浙江近岸陆域海水养殖氮磷排放通量估算

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Estimation of nitrogen and phosphorus fluxes from land-based

mariculture areas in coastal Zhejiang province

DU Yiwei¹，LI Xiaoguang²，LIN Tian¹’

（1.Colege of Oceanographyand Ecological Science，Shanghai Ocean University，Shanghai 201306，China；2.Basin Research Center for WaterPolution Control，Chinese Research Academyof Environmental Sciences，Beijing 100012，China）

Abstract ： Understanding nutrient fluxinaquaculture systems is criticalforsustainable coastal environmental management. Thisstudycomprehensivelyinvestigatednitrogenandphosphorus dynamics inland-based maricuitureacross four coastal cities of Zhejiang province：Ningbo，Taizhou，Wenzhou，and Zhoushan，utizing datafrom1018sampling points atmarine outfalls. Elemental concentration analyses revealed total nitrogen levels ranging from 0.015 to 36.000mg/L ，with total phosphorus concentrations between 0.005 and 2.860mg/L .Notably，over 90% of the samples remained within Category Il of theZhejiang Province MaricultureTailwaterDischarge Standards，indicatingrelativelycontrolldnutrientemissions. Employing bothchemicalanalysisand polutiondischargecoeficientmethodologies，weestimatedtheannual nutrient flux fromland-based mariculture tailwaters.Chemicalanalysis methods indicatedannualtotal nitrogenand phosphorus fluxesof 2969.2t and 83.6t ，respectively. Significantly，the third and fourth quarters contributed 84.4% of the annual nutrient flux， coinciding with peak harvesting periodsand influenced by complex hydrodynamic factors including oceanic currents and YangtzeRiverdilutionwaters.Comparativeanalysisbetweenmethodological approachesrevealedsubstantial discrepancies，with polution discharge coeficient methods estimating higher annual fluxes（4 634.3 t nitrogenand 801.4t phosphorus）.These variations suggest considerable nutrientsequestration within bottm sediments，presenting potential long-termenvironmentalimplications.Thecontinuousaccumulationofnitrogenandphosphorusinsedimentary environments raises critical concerns about secondary nutrient release mechanisms and escalating eutrophication risks in adjacent marine ecosystems.These findings underscore the necessityforsophisticated nutrient management strategies in coastal mariculture systems.

Keywords：chemical analysis method；total nitrogenand total phosphorus；fluxes；land-basedmariculture；coastal Zhejiang

中国作为西太平洋沿岸的海洋大国，拥有丰富的海洋资源，海洋经济是我国经济发展的重要组成部分。（剩余11013字）