[Objective]This study aims to investigate the multi-body hydrodynamic interaction mechanisms during offshore lifting operations of aquaculture net cages in wind-fishery integration systems.By integrating numerical sim...[Objective]This study aims to investigate the multi-body hydrodynamic interaction mechanisms during offshore lifting operations of aquaculture net cages in wind-fishery integration systems.By integrating numerical simulations and dynamic analysis methods,this study systematically investigates the coupled dynamic response characteristics during the cage-carrier vessel separation process to reveal its dynamic evolution patterns and key influence mechanisms.[Method]Based on potential flow theory,a fully coupled dynamic analysis model of crane vessel-net cage-semi-submersible barge was established for a marine ranch project in Guangdong.The complete lifting process was dynamically simulated using SESAM software.Five typical operating sea states were configured to investigate the influence of wave parameters on the system's motion response under combined wave-current-wind actions.[Result]The results demonstrate that wave period dominates the system stability.Under short-period conditions,the system maintains stable motion with relatively small horizontal relative displacements,while long-period conditions excite low-frequency resonance,leading to significant slow-drift motions.Vertical response analysis reveals that long-period waves cause severe relative displacement fluctuations between the cage and semi-submersible vessel,with actual displacement amplitudes doubling the preset safety target of 2.045 m.Quantitative analysis further indicates that when significant wave height increases from 1.0 m to 1.5 m,the actual displacement amplitude increases by approximately 20%relative to the target displacement of 2.045 m,demonstrating that its influence is significantly weaker than the displacement variations induced by wave period changes.The complete dynamic simulation successfully captures the continuous dynamic response characteristics during the lifting process.[Conclusion]This research clarifies the influence mechanisms of wave parameters on the cage lifting process,identifying wave period as the crucial factor for operational safety.An operation window assessment method incorporating multi-body coupling effects is established,proposing a safety criterion with peak period not exceeding six seconds as the core requirement.The findings provide theoretical foundation for safe installation of marine ranch net cages and offer valuable references for similar offshore lifting operations.展开更多
Mapping potential areas for finfish mariculture,particularly high-yield regions,is crucial for the proper utilization of marine space and global food security.Physiological models(growth performance models)that consid...Mapping potential areas for finfish mariculture,particularly high-yield regions,is crucial for the proper utilization of marine space and global food security.Physiological models(growth performance models)that consider the spatiotemporal heterogeneity of the marine environment are a potentially effective approach to achieving this goal.In the present study,we developed an integrated model that combines the thermal performance curve and spatiotemporal heterogeneity of the marine environment to map the global high-yield potential mariculture areas for 27 commercial finfish species.Our results showed that the current sizes of the potentially suitable areas(achieving 50% of the maximum growth rate for at least six months annually)and high-yield areas(achieving 75% of the maximum growth rate throughout a year)are(8.00±0.30)×106 and(5.96±0.13)×106 km2,respectively.Currently,the sizes of suitable and high-yield areas for warm-water mariculture fish are larger than those for other species.The growth potential of suitable mariculture areas is higher at mid and low latitudes than at high latitudes.Under the two shared socioeconomic pathway scenarios(SSP1-2.6 and SSP5-8.5),the sizes of both suitable and high-yield areas will increase by 2050.However,there is the potential for finfish mariculture to respond differently to climate change among species and regions,and cold-water fish may benefit from global warming.Overall,the global potential for suitable high-yield mariculture areas continues to increase,making finfish mariculture an important contributor to global food security.展开更多
Evaluating species composition and dynamic shifts within fouling communities is essential for developing effective strate-gies to manage biofouling in marine fish aquaculture.The coastal area in the Yellow Sea is a ke...Evaluating species composition and dynamic shifts within fouling communities is essential for developing effective strate-gies to manage biofouling in marine fish aquaculture.The coastal area in the Yellow Sea is a key area for cage aquaculture in China;however,this region faces significant challenges from biofouling organisms.Here,we employed an experimental approach in a filed mesocosm in a net cage aquaculture area in the Yellow Sea,with weekly monitoring of changes in macrofouling species on mesh nets and in the seawater,to assess the utility of water eDNA metabarcoding for identifying macrofoulers.We compared the temporal variation patterns in the composition and diversity of macrofouling communities identified through morphological method as well as COI and 18S rRNA metabarcoding.The results showed that metabarcoding detected the majority of macrofoulers identified through morphological method(64%),and revealed additional species that were overlooked by traditional monitoring approach.Furthermore,the changes in diversity and community composition over sampling dates in COI data were generally consistent with those in morphological identification,although a temporal lag existed between these two approaches.A notable shift in the fouling community occurred at the end of June with the appearance of Ectopleura crocea and Caprella sp.,marking a pivotal change in its structure.Future research could focus on developing targeted primers for these key fouling species,which would enhance the efficiency of monitoring efforts.展开更多
