Isotopic signatures and nutritional composition of selected macrobenthos from the site F cold seep in the South China Sea

Abstract

Understanding the food sources and nutrient structures is crucial for grasping the community structure and function. At Site F, which is characterized by active seepages, a diverse macrobenthos community thrives. Carbon and nitrogen isotopic values vary among species and between species and their environment. We have constructed a hypothetical food web for Site F, which includes four trophic levels and encompasses 22 species. Two distinct communities were identified based on the presence or absence of seepage, and their complexity was compared using Bayesian metrics and specialization index. Our findings suggest that the availability and diversity of food resources, coupled with abiotic pressures and biotic interactions, play a crucial role in shaping community complexity. The non-seep community exhibited lower species richness and diversity, resulting in reduced community complexity compared to the seep community at Site F. These results contribute to a deeper understanding of nutritional ecology and community structure at Site F cold seep.