On the basis of computational fluid dynamics,the flow field characteristics of multi-trophic artificial reefs,including the flow field distribution features of a single reef under three different velocities and the ef...On the basis of computational fluid dynamics,the flow field characteristics of multi-trophic artificial reefs,including the flow field distribution features of a single reef under three different velocities and the effect of spacing between reefs on flow scale and the flow state,were analyzed.Results indicate upwelling,slow flow,and eddy around a single reef.Maximum velocity,height,and volume of upwelling in front of a single reef were positively correlated with inflow velocity.The length and volume of slow flow increased with the increase in inflow velocity.Eddies were present both inside and backward,and vorticity was positively correlated with inflow velocity.Space between reefs had a minor influence on the maximum velocity and height of upwelling.With the increase in space from 0.5 L to 1.5 L(L is the reef lehgth),the length of slow flow in the front and back of the combined reefs increased slightly.When the space was 2.0 L,the length of the slow flow decreased.In four different spaces,eddies were present inside and at the back of each reef.The maximum vorticity was negatively correlated with space from 0.5 L to 1.5 L,but under 2.0 L space,the maximum vorticity was close to the vorticity of a single reef under the same inflow velocity.展开更多
Bivalves and seaweeds are important cleaners that are widely used in integrated multi-trophic aquaculture(IMTA) systems. A beneficial relationship between seaweed and bivalve in the seaweedbased IMTA system has been c...Bivalves and seaweeds are important cleaners that are widely used in integrated multi-trophic aquaculture(IMTA) systems. A beneficial relationship between seaweed and bivalve in the seaweedbased IMTA system has been confirmed, but the trophic importance of seaweed-derived particulate organic materials to the co-cultured bivalve is still unclear. We evaluated the trophic importance of the kelp Saccharina japonica to the co-cultured scallop Chlamys farreri in a typical IMTA farm in Sungo Bay(Weihai, North China). The dynamics of detritus carbon in the water were monitored during the culturing period. The proportion of kelp-derived organic matter in the diet of the co-cultured scallop was assessed via the stable carbon isotope method. Results showed that the detritus carbon in the water ranged from 75.52 to 265.19 μg/L, which was 25.6% to 73.8% of total particulate organic carbon(TPOC) during the study period. The amount of detritus carbon and its proportion in the TPOC changed throughout the culture cycle of the kelp. Stable carbon isotope analysis showed that the cultured scallop obtained 14.1% to 42.8% of its tissue carbon from the kelp, and that the percentages were closely correlated with the proportion of detritus carbon in the water( F =0.993, P= 0.003). Evaluation showed that for 17 000 tons(wet weight) of annual scallop production, the kelp contributed about 139.3 tons of carbon(535.8 tons of dry mass). This confirms that cultured kelp plays a similar trophic role in IMTA systems as it does in a natural kelp bed. It is a major contributor to the detritus pool and supplies a vital food source to filter-feeding scallops in the IMTA system, especially during winter and early spring when phytoplankton are scarce.展开更多
Introduction:China is responsible for more than 60%of global aquaculture production.As the frontiers of food production have expanded,the cultivation of marine organisms in coastal zones and the open ocean has grown r...Introduction:China is responsible for more than 60%of global aquaculture production.As the frontiers of food production have expanded,the cultivation of marine organisms in coastal zones and the open ocean has grown rapidly.The dominant mariculture industry in China is suspended mariculture,which uses net cages,ropes,or other structures suspended in the water column to cultivate aquatic organisms.This systematic,quantitative review provides a clear and comprehensive account of research that has investigated the adverse impacts of suspended mariculture in China and reviews research that has applied Integrated Multi-Trophic Aquaculture(IMTA)systems for mitigating impacts.This work builds on 218 peer reviewed papers that have been published in English-language journals.Outcomes:Eighteen impacts were identified,including chemical,ecological,physical,and socioeconomic impacts.Eighteen measures for improving suspended mariculture were recommended consisting of government department,farm management,and ecological engineering measures.IMTA was the most frequently recommended measure.The capabil-ities of IMTA for bioremediation and increased farm production were the most frequently studied advantages.Seven other benefits have been explored but remain understudied.The current challenges facing the expansion of commercial IMTA include limited use of new technology,limited skills development,decreasing production of low trophic-level species,biogeographic and temporal barriers,and negative system feedbacks.Conclusion:Despite challenges,implementing commercial IMTA is a promising measure for reducing the impacts of sus pended mariculture because it presents a range of secondary benefits that can improve the overall sustainability of aquaculture in the coastal zone.展开更多
基金supported by the National Natural Science Foundation of China(No.32002442)the National Key R&D Program(No.2019YFD0902101).
文摘On the basis of computational fluid dynamics,the flow field characteristics of multi-trophic artificial reefs,including the flow field distribution features of a single reef under three different velocities and the effect of spacing between reefs on flow scale and the flow state,were analyzed.Results indicate upwelling,slow flow,and eddy around a single reef.Maximum velocity,height,and volume of upwelling in front of a single reef were positively correlated with inflow velocity.The length and volume of slow flow increased with the increase in inflow velocity.Eddies were present both inside and backward,and vorticity was positively correlated with inflow velocity.Space between reefs had a minor influence on the maximum velocity and height of upwelling.With the increase in space from 0.5 L to 1.5 L(L is the reef lehgth),the length of slow flow in the front and back of the combined reefs increased slightly.When the space was 2.0 L,the length of the slow flow decreased.In four different spaces,eddies were present inside and at the back of each reef.The maximum vorticity was negatively correlated with space from 0.5 L to 1.5 L,but under 2.0 L space,the maximum vorticity was close to the vorticity of a single reef under the same inflow velocity.
