Integrated multi-trophic aquaculture(IMTA)has been considered as an ecofriendly culture system providing a potential solution to environmental risks caused by intensive monoculture system.However,the impact of IMTA on...Integrated multi-trophic aquaculture(IMTA)has been considered as an ecofriendly culture system providing a potential solution to environmental risks caused by intensive monoculture system.However,the impact of IMTA on phytoplankton remains unclear.In this study,the spatial and temporal variations of phytoplankton in Sanggou Bay were investigated seasonally based on 21 sampling sites covering three cultivation zones(bivalve zone,IMTA zone,and kelp zone)and one control zone(without aquatic cultivation).In total,128 phytoplankton species,with diatoms and dinoflagellates as the dominant groups,were obtained across the whole year,and the mean Shannon diversity index(H')and species richness(SR)were determined as 1.39 and 9.39,respectively.The maximum chlorophyll a(Chl-a)(6.32μg L^(-1))and plankton diversity(H'of 1.97)occurred in summer and autumn,respectively.Compared to other zones,the bivalve zone displayed significantly higher Chl-a and lower H'in majority of time.Pairwise PERMANOVA analysis indicated that the phytoplankton assemblage in the bivalve zone was significantly different with the control and kelp zones,while the IMTA zone maintained close to other three zones.Based on generalized additive models,temperature,NO_(2)^(-)-N,N/P ratio,SiO_(3)^(2-)-Si,and salinity were determined as the key factors underlying Chl-a and phytoplankton diversity.Addi-tionally,the results of redundancy analysis further indicated that the phytoplankton assemblage in the bivalve zone is positively re-lated with nutrients such as NO_(3)^(-)-N and NH_(4)^(+)-N as well as water depth,while the phytoplankton assemblages in the kelp,control,and IMTA zones are associated with NO_(2)^(-)-N,SiO_(3)^(2-)-Si,and salinity.Taken all observations into consideration together,it can be inferred that IMTA can effectively reduce Chl-a level compared to bivalve monoculture by reducing the nutrients.However,the SR,H’,and species composition of phytoplankton are primarily determined by local environment factors such as temperature,water depth,salinity and SiO_(3)^(2-)-Si.展开更多
Naturally existing stable carbon and nitrogen isotopes are important in the study of sedimentary organic matter sources. To identify the sources of sedimentary organic matter in Sanggou Bay and its adjacent areas, whi...Naturally existing stable carbon and nitrogen isotopes are important in the study of sedimentary organic matter sources. To identify the sources of sedimentary organic matter in Sanggou Bay and its adjacent areas, which is characterized by high-density shellfish and seaweed aquaculture, the grain size, organic carbon (OC), total nitrogen (TN), carbon and nitrogen isotopic composition (δ13C andδ15N) of organic matter in the surface sediment were determined. The results showed that, in August, sedimentary OC and TN ranged from 0.17% to 0.76% and 0.04% to 0.14%, respectively. In November, OC and TN ranged from 0.23% to 0.87% and 0.05% to 0.14%, respectively. There was a significant positive correlation between OC and TN (R=0.98, P<0.0001), indicating that OC and TN were homologous. In August, theδ13C andδ15N of organic matter varied from -23.06‰ to -21.59‰ and 5.10‰ to 6.31‰, respectively. In November,δ13C andδ15N ranged from -22.87‰ to -21.34‰ and 5.13‰ to 7.31‰, respectively. This study found that the major sources of sedimentary organic matter were marine shellfish biodeposition, seaweed farming, and soil organic matter. Using a three-end-member mixed model, we estimated that the dominant source of sedimentary organic matter was shellfish biodeposition, with an average contribution rate of 65.53% in August and 43.00% in November. Thus, shellfish farming had a significant influence on the coastal carbon cycle.展开更多
