Mortality is normal and natural in aquaculture experiments. However, it becomes a problem when measuring feed intake as a component of nutrient utilization parameters such as： feed conversion ratio, feed conversion e...Mortality is normal and natural in aquaculture experiments. However, it becomes a problem when measuring feed intake as a component of nutrient utilization parameters such as： feed conversion ratio, feed conversion efficiency, apparent net protein utilization, protein efficiency ratio and protein productive value. In order to accurately evaluate feed intake with due consideration of mortality encountered, a formulae was developed using empirical data obtained from an experiement that had mortality. The formulae Fwas： total feed consumed by numbers of survived fishes=DL∑i=1n（Fi/Ni）N. Where, D=Numbers of days fishes were fed within each period ibefore it was adjusted（e.g fortnight）, it was constant throught period of experiment; F=Uantity of feed fed per day for a fortnight before the quantity was adjusted, it changed every fortnight; L=Numbers of living fishes at the end of experimental period; N=Numbers of fishes at each weighing period, it might change every fortnight or might be constant if no mortality occurred; while n=Numbers of times fishes were weighed and quantity of feed was adjusted but this did not include the final weighing at the termination of experiment. However, if the fishes were weighed weekly, then D=6.展开更多
In order to enhance the resources, some fishes were introduced into Xiangmoshan reservoir. The introduced fishes consisted of different ecotypes such as silver carp （Hypophthahnichthys rnolitrix （Cuvier et Valencien...In order to enhance the resources, some fishes were introduced into Xiangmoshan reservoir. The introduced fishes consisted of different ecotypes such as silver carp （Hypophthahnichthys rnolitrix （Cuvier et Valenciennes））, big head （Aristichthys nobilis （Richardso）） and lake herring （Coregonus clupeaformis （Mitchill）） that were plankton feeders, common carp （Cyprinus carpio Linnaeus） and crucian carp （Carassius auratus gibelio） belonging to the polyphagia, and also the non-native predator Walleye （Stizostedion vitreum （Mitchill）） and big mouth （Silurus soldatovi rneridonalis Chen）, et al. Among there were not only the cool water fish Peled （Coregonus peled （Gmelin））, but also the warm water fish big mouth. The introduction of non-native fishes resulted in ecosystem changes of the reservoir and some native fishes had gone to decrease their population sizes or been in the condition of depopulation such as Opsariichthys uncirostris arnurensis （Berg）, Rhodeus sericeus （Pallas） and Silurus asotus （Linnaeus）. The native common carp had disappeared after the introduction of non-native species. Roach （Rutilus rutilus lacustris （Pallas） had been thriven for one or two generations after its introduction and immeidiatly disappeared. Silver fish （Protosalanx hyalocranius （Abbott））, Lake herring （Coregonus clupeaformis （Mitchill）） and Walleye （Stizostedion vitreum （Mitchill）） died several years after the introduction, so most of the introduced species has passed out of existence. Via many years introduction of different fishes, composition of species and the structure of the population in the reservoir had been changed obviously. It was necessary to further estimate whether the ecosystem of the reservoir had been damaged.展开更多
[Objective]Implementation of the Ten-Year Fishing Ban policy may alter fish diversity and niche characteristics of dominant species in spawning grounds within the National Nature Reserve for Rare and Endemic Fish in t...[Objective]Implementation of the Ten-Year Fishing Ban policy may alter fish diversity and niche characteristics of dominant species in spawning grounds within the National Nature Reserve for Rare and Endemic Fish in the Upper Yangtze River.This study initiated continuous monitoring of natural spawning habitats from February 2022 to assess these ecological changes.[Methods]Environmental DNA(eDNA)metabarcoding was employed to analyze fish species composition,biodiversity patterns,and niche parameters of dominant species.Water sampling followed the CEN/TS 19461 standard across five monitoring transects(ZT1-ZT5).[Results]The eDNA analysis detected 45 species of fish belonging to 38 genera,13 families,and 3 orders were detected through environmental DNA(eDNA)in this survey,including 10 species endemic to the upper reaches of the Yangtze River,such as Procypris rabaudi and Myxocyprinus asiaticus.The fish community was mainly composed of bottom-dwelling,settling ovum-producing,omnivorous fish.The variation ranges of the Chao1 index,ACE index,Shannon index,and Simpson index are 736~996,719~965,1.58~3.23,and 0.83~0.99,respectively,indicating that fish species in spawning sites are abundant and community distribution uniformity is high.All indexes are highest at ZT1 monitoring points.Cluster analysis showed that,at a certain similarity level,fish community types in spawning sites could be basically divided into two groups:ZT1,ZT3,and ZT5 clustered together,and ZT2 and ZT4 clustered together,indicating similar fish community habitats.There are 9 dominant fish species in typical deep pool habitats in the reserve,with niche widths(Bi)ranging from 1.13 to 3.87.The dominant fish species are broad and medium niche fish,such as Cyprinus carpio and Hemiculter tchangi,with the niche overlap index(Oik)of some dominant fish species reaching more than 0.95.This indicates fierce competition for resources among the fish in this spawning ground.[Conclusion]The Zhutuo spawning ground demonstrates high species richness with homogeneous community structure and intense resource competition.This study establishes an eDNA-based monitoring framework that enhances conventional survey method,providing critical baseline data for adaptive management under the fishing moratorium regime.展开更多
