Crab populations play a major role in net bioturbation of the coastal tracts of the Sagar Island, Hugli Estuary, India. The activities attest to scraping, churning, ingesting, burrowing substrate sediment for feeding, dwelling etc. Non-random distribution of bioturbated patches zone averaged for ten spatial zones indicates percent area bioturbation varying between 0.08% and 29.92%. No significant correlation exists between biological vis-a-vis geomorphological or sedimentological parameters as recorded under 12 chosen parameters varying in zones (Z1–Z10) and zone clusters (A, B and C). Bioturbated sediments, however, possess coarser mean size and better sorting than non-bioturbated sediments. We predict genetic link between biogenic coarsening of sediments and selective substrate aggradation as recorded in the zones (Z5 and Z6) of higher bioturbation (by percent area) over a decade (between 2008 and 2018). Onshore sediment transport in the study area appears to be influenced by the biogenic reworking and subsequent textural modifications of the substrate sediment. Fining landward trend is perceptible in the post-monsoon, non-bioturbated sediments that escaped seasonal storm reworking and biogenic reworking. Gradual inundation of the substrate is interpreted from the fining up sediment succession and the plant/animal traces preserved in them. This assay at Sagar Island predicts a constructive role of biogenic reworking by crab populations on sediment transport and substrate aggradation. Outcome of the present study may be applied to reconstruct sedimentation milieu in similar bioturbated and tidally influenced, retreating delta margin settings.

螃蟹种群在印度休利河口萨加尔岛沿海地区的净生物扰动中发挥重要作用。这些活动证明可以刮擦，搅动，摄取，挖掘基质沉积物以进行取食，居住等。平均十个空间区域的生物扰动区的非随机分布表明，生物扰动的百分比范围在0.08％至29.92％之间。在区域（Z1-Z10）和区域群（A，B和C）中变化的12个选定参数下记录的生物学地貌或沉积学参数之间没有显着相关性。然而，生物扰动的沉积物比非生物扰动的沉积物具有更粗的平均尺寸和更好的分类。我们预测了十年（2008年至2018年）更高的生物扰动区域（按面积百分比计）中记录的沉积物生物粗化与选择性底物聚集之间的遗传联系。研究区域内陆上沉积物的运输似乎受到底泥沉积物的生物成因改造和随后的构造改变的影响。在季风后，非生物扰动的沉积物中逃脱了季节性风暴改造和生物成因改造后，可以看到精细的陆上趋势。从细化的沉积物演替和保存在其中的植物/动物痕迹可以解释基质的逐渐淹没。萨加尔岛（Sagar Island）的这项试验预测，螃蟹种群进行生物基因改造对沉积物运输和底物聚集具有建设性作用。