摘要[Objective]This study aims to investigate the multi-body hydrodynamic interaction mechanisms during offshore lifting operations of aquaculture net cages in wind-fishery integration systems.By integrating numerical simulations and dynamic analysis methods,this study systematically investigates the coupled dynamic response characteristics during the cage-carrier vessel separation process to reveal its dynamic evolution patterns and key influence mechanisms.[Method]Based on potential flow theory,a fully coupled dynamic analysis model of crane vessel-net cage-semi-submersible barge was established for a marine ranch project in Guangdong.The complete lifting process was dynamically simulated using SESAM software.Five typical operating sea states were configured to investigate the influence of wave parameters on the system's motion response under combined wave-current-wind actions.[Result]The results demonstrate that wave period dominates the system stability.Under short-period conditions,the system maintains stable motion with relatively small horizontal relative displacements,while long-period conditions excite low-frequency resonance,leading to significant slow-drift motions.Vertical response analysis reveals that long-period waves cause severe relative displacement fluctuations between the cage and semi-submersible vessel,with actual displacement amplitudes doubling the preset safety target of 2.045 m.Quantitative analysis further indicates that when significant wave height increases from 1.0 m to 1.5 m,the actual displacement amplitude increases by approximately 20%relative to the target displacement of 2.045 m,demonstrating that its influence is significantly weaker than the displacement variations induced by wave period changes.The complete dynamic simulation successfully captures the continuous dynamic response characteristics during the lifting process.[Conclusion]This research clarifies the influence mechanisms of wave parameters on the cage lifting process,identifying wave period as the crucial factor for operational safety.An operation window assessment method incorporating multi-body coupling effects is established,proposing a safety criterion with peak period not exceeding six seconds as the core requirement.The findings provide theoretical foundation for safe installation of marine ranch net cages and offer valuable references for similar offshore lifting operations.
基金supported by the National Natural Science Founda-tion of China(42025604)the Fundamental Research Funds for the Central Universities of the Ocean University of China.
摘要Mapping potential areas for finfish mariculture,particularly high-yield regions,is crucial for the proper utilization of marine space and global food security.Physiological models(growth performance models)that consider the spatiotemporal heterogeneity of the marine environment are a potentially effective approach to achieving this goal.In the present study,we developed an integrated model that combines the thermal performance curve and spatiotemporal heterogeneity of the marine environment to map the global high-yield potential mariculture areas for 27 commercial finfish species.Our results showed that the current sizes of the potentially suitable areas(achieving 50% of the maximum growth rate for at least six months annually)and high-yield areas(achieving 75% of the maximum growth rate throughout a year)are(8.00±0.30)×106 and(5.96±0.13)×106 km2,respectively.Currently,the sizes of suitable and high-yield areas for warm-water mariculture fish are larger than those for other species.The growth potential of suitable mariculture areas is higher at mid and low latitudes than at high latitudes.Under the two shared socioeconomic pathway scenarios(SSP1-2.6 and SSP5-8.5),the sizes of both suitable and high-yield areas will increase by 2050.However,there is the potential for finfish mariculture to respond differently to climate change among species and regions,and cold-water fish may benefit from global warming.Overall,the global potential for suitable high-yield mariculture areas continues to increase,making finfish mariculture an important contributor to global food security.
基金supported by grants from the National Key Research and Development Program of China(No.2023YFD2401103)the Fundamental Research Funds for the Central Universities.
摘要Evaluating species composition and dynamic shifts within fouling communities is essential for developing effective strate-gies to manage biofouling in marine fish aquaculture.The coastal area in the Yellow Sea is a key area for cage aquaculture in China;however,this region faces significant challenges from biofouling organisms.Here,we employed an experimental approach in a filed mesocosm in a net cage aquaculture area in the Yellow Sea,with weekly monitoring of changes in macrofouling species on mesh nets and in the seawater,to assess the utility of water eDNA metabarcoding for identifying macrofoulers.We compared the temporal variation patterns in the composition and diversity of macrofouling communities identified through morphological method as well as COI and 18S rRNA metabarcoding.The results showed that metabarcoding detected the majority of macrofoulers identified through morphological method(64%),and revealed additional species that were overlooked by traditional monitoring approach.Furthermore,the changes in diversity and community composition over sampling dates in COI data were generally consistent with those in morphological identification,although a temporal lag existed between these two approaches.A notable shift in the fouling community occurred at the end of June with the appearance of Ectopleura crocea and Caprella sp.,marking a pivotal change in its structure.Future research could focus on developing targeted primers for these key fouling species,which would enhance the efficiency of monitoring efforts.