The dissolved silicate concentrations in the supernatant of sediment trap sampling bottles retrieved from deep water (1000-3000 m) at four stations in the South China Sea (SCS) were measured to calculate the underestimated flux of biogenic silica (bSi) in sinking particles due to bSi dissolution. High dissolved silicate concentrations in the supernatant, ranging from 122.6 to 1365.8 μmol/L, indicated significant dissolution of particulate bSi in the sampling bottles. Underestimation of the bSi flux in the SCS by ~2% to ~34% (average: ~10%) due to bSi dissolution was revealed, and the degree of underestimation increased with decreasing total bSi flux. The amount of bSi dissolved within the sampling series at each station was generally positively correlated with dissolution time and to a certain extent influenced by the bSi amount collected by the sampling bottles under a low bSi sinking flux. Apparently stronger bSi dissolution was found at two of the four stations due to relatively high bSi dissolution rates, which were possibly related to a higher reactive surface area of the bSi or bacterial activity. Overall, our results demonstrated that the considerable bSi dissolution in sediment trap sampling bottles should not be ignored, especially in the low-productivity oligotrophic ocean, and bSi flux calibration via measurement of the dissolved silicate in sampling bottles is necessary. To reduce bSi flux underestimation due to the deployment of time-series sediment traps, larger-volume sampling bottles should be avoided in the oligotrophic open ocean, and sinking particle samples should be analyzed as soon as the sediment traps are recovered.

测量南海（SCS）四个站点从深水（1000-3000 m）回收的沉积物捕集器采样瓶上清液中溶解的硅酸盐浓度，以计算由于下沉颗粒而被低估的生物二氧化硅（bSi）通量到 bSi 溶解。上清液中溶解的硅酸盐浓度高，范围从 122.6 到 1365.8 μmol/L，表明采样瓶中颗粒 bSi 的溶解显着。由于 bSi 溶解，SCS 中 bSi 通量被低估了 ~2% 到 ~34%（平均：~10%），并且低估程度随着总 bSi 通量的减少而增加。在每个站点的采样系列中溶解的bSi量通常与溶解时间呈正相关，并且在一定程度上受到在低bSi下沉通量下采样瓶收集的bSi量的影响。由于相对较高的 bSi 溶解速率，在四个站点中的两个站点发现明显更强的 bSi 溶解，这可能与 bSi 的较高反应表面积或细菌活性有关。总体而言，我们的结果表明，沉积物捕集器采样瓶中的大量 bSi 溶解不应被忽视，特别是在低产贫营养海洋中，以及 bSi 通量校准 这可能与 bSi 的较高反应表面积或细菌活性有关。总体而言，我们的结果表明，沉积物捕集器采样瓶中的大量 bSi 溶解不应被忽视，特别是在低产贫营养海洋中，以及 bSi 通量校准 这可能与 bSi 的较高反应表面积或细菌活性有关。总体而言，我们的结果表明，沉积物捕集器采样瓶中的大量 bSi 溶解不应被忽视，特别是在低产贫营养海洋中，以及 bSi 通量校准通过必须测量取样瓶中溶解的硅酸盐。为了减少由于部署时间序列沉积物陷阱而导致的 bSi 通量低估，应避免在贫营养开阔海洋中使用较大体积的采样瓶，并在沉积物陷阱恢复后立即分析下沉颗粒样品。