University of Helsinki, Tvärminne Zoological Station, J. A. Palménin Tie 260, 10900 Hanko, Finland.
Stockholm University, Department of Ecology, Environment and Plant Science, 106 91 Stockholm, Sweden; Stockholm University, Baltic Sea Centre, 106 91 Stockholm, Sweden.
Mar Environ Res. 2020 Dec;162:105163. doi: 10.1016/j.marenvres.2020.105163. Epub 2020 Oct 5.
Shallow coastal zones may provide cross-habitat nutrient subsidies for benthic communities offshore, as macrophyte matter can drift to deeper sediments. To study the relative importance of carbon and nutrient flows derived from different primary food sources in a coastal ecosystem, the diets of clam Macoma balthica, polychaete Marenzelleria spp. and mussel Mytilus trossulus were examined across environmental gradients in the northern Baltic Sea using a triple-isotope approach (i.e. C, N and S) and Bayesian mixing models (MixSIAR). Our results suggest that in shallow habitats, production from Fucus vesiculosus is the primary energy source for M. balthica. The proportion of macroalgae-derived matter in the diet of M. balthica and Marenzelleria spp. decreased following a depth gradient. Our models for M. trossulus indicate that the pelagic POM dominates its diet. Our results indicate a trophic connectivity between shallow macrophyte-dominated and deeper habitats, which receive significant amounts of nutrient subsidies from shallower areas.
浅海区域可能会为近海底栖生物群落提供跨生境的营养物质补贴，因为大型藻类物质可能会漂移到更深的沉积物中。为了研究沿海生态系统中不同初级食物源产生的碳和营养物质流的相对重要性，我们使用三同位素方法（即 C、N 和 S）和贝叶斯混合模型（MixSIAR），在波罗的海北部沿环境梯度研究了贻贝 Macoma balthica、多毛类 Marenzelleria spp. 和贻贝 Mytilus trossulus 的饮食结构。我们的研究结果表明，在浅海生境中，泡叶藻的产量是贻贝 Macoma balthica 的主要能量来源。贻贝 Macoma balthica 和 Marenzelleria spp. 饮食中来源于大型藻类的物质比例随着深度梯度的增加而减少。我们对贻贝 Mytilus trossulus 的模型表明，浮游 POM 是其饮食的主要组成部分。我们的研究结果表明，浅海以大型藻类为主的生境和更深的生境之间存在营养连通性，这些生境从较浅的区域获得大量的营养物质补贴。
