A freshwater-induced barrier layer (BL) is a common physical phenomenon both in coastal waters and the open ocean. To examine the effects of BL on the biological production and the associated carbon export, a physical-biogeochemical survey was conducted in the Bay of Bengal. Severe depletions of surface phosphorus and the deepening of the nutricline were observed at the BL-affected stations due to the vertical mixing prohibition. The lowered surface chlorophyll a (Chl a) and squeezed deep Chl a maximum (DCM) layer also resulted in the ~18% lowered vertically integrated Chl a at the said stations. The composition of the net-sampled zooplankton was altered, and the abundance decreased by half at the BL-affected station (29.68 ind. m⁻³) compared with the unaffected station (55.52 ind. m⁻³). Such reductions in major zooplankton groups were confirmed by a video plankton recorder (VPR). The VPR observation indicated that there was a lower (by one-half) abundance of detritus at the BL-affected station, while the much lower carbon export flux rates were estimated to be at the BL-affected station (0.31 mg C m⁻² d⁻¹) rather than the unaffected station (0.77 mg C m⁻² d⁻¹). An idealized one-dimensional nutrient-phytoplankton-detritus model identified that the existence of BL can lead to decreased surface nutrients and phytoplankton concentrations, squeezed DCM layers, and lower detritus abundances. Finally, this study indicated that BL layers inhibit biological production and reduce carbon export, thus playing an important role in the ocean biogeochemical cycles.

淡水诱导屏障层 (BL) 是沿海水域和公海中常见的物理现象。为了检查 BL 对生物生产和相关碳输出的影响，在孟加拉湾进行了物理-生物地球化学调查。由于垂直混合禁止，在受 BL 影响的站点观察到表面磷的严重消耗和营养线的加深。降低表面叶绿素一种 （氯 一种) 并挤压深 Chl 一种 最大 (DCM) 层也导致垂直整合的 Chl 降低约 18% 一种在上述车站。净采样浮游动物的组成发生了改变，与未受影响站（55.52 ind. m ^-3）相比，受 BL 影响站（29.68 ind. m ^-3）的丰度减少了一半。浮游生物录像机（VPR）证实了主要浮游动物群的这种减少。VPR 观测表明，受 BL 影响的站的碎屑丰度较低（二分之一），而估计受 BL 影响的站的碳输出通量率要低得多（0.31 mg C m ^-2 d ^-1 ) 而不是未受影响的站 (0.77 mg C m ^-2 d ^-1）。理想化的一维养分-浮游植物-碎屑模型确定 BL 的存在可导致表面养分和浮游植物浓度降低、DCM 层受挤压和碎屑丰度降低。最后，本研究表明BL层抑制生物生产并减少碳输出，从而在海洋生物地球化学循环中发挥重要作用。