In this study, we assessed the burial fluxes and source appointment of different forms of carbon in core sediments collected from culture areas in the Sanggou Bay, and preliminarily analyzed the reasons for the greate...In this study, we assessed the burial fluxes and source appointment of different forms of carbon in core sediments collected from culture areas in the Sanggou Bay, and preliminarily analyzed the reasons for the greater proportion of inorganic carbon burial fluxes (BFTIc). The average content of total carbon (TC) in the Sanggou Bay was 2.14%. Total organic carbon (TOC) accounted for a small proportion in TC, more than 65% of which derived from terrigenous organic carbon (Ct), and while the proportion of marine-derived organic carbon (Ca) increased significantly since the beginning of large-scale aquaculture. Total inorganic carbon (TIC) accounted for 60%-75% of TC, an average of which was 60%, with a maximum up to 90% during flourishing periods (1880-1948) of small natural shellfish derived from seashells inorganic carbon (SheU-IC). The TC burial fluxes ranged from 31 g/(m2.a) to 895 g/(m2.a) with an average of 227 g/(m2.a), which was dominated by TIC (about 70%). Shell-IC was the main source of TIC and even TC. As the main food of natural shellfish, biogenic silica (BSi) negatively correlated with BFTIc through affecting shellfish breeding. BFTIc of Sta. S1, influenced greatly by the Yellow Sea Coastal Current, had a certain response to Pacific Decadal Oscillation (PDO) in some specific periods.展开更多
The phosphorus cycle is studied during 2013–2014 in the Sanggou Bay(SGB), which is a typical aquaculture area in northern China. The forms of measured phosphorus include dissolved inorganic phosphorus(DIP), disso...The phosphorus cycle is studied during 2013–2014 in the Sanggou Bay(SGB), which is a typical aquaculture area in northern China. The forms of measured phosphorus include dissolved inorganic phosphorus(DIP), dissolved organic phosphorus(DOP), particulate inorganic phosphorus(PIP), and particulate organic phosphorus(POP).DIP and PIP are the major forms of total dissolved phosphorus(TDP) and total particulate phosphorus(TPP),representing 51%–75% and 53%–80%, respectively. The concentrations and distributions of phosphorus forms vary among seasons relative to aquaculture cycles, fluvial input, and hydrodynamic conditions. In autumn the concentration of DIP is significantly higher than in other seasons(P〈0.01), and higher concentrations are found in the west of the bay. In winter and spring the phosphorus concentrations are higher in the east of the bay than in the west. In summer, the distributions of phosphorus forms are uniform. A preliminary phosphorus budget is developed, and shows that SGB is a net sink of phosphorus. A total of 1.80×10^7 mol/a phosphorus is transported into the bay. The Yellow Sea is the major source of net input of phosphorus(61%), followed by submarine groundwater discharge(SGD)(27%), river input(11%), and atmospheric deposition(1%). The main phosphorus sink is the harvest of seaweeds(Saccharina japonica and Gracilaria lemaneiformis), bivalves(Chlamys farreri),and oysters(Crassostrea gigas), accounting for a total of 1.12×10^7 mol/a. Burial of phosphorus in sediment is another important sink, accounting for 7.00×10^6 mol/a. Biodeposition by bivalves is the major source of phosphorus in sediment, accounting for 54% of the total.展开更多
The standing crop and primary production of benthic microalgae on tidal flats have seasonally been observed in the Sanggou and Jiaozhou Bays of the northern China coast during 1999 - 2000. The results show that the an...The standing crop and primary production of benthic microalgae on tidal flats have seasonally been observed in the Sanggou and Jiaozhou Bays of the northern China coast during 1999 - 2000. The results show that the annual primary productions of benthic microalgae on tidal flats in the two bays are 2 532 and 7 542 tons carbon, which would be able to support 3.1 x 103 and 9.2 x 103 tons shellfish meat, respectively. The nature of sediment is essential for governing the biomass and primary production of benthic microalgae on tidal flats. The biomass and primary production of benthic microalgae on tidal flats with muddy sediments are higher than those with sandy sediments, which resulted from higher nutrient concentration and lower grazing pressure. That is the reason why in comparison with Xiangshan Bay the standing crop and production of benthic microalgae on tidal flats of the Sanggou and Jiaozhou Bays are low. Light was a key factor controlling vertical distribution of biomass and production of benthic microalgae on tidal flats of the two bays, resulted in appearance of maximum chlorophyll a and primary production at the surface layer and sharply decreased with depth of sediment.展开更多
基金supported by the National Science and Technology Basic Resources Investigation Program of China(No.2018FY100206)the National Natural Science Foundation of China(Nos.31902370 and 42276099)+2 种基金the Ningbo Public Welfare Science and Technology Program(No.2022S161)the Key Program of Science and Technology Innovation in Ningbo(No.2023Z118)the National Key Research and Development Program of China(No.2018YFD0900703).