Estimating trawler fishing effort plays a critical role in characterizing marine fisheries activities,quantifying the ecological impact of trawling,and refining regulatory frameworks and policies.Understanding trawler...Estimating trawler fishing effort plays a critical role in characterizing marine fisheries activities,quantifying the ecological impact of trawling,and refining regulatory frameworks and policies.Understanding trawler fishing inputs offers crucial scientific data to support the sustainable management of offshore fishery resources in China.An XGBoost algorithm was introduced and optimized through Harris Hawks Optimization(HHO),to develop a model for identifying trawler fishing behaviour.The model demonstrated exceptional performance,achieving accuracy,sensitivity,specificity,and the Matthews correlation coefficient of 0.9713,0.9806,0.9632,and 0.9425,respectively.Using this model to detect fishing activities,the fishing effort of trawlers from Shandong Province in the sea area between 119°E to 124°E and 32°N to 40°N in 2021 was quantified.A heatmap depicting fishing effort,generated with a spatial resolution of 1/8°,revealed that fishing activities were predominantly concentrated in two regions:121.1°E to 124°E,35.7°N to 38.7°N,and 119.8°E to 122.8°E,33.6°N to 35.4°N.This research can provide a foundation for quantitative evaluations of fishery resources,which can offer vital data to promote the sustainable development of marine capture fisheries.展开更多
[Objective]The channel straightening project of the Pinglu Canal has fragmented the river course,compromising the integrity of original river course and causing ecosystem patchiness.Understanding the current status of...[Objective]The channel straightening project of the Pinglu Canal has fragmented the river course,compromising the integrity of original river course and causing ecosystem patchiness.Understanding the current status of fish resources and the characteristics of their diversity is crucial for the ecological management of the Pinglu Canal.[Methods]During the spring and autumn in 2021 and 2022,a survey of fish resources and species diversity in the Pinglu Canal was conducted using multi-mesh gill nets.A total of 125 fish species were collected,belonging to 10 orders,34 families,and 89 genera.[Results]The result showed that the Pinglu Canal contained three nationally protected Class II species,two endemic species of the Qinjiang River,three anadromous/migratory species,and eight invasive species,accounting for 2.4%,1.6%,2.4%,and 6.4%of the total species,respectively.The fish community primarily consisted of mid-and bottom-dwelling,adhesive-egg-laying,and omnivorous species.The Shannon-Wiener,Simpson,Margalef,and Pielou indices of the fish community in the Pinglu Canal ranged from 2.347 to 2.757,0.081 to 0.151,3.493 to 4.382,and 0.812 to 0.892,respectively.These indices showed relatively uniform distribution across different river reaches.[Conclusion]The result indicate that the fish community structure in the Pinglu Canal is relatively uniform.The reach from the Yujiang River to the Shaping River shows higher stability,while other river reaches experience moderate or severe disturbances.This study provides supplementary baseline data on the fish community structure in the Pinglu Canal and explores the potential impact of inter-basin connectivity on fish resources,aiming to provide a scientific basis for habitat restoration assessments after the channel straightening project.展开更多
[Objective]Fish pose estimation(FPE)provides fish physiological information,facilitating health monitoring in aquaculture.It aids decision-making in areas such as fish behavior recognition.When fish are injured or def...[Objective]Fish pose estimation(FPE)provides fish physiological information,facilitating health monitoring in aquaculture.It aids decision-making in areas such as fish behavior recognition.When fish are injured or deficient,they often display abnormal behaviors and noticeable changes in the positioning of their body parts.Moreover,the unpredictable posture and orientation of fish during swimming,combined with the rapid swimming speed of fish,restrict the current scope of research in FPE.In this research,a FPE model named HPFPE is presented to capture the swimming posture of fish and accurately detect their key points.[Methods]On the one hand,this model incorporated the CBAM module into the HRNet framework.The attention module enhanced accuracy without adding computational complexity,while effectively capturing a broader range of contextual information.On the other hand,the model incorporated dilated convolution to increase the receptive field,allowing it to capture more spatial context.[Results and Discussions]Experiments showed that compared with the baseline method,the average precision(AP)of HPFPE based on different backbones and input sizes on the oplegnathus punctatus datasets had increased by 0.62,1.35,1.76,and 1.28 percent point,respectively,while the average recall(AR)had also increased by 0.85,1.50,1.40,and 1.00,respectively.Additionally,HPFPE outperformed other mainstream methods,including DeepPose,CPM,SCNet,and Lite-HRNet.Furthermore,when compared to other methods using the ornamental fish data,HPFPE achieved the highest AP and AR values of 52.96%,and 59.50%,respectively.[Conclusions]The proposed HPFPE can accurately estimate fish posture and assess their swimming patterns,serving as a valuable reference for applications such as fish behavior recognition.展开更多
