Understanding the catch composition of multispecies fisheries is fundamental to effective spatial fishery management.In the Equatorial Western and Central Pacific Ocean(EWCPO),the main catches of the tuna purse-seine ...Understanding the catch composition of multispecies fisheries is fundamental to effective spatial fishery management.In the Equatorial Western and Central Pacific Ocean(EWCPO),the main catches of the tuna purse-seine fishery include skipjack tuna(Katsuwonus pelamis),yellowfin tuna(Thunnus albacares),and bigeye tuna(Thunnus obesus).Studying the spatiotemporal distribution of the catch composition in the context of climate change contributes to the sustainable development of this fishery.Our study analyzed purse seine fishery data and environmental data from 1997 to 2019,using a random forest model to explore the changing mechanisms of catch composition under different El Niño-Southern Oscillation(ENSO)episodes with catch mean trophic level(CMTL)as the response variable.Emerging hot spot analysis was used to identify significant spatiotemporal hot(cold)spot areas.The results revealed two hot spot areas,namely the western hotspot area(WHA)and the eastern hotspot area(EHA),and two cold spot areas,namely the northern cold spot area(NCA)and the southern cold spot area(SCA).EHA spans the entire central Pacific east of 170°E among different ENSO episodes,expanding and contracting in tandem with the 28℃isotherm.WHA is mainly influenced by surface organic matter and the Western Boundary Currents and remains among different ENSO episodes.NCA is formed by the westerly anomalies and positive wind stress curl anomalies and exists only under La Niña episodes.SCA persists within the unproductive South Equatorial Current(SEC)and remains stable among different ENSO episodes.Our study contributes to revealing the spatiotemporal dynamics in tuna catch composition and their relationships with environmental factors and interspecies competition,providing valuable insights for ecosystem-based dynamic fishery management.展开更多
The migration route of oceanic squid provides critical information for us to understand their spatial and temporal variations.Mark-recapture and electronic tags tend to be problematic during processing.Cephalopod hard...The migration route of oceanic squid provides critical information for us to understand their spatial and temporal variations.Mark-recapture and electronic tags tend to be problematic during processing.Cephalopod hard structures such as the beak,containing abundant ecological information with stable morphology and statolithlike sequences of growth increments,may provide information for studying spatio-temporal distribution.In this study,we developed a method,which is based on elemental concentration of beaks at different ontogenetic stages and sampling locations,to reconstruct the squid migration route.We applied this method to Ommastrephes bartramii in the North Pacific Ocean.Nine trace elements were detected in the rostrum sagittal sections(RSS)of the beak using laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS).For those elements,significant differences were found between the different ontogenetic stages for phosphorus(P),copper(Cu)and zinc(Zn).Sodium(Na),P and Zn were chosen as indicators of sea surface temperature(SST)and a regression model was estimated.The high probability of occurrence in a particular area represented the possible optimal squid location based on a Bayesian model.A reconstructed migration route in this study,combining all the locations at different ontogenetic stages,was consistent with that hypothesized in previous studies.This study demonstrates that the beak can provide useful information for identifying the migration routes of oceanic squid.展开更多
We quantified theδ^13C andδ^15N values in the lower beaks of Humboldt squid,Dosidicus gigas,collected from international waters off Costa Rica,Ecuador,Peru and Chile by Chinese squid jigging vessels during 2009,2010...We quantified theδ^13C andδ^15N values in the lower beaks of Humboldt squid,Dosidicus gigas,collected from international waters off Costa Rica,Ecuador,Peru and Chile by Chinese squid jigging vessels during 2009,2010 and 2013.There was a significant difference in the isotopic values among regions with the lowest value off Ecuador and the highest off Chile,which were interpreted as a function of trophic effects as well as baseline values.However,constant trophic level of D.gigas across its geographic range showed that spatial variation in the baseline of primary production is the main driver responsible for the observed geographic isotope variability.Inter-regional difference and intra-regional convergence of isotope values indicated squid off Costa Rica,Ecuador and Chile belong to different geographically segregated populations,which were previously proved by integrated population identifying method.In contrast,the higher variations inδ^13C andδ^15N values in a given size group suggest the squid off Peru move and forage in different places.Moreover,potential population exchange could be responsible for the overlap of the isotope values between the squid off Peru and off Chile.On the whole,the spatial difference in isotopic values of Humboldt squid beaks improves our understanding of potential geographic population connectivity and movement.展开更多
Swordtip squid(Uroteuthis edulis)is one of the important economical fishing target species in the East China Sea.Uroteuthis edulis is characterized by rapid growth,extensive migration,and long spawning period and sens...Swordtip squid(Uroteuthis edulis)is one of the important economical fishing target species in the East China Sea.Uroteuthis edulis is characterized by rapid growth,extensive migration,and long spawning period and sensitive to surrounding environment.In order to assess its stock status,it is necessary to explore its spawning season,growth patterns of different populations and their relationship with the environment in advance.In this paper,based on the samples of U.edulis collected in the East China Sea from September 2017 to March 2018,we explored the relationships between daily growth of statolith microstructure and environmental variables by gradient forest method and generalized additive model.The spawning season of U.edulis was found to be nearly one year,and two dominant season groups were found:the spring group with the peak period of April and the summer group with the peak period of August.Water temperature in the depth of 25 m(Temp_25),sea surface temperature(SST)and zonal velocity were the key environmental variables for the daily growth of April-spawning group.The most suitable environmental conditions for the growth of April-spawning group were water temperature(24-27℃)and velocity(0.1-0.3 m/s).SST,Temp_25 and mixed layer depth were the key environment variables for the daily growth of August-spawning group.The most suitable environmental conditions for the growth of Augustspawning group were water temperature(21-28℃)and water depth(0-50 m).Key environmental variables of different groups suggested that early growth was significantly affected by seasonal changes of water temperature,current velocity and prey abundance.This study explored the relationships between early growth and environmental variables and provided the scientific guidance for the management and conservation of U.edulis.展开更多