基金Supported by the National Key Technologies R&D Program of China(No.2011BAD13B02)the NSFC-Shandong Joint Fund for Marine Science Research Centers(No.U1406403)the Marine Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA11020704)
文摘Bivalves and seaweeds are important cleaners that are widely used in integrated multi-trophic aquaculture(IMTA) systems. A beneficial relationship between seaweed and bivalve in the seaweedbased IMTA system has been confirmed, but the trophic importance of seaweed-derived particulate organic materials to the co-cultured bivalve is still unclear. We evaluated the trophic importance of the kelp Saccharina japonica to the co-cultured scallop Chlamys farreri in a typical IMTA farm in Sungo Bay(Weihai, North China). The dynamics of detritus carbon in the water were monitored during the culturing period. The proportion of kelp-derived organic matter in the diet of the co-cultured scallop was assessed via the stable carbon isotope method. Results showed that the detritus carbon in the water ranged from 75.52 to 265.19 μg/L, which was 25.6% to 73.8% of total particulate organic carbon(TPOC) during the study period. The amount of detritus carbon and its proportion in the TPOC changed throughout the culture cycle of the kelp. Stable carbon isotope analysis showed that the cultured scallop obtained 14.1% to 42.8% of its tissue carbon from the kelp, and that the percentages were closely correlated with the proportion of detritus carbon in the water( F =0.993, P= 0.003). Evaluation showed that for 17 000 tons(wet weight) of annual scallop production, the kelp contributed about 139.3 tons of carbon(535.8 tons of dry mass). This confirms that cultured kelp plays a similar trophic role in IMTA systems as it does in a natural kelp bed. It is a major contributor to the detritus pool and supplies a vital food source to filter-feeding scallops in the IMTA system, especially during winter and early spring when phytoplankton are scarce.
基金This work was supported by the Science Technology and Innovation Commission,Shenzhen Municipality,China[ZDSYSY20140509155229806]Sustainable Fisheries Development Fund,Hong Kong Agriculture Fisheries and Conservation Department[SFDF-0016]Sustainable Ecological Aquaculture Project,City University of Hong Kong[9610320].
文摘Introduction:China is responsible for more than 60%of global aquaculture production.As the frontiers of food production have expanded,the cultivation of marine organisms in coastal zones and the open ocean has grown rapidly.The dominant mariculture industry in China is suspended mariculture,which uses net cages,ropes,or other structures suspended in the water column to cultivate aquatic organisms.This systematic,quantitative review provides a clear and comprehensive account of research that has investigated the adverse impacts of suspended mariculture in China and reviews research that has applied Integrated Multi-Trophic Aquaculture(IMTA)systems for mitigating impacts.This work builds on 218 peer reviewed papers that have been published in English-language journals.Outcomes:Eighteen impacts were identified,including chemical,ecological,physical,and socioeconomic impacts.Eighteen measures for improving suspended mariculture were recommended consisting of government department,farm management,and ecological engineering measures.IMTA was the most frequently recommended measure.The capabil-ities of IMTA for bioremediation and increased farm production were the most frequently studied advantages.Seven other benefits have been explored but remain understudied.The current challenges facing the expansion of commercial IMTA include limited use of new technology,limited skills development,decreasing production of low trophic-level species,biogeographic and temporal barriers,and negative system feedbacks.Conclusion:Despite challenges,implementing commercial IMTA is a promising measure for reducing the impacts of sus pended mariculture because it presents a range of secondary benefits that can improve the overall sustainability of aquaculture in the coastal zone.
文摘2006年8～9月,在浙江象山港花鲈（Lateolabrax japonicus）养殖网箱中吊养真江蓠（Gracilaria verrucosa）对网箱养殖造成的水体富营养化进行生态修复研究。通过45d内的平面监测、定点跟踪监测和断面监测,结果表明：该网箱养殖区水体呈严重富营养化状态,营养状态指数（E）为32.00,其营养盐分布由高浓度的中心区向周围150m非养殖水域扩散;真江蓠对养殖区的富营养化海水具有较好的修复效果：江蓠生态修复区及其相邻网箱中水体PO4-P、NO2-N、NH4-N和NO3-N含量显著低于非修复区（P〈0.01）,修复区海水PO4-P、NO2-N、NH4-N和NO3-N浓度比非修复区分别降低22%～58%、24%～48%、22%～61%和24%～47%。养殖真江蓠45d后,修复区水体DO浓度和透明度显著高于非修复区（P〈0.05）,DO平均提高28%,透明度平均提高30%;而修复区水体Chl-a浓度显著低于非修复区（P〈0.05）,平均降低49%。通过建立基于N平衡的鱼藻生态养殖模式,每收获1kg花鲈至少需要匹配江蓠4.7 kg wetwt才可实现对鱼类排放N的完全吸收。因此网箱内栽培江蓠的混合生态养殖模式,可平衡因经济动物养殖所带来的额外营养负荷,有利于实现动物养殖环境的自我修复。
