FEATURE AND BEHAVIOR OF NITROGEN AND PHOSPHOROUS NUTRENTS IN SHRIMP PONDS

Of nitr ogen and pho spho rus nut rients of shrimp po nds, fea ture and behav ior w ere discussed according to inv est ig ato n results. Seasonal change of IN w as much big ger, especia lly in last per iod of shr imp culture, than that of IP w hich w as stable dur ing the sho le cultur e per iod. Both IN and IP o f vert ical dist ribut ion w ere even in the w ater s. The re w as obvio usly seasona l change on IN fo ex isting fo rm. Moreo ver, it was dif ferent f rom the open w aters that NO2 - N w as also o ne o f the main IN forms. In the mo st culture per iod, IN w as in the po or level and , there fore, became the main rest rict facto r o f pho toplankto n pro ductiv ity. Otherw ise, cir cl ing rate o f IN and I P co uld be increa sed by higher density pho to phankto n in shrimp ponds.