Mariculture has rapidly grown worldwide, which might greatly influence the biogeochemical cycle of organic carbon in coastal seas. In this study, several geochemical parameters, including grain size composition, sedim...Mariculture has rapidly grown worldwide, which might greatly influence the biogeochemical cycle of organic carbon in coastal seas. In this study, several geochemical parameters, including grain size composition, sedimentary total organic carbon (TOC), total nitrogen (TN), stable carbon (δ13C) and nitrogen (δ15N) isotopic compositions, were analyzed for surface sediments collected from different mariculture zones of Sanggou Bay and in different seasons. We investigated the composition and distribution of or- ganic matter in surface sediments and further evaluated the contribution of mariculture activities to TOC sources. The TOC and TN contents (mass percentage) in the bay were in the range of 0.14% to 1.45% and 0.03% to 0.20%, respectively. The spatial distribution indicated that sedimentary TOC and TN contents in shellfish monoculture and shellfish-kelp polyculture zones were higher than in other mariculture zones, which might be related to grain size composition and mariculture organisms. Seasonal variations of TOC contents were observed in different mariculture zones. The TOC/TN atomic ratio (C/N),δ13C and δ15N were in the ranges of 5.97 to 10.97, 21.76‰ to 13.14‰ and 2.13‰ to 8.08‰, respectively, implying that sedimentary organic matter in Sanggou Bay was the mixture of marine phytoplankton, terrestrial and maricultural sources. A simple mixing model based on δ13C was applied and the results indicated that the relative contributions of organic carbon sources in Sanggou Bay followed the order kelp (36.6%) marine phytoplankton (28.7%) shellfish bio-deposition (23.8%) terrestrial input (10.9%). Surface sediments in Sanggou Bay were domi- nated by mariculture-derived organic carbon, which on average accounted for 60.4% of TOC.展开更多
基金funded by Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDA23050402)the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology (Qingdao) (No. 2018SDKJ0501-3)+2 种基金the National Natural Science Foundation of China (No. 41276172)the Special Fund of Basic Research for Central non-profit Scientific Research Institute (No. 2014A01 YY01)Special Fund of Basic Research for Chinese Academy of Fishery Sciences (Nos. 2016HY-JC01-01 and 2017GH09)
文摘Mariculture has rapidly grown worldwide, which might greatly influence the biogeochemical cycle of organic carbon in coastal seas. In this study, several geochemical parameters, including grain size composition, sedimentary total organic carbon (TOC), total nitrogen (TN), stable carbon (δ13C) and nitrogen (δ15N) isotopic compositions, were analyzed for surface sediments collected from different mariculture zones of Sanggou Bay and in different seasons. We investigated the composition and distribution of or- ganic matter in surface sediments and further evaluated the contribution of mariculture activities to TOC sources. The TOC and TN contents (mass percentage) in the bay were in the range of 0.14% to 1.45% and 0.03% to 0.20%, respectively. The spatial distribution indicated that sedimentary TOC and TN contents in shellfish monoculture and shellfish-kelp polyculture zones were higher than in other mariculture zones, which might be related to grain size composition and mariculture organisms. Seasonal variations of TOC contents were observed in different mariculture zones. The TOC/TN atomic ratio (C/N),δ13C and δ15N were in the ranges of 5.97 to 10.97, 21.76‰ to 13.14‰ and 2.13‰ to 8.08‰, respectively, implying that sedimentary organic matter in Sanggou Bay was the mixture of marine phytoplankton, terrestrial and maricultural sources. A simple mixing model based on δ13C was applied and the results indicated that the relative contributions of organic carbon sources in Sanggou Bay followed the order kelp (36.6%) marine phytoplankton (28.7%) shellfish bio-deposition (23.8%) terrestrial input (10.9%). Surface sediments in Sanggou Bay were domi- nated by mariculture-derived organic carbon, which on average accounted for 60.4% of TOC.