文摘Mortality is normal and natural in aquaculture experiments. However, it becomes a problem when measuring feed intake as a component of nutrient utilization parameters such as： feed conversion ratio, feed conversion efficiency, apparent net protein utilization, protein efficiency ratio and protein productive value. In order to accurately evaluate feed intake with due consideration of mortality encountered, a formulae was developed using empirical data obtained from an experiement that had mortality. The formulae Fwas： total feed consumed by numbers of survived fishes=DL∑i=1n（Fi/Ni）N. Where, D=Numbers of days fishes were fed within each period ibefore it was adjusted（e.g fortnight）, it was constant throught period of experiment; F=Uantity of feed fed per day for a fortnight before the quantity was adjusted, it changed every fortnight; L=Numbers of living fishes at the end of experimental period; N=Numbers of fishes at each weighing period, it might change every fortnight or might be constant if no mortality occurred; while n=Numbers of times fishes were weighed and quantity of feed was adjusted but this did not include the final weighing at the termination of experiment. However, if the fishes were weighed weekly, then D=6.
文摘In order to enhance the resources, some fishes were introduced into Xiangmoshan reservoir. The introduced fishes consisted of different ecotypes such as silver carp （Hypophthahnichthys rnolitrix （Cuvier et Valenciennes））, big head （Aristichthys nobilis （Richardso）） and lake herring （Coregonus clupeaformis （Mitchill）） that were plankton feeders, common carp （Cyprinus carpio Linnaeus） and crucian carp （Carassius auratus gibelio） belonging to the polyphagia, and also the non-native predator Walleye （Stizostedion vitreum （Mitchill）） and big mouth （Silurus soldatovi rneridonalis Chen）, et al. Among there were not only the cool water fish Peled （Coregonus peled （Gmelin））, but also the warm water fish big mouth. The introduction of non-native fishes resulted in ecosystem changes of the reservoir and some native fishes had gone to decrease their population sizes or been in the condition of depopulation such as Opsariichthys uncirostris arnurensis （Berg）, Rhodeus sericeus （Pallas） and Silurus asotus （Linnaeus）. The native common carp had disappeared after the introduction of non-native species. Roach （Rutilus rutilus lacustris （Pallas） had been thriven for one or two generations after its introduction and immeidiatly disappeared. Silver fish （Protosalanx hyalocranius （Abbott））, Lake herring （Coregonus clupeaformis （Mitchill）） and Walleye （Stizostedion vitreum （Mitchill）） died several years after the introduction, so most of the introduced species has passed out of existence. Via many years introduction of different fishes, composition of species and the structure of the population in the reservoir had been changed obviously. It was necessary to further estimate whether the ecosystem of the reservoir had been damaged.
文摘[Objective]Implementation of the Ten-Year Fishing Ban policy may alter fish diversity and niche characteristics of dominant species in spawning grounds within the National Nature Reserve for Rare and Endemic Fish in the Upper Yangtze River.This study initiated continuous monitoring of natural spawning habitats from February 2022 to assess these ecological changes.[Methods]Environmental DNA(eDNA)metabarcoding was employed to analyze fish species composition,biodiversity patterns,and niche parameters of dominant species.Water sampling followed the CEN/TS 19461 standard across five monitoring transects(ZT1-ZT5).[Results]The eDNA analysis detected 45 species of fish belonging to 38 genera,13 families,and 3 orders were detected through environmental DNA(eDNA)in this survey,including 10 species endemic to the upper reaches of the Yangtze River,such as Procypris rabaudi and Myxocyprinus asiaticus.The fish community was mainly composed of bottom-dwelling,settling ovum-producing,omnivorous fish.The variation ranges of the Chao1 index,ACE index,Shannon index,and Simpson index are 736~996,719~965,1.58~3.23,and 0.83~0.99,respectively,indicating that fish species in spawning sites are abundant and community distribution uniformity is high.All indexes are highest at ZT1 monitoring points.Cluster analysis showed that,at a certain similarity level,fish community types in spawning sites could be basically divided into two groups:ZT1,ZT3,and ZT5 clustered together,and ZT2 and ZT4 clustered together,indicating similar fish community habitats.There are 9 dominant fish species in typical deep pool habitats in the reserve,with niche widths(Bi)ranging from 1.13 to 3.87.The dominant fish species are broad and medium niche fish,such as Cyprinus carpio and Hemiculter tchangi,with the niche overlap index(Oik)of some dominant fish species reaching more than 0.95.This indicates fierce competition for resources among the fish in this spawning ground.[Conclusion]The Zhutuo spawning ground demonstrates high species richness with homogeneous community structure and intense resource competition.This study establishes an eDNA-based monitoring framework that enhances conventional survey method,providing critical baseline data for adaptive management under the fishing moratorium regime.
