Contribution of sulfur-oxidizing bacteria to benthic food webs viewed via sulfur stable isotope analysis

Abstract

Quantifying the contribution of primary production by sulfur-oxidizing bacteria (SOB) to benthic food webs is important for understanding energy and material flows in aquatic ecosystems, including chemosynthesis-based ecosystems. Sulfur stable isotope ratios (δ³⁴S) are a powerful tool for assessing sulfide utilization by SOB in sediments. In this review, I introduce the methodological approaches (δ³⁴S-based mixing model) used for estimating the contribution of SOB-derived organic matter to the nutrient resources of benthic fauna, and highlight three case studies that used this method in a deep-sea chemosynthesis-based ecosystem, whale-fall ecosystems, and a freshwater lake ecosystem. Finally, I discuss the advantages and limitations of this method for improving evaluations.