浙江近岸陸域海水養(yǎng)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
中國作為西太平洋沿岸的海洋大國,擁有豐富的海洋資源,海洋經(jīng)濟是我國經(jīng)濟發(fā)展的重要組成部分。(剩余11013字)