文摘Integrated multi-trophic aquaculture(IMTA)has been considered as an ecofriendly culture system providing a potential solution to environmental risks caused by intensive monoculture system.However,the impact of IMTA on phytoplankton remains unclear.In this study,the spatial and temporal variations of phytoplankton in Sanggou Bay were investigated seasonally based on 21 sampling sites covering three cultivation zones(bivalve zone,IMTA zone,and kelp zone)and one control zone(without aquatic cultivation).In total,128 phytoplankton species,with diatoms and dinoflagellates as the dominant groups,were obtained across the whole year,and the mean Shannon diversity index(H')and species richness(SR)were determined as 1.39 and 9.39,respectively.The maximum chlorophyll a(Chl-a)(6.32μg L^(-1))and plankton diversity(H'of 1.97)occurred in summer and autumn,respectively.Compared to other zones,the bivalve zone displayed significantly higher Chl-a and lower H'in majority of time.Pairwise PERMANOVA analysis indicated that the phytoplankton assemblage in the bivalve zone was significantly different with the control and kelp zones,while the IMTA zone maintained close to other three zones.Based on generalized additive models,temperature,NO_(2)^(-)-N,N/P ratio,SiO_(3)^(2-)-Si,and salinity were determined as the key factors underlying Chl-a and phytoplankton diversity.Addi-tionally,the results of redundancy analysis further indicated that the phytoplankton assemblage in the bivalve zone is positively re-lated with nutrients such as NO_(3)^(-)-N and NH_(4)^(+)-N as well as water depth,while the phytoplankton assemblages in the kelp,control,and IMTA zones are associated with NO_(2)^(-)-N,SiO_(3)^(2-)-Si,and salinity.Taken all observations into consideration together,it can be inferred that IMTA can effectively reduce Chl-a level compared to bivalve monoculture by reducing the nutrients.However,the SR,H’,and species composition of phytoplankton are primarily determined by local environment factors such as temperature,water depth,salinity and SiO_(3)^(2-)-Si.
基金The Joint Fund Project of National Fund Committee and Shandong Province under contract No.U1406403the State Oceanic Administration Project of China under contract Nos DOMEP(MEA)-01-01 and DOMEP(MEA)-02
文摘Naturally existing stable carbon and nitrogen isotopes are important in the study of sedimentary organic matter sources. To identify the sources of sedimentary organic matter in Sanggou Bay and its adjacent areas, which is characterized by high-density shellfish and seaweed aquaculture, the grain size, organic carbon (OC), total nitrogen (TN), carbon and nitrogen isotopic composition (δ13C andδ15N) of organic matter in the surface sediment were determined. The results showed that, in August, sedimentary OC and TN ranged from 0.17% to 0.76% and 0.04% to 0.14%, respectively. In November, OC and TN ranged from 0.23% to 0.87% and 0.05% to 0.14%, respectively. There was a significant positive correlation between OC and TN (R=0.98, P<0.0001), indicating that OC and TN were homologous. In August, theδ13C andδ15N of organic matter varied from -23.06‰ to -21.59‰ and 5.10‰ to 6.31‰, respectively. In November,δ13C andδ15N ranged from -22.87‰ to -21.34‰ and 5.13‰ to 7.31‰, respectively. This study found that the major sources of sedimentary organic matter were marine shellfish biodeposition, seaweed farming, and soil organic matter. Using a three-end-member mixed model, we estimated that the dominant source of sedimentary organic matter was shellfish biodeposition, with an average contribution rate of 65.53% in August and 43.00% in November. Thus, shellfish farming had a significant influence on the coastal carbon cycle.
