Filter-feeding shellfish are common benthos and significantly affect the biogeochemical cycle in the shallow coastal ecosystems.Ark clam Scapharca subcrenata is one of the widely cultured bivalve species in many coast...Filter-feeding shellfish are common benthos and significantly affect the biogeochemical cycle in the shallow coastal ecosystems.Ark clam Scapharca subcrenata is one of the widely cultured bivalve species in many coastal areas owing to its tremendous economic value.However,there is little information regarding the effects of the bioturbation of S.subcrenata on the fluxes of nutrient exchange in the sediment-water interface(SWI).In this regard,S.subcrenata was sampled during October 2016 to determine the effects of its bioturbation activity on the nutrient exchange flux of the SWI.The results showed that the biological activity of S.subcrenata could increase the diffusion depth and the rate of the nutrients exchange in the sediments.The bioturbation of S.subcrenata could allow the nutrients to permeate into the surface sediments at 6-10cm and increase the release rate of nutrients at the SWI.The releasing fluxes of DIN and PO43−-P in the culture area were found to be around three times higher than that in the non-cultured region.The culture of S.subcrenata has been proved to be an important contributor to nutrient exchange across the SWI in the farming area of Haizhou Bay.Nutrients exchange in the SWI contributes a part of 86%DIN,71%PO43−-P and 18%SiO32−-Si for the aquaculture farm.展开更多
Two Ecopath mass-balance models were implemented for evaluating the structure and function of Haizhou Bay Ecological Restoration Area ecosystem using 14 ecological indicators in two distinctive years(2003 and 2013). T...Two Ecopath mass-balance models were implemented for evaluating the structure and function of Haizhou Bay Ecological Restoration Area ecosystem using 14 ecological indicators in two distinctive years(2003 and 2013). The results showed that the size of HZERA ecosystem became larger as total biomass was increased in last decade, especially in primary producer and zooplankton groups. Total system throughput increased from 7496.00 t km^(-2) yr^(-1) to 9547.54 t km^(-2) yr^(-1). The P/R(production/respiration) ratio decreased over the decade. Finn's cycling index and Finn's mean path length increased over the decade. No keystone species(KS) occurred during ten years; however, evidences of top-down control in 2003 and 2013 models were demonstrated by high KS value belonging to Lophius litulon group in food web. Drawing upon Odum's theory of ecosystem maturity, the structured, web-like ecosystem of 2013 model had developed into a highly mature system compared with that of 2003 model.展开更多
基金supported by the Young Orient Scholars Programme of Shanghaithe Doctoral Scientific Research Starting Foundation of Shanghai Ocean University+2 种基金the Shanghai Special Research Fund for Training College’s Young Teachersthe Fund for Ministry of Agriculture Readjusting the Industrial Structure: Sea Farming Demonstration Project of Haizhou Bay in Jiangsu Province (Nos. D-8006-12-0018, D8006-15-8014)the Special Fund for Agro-Scientific Research in the Public Interest (No. 201303047)
文摘Filter-feeding shellfish are common benthos and significantly affect the biogeochemical cycle in the shallow coastal ecosystems.Ark clam Scapharca subcrenata is one of the widely cultured bivalve species in many coastal areas owing to its tremendous economic value.However,there is little information regarding the effects of the bioturbation of S.subcrenata on the fluxes of nutrient exchange in the sediment-water interface(SWI).In this regard,S.subcrenata was sampled during October 2016 to determine the effects of its bioturbation activity on the nutrient exchange flux of the SWI.The results showed that the biological activity of S.subcrenata could increase the diffusion depth and the rate of the nutrients exchange in the sediments.The bioturbation of S.subcrenata could allow the nutrients to permeate into the surface sediments at 6-10cm and increase the release rate of nutrients at the SWI.The releasing fluxes of DIN and PO43−-P in the culture area were found to be around three times higher than that in the non-cultured region.The culture of S.subcrenata has been proved to be an important contributor to nutrient exchange across the SWI in the farming area of Haizhou Bay.Nutrients exchange in the SWI contributes a part of 86%DIN,71%PO43−-P and 18%SiO32−-Si for the aquaculture farm.
基金supported by the grants of Haibay ma-rine ranching demonstration (Nos.D-8006-12-0018 and D8006-15-8014)special projects of the agriculture public sector (Nos.201003068 and 201303047)
文摘Two Ecopath mass-balance models were implemented for evaluating the structure and function of Haizhou Bay Ecological Restoration Area ecosystem using 14 ecological indicators in two distinctive years(2003 and 2013). The results showed that the size of HZERA ecosystem became larger as total biomass was increased in last decade, especially in primary producer and zooplankton groups. Total system throughput increased from 7496.00 t km^(-2) yr^(-1) to 9547.54 t km^(-2) yr^(-1). The P/R(production/respiration) ratio decreased over the decade. Finn's cycling index and Finn's mean path length increased over the decade. No keystone species(KS) occurred during ten years; however, evidences of top-down control in 2003 and 2013 models were demonstrated by high KS value belonging to Lophius litulon group in food web. Drawing upon Odum's theory of ecosystem maturity, the structured, web-like ecosystem of 2013 model had developed into a highly mature system compared with that of 2003 model.
