Abstract:

The distributions and changes of nutrients in Prydz Bay were investigated during CHINARE 6 and CHINARE 9, and the new productions were estimated by using mass balance method. The results showed that in CHINARE 6, the consumptions of NO 3 N、PO 4 P、SiO 3 Si were 1064.8、69.2、2196.9mmol/m 2,the uptake ratio of N and Si to P were 15 3, 31.7,respectively, and new production was 992.4 mgC/(m 2·d) ; and that in CHINARE 9, the depletions of NO 3 N、PO 4 P was 551.9、41.2mmol/m 2,respectively,the uptake ratio of N to P was 13.4,and the new production was 390.1 mgC/(m 2·d),indicating significant annual and /or seasonal variation. New productions were both greater than the primary production determined by 14 C trace method,demonstrating there existed rather higher new production in Prydz Bay in austral summer. The uptake ratio of nutrients in Prydz Bay, however, is different from the previous values obtained from the open sea,showing the regional difference of uptake and regeneration of nutrients in Southern Ocean. Finally the annual change of new production and the characteristics of phytoplankton production were discussed.