Burrowing crabs are main constituent of estuarine wetlands ecosystems, and provide a variety of ecosystem functions including providing food for waterbirds and fishes, promoting nutrients cycling, and processing sediments deposition. Helice tientsinensis is the dominant crab species which inhabits almost the entire intertidal marshes of the Yellow River Delta. However, for a long time we ignored the crab bioturbation in this area. We know little about whether crabs have potential effects on sediment environment. Here, we investigated the crab burrow characteristics in three marsh zones, and we also analysed the sediment parameters among crab burrow mounds (chimneys), flats (flat areas between burrows), controls (outside of crab bed) and crab fecal deposit. We found that sediment was softer in crab burrow mounds than in flat and control areas. Higher crab density indicates softer sediment. Crab burrow mounds had saltier soil than the flats. Our results showed that sediment total nitrogen, total carbon and organic matter varied among mounds, flats, controls and crab fecal deposit, which indicated that crab bioturbation have potential effects on sediments redistribution and nutrients cycling. Our study is essential to clear the roles of crabs in ecosystems and will benefit for coastal saltmarsh protection and restoration.

穴居螃蟹是河口湿地生态系统的主要组成部分，并提供多种生态系统功能，包括为水鸟和鱼类提供食物，促进养分循环以及处理沉积物沉积。田螺是主要的蟹种，栖息在黄河三角洲几乎所有的潮间带沼泽中。但是，很长一段时间以来，我们都忽略了该地区的螃蟹生物扰动。我们对螃蟹是否会对沉积物环境产生潜在影响知之甚少。在这里，我们调查了三个沼泽地带的螃蟹洞穴特征，并分析了螃蟹洞穴丘（烟囱），平坦（洞穴之间的平坦区域），对照（螃蟹床外）和螃蟹粪便沉积物之间的沉积物参数。我们发现，在蟹洞中的沉积物比在平坦和控制区域中的沉积物更软。较高的蟹密度表示较软的沉积物。蟹穴土比平地更咸。我们的结果表明，沉积物的总氮，总碳和有机质在土墩，公寓，对照和蟹粪沉积物中有所不同，这表明螃蟹的生物扰动对沉积物的再分配和养分循环具有潜在的影响。我们的研究对于清除螃蟹在生态系统中的作用至关重要，并将对沿海盐沼的保护和恢复有益。