. Generally, the present study showed that the growth rate was the highest at the third molting stage, indicating its important effect on the growth and culture practice at this stage. Meanwhile, the results showed that the larger size of juveniles, the larger size of adults would be.
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.
2017, 26(5):743-750.
DOI: 10.12024/jsou.20161201933
Abstract:
Skipjack tuna (Katsuwonus pelamis) is one of the tuna species in the tropical Pacific waters, and is one of the main fishing targets by Chinese tuna purse seine fleets. In this paper, according to the fishing data during 1995 to 2012 in the Western and Central Pacific Ocean waters (5°N-10°S and 125°E-135°W), combined with the remote sensing data of sea surface temperature (SST) and sea surface height (SSH), the frequency distribution method is used to analyze the suitable environmental range (SST and SSH) for skipjack tuna in the Western and Central Pacific Ocean. And the envelope method is also used to establish the suitability index (SI) based on SST and SSH in each quarter. The habitat suitability index (HSI) model is established to calculate the habitat suitability index by using the method of arithmetic average (AMM) and the geometric average method (GMM), and the catch data in 2013 is used to verify. The results show that the skipjack tuna is distributed in the waters with SST ranging from 28 ℃ to 30.5 ℃ and SSH ranging from 65 cm to 95 cm. In terms of fishing effort (fishing days) used as SI, the external envelope method of SI with SST and SSH is the most suitable. For establishing arithmetic average method of skipjack tuna, the suitable weights of SST in each quarter were 0.7, 0.6, 0.3 and 0.6 in the Western and Central Pacific Ocean. It is concluded that the environmental factors in different seasons have different effects on skipjack tuna distribution in the Western and Central Pacific Ocean.
Skipjack tuna (Katsuwonus pelamis) is one of the tuna species in the tropical Pacific waters, and is one of the main fishing targets by Chinese tuna purse seine fleets. In this paper, according to the fishing data during 1995 to 2012 in the Western and Central Pacific Ocean waters (5°N-10°S and 125°E-135°W), combined with the remote sensing data of sea surface temperature (SST) and sea surface height (SSH), the frequency distribution method is used to analyze the suitable environmental range (SST and SSH) for skipjack tuna in the Western and Central Pacific Ocean. And the envelope method is also used to establish the suitability index (SI) based on SST and SSH in each quarter. The habitat suitability index (HSI) model is established to calculate the habitat suitability index by using the method of arithmetic average (AMM) and the geometric average method (GMM), and the catch data in 2013 is used to verify. The results show that the skipjack tuna is distributed in the waters with SST ranging from 28 ℃ to 30.5 ℃ and SSH ranging from 65 cm to 95 cm. In terms of fishing effort (fishing days) used as SI, the external envelope method of SI with SST and SSH is the most suitable. For establishing arithmetic average method of skipjack tuna, the suitable weights of SST in each quarter were 0.7, 0.6, 0.3 and 0.6 in the Western and Central Pacific Ocean. It is concluded that the environmental factors in different seasons have different effects on skipjack tuna distribution in the Western and Central Pacific Ocean.
2017, 26(1):113-120.
DOI: 10.12024/jsou.20160601795
Abstract:
Skipjack tuna, Katsuwonus pelamis, is an important economic species in the central-west Pacific Ocean, and this species is vulnerable to the change of marine environment. In this paper, according to the abundance index(unit net yield, CPUE) of skipjack tuna collected from the tuna large purse seine fisheries in the central-west Pacific Ocean from 1995 to 2010, combined with the El Nino/La Nina events(expressed by NINO 3.4 index), the influence of El Nino/La Nina on the abundance index of skipjack was studied with the time series analysis. The results showed that the yearly and seasonal abundance index of skipjack varied greatly in 16 years, in which the maximum monthly CPUE appeared in February 1995 with 30.37 t/net, and the minimum occurred in October 1997 with 5.35 t/net. The effect of Nino 3.4 index on monthly CPUE lagged 0-2 months in time, but the synchronization(lag 0 month) had the highest correlation. The Nino 3.4 index and monthly CPUE had significant negative correlation. According to the level of 16 years abundance index of skipjack and Nino 3.4 index, we chose four months(August to February of the next year) of CPUE values as studying object, and divided 16 years into two periods:1) First period was before 2000, this time period had a strong El Nino(SSTA>1.0℃), strong La Nina(SSTA<1.0℃) and normal years(0.5℃ < SSTA < 0.5℃). When the strong El Nino year occurred(1997), the abundance index of skipjack was at a lower level with monthly CPUE of 7.05 t/net. When a strong La Nina(1998) occurs, the abundance index was high with monthly CPUE of 19.61 t/net. 2) The second period was after 2000, which contains weak El Nino(0.5℃ < SSTA < 1.0℃), weak La Nina(-1.0℃ < SSTA < -0.5℃) and normal years(-0.5℃ < SSTA < 0.5℃). In the years of weak El Nino, the abundance index of skipjack(such as, the average CPUEs in 2002 and 2006 are 15.27 t/net and 16.81 t/net respectively) fluctuated around the mean CPUE value(15.73 t/net), but still lower than that in the La Nina year's(19.90 t/net). Both the CPUEs during weak El Nino and weak La Nina were higher than that in the normal year(14.16 t/net). In conclusion, the temporal and spatial abundance index of skipjack varied with both the changes of marine environment and the primary productivity caused by the El Nino/La Nina phenomenon.
Skipjack tuna, Katsuwonus pelamis, is an important economic species in the central-west Pacific Ocean, and this species is vulnerable to the change of marine environment. In this paper, according to the abundance index(unit net yield, CPUE) of skipjack tuna collected from the tuna large purse seine fisheries in the central-west Pacific Ocean from 1995 to 2010, combined with the El Nino/La Nina events(expressed by NINO 3.4 index), the influence of El Nino/La Nina on the abundance index of skipjack was studied with the time series analysis. The results showed that the yearly and seasonal abundance index of skipjack varied greatly in 16 years, in which the maximum monthly CPUE appeared in February 1995 with 30.37 t/net, and the minimum occurred in October 1997 with 5.35 t/net. The effect of Nino 3.4 index on monthly CPUE lagged 0-2 months in time, but the synchronization(lag 0 month) had the highest correlation. The Nino 3.4 index and monthly CPUE had significant negative correlation. According to the level of 16 years abundance index of skipjack and Nino 3.4 index, we chose four months(August to February of the next year) of CPUE values as studying object, and divided 16 years into two periods:1) First period was before 2000, this time period had a strong El Nino(SSTA>1.0℃), strong La Nina(SSTA<1.0℃) and normal years(0.5℃ < SSTA < 0.5℃). When the strong El Nino year occurred(1997), the abundance index of skipjack was at a lower level with monthly CPUE of 7.05 t/net. When a strong La Nina(1998) occurs, the abundance index was high with monthly CPUE of 19.61 t/net. 2) The second period was after 2000, which contains weak El Nino(0.5℃ < SSTA < 1.0℃), weak La Nina(-1.0℃ < SSTA < -0.5℃) and normal years(-0.5℃ < SSTA < 0.5℃). In the years of weak El Nino, the abundance index of skipjack(such as, the average CPUEs in 2002 and 2006 are 15.27 t/net and 16.81 t/net respectively) fluctuated around the mean CPUE value(15.73 t/net), but still lower than that in the La Nina year's(19.90 t/net). Both the CPUEs during weak El Nino and weak La Nina were higher than that in the normal year(14.16 t/net). In conclusion, the temporal and spatial abundance index of skipjack varied with both the changes of marine environment and the primary productivity caused by the El Nino/La Nina phenomenon.