Accurately building the relationship between the oceanographic environment and the distribution of neon flying squid(Ommastrephes bartramii)is very important to understand the potential habitat pattern of O.bartramii....Accurately building the relationship between the oceanographic environment and the distribution of neon flying squid(Ommastrephes bartramii)is very important to understand the potential habitat pattern of O.bartramii.However,when building the prediction model of O.bartramii with traditional oceanographic variables(e.g.,chlorophyll a concentration(Chl a)and sea surface temperature(SST))from space-borne observations,part of the important spectrum characteristics of the oceanic surface could be masked by using the satellite data products directly.In this study,the neglected remote sensing information(i.e.,spectral remote sensing reflectance(Rrs)and brightness temperature(BT))is firstly incorporated to build the prediction model of catch per unit effort(CPUE)of O.bartramii from July to December during 2014–2018 in the Northwest Pacific Ocean.Results show that both the conventional oceanographic variables and the neglected remote sensing data are suitable for building the prediction model,whereas the overall root mean square error(RMSE)of the predicted CPUE of O.bartramii with the former is typically less accurate than that with the latter.Hence,the Rrs and BT could be a more suitable data source than the Chl a and SST to predict the distribution of O.bartramii,highlighting that the potential value of the neglected variables in understanding the habitat suitability of O.bartramii.展开更多
The quality of environmental data and its possible impact on the marine species habitat modelling are often overlooked while the sources for these data are increasing.This study selected sea surface temperature(SST)fr...The quality of environmental data and its possible impact on the marine species habitat modelling are often overlooked while the sources for these data are increasing.This study selected sea surface temperature(SST)from two commonly used sources,the NOAA Ocean Watch and IRI/LDEO Climate Data Library,and then constructed habitat suitability index model to evaluate the influences of SST from the two sources on the outcomes of Ommastrephes bartramii habitat models for the months of July–October in the Northwest Pacific Ocean during 1996–2012.This study examined the differences in the amount of estimated unfavourable/favourable habitat area when the SST used for model building and inference were the same or different.Dynamics in suitable habitat area calculated from SST was insensitive to the two different SST products.In the fishing season of O.bartramii,the changes of magnitude and trend of monthly suitable habitat area in August and September were similar over time,whereas there were large differences for July and October.Importantly,there is a substantial lack of consistency in the O.bartramii habitat distribution based on SST of two sources.This study considered the sources of environmental data for habitat modelling and then inferred species habitat distribution whether by the same or different data source.展开更多
The Humboldt current system(HCS)sustains the highest global fishing catch for individual species.It is susceptible to interannual and decadal climate variability,which cause species-,community-,and ecosystem-level cha...The Humboldt current system(HCS)sustains the highest global fishing catch for individual species.It is susceptible to interannual and decadal climate variability,which cause species-,community-,and ecosystem-level changes.Therefore,systematically exploring changes in the fishery ecosystem structure driven by climate variability is beneficial for fishery management in the region.In this study,a combination of large-scale climate,regional environmental,and functional groups catch data was used to detect regime shifts in the fishery ecosystem structure within the HCS and to investigate the possible impact mechanisms of climate variability.The results indicated that obvious decadal changes in the fishery ecosystem structure within the HCS align with inferred regime shifts in the early to mid-1970s,mid-1980s,and late 1990s.These shifts corresponded well to climate and regional environment regime shifts during these periods.Among the climate and environmental variables studied,the first and third principal components of climate index and the first principal component of regional environmental variables showed higher ecological importance for fishery ecosystem structure variations within the HCS.This suggest that fluctuations in the Aleutian Low and El Nino–Southern Oscillation significantly affected the regional environment,characterized by heat and wind speed,and consequently induced alterations in the fishery ecosystem structure.This study contributes to holistic understanding of climate-driven changes in the fishery ecosystem structure within the HCS,providing a robust foundation for ecosystem-based fisheries management.展开更多
Improving the accuracy of fishing ground prediction for oceanic economic species has always been one of the most concerning issues in fisheries research.Recent studies have confirmed that deep learning has achieved su...Improving the accuracy of fishing ground prediction for oceanic economic species has always been one of the most concerning issues in fisheries research.Recent studies have confirmed that deep learning has achieved superior results over traditional methods in the era of big data.However,the deep learning-based fishing ground prediction model with a single environment suffers from the problem that the area of the fishing ground is too large and not concentrated.In this study,we developed a deep learning-based fishing ground prediction model with multiple environmental factors using neon flying squid(Ommastrephes bartramii)in Northwest Pacific Ocean as an example.Based on the modified U-Net model,the approach involves the sea surface temperature,sea surface height,sea surface salinity,and chlorophyll a as inputs,and the center fishing ground as the output.The model is trained with data from July to November in 2002-2019,and tested with data of 2020.We considered and compared five temporal scales(3,6,10,15,and 30 days)and seven multiple environmental factor combinations.By comparing different cases,we found that the optimal temporal scale is 30 days,and the optimal multiple environmental factor combination contained SST and Chl a.The inclusion of multiple factors in the model greatly improved the concentration of the center fishing ground.The selection of a suitable combination of multiple environmental factors is beneficial to the precise spatial distribution of fishing grounds.This study deepens the understanding of the mechanism of environmental field influence on fishing grounds from the perspective of artificial intelligence and fishery science.展开更多
