Snails aren't the only grazers of naturally-decaying marshgrass. Amphipods do it too. These are adults of Uhlorchestia spartinophila, the most common shoot-associated amphipod in the smooth-cordgrass marsh. Here is one that is not anesthetized . These talitrids are almost always found on cordgrass shoots, not down on or in the marsh sediment. Their grazing is not as intense as that of periwinkles, and usually only the leaf and fungal material at and near the leaf surface is removed (as in this image). I have watched them as they carefully pick out the parts of the decaying leaf that they want (they're not bashful when they're hungry). They will scoop out the contents of fungal ascomata (the sexual-spore-containing structures) in decaying leaves, and they will eat pure mycelium of saltmarsh ascomycetes if it is offered to them. See Graça et al, 2000, Mar Biol 136:281-289; Newell & Porter, 2000, pