Sediment macrofauna play a vital role in sustaining aquatic food webs and biogeochemical cycles. Previous research demonstrated that bioturbation indirectly affects methane (CH₄) dynamics through mobilization of porewater and alteration of microbial processes in the surrounding sediment. However, little is known on the direct contribution of macrofauna holobionts (the assemblage of invertebrate host and associated microbiome) to biogeochemical fluxes. Here, we investigated how 19 taxa of macrofauna holobionts, from different estuarine habitats spanning 40° to 63° latitude, directly contribute to CH₄ fluxes. Deep burrowing infauna and deposit feeders were responsible for the highest CH₄ production, whereas epifauna and filter feeders promoted oxidative CH₄ consumption. Among the different environmental parameters, salinity was inversely correlated with CH₄ production by macrofauna holobionts, with the process suppressed at high salinity (≥ 33). This study provides empirical evidence on how functional traits and environmental factors influence sediment invertebrates' contribution to CH₄ fluxes.

中文翻译：

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无脊椎动物全生物对沿海沉积物甲烷释放的直接贡献

大型沉积物在维持水生食物网和生物地球化学循环方面发挥着至关重要的作用。先前的研究表明，生物扰动通过孔隙水的流动和周围沉积物中微生物过程的改变间接影响甲烷（CH ₄）动态。然而，人们对大型动物全生物（无脊椎动物宿主和相关微生物组的组合）对生物地球化学通量的直接贡献知之甚少。在这里，我们研究了来自纬度 40° 至 63° 不同河口生境的 19 个大型动物全生物类群如何直接影响 CH ₄通量。深穴动物和沉积物饲养动物产生最高的 CH ₄产量，而表层动物和滤食动物则促进氧化 CH ₄消耗。在不同的环境参数中，盐度与大型动物全生物产生的CH ₄呈负相关，且该过程在高盐度（≥ 33）下受到抑制。本研究提供了关于功能性状和环境因素如何影响沉积物无脊椎动物对CH ₄通量的贡献的经验证据。