Abstract Understanding the role of benthic organisms in marine sediments is becoming increasingly important with the growing problem of eutrophication of marine ecosystems around the world, including the Baltic Sea. Therefore, we have conducted a series of incubation experiments on sediment cores collected from sites characterized by varying oxygen conditions and measured the influx (uptake by sediment) of oxygen as well as the sediment–water exchange of phosphate, ammonia and silicate. The research involved macrozoobenthic communities that clearly reflect oxygen deficiency episodes in the past. We also used Fick's first law to calculate diffusive fluxes of nutrients. The size and direction of benthic fluxes largely depend on physicochemical conditions. Silicate fluxes were affected by the biomass of macrozoobenthos in the surface layer of sediments, while those of phosphate – effluxes – by the biomass of the Baltic tellin Limecola balthica and Marenzelleria polychaetes. Despite oxic conditions in all incubated cores, we observed a phosphate release at most sites. The estimation of substance fluxes at the sediment–water interface based on the incubation experiments gave comparable values – to those of diffusive fluxes – only in areas without benthic communities. We have demonstrated how benthic macrofauna affects the exchange of substances at the sediment–water interface when bottom-water oxygen conditions fluctuate between normoxic and hypoxic.

中文翻译：

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波罗的海间歇性缺氧区外围大型底栖动物群影响下的氧和养分的底栖通量

摘要 随着包括波罗的海在内的世界各地海洋生态系统富营养化问题日益严重，了解底栖生物在海洋沉积物中的作用变得越来越重要。因此，我们对从氧气条件不同的地点收集的沉积物岩心进行了一系列孵化实验，并测量了氧气的流入（沉积物吸收）以及磷酸盐、氨和硅酸盐的沉积物 - 水交换。该研究涉及大型底栖动物群落，这些群落清楚地反映了过去的缺氧情况。我们还使用菲克第一定律来计算养分的扩散通量。底栖通量的大小和方向很大程度上取决于物理化学条件。硅酸盐通量受沉积物表层大型底栖动物生物量的影响，而磷酸盐通量受波罗的海泰林 Limecola balthica 和 Marenzelleria polychaetes 生物量的影响。尽管在所有孵化的核心中都有氧条件，但我们在大多数地点观察到磷酸盐释放。仅在没有底栖群落的区域，基于孵化实验对沉积物-水界面物质通量的估计给出了与扩散通量相当的值。我们已经证明，当底水氧气条件在常氧和缺氧之间波动时，底栖大型动物如何影响沉积物 - 水界面的物质交换。尽管在所有孵化的核心中都有氧条件，但我们在大多数地点观察到磷酸盐释放。仅在没有底栖群落的区域，基于孵化实验对沉积物-水界面物质通量的估计给出了与扩散通量相当的值。我们已经证明，当底水氧气条件在常氧和缺氧之间波动时，底栖大型动物如何影响沉积物 - 水界面的物质交换。尽管在所有孵化的核心中都有氧条件，但我们在大多数地点观察到磷酸盐释放。仅在没有底栖群落的区域，基于孵化实验对沉积物-水界面物质通量的估计给出了与扩散通量相当的值。我们已经证明，当底水氧气条件在常氧和缺氧之间波动时，底栖大型动物如何影响沉积物 - 水界面的物质交换。