Flaxseed cake contains cyanogenic glucosides, which can be metabolized into hydrocyanic acid in an animal's body, leading to asphyxia poisoning in cells. Beta-glucosidase is highly efficient in degrading cyanogeni...Flaxseed cake contains cyanogenic glucosides, which can be metabolized into hydrocyanic acid in an animal's body, leading to asphyxia poisoning in cells. Beta-glucosidase is highly efficient in degrading cyanogenic glucosides. The Cattle may have b-glucosidase-producing strains in the intestinal tract after eating small amounts of flaxseed cake for a long time. This study aimed to isolate of a strain from cow dung that produces b-glucosidase with high activity and can significantly reduce the amount of cyanogenic glucosides. We used cow dung as the microflora source and an esculin agar as the selective medium. After screening with 0.05% esculin and 0.01% ferric citrate, we isolated 5 strains producing high amounts of b-glucosidase. In vitro flaxseed cake fermentation was fermented by these 5 strains, in which the strain M-2 exerted the best effect(P < 0.05). The strain M-2 was identified as Lichtheimia ramosa and used as the fermentation strain to optimize the fermentation parameters by a single factor analysis and orthogonal experimental design. The optimum condition was as follows: inoculum size3%, water content 60%, time 144 h, and temperature 32℃. Under this condition, the removal rate of cyanogenic glucosides reached 89%, and crude protein increment reached 44%. These results provided a theoretical basis for the removal of cyanogenic glucosides in flaxseed and the comprehensive utilization of flaxseed cake.展开更多
To determine the age and growth of Uroteuthis chinensis and U.edulis,growth increments of the lateral dome of the statolith were used in the present study.Specimens of the two species caught in the South China Sea(SCS...To determine the age and growth of Uroteuthis chinensis and U.edulis,growth increments of the lateral dome of the statolith were used in the present study.Specimens of the two species caught in the South China Sea(SCS)and East China Sea(ECS)were used to compare the age and growth differences between sexes.In the present study,we found the two species have similar lifespans of less than 200 days.We also found that there were significant differences in the relationships between mantle length and body weight for two species and for both sexes in the same species.The back-calculated hatching date for the two species was similar,i.e.October to January for specimens caught in spring,and March to June for specimens caught in summer(U.edulis)or autumn(U.chinensis).Exponential and logistic growth curves were fitted to build the age and mantle length relationship.Both growth curves showed that U.chinensis has a larger mantle length than U.edulis at the same age.The results of the growth rates also showed that U.chinensis grows faster than U.edulis.However,there are discrepancies between previous studies and the present study on the lifespan of the two species.Also,the sample size of the present study is small especially for U.edulis.Hence,future studies should be conducted to validate the daily periodicity of growth increment in the regions of statolith(except for the lateral dome which has been validated)and the sample size should be increased for age and growth studies.展开更多
Gladius is an accepted hard tissue for determining the age,size-specific growth,and trophic dynamics of pelagic squid.However,little is known about the inter-and intra-stock variability of gladius growth pattern and i...Gladius is an accepted hard tissue for determining the age,size-specific growth,and trophic dynamics of pelagic squid.However,little is known about the inter-and intra-stock variability of gladius growth pattern and increment deposition.In this study,the gladius growth patterns with somatic growth and gonad development were evaluated for two geographic stocks of the jumbo squid(Dosidicus gigas)in the tropical Pacific Ocean.The microstructure and periodicity of the gladius growth increments were also investigated.Results showed varied correlations between four gladius morphometric characteristics with dorsal mantle length,while growth in body weight almost followed a power model.Sexual gladius growth patterns occurred with gonad development,possibly due to different biological functions of these gladius parts and sex-specific energetic allocations.Gladius increments were observed formation in the stem and lateral plate and could be consistently enumerated.The daily periodicity of increment deposition,at least over 144 days old,was validated by comparing gladius increments with the ages obtained from the statoliths.The different oceanographic conditions between two areas likely influence the gladius growth and increment deposition and promote higher increment counts in squid from equatorial waters.Above all,these results provided new information on gladius microstructures and growth increment in different stocks of D.gigas and confirmed the use of this tissue for size-specific growth and age determination.展开更多
Biological reference point(BRP)is one of the essential components in the management strategy evaluation that is used to determine the status of fishery stock and set management regulations.However,as BRPs can be deriv...Biological reference point(BRP)is one of the essential components in the management strategy evaluation that is used to determine the status of fishery stock and set management regulations.However,as BRPs can be derived from different models and many different BRPs are available,the effectiveness and consistency of different BRPs should be evaluated before being applied to fisheries management.In this study,we used a computation-intensive approach to identify optimal BRPs.We systematically evaluated 1500 combinations of alternative BRPs in managing the bigeye tuna(Thunnus obesus)and yellowfin tuna(Thunnus albacares)fisheries in the Indian Ocean.The effectiveness and consistency of these BRPs were evaluated using four performance measures related to fisheries landing performance and biomass conservation.Monte Carlo simulation was used to evaluate various uncertainties.The results suggest that the proposed computation-intensive approach can be effective in identifying optimal BRPs with respect to a set of defined performance measures.We found that the current maximum sustainable yield(MSY)-based BRP combinations are effective target BRPs to manage the bigeye and yellowfin tuna fisheries with the“linear”harvest control rule(HCR).However,using the“knife-edge”HCR,better BRPs could be found for both the bigeye and yellowfin tuna fisheries management with improved fisheries and conservation performance.The framework developed in this study can be used to identify suitable BRPs based on a set of defined performance measures for other fisheries.展开更多
