Concentrations of major biogenic elements in the photic layer of the Kandalaksha Bay and production of organic matter

Data on spatial and temporal variability of concentrations and speciations of major nutrients (oxygen, phosphorus, nitrogen, and silicon) in deep waters of the Kandalaksha Bay are presented. Main variations of nutrients in the photic layer associate with seasonal variations in intensity of production and degradation processes. High primary productivity in the spring-summer period results in oxygen oversaturation (103-115%), minimum concentrations of mineral silicon, phosphorus and nitrogen along with increase of their organic forms. Simultaneously under pycnocline concentrations of mineral silicon, phosphorus and nitrogen increase with depth. Distribution of mineral silicon and phosphorus in the deep water layers is under significant influence of waters entering from the Gorlo Straight. In deep water part of the bay nitrogen occurs mainly in organic forms, while phosphorus occurs mainly in mineral forms. An estimation of new primary production on the base of seasonal variations of major nutrient concentrations has been done and great contribution of primary production from recycling of biogenic elements to productivity of these waters has been revealed.本数据集呈现了坎达拉克沙湾（Kandalaksha Bay）深水区域主要营养盐（氧、磷、氮、硅）的浓度与形态的时空变化特征。透光层（photic layer）内营养盐的主要变化与生产和降解过程强度的季节波动密切相关。春夏季节的高初级生产力会导致水体氧过饱和（103%~115%），同时矿质态硅、磷、氮浓度降至最低，而其有机态组分占比升高。与此同时，密度跃层（pycnocline）下方的矿质态硅、磷、氮浓度随水深增加而升高。深水层中矿质态硅与磷的分布显著受戈尔洛海峡（Gorlo Straight）输入水体的影响。在海湾深水区域，氮主要以有机态形式存在，而磷则以矿质态为主要赋存形态。本研究基于主要营养盐浓度的季节波动估算了新初级生产力，并揭示了生源元素循环再生过程对该水域初级生产力的显著贡献。