文摘Estimating trawler fishing effort plays a critical role in characterizing marine fisheries activities,quantifying the ecological impact of trawling,and refining regulatory frameworks and policies.Understanding trawler fishing inputs offers crucial scientific data to support the sustainable management of offshore fishery resources in China.An XGBoost algorithm was introduced and optimized through Harris Hawks Optimization(HHO),to develop a model for identifying trawler fishing behaviour.The model demonstrated exceptional performance,achieving accuracy,sensitivity,specificity,and the Matthews correlation coefficient of 0.9713,0.9806,0.9632,and 0.9425,respectively.Using this model to detect fishing activities,the fishing effort of trawlers from Shandong Province in the sea area between 119°E to 124°E and 32°N to 40°N in 2021 was quantified.A heatmap depicting fishing effort,generated with a spatial resolution of 1/8°,revealed that fishing activities were predominantly concentrated in two regions:121.1°E to 124°E,35.7°N to 38.7°N,and 119.8°E to 122.8°E,33.6°N to 35.4°N.This research can provide a foundation for quantitative evaluations of fishery resources,which can offer vital data to promote the sustainable development of marine capture fisheries.
文摘[Objective]The channel straightening project of the Pinglu Canal has fragmented the river course,compromising the integrity of original river course and causing ecosystem patchiness.Understanding the current status of fish resources and the characteristics of their diversity is crucial for the ecological management of the Pinglu Canal.[Methods]During the spring and autumn in 2021 and 2022,a survey of fish resources and species diversity in the Pinglu Canal was conducted using multi-mesh gill nets.A total of 125 fish species were collected,belonging to 10 orders,34 families,and 89 genera.[Results]The result showed that the Pinglu Canal contained three nationally protected Class II species,two endemic species of the Qinjiang River,three anadromous/migratory species,and eight invasive species,accounting for 2.4%,1.6%,2.4%,and 6.4%of the total species,respectively.The fish community primarily consisted of mid-and bottom-dwelling,adhesive-egg-laying,and omnivorous species.The Shannon-Wiener,Simpson,Margalef,and Pielou indices of the fish community in the Pinglu Canal ranged from 2.347 to 2.757,0.081 to 0.151,3.493 to 4.382,and 0.812 to 0.892,respectively.These indices showed relatively uniform distribution across different river reaches.[Conclusion]The result indicate that the fish community structure in the Pinglu Canal is relatively uniform.The reach from the Yujiang River to the Shaping River shows higher stability,while other river reaches experience moderate or severe disturbances.This study provides supplementary baseline data on the fish community structure in the Pinglu Canal and explores the potential impact of inter-basin connectivity on fish resources,aiming to provide a scientific basis for habitat restoration assessments after the channel straightening project.
文摘[Objective]Fish pose estimation(FPE)provides fish physiological information,facilitating health monitoring in aquaculture.It aids decision-making in areas such as fish behavior recognition.When fish are injured or deficient,they often display abnormal behaviors and noticeable changes in the positioning of their body parts.Moreover,the unpredictable posture and orientation of fish during swimming,combined with the rapid swimming speed of fish,restrict the current scope of research in FPE.In this research,a FPE model named HPFPE is presented to capture the swimming posture of fish and accurately detect their key points.[Methods]On the one hand,this model incorporated the CBAM module into the HRNet framework.The attention module enhanced accuracy without adding computational complexity,while effectively capturing a broader range of contextual information.On the other hand,the model incorporated dilated convolution to increase the receptive field,allowing it to capture more spatial context.[Results and Discussions]Experiments showed that compared with the baseline method,the average precision(AP)of HPFPE based on different backbones and input sizes on the oplegnathus punctatus datasets had increased by 0.62,1.35,1.76,and 1.28 percent point,respectively,while the average recall(AR)had also increased by 0.85,1.50,1.40,and 1.00,respectively.Additionally,HPFPE outperformed other mainstream methods,including DeepPose,CPM,SCNet,and Lite-HRNet.Furthermore,when compared to other methods using the ornamental fish data,HPFPE achieved the highest AP and AR values of 52.96%,and 59.50%,respectively.[Conclusions]The proposed HPFPE can accurately estimate fish posture and assess their swimming patterns,serving as a valuable reference for applications such as fish behavior recognition.
