Complex sentence: Feeding on plant matter (detritivory) assists in recycling organic matter and produces animal biomass which is a source of food for vertebrate predators, e.g. reptiles, birds, otters, and inshore fishes that come in at high tide.
Split into simpler sentences: Feeding on plant matter assists in recycling organic matter and produces animal biomass. Animal biomass is a source of food for vertebrate predators; e.g. reptiles, birds, otters, and inshore fishes that come in at high tide.