AEI prepress abstract  -  DOI: https://doi.org/10.3354/aei00248

Sediment phosphorus forms and sorption characteristics by biodisturbance of sea cucumber Apostichopus japonicus

Yi-Ran Hou, Yong-Jun Sun, Qin-Feng Gao*, Shuang-Lin Dong, Bin Wen, Zhe Pan, Liu Chengyue

*Email: qfgao@ouc.edu.cn

ABSTRACT: An 84-day experiment was carried out to investigate the impact of sea cucumber Apostichopus japonicus (Selenka) bioturbation on the different phosphorus forms and phosphorus sorption characteristics in the sediment. Sea cucumbers were cultured in fiberglass tanks (30 × 40 × 50 cm) with 5 cm-thick sediment, which were divided to four groups according to the culture densities, i.e., 0 ind/tank, 4 ind/tank, 6 ind/tank and 8 ind/tank. For each of the four densities, four replicates of sea cucumbers were cultured. Results showed that the increasing culture density of sea cucumber significantly increased the content of NaOH extractable P (NaOH-P) and decreased the content of organic phosphorus (OP) in sediment. Phosphorus maximum buffer capacity (MBC) and energy adsorption (Kf) values of sediment in lower density groups (0 ind/tank and 4 ind/tank) decreased significantly with time, while no temporal changes in MBC and Kf values of sediment of higher density groups (6 ind/tank and 8 ind/tank) were observed. The sea cucumbers facilitated the decomposition of OP and the formation of NaOH-P in sediment, and improved the ability and capacity of phosphorus sorption of sediment with the increasing culture density.