基金The National Basic Research Program(973 Program)of China under contract No.2010CB428902the Special Scientific Research Funds for Central Non-profit Institutes,Chinese Academy of Fishery Sciences under contract No.2014A01YY01the Management of Central Public-interest Scientific Institution Basal Research Fund under contract No.20603022013003
文摘In this study, we assessed the burial fluxes and source appointment of different forms of carbon in core sediments collected from culture areas in the Sanggou Bay, and preliminarily analyzed the reasons for the greater proportion of inorganic carbon burial fluxes (BFTIc). The average content of total carbon (TC) in the Sanggou Bay was 2.14%. Total organic carbon (TOC) accounted for a small proportion in TC, more than 65% of which derived from terrigenous organic carbon (Ct), and while the proportion of marine-derived organic carbon (Ca) increased significantly since the beginning of large-scale aquaculture. Total inorganic carbon (TIC) accounted for 60%-75% of TC, an average of which was 60%, with a maximum up to 90% during flourishing periods (1880-1948) of small natural shellfish derived from seashells inorganic carbon (SheU-IC). The TC burial fluxes ranged from 31 g/(m2.a) to 895 g/(m2.a) with an average of 227 g/(m2.a), which was dominated by TIC (about 70%). Shell-IC was the main source of TIC and even TC. As the main food of natural shellfish, biogenic silica (BSi) negatively correlated with BFTIc through affecting shellfish breeding. BFTIc of Sta. S1, influenced greatly by the Yellow Sea Coastal Current, had a certain response to Pacific Decadal Oscillation (PDO) in some specific periods.
基金The National Basic Research Program of China(973 Program)under contract No.2011CB409802the National Natural Science Foundation of China under contract No.41521064+1 种基金the Taishan Scholars Program of Shandong Province of Chinathe Aoshan Talents Program Supported by Qingdao National Laboratory for Marine Science and Technology under contract No.2015ASTP-OS08
文摘The phosphorus cycle is studied during 2013–2014 in the Sanggou Bay(SGB), which is a typical aquaculture area in northern China. The forms of measured phosphorus include dissolved inorganic phosphorus(DIP), dissolved organic phosphorus(DOP), particulate inorganic phosphorus(PIP), and particulate organic phosphorus(POP).DIP and PIP are the major forms of total dissolved phosphorus(TDP) and total particulate phosphorus(TPP),representing 51%–75% and 53%–80%, respectively. The concentrations and distributions of phosphorus forms vary among seasons relative to aquaculture cycles, fluvial input, and hydrodynamic conditions. In autumn the concentration of DIP is significantly higher than in other seasons(P〈0.01), and higher concentrations are found in the west of the bay. In winter and spring the phosphorus concentrations are higher in the east of the bay than in the west. In summer, the distributions of phosphorus forms are uniform. A preliminary phosphorus budget is developed, and shows that SGB is a net sink of phosphorus. A total of 1.80×10^7 mol/a phosphorus is transported into the bay. The Yellow Sea is the major source of net input of phosphorus(61%), followed by submarine groundwater discharge(SGD)(27%), river input(11%), and atmospheric deposition(1%). The main phosphorus sink is the harvest of seaweeds(Saccharina japonica and Gracilaria lemaneiformis), bivalves(Chlamys farreri),and oysters(Crassostrea gigas), accounting for a total of 1.12×10^7 mol/a. Burial of phosphorus in sediment is another important sink, accounting for 7.00×10^6 mol/a. Biodeposition by bivalves is the major source of phosphorus in sediment, accounting for 54% of the total.
基金This study was supported by EC Project under contract No.ERB3514PL97 2439 with the contract No.ERB IC18-CT98-0291.
文摘The standing crop and primary production of benthic microalgae on tidal flats have seasonally been observed in the Sanggou and Jiaozhou Bays of the northern China coast during 1999 - 2000. The results show that the annual primary productions of benthic microalgae on tidal flats in the two bays are 2 532 and 7 542 tons carbon, which would be able to support 3.1 x 103 and 9.2 x 103 tons shellfish meat, respectively. The nature of sediment is essential for governing the biomass and primary production of benthic microalgae on tidal flats. The biomass and primary production of benthic microalgae on tidal flats with muddy sediments are higher than those with sandy sediments, which resulted from higher nutrient concentration and lower grazing pressure. That is the reason why in comparison with Xiangshan Bay the standing crop and production of benthic microalgae on tidal flats of the Sanggou and Jiaozhou Bays are low. Light was a key factor controlling vertical distribution of biomass and production of benthic microalgae on tidal flats of the two bays, resulted in appearance of maximum chlorophyll a and primary production at the surface layer and sharply decreased with depth of sediment.