Biogenic silica standing stock and productivity on the Mississippi-Alabama Shelf, March to July, 2016

Diatoms are an important phytoplankton group in this region as they can dominate both the standing stock of phytoplankton and the rate of primary production at times. Unlike other phytoplankton groups, diatoms have an obligate requirement for silicon. Because diatoms can be important to regional primary production, there can be a strong coupling between the regional C and Si cycles. Because of this coupling, measurement of biogenic silica (bSi) production is a useful proxy to deduce the diatom-specific contribution to community rates, as silicoflagellates and radiolarians (which both use Si to build shells) are comparatively minor in biomass and grow slower than diatoms. Data were collected during cruises PTS02 and PTS03 on the Mississippi-Alabama shelf from March-July, 2016. This dataset supports the publication: Dzwonkowski, B., Greer, A.T., Briseño-Avena, C., Krause, J.W., Soto, I.M., Hernandez, F.J., Deary, A.L., Wiggert, J.D., Joung, D., Fitzpatrick, P.J., O'Brien, S.J., Dykstra, S.L., Lau, Y., Cambazoglu, M.K., Lockridge, G., Howden, S.D., Shiller, A.M., and Graham, W.M. (2017). Estuarine influence on biogeochemical properties of the Alabama shelf during the fall season. Continental Shelf Research, 140: 96-109 doi: 10.1016/j.csr.2017.05.001. Related size-fractionated nitrate uptake and primary productivity data can be found in GRIIDC dataset R4.x260.000:0092.

硅藻是该区域一类重要的浮游植物（phytoplankton）类群，它们有时可在浮游植物现存量与初级生产速率两方面占据主导地位。与其他浮游植物类群不同，硅藻对硅存在绝对需求。鉴于硅藻对区域初级生产具有重要意义，区域碳循环与硅循环之间会形成紧密的耦合关系。基于这一耦合机制，生源硅（biogenic silica, bSi）的产量测量可作为有效代用指标，用以推断硅藻对群落生产速率的专属贡献——这是因为硅鞭藻（silicoflagellates）与放射虫（radiolarians）虽均利用硅构建壳体，但其生物量相对较低，且生长速率慢于硅藻。本数据集采集于2016年3月至7月在密西西比-阿拉巴马陆架开展的PTS02与PTS03航次。本数据集支持以下已发表成果：Dzwonkowski, B.、Greer, A.T.、Briseño-Avena, C.、Krause, J.W.、Soto, I.M.、Hernandez, F.J.、Deary, A.L.、Wiggert, J.D.、Joung, D.、Fitzpatrick, P.J.、O'Brien, S.J.、Dykstra, S.L.、Lau, Y.、Cambazoglu, M.K.、Lockridge, G.、Howden, S.D.、Shiller, A.M. 及 Graham, W.M.（2017）。《秋季阿拉巴马陆架的河口对生物地球化学特征的影响》，《大陆架研究（Continental Shelf Research）》，140卷：96-109页，DOI: 10.1016/j.csr.2017.05.001。相关的分级粒径硝酸盐吸收与初级生产力数据可在GRIIDC数据集R4.x260.000:0092中获取。