Sea level rise,amplified by anthropogenic climate change,causes visible impacts on wildlife habitats in low-lying coastal areas.However,the potential consequences of sea level height(SLH)changes for pelagic fish habit...Sea level rise,amplified by anthropogenic climate change,causes visible impacts on wildlife habitats in low-lying coastal areas.However,the potential consequences of sea level height(SLH)changes for pelagic fish habitats in the open oceans are poorly understood,especially for climate-sensitive Ommastrephid squid.In this study,the impacts of SLH changes were estimated under three different SLH change scenarios(5 cm,20 cm,and 35 cm)for the western stock of winter-spring neon flying squid Ommastrephes bartramii,an ecologically-and commercially-important species in the northwest Pacific Ocean(NWPO).A habitat suitability index(HSI)modeling approach was applied to predict the habitat suitability of O.bartramii,using data from 2006 to 2014 for model construction and data from 2015 for model validation.Results showed that the decreasing catch-per-unit-effort(CPUE)of O.bartramii from 2006 to 2015 was highly correlated with the increases in sea level height(SLH).Significant positive relationships were found between the HSI values for latitudinal centers of gravity(LATGHSI)and SLH.The monthly-averaged HSI of O.bartramii was negatively correlated with the SLH,except in July and November.SLH scenarios revealed that the predicted suitable habitat(areas with HSI≥0.6)exhibited a decreasing trend with increasing SLH from August to October.In July and November,the suitable habitat initially increased in the+5 cm and+20 cm scenarios,but largely declined under the+35 cm scenario.The poor habitat(areas with HSI≤0.2)significantly increased under all SLH scenarios.A poleward shift of LATGHSI was observed under all scenarios.These findings suggest that the O.bartramii habitats in the NWPO are at risk to SLH changes and have important implications for better conservation and fishery management regarding pelagic short-lived Ommastrephid squid in global oceans.展开更多
The neon flying squid(Ommastrephes bartramii)in the Northwest Pacific Ocean is one economically important cephalopod,largely exploited by squid jigging fleets from Chinese Mainland,Japan,and Chinese Taibei.In this stu...The neon flying squid(Ommastrephes bartramii)in the Northwest Pacific Ocean is one economically important cephalopod,largely exploited by squid jigging fleets from Chinese Mainland,Japan,and Chinese Taibei.In this study,a Bayesian Bio-economic model was developed using fishery data from Chinese Mainland,Japan,and Chinese Taibei,and relevant fishery economic data from Chinese Mainland.The stock assessment and risk analysis of alternative management strategies for O.bartramii were carried out.Three prior distributions(i.e.,uniform,normal and logarithmic normal)for model parameters were assumed in different scenarios.The results showed that the estimated model parameters and reference points such as maximum sustainable yield(MSY),maximum economic yield(MEY),bio-economic balance point(BE)and fishing mortality were similar in the scenarios of normal and logarithmic normal prior assumptions.However,the estimates were larger in the scenario of uniform prior assumption.The fishing mortalities and annual catches from 1996 to 2008 were lower than the reference points F_(0.1) and MSY in all the three scenarios,indicating that O.bartramii stock is at sustainable exploited level.The results of decision analysis indicated that under the same harvest rate,the catch and biomass in 2023 from the uniform assumption were the highest.However,the highest probability of the collapse was found for squid resources after 2023.Our findings suggested that the harvest rate of 0.4 appeared to be the best management regulation under the uniform assumption,and the MSY would be 200 thousand tons.In addition,the harvest rate of 0.5 would be the best management regulation under the other two assumptions,and the MSY would be 180 thousand tons,which balanced the desire for high yields and the healthy population.The results of this study could be used to provide management suggestions for neon flying squid in the Northwest Pacific Ocean.展开更多
Isotopic signatures have been extensively used to reconstruct marine organism trophic habitat over their lifetime.In this study,sequential stable isotopic values ofδ13C andδ15N in eye lenses were measured to invest...Isotopic signatures have been extensively used to reconstruct marine organism trophic habitat over their lifetime.In this study,sequential stable isotopic values ofδ13C andδ15N in eye lenses were measured to investigate the trophic history of Dosidicus gigas during ontogeny.A total of 281 segments from 33 lenses were examined withδ13C ranging from−20.17‰to−16.11‰andδ15N ranging from 5.15‰to 18.74‰.Sequential increasing but variableδ13C andδ15N values in eye lenses indicated that the prey used in the model had a wide range of values,it became able to consume prey from higher trophic levels,perhaps to maximize feeding success.High inter-individual differences in the range and considerable inter-individual variation in the trend of the isotopic values of the sequential segments from the nuclear to the periphery were considered to be the result of the effects of food and the best feeding strategy.These inter-individual isotopic differences in the life history of D.gigas confirmed the high degree of plasticity of feeding for this squid and its high potential to adapt to environmental change.Inter-individual differences ofδ15N values in the growth of D.gigas were more likely to be caused by differences in the baseline values of isotopes.According to the population discrimination model ofδ15N value changes during ontogeny,the D.gigas off Peru fit the model of“generalist population-generalist individuals”.展开更多
Climate change has had large impacts on marine animals,including neon flying squid Ommastrephes bartramii(O.bartramii)in the North Pacific Ocean.O.bartramii statoliths from 2012,2015,and 2016 were used to evaluate the...Climate change has had large impacts on marine animals,including neon flying squid Ommastrephes bartramii(O.bartramii)in the North Pacific Ocean.O.bartramii statoliths from 2012,2015,and 2016 were used to evaluate the variations in life cycle events.The relationship between mantle length and body weight showed significant differences between years and gender.The oldest squid was collected in 2016 at 271 days old,further proving that O.bartramii has nearly a 1-year life span.The hatching season ranged from December to May and the peak hatching time in 2015 was one-half month later than in 2012 and 2016.Growth rates varied with environmental factors such as sea surface temperature(SST)and chlorophyll a concentration(chl.a),indicating that higher SST and chl.a concentrations led to faster growth.An extreme El Ni˜no event with lower SST in 2015 also led to younger age class and slower growth rates.The occurrence of differences in body size and growth rates between years,caused by the interannual variations of environmental factors,makes it necessary to use separate growth curves for different years when analyzing North Pacific O.Bartramii populations.展开更多
基金The National Key Research and Development Program of China under contract No.2023YFD2401303.
