School of Earth and Environmental Sciences & Research Institute of Oceanography, Seoul National University, Seoul 08826, Republic of Korea.
Department of Ocean Sciences, Inha University, Incheon 22212, Republic of Korea.
Mar Pollut Bull. 2021 Oct;171:112780. doi: 10.1016/j.marpolbul.2021.112780. Epub 2021 Jul 31.
The physical functions of extracellular polymeric substances (EPS), viz., by-product of microphytobenthos (MPB), in tidal flat system are well documented, but some ecological aspects remain unknown. We investigated MPB biomass (Chl-a), EPS, diatom assemblage, and erodibility in two contrasting tidal flat environments (megatidal vs. macrotidal flat) in the Yellow Sea. Thick biofilms were observed when MPB bloomed, with high Chl-a and increased EPS concentrations. Among diatom genera, Navicula was the most dominant taxa found over the year (mean 41%) in both areas. Compared with non-bloom periods, the erodibility decreased by 54-73% as biofilm thickened during the blooms. It was attributed to the elevated abundance of large-sized (>40 μm) Navicula, which was expected to secrete large amounts of EPS. Overall, we successfully demonstrated spatiotemporal differences of sediment stabilization that significantly related to ecological variations of MPB, and identified the key diatom genus as a "sediment stabilizer" in the typical tidal flats of the Yellow Sea.
已记录了胞外聚合物物质 (EPS) 的物理功能，即微藻底栖生物 (MPB) 的副产物，在潮滩系统中的功能，但仍有一些生态方面的问题尚不清楚。我们在黄海的两个具有对比性的潮滩环境（大潮滩和小潮滩）中调查了 MPB 生物量 (Chl-a)、EPS、硅藻组合和可蚀性。当 MPB 大量繁殖时，观察到厚厚的生物膜，具有高的 Chl-a 和增加的 EPS 浓度。在硅藻属中，全年发现的优势种是 Navicula（平均 41%），在两个地区都有发现。与非繁殖期相比，当生物膜在繁殖期变厚时，可蚀性降低了 54-73%。这归因于大型 Navicula 的丰度增加，预计其会分泌大量的 EPS。总的来说，我们成功地证明了沉积物稳定化的时空差异与 MPB 的生态变化显著相关，并确定了关键的硅藻属是黄海典型潮滩中的“沉积物稳定器”。
