Abstract: This paper studied the respective contribution of feeding and non-feeding marine culture on seawater and red tide occurrence.The results showed that the annual output of marine had a positive correlation with the nutrients and COD in the Yellow Sea and Bohai Sea,of which,the correlation between DIN content and shrimp yield was significant.The output also had a positive correlation with the occurrence times of red tide recorded in the Yellow and Sea Bohai Sea.These results illustrated that the self-pollution of marine culture had a significant influence on the eutrophication and red tide occurred in the neighboring waters.It was estimated that the amounts of N,P and COD entered into seawater through the marine culture in the Yellow Sea and Bohai Sea accounted for 2.8%,5.3% and 1.8% of the amounts of corresponding land-based pollutants entered to the sea,respectively. Although the discharge of the pollutants produced by marine culture was less than that produced by other human activities,some local waters,especially dense marine culture areas,would bring out some additive effects on environment.Therefore,the pollutants discharged by marine culture were very likely to be an important factor stimulating the eutrophication and red tide occurrence in coastal waters,which should be paid adequate attention.

Key words: Farmyard manure, Fertilization, Shaanxi Province