文摘Understanding the catch composition of multispecies fisheries is fundamental to effective spatial fishery management.In the Equatorial Western and Central Pacific Ocean(EWCPO),the main catches of the tuna purse-seine fishery include skipjack tuna(Katsuwonus pelamis),yellowfin tuna(Thunnus albacares),and bigeye tuna(Thunnus obesus).Studying the spatiotemporal distribution of the catch composition in the context of climate change contributes to the sustainable development of this fishery.Our study analyzed purse seine fishery data and environmental data from 1997 to 2019,using a random forest model to explore the changing mechanisms of catch composition under different El Niño-Southern Oscillation(ENSO)episodes with catch mean trophic level(CMTL)as the response variable.Emerging hot spot analysis was used to identify significant spatiotemporal hot(cold)spot areas.The results revealed two hot spot areas,namely the western hotspot area(WHA)and the eastern hotspot area(EHA),and two cold spot areas,namely the northern cold spot area(NCA)and the southern cold spot area(SCA).EHA spans the entire central Pacific east of 170°E among different ENSO episodes,expanding and contracting in tandem with the 28℃isotherm.WHA is mainly influenced by surface organic matter and the Western Boundary Currents and remains among different ENSO episodes.NCA is formed by the westerly anomalies and positive wind stress curl anomalies and exists only under La Niña episodes.SCA persists within the unproductive South Equatorial Current(SEC)and remains stable among different ENSO episodes.Our study contributes to revealing the spatiotemporal dynamics in tuna catch composition and their relationships with environmental factors and interspecies competition,providing valuable insights for ecosystem-based dynamic fishery management.
基金The National Natural Science Foundation of China under contract No.NSFC4147129the China Postdoctoral Science Foundation under contract No.2017M610277+1 种基金the Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources(Shanghai Ocean University),Ministry of Education under contract No.A1-0203-00-2009-6the Fund of Key Laboratory of Open-Sea Fishery Development,Ministry of Agriculture,China under contract LOF 2018-02
文摘The migration route of oceanic squid provides critical information for us to understand their spatial and temporal variations.Mark-recapture and electronic tags tend to be problematic during processing.Cephalopod hard structures such as the beak,containing abundant ecological information with stable morphology and statolithlike sequences of growth increments,may provide information for studying spatio-temporal distribution.In this study,we developed a method,which is based on elemental concentration of beaks at different ontogenetic stages and sampling locations,to reconstruct the squid migration route.We applied this method to Ommastrephes bartramii in the North Pacific Ocean.Nine trace elements were detected in the rostrum sagittal sections(RSS)of the beak using laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS).For those elements,significant differences were found between the different ontogenetic stages for phosphorus(P),copper(Cu)and zinc(Zn).Sodium(Na),P and Zn were chosen as indicators of sea surface temperature(SST)and a regression model was estimated.The high probability of occurrence in a particular area represented the possible optimal squid location based on a Bayesian model.A reconstructed migration route in this study,combining all the locations at different ontogenetic stages,was consistent with that hypothesized in previous studies.This study demonstrates that the beak can provide useful information for identifying the migration routes of oceanic squid.
基金The Shanghai Pujiang Program under contract No.18PJ1404100the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning under contract No.0810000243the National Natural Science Foundation of China under contract Nos 41306127 and 41276156
文摘We quantified theδ^13C andδ^15N values in the lower beaks of Humboldt squid,Dosidicus gigas,collected from international waters off Costa Rica,Ecuador,Peru and Chile by Chinese squid jigging vessels during 2009,2010 and 2013.There was a significant difference in the isotopic values among regions with the lowest value off Ecuador and the highest off Chile,which were interpreted as a function of trophic effects as well as baseline values.However,constant trophic level of D.gigas across its geographic range showed that spatial variation in the baseline of primary production is the main driver responsible for the observed geographic isotope variability.Inter-regional difference and intra-regional convergence of isotope values indicated squid off Costa Rica,Ecuador and Chile belong to different geographically segregated populations,which were previously proved by integrated population identifying method.In contrast,the higher variations inδ^13C andδ^15N values in a given size group suggest the squid off Peru move and forage in different places.Moreover,potential population exchange could be responsible for the overlap of the isotope values between the squid off Peru and off Chile.On the whole,the spatial difference in isotopic values of Humboldt squid beaks improves our understanding of potential geographic population connectivity and movement.
基金The National Key R&D Program of China under contract No.2019YFD0901404the National Natural Science Foundation of China under contract No.41876141+1 种基金the Shanghai Science and Technology Innovation Program under contract No.19DZ1207502the Fund of Key Laboratory of Open-Sea Fishery Development,Ministry of Agriculture and Rural Affairs under contract No.LOF 2018-02。
文摘Swordtip squid(Uroteuthis edulis)is one of the important economical fishing target species in the East China Sea.Uroteuthis edulis is characterized by rapid growth,extensive migration,and long spawning period and sensitive to surrounding environment.In order to assess its stock status,it is necessary to explore its spawning season,growth patterns of different populations and their relationship with the environment in advance.In this paper,based on the samples of U.edulis collected in the East China Sea from September 2017 to March 2018,we explored the relationships between daily growth of statolith microstructure and environmental variables by gradient forest method and generalized additive model.The spawning season of U.edulis was found to be nearly one year,and two dominant season groups were found:the spring group with the peak period of April and the summer group with the peak period of August.Water temperature in the depth of 25 m(Temp_25),sea surface temperature(SST)and zonal velocity were the key environmental variables for the daily growth of April-spawning group.The most suitable environmental conditions for the growth of April-spawning group were water temperature(24-27℃)and velocity(0.1-0.3 m/s).SST,Temp_25 and mixed layer depth were the key environment variables for the daily growth of August-spawning group.The most suitable environmental conditions for the growth of Augustspawning group were water temperature(21-28℃)and water depth(0-50 m).Key environmental variables of different groups suggested that early growth was significantly affected by seasonal changes of water temperature,current velocity and prey abundance.This study explored the relationships between early growth and environmental variables and provided the scientific guidance for the management and conservation of U.edulis.
