(Table 2) Concentrations and isotopic compositions of pyrite and sulfate sulfur in argillaceous sediments outside the gas hydrate seep zone, Sea of Okhotsk@en

Isotopic analysis of organic matter from bottom sediments and soft tissues of bivalve Conchocoele from a community near the gas-hydrate seep off the Paramushir Island indicates that the intramolecular energy of energy-rich compounds H2S and methane, which are products of early diagenesis, is used for chemical synthesis by free-living symbiotic sulfur-oxidizing, sulfur reducing, and methane-oxidizing bacteria in the community.