The Effects of N,P Concentrations of Sea Water on the N,P Absorption by Betaphycus Gelatinum

Key words: 
• Betaphycus gelatium /
• eutrophication /
• nitrogen /
• phosphorus /
• uptake rate

Abstract: Sea water and Betaphycus gelatinum were collected in algae fields of Changjiang,Qionghai and Wenchang,Hainan to determine the inorganic N,P content in both sea water and B. gelatinum. The correlationship of N and P content between the sea water and B. gelatinum was analyzed by using SPSS19 statistical software.The results showed that the seawater N and P contents in the algae fields were positively correlated with the N and P content of B. gelatinum,with the regression equation being y = 0. 053 3x- 0. 003,R²= 0. 922 5,P ＜ 0. 05 for N content and y = 2. 966 3x + 0. 022 9,R²= 0. 846 2,P ＜ 0. 05 for P content. B. gelatinum was then cultured under laboratory conditions in sea water at different concentrations of inorganic N and P( 5,10,15,20,25,30,35,40 μmol·L^-1 to observe its absorption of inorganic N and P. The results show that B. gelatinum absorbed more inorganic N with the increase of seawater N concentration but the absorption decreased gradually when the seawater N concentration was higher than 40 μmol·L^-1. B. gelatinum increased its absorption of inorganic P with the seawater P concentration,but the increase tended to be gentle when the seawater concentration was upto 1. 5 μmol·L^-1. B. gelatinum absorbed inorganic N from seawater selectively,preferentially NH₄-N,followed by NO₃-N and NO₂-N from the seawater of the same N concentration. Determination of the N and P content in B. gelatinum also showed that B. gelatinum could remove 15. 33 ton of N and 73. 33 ton of P per 1000 ton of algae from sea water in the algae fields.