基金The National Key Research and Development Program of China under contract No.2019YFD0901404the National Natural Science Foundation of China under contract No.42174016+1 种基金the Shanghai Science and Technology Innovation Action Plan under contract No.19DZ1207502the Open Fund of State Key Laboratory of Satellite Ocean Environment Dynamics,Second Institute of Oceanography,Ministry of Natural Resources under contract No.QNHX2324。
文摘Accurately building the relationship between the oceanographic environment and the distribution of neon flying squid(Ommastrephes bartramii)is very important to understand the potential habitat pattern of O.bartramii.However,when building the prediction model of O.bartramii with traditional oceanographic variables(e.g.,chlorophyll a concentration(Chl a)and sea surface temperature(SST))from space-borne observations,part of the important spectrum characteristics of the oceanic surface could be masked by using the satellite data products directly.In this study,the neglected remote sensing information(i.e.,spectral remote sensing reflectance(Rrs)and brightness temperature(BT))is firstly incorporated to build the prediction model of catch per unit effort(CPUE)of O.bartramii from July to December during 2014–2018 in the Northwest Pacific Ocean.Results show that both the conventional oceanographic variables and the neglected remote sensing data are suitable for building the prediction model,whereas the overall root mean square error(RMSE)of the predicted CPUE of O.bartramii with the former is typically less accurate than that with the latter.Hence,the Rrs and BT could be a more suitable data source than the Chl a and SST to predict the distribution of O.bartramii,highlighting that the potential value of the neglected variables in understanding the habitat suitability of O.bartramii.
基金The National Key R&D Program of China under contract Nos 2019YFD0901401 and 2019YFD0901404the National Natural Science Foundation of China under contract No.NSFC41876141+1 种基金the Shanghai Science and Technology Innovation Program under contract No.19DZ1207502the Construction and Application of Natural Resources Satellite Remote Sensing Technology System under contract No.202101004。
文摘The quality of environmental data and its possible impact on the marine species habitat modelling are often overlooked while the sources for these data are increasing.This study selected sea surface temperature(SST)from two commonly used sources,the NOAA Ocean Watch and IRI/LDEO Climate Data Library,and then constructed habitat suitability index model to evaluate the influences of SST from the two sources on the outcomes of Ommastrephes bartramii habitat models for the months of July–October in the Northwest Pacific Ocean during 1996–2012.This study examined the differences in the amount of estimated unfavourable/favourable habitat area when the SST used for model building and inference were the same or different.Dynamics in suitable habitat area calculated from SST was insensitive to the two different SST products.In the fishing season of O.bartramii,the changes of magnitude and trend of monthly suitable habitat area in August and September were similar over time,whereas there were large differences for July and October.Importantly,there is a substantial lack of consistency in the O.bartramii habitat distribution based on SST of two sources.This study considered the sources of environmental data for habitat modelling and then inferred species habitat distribution whether by the same or different data source.
基金financially supported by the National Key R&D Program of China(2023YFD2401303)the Shanghai talent development funding(2021078)the Natural Science Foundation of Shanghai(23ZR1427100)
文摘The Humboldt current system(HCS)sustains the highest global fishing catch for individual species.It is susceptible to interannual and decadal climate variability,which cause species-,community-,and ecosystem-level changes.Therefore,systematically exploring changes in the fishery ecosystem structure driven by climate variability is beneficial for fishery management in the region.In this study,a combination of large-scale climate,regional environmental,and functional groups catch data was used to detect regime shifts in the fishery ecosystem structure within the HCS and to investigate the possible impact mechanisms of climate variability.The results indicated that obvious decadal changes in the fishery ecosystem structure within the HCS align with inferred regime shifts in the early to mid-1970s,mid-1980s,and late 1990s.These shifts corresponded well to climate and regional environment regime shifts during these periods.Among the climate and environmental variables studied,the first and third principal components of climate index and the first principal component of regional environmental variables showed higher ecological importance for fishery ecosystem structure variations within the HCS.This suggest that fluctuations in the Aleutian Low and El Nino–Southern Oscillation significantly affected the regional environment,characterized by heat and wind speed,and consequently induced alterations in the fishery ecosystem structure.This study contributes to holistic understanding of climate-driven changes in the fishery ecosystem structure within the HCS,providing a robust foundation for ecosystem-based fisheries management.
基金supported in part by the National Natural Science Foundation of China under Grant 41876141 and Grant 42006159in part by the National Key R&D Programme of China under Grant 2019YFD0901404.
文摘Improving the accuracy of fishing ground prediction for oceanic economic species has always been one of the most concerning issues in fisheries research.Recent studies have confirmed that deep learning has achieved superior results over traditional methods in the era of big data.However,the deep learning-based fishing ground prediction model with a single environment suffers from the problem that the area of the fishing ground is too large and not concentrated.In this study,we developed a deep learning-based fishing ground prediction model with multiple environmental factors using neon flying squid(Ommastrephes bartramii)in Northwest Pacific Ocean as an example.Based on the modified U-Net model,the approach involves the sea surface temperature,sea surface height,sea surface salinity,and chlorophyll a as inputs,and the center fishing ground as the output.The model is trained with data from July to November in 2002-2019,and tested with data of 2020.We considered and compared five temporal scales(3,6,10,15,and 30 days)and seven multiple environmental factor combinations.By comparing different cases,we found that the optimal temporal scale is 30 days,and the optimal multiple environmental factor combination contained SST and Chl a.The inclusion of multiple factors in the model greatly improved the concentration of the center fishing ground.The selection of a suitable combination of multiple environmental factors is beneficial to the precise spatial distribution of fishing grounds.This study deepens the understanding of the mechanism of environmental field influence on fishing grounds from the perspective of artificial intelligence and fishery science.
