FromJuly23rdtoAugust15th,2001,afieldcultivationexperimentwascarriedouttodeterminethelimitationfactorsofphytoplanktonintheYangtzeRiverestuaryandtheadjacentareas.TheresultsindicatedthatthepotentiallimitingnutrientwasphosphorusintheYangtzeRiverdilutedwaterarea,nitrogenintheoffshoreoftheYangtzeRiverestuaryandtheconversionofphosphorustonitrogeninthemiddlearea.Ironandsiliconwerenotthepotentiallimitingfactors.Ifthereweresomekindsoflimitingfactorsinthewater,thegrowthofphytoplanktonwouldbelimitedobviously.Incaseofdisappearanceofthelimitingfactor,thephytoplanktonwouldgrowfast.WhentheNoctilucascintiuansbloomoccurred,thephytoplanktonbiomasslevelwasverylowinashorttimeduetothegrazingpressure.Whenthegrazingpressuredisappeared,thephytoplanktonwouldgrowquicklyinabundantnutrientscondition.