Are polychaetes decomposers

yes, they are decomposers. (ew!) here is a little paragragh I found a little bit about decomposing.

The decomposer community, though not readily visible by virtue of its small size, is an important component of the ACE Basin study area. The term decomposers is used to describe a guild of organisms (e.g., bacteria, fungi, crabs) that process organic constituents (e.g., plant material) to release carbon and other nutrients such as nitrogen (N) and phosphorus (P). This process creates a key link in transfer of energy and cycling of nutrients between varioustrophic groups in an ecosystem. This transfer of energy from one trophic group to another occurs via the consumption, death and decay of organisms. The breakdown of organic matter and conversion of organically bound nutrients into basic inorganic forms is called mineralization.