Effects of dissolved oxygen and sediment on decomposition of Sargassum thunbergii debris
CHEN Yifan
WANG Kai
LIU Zhangbin
ZHAO Xu
CHENG Xiaopeng
ZHU Yue
ZHANG Shouyu
LIU Hongsheng
Abstract：Sargassum thunbergii,the dominant macroalgal species inhabiting Gouqi Island,was select-ed as the researching object to explore the release of macroalgal nutrients and the effects of dissolved oxygen and sediment on its decomposition during the process of litter decomposition and detritus forma-tion through indoor experimental simulation.The results showed that S.thunbergii decomposed rap-idly at the early stage of decomposition;the dry matter loss rate was high and the contents of ortho-phosphate and active acid salt in water increased significantly.The dry matter residue rate of S.thun-bergii was significantly correlated with the decomposition time(P＜0.01).After 48 days,the dry mat-ter residue rate of S.thunbergii was lower than 30％.High oxygen condition promoted the decomposi-tion of S.thunbergii and the release of inorganic nitrogen and reactive silicate.Under low oxygen con-dition,the decomposition of S.thunbergii reduced the pH of water and promoted the release of ortho-phosphate.At the later stage of decomposition,the absorption rate of nutrients by microorganisms in sediment was higher than that of algal decomposition,and the content of nutrients in water gradually decreased.The decomposition process of S.thunbergii was affected by the dissolved oxygen content and substrate conditions.Our findings may serve as a basis of exploring the effect of macroalgal decom-position on the ecosystem service efficiency of algal farms inhabiting the island and reef waters.
Keywords：Sargassum thunbergiisedimentdissolved oxygendegradation ratenutrient
Publication Date：2023-12-28
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：9( 91-99 )