基金supported by Jiangsu Science and Technology Major Project (BA2016036)Lanzhou Science and Technology Funds (2015-3-81)Gansu Science and Technology Major Project (17ZD2FA009)
文摘Flaxseed cake contains cyanogenic glucosides, which can be metabolized into hydrocyanic acid in an animal's body, leading to asphyxia poisoning in cells. Beta-glucosidase is highly efficient in degrading cyanogenic glucosides. The Cattle may have b-glucosidase-producing strains in the intestinal tract after eating small amounts of flaxseed cake for a long time. This study aimed to isolate of a strain from cow dung that produces b-glucosidase with high activity and can significantly reduce the amount of cyanogenic glucosides. We used cow dung as the microflora source and an esculin agar as the selective medium. After screening with 0.05% esculin and 0.01% ferric citrate, we isolated 5 strains producing high amounts of b-glucosidase. In vitro flaxseed cake fermentation was fermented by these 5 strains, in which the strain M-2 exerted the best effect(P < 0.05). The strain M-2 was identified as Lichtheimia ramosa and used as the fermentation strain to optimize the fermentation parameters by a single factor analysis and orthogonal experimental design. The optimum condition was as follows: inoculum size3%, water content 60%, time 144 h, and temperature 32℃. Under this condition, the removal rate of cyanogenic glucosides reached 89%, and crude protein increment reached 44%. These results provided a theoretical basis for the removal of cyanogenic glucosides in flaxseed and the comprehensive utilization of flaxseed cake.
基金This work was funded by the National Science Foundation of China(NSFC41306127 and NSFC41276156).
文摘To determine the age and growth of Uroteuthis chinensis and U.edulis,growth increments of the lateral dome of the statolith were used in the present study.Specimens of the two species caught in the South China Sea(SCS)and East China Sea(ECS)were used to compare the age and growth differences between sexes.In the present study,we found the two species have similar lifespans of less than 200 days.We also found that there were significant differences in the relationships between mantle length and body weight for two species and for both sexes in the same species.The back-calculated hatching date for the two species was similar,i.e.October to January for specimens caught in spring,and March to June for specimens caught in summer(U.edulis)or autumn(U.chinensis).Exponential and logistic growth curves were fitted to build the age and mantle length relationship.Both growth curves showed that U.chinensis has a larger mantle length than U.edulis at the same age.The results of the growth rates also showed that U.chinensis grows faster than U.edulis.However,there are discrepancies between previous studies and the present study on the lifespan of the two species.Also,the sample size of the present study is small especially for U.edulis.Hence,future studies should be conducted to validate the daily periodicity of growth increment in the regions of statolith(except for the lateral dome which has been validated)and the sample size should be increased for age and growth studies.
基金This work was supported by National Natural Science Foundation of China(41541042)National Natural Science Foundation of Shanghai(17ZR1413000)Shanghai Leading Academic Discipline Project(Fisheries Discipline)and Laboratory for Marine Fisheries Science and Food Production Processes,Qingdao National Laboratory for Marine Science and Technology(2017-1A03).
文摘Gladius is an accepted hard tissue for determining the age,size-specific growth,and trophic dynamics of pelagic squid.However,little is known about the inter-and intra-stock variability of gladius growth pattern and increment deposition.In this study,the gladius growth patterns with somatic growth and gonad development were evaluated for two geographic stocks of the jumbo squid(Dosidicus gigas)in the tropical Pacific Ocean.The microstructure and periodicity of the gladius growth increments were also investigated.Results showed varied correlations between four gladius morphometric characteristics with dorsal mantle length,while growth in body weight almost followed a power model.Sexual gladius growth patterns occurred with gonad development,possibly due to different biological functions of these gladius parts and sex-specific energetic allocations.Gladius increments were observed formation in the stem and lateral plate and could be consistently enumerated.The daily periodicity of increment deposition,at least over 144 days old,was validated by comparing gladius increments with the ages obtained from the statoliths.The different oceanographic conditions between two areas likely influence the gladius growth and increment deposition and promote higher increment counts in squid from equatorial waters.Above all,these results provided new information on gladius microstructures and growth increment in different stocks of D.gigas and confirmed the use of this tissue for size-specific growth and age determination.
基金This project is financially supported by the Shanghai Ocean University International Center for Marine Sciences and Innovation Program of Shanghai Municipal Education Commission(12YZ134).
文摘Biological reference point(BRP)is one of the essential components in the management strategy evaluation that is used to determine the status of fishery stock and set management regulations.However,as BRPs can be derived from different models and many different BRPs are available,the effectiveness and consistency of different BRPs should be evaluated before being applied to fisheries management.In this study,we used a computation-intensive approach to identify optimal BRPs.We systematically evaluated 1500 combinations of alternative BRPs in managing the bigeye tuna(Thunnus obesus)and yellowfin tuna(Thunnus albacares)fisheries in the Indian Ocean.The effectiveness and consistency of these BRPs were evaluated using four performance measures related to fisheries landing performance and biomass conservation.Monte Carlo simulation was used to evaluate various uncertainties.The results suggest that the proposed computation-intensive approach can be effective in identifying optimal BRPs with respect to a set of defined performance measures.We found that the current maximum sustainable yield(MSY)-based BRP combinations are effective target BRPs to manage the bigeye and yellowfin tuna fisheries with the“linear”harvest control rule(HCR).However,using the“knife-edge”HCR,better BRPs could be found for both the bigeye and yellowfin tuna fisheries management with improved fisheries and conservation performance.The framework developed in this study can be used to identify suitable BRPs based on a set of defined performance measures for other fisheries.
基金This study was financially supported by the National Key R&D Program of China(2019YFD0901405)National Natural Science Foundation of China(41906073)+1 种基金the Natural Science Foundation of Shanghai(19ZR1423000)the Shanghai Universities First-Class Disciplines Project(Fisheries A).
