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90年代,氮的储量在波罗的海北部有上升的趋势,这可以用脱氮作用变化来解释所观察到的在氮储量方面的某些波动情况。虽然脱氮作用是一个缺氧过程,但沉积物可以被适度氧化,所以通过脱氮作用除去氮还是一种比较有效的方法。人们注意到,1973～1999年27年的时间里,波罗的海北部SiO_4与DIN(DIN=NO_3+NH_4)的比率大大降低了。假如可溶性的硅能够限制浮游植物赤潮的话,那么由硅藻引发的赤潮就会消失而由鞭毛藻所取代,从而导致磷酸盐储存并且沉积下来。7年以后,以前曾经流入这里的高盐水已经随着时间的推移而消失并且缺氧现象已经扩散到周围很大的一片区域。在海底深处,磷的含量已开始增长并且脱氮能力正在减弱。因此,从长远观点看,如果能使氮和磷的含量减少到最低水平,那么将有可能帮助波罗的海摆脱因富营养化而造成的影响。
In the 1990s, there was an upward trend in nitrogen reserves in the northern part of the Baltic Sea, which explained some of the observed fluctuations in nitrogen reserves using changes in denitrification. Although denitrification is an anoxic process, sediments can be moderately oxidized, so removing nitrogen by denitrification is a more effective method. It is noted that the ratio of SiO_4 to DIN (DIN = NO_3 + NH_4) in the northern Baltic Sea decreased significantly over the 27 years from 1973 to 1999. If soluble silicon can limit phytoplankton red tide, the red tide caused by diatoms disappears and replaced by dinoflagellates, causing the phosphate to be stored and deposited. Seven years later, the high salt water that had previously flowed in here has disappeared over time and hypoxia has spread to much of the surrounding area. Deep in the ocean, phosphorus levels have started to grow and denitrification is declining. Therefore, in the long term, if nitrogen and phosphorous can be minimized, it may be possible to help the Baltic Sea get rid of the effects of eutrophication.