文摘Sea level rise,amplified by anthropogenic climate change,causes visible impacts on wildlife habitats in low-lying coastal areas.However,the potential consequences of sea level height(SLH)changes for pelagic fish habitats in the open oceans are poorly understood,especially for climate-sensitive Ommastrephid squid.In this study,the impacts of SLH changes were estimated under three different SLH change scenarios(5 cm,20 cm,and 35 cm)for the western stock of winter-spring neon flying squid Ommastrephes bartramii,an ecologically-and commercially-important species in the northwest Pacific Ocean(NWPO).A habitat suitability index(HSI)modeling approach was applied to predict the habitat suitability of O.bartramii,using data from 2006 to 2014 for model construction and data from 2015 for model validation.Results showed that the decreasing catch-per-unit-effort(CPUE)of O.bartramii from 2006 to 2015 was highly correlated with the increases in sea level height(SLH).Significant positive relationships were found between the HSI values for latitudinal centers of gravity(LATGHSI)and SLH.The monthly-averaged HSI of O.bartramii was negatively correlated with the SLH,except in July and November.SLH scenarios revealed that the predicted suitable habitat(areas with HSI≥0.6)exhibited a decreasing trend with increasing SLH from August to October.In July and November,the suitable habitat initially increased in the+5 cm and+20 cm scenarios,but largely declined under the+35 cm scenario.The poor habitat(areas with HSI≤0.2)significantly increased under all SLH scenarios.A poleward shift of LATGHSI was observed under all scenarios.These findings suggest that the O.bartramii habitats in the NWPO are at risk to SLH changes and have important implications for better conservation and fishery management regarding pelagic short-lived Ommastrephid squid in global oceans.
基金This work was funded by Natural Science Foundation of China(41876141)the Funding Scheme for Training Young Teachers in Shanghai Colleges and the Shanghai Leading Academic Discipline Project(Fisheries Discipline).
文摘The neon flying squid(Ommastrephes bartramii)in the Northwest Pacific Ocean is one economically important cephalopod,largely exploited by squid jigging fleets from Chinese Mainland,Japan,and Chinese Taibei.In this study,a Bayesian Bio-economic model was developed using fishery data from Chinese Mainland,Japan,and Chinese Taibei,and relevant fishery economic data from Chinese Mainland.The stock assessment and risk analysis of alternative management strategies for O.bartramii were carried out.Three prior distributions(i.e.,uniform,normal and logarithmic normal)for model parameters were assumed in different scenarios.The results showed that the estimated model parameters and reference points such as maximum sustainable yield(MSY),maximum economic yield(MEY),bio-economic balance point(BE)and fishing mortality were similar in the scenarios of normal and logarithmic normal prior assumptions.However,the estimates were larger in the scenario of uniform prior assumption.The fishing mortalities and annual catches from 1996 to 2008 were lower than the reference points F_(0.1) and MSY in all the three scenarios,indicating that O.bartramii stock is at sustainable exploited level.The results of decision analysis indicated that under the same harvest rate,the catch and biomass in 2023 from the uniform assumption were the highest.However,the highest probability of the collapse was found for squid resources after 2023.Our findings suggested that the harvest rate of 0.4 appeared to be the best management regulation under the uniform assumption,and the MSY would be 200 thousand tons.In addition,the harvest rate of 0.5 would be the best management regulation under the other two assumptions,and the MSY would be 180 thousand tons,which balanced the desire for high yields and the healthy population.The results of this study could be used to provide management suggestions for neon flying squid in the Northwest Pacific Ocean.
基金the English text of a draft of this manuscript.This work was sponsored by the Shanghai Pujiang Program(No.18PJ1404100)the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning,China(No.0810000243)the National Natural Science Foundation of China(Nos.41306127 and 41276156).
文摘Isotopic signatures have been extensively used to reconstruct marine organism trophic habitat over their lifetime.In this study,sequential stable isotopic values ofδ13C andδ15N in eye lenses were measured to investigate the trophic history of Dosidicus gigas during ontogeny.A total of 281 segments from 33 lenses were examined withδ13C ranging from−20.17‰to−16.11‰andδ15N ranging from 5.15‰to 18.74‰.Sequential increasing but variableδ13C andδ15N values in eye lenses indicated that the prey used in the model had a wide range of values,it became able to consume prey from higher trophic levels,perhaps to maximize feeding success.High inter-individual differences in the range and considerable inter-individual variation in the trend of the isotopic values of the sequential segments from the nuclear to the periphery were considered to be the result of the effects of food and the best feeding strategy.These inter-individual isotopic differences in the life history of D.gigas confirmed the high degree of plasticity of feeding for this squid and its high potential to adapt to environmental change.Inter-individual differences ofδ15N values in the growth of D.gigas were more likely to be caused by differences in the baseline values of isotopes.According to the population discrimination model ofδ15N value changes during ontogeny,the D.gigas off Peru fit the model of“generalist population-generalist individuals”.
基金funded by the National Key R&D Program of China(2019YFD0901404)National Science Foundation of China(41876141)+1 种基金Shanghai Science and Technology Innovation Program(19DZ1207502)Fund of Key Laboratory of Open-Sea Fishery Development,Ministry of Agriculture,P.R.China(LOF 2018-02).
文摘Climate change has had large impacts on marine animals,including neon flying squid Ommastrephes bartramii(O.bartramii)in the North Pacific Ocean.O.bartramii statoliths from 2012,2015,and 2016 were used to evaluate the variations in life cycle events.The relationship between mantle length and body weight showed significant differences between years and gender.The oldest squid was collected in 2016 at 271 days old,further proving that O.bartramii has nearly a 1-year life span.The hatching season ranged from December to May and the peak hatching time in 2015 was one-half month later than in 2012 and 2016.Growth rates varied with environmental factors such as sea surface temperature(SST)and chlorophyll a concentration(chl.a),indicating that higher SST and chl.a concentrations led to faster growth.An extreme El Ni˜no event with lower SST in 2015 also led to younger age class and slower growth rates.The occurrence of differences in body size and growth rates between years,caused by the interannual variations of environmental factors,makes it necessary to use separate growth curves for different years when analyzing North Pacific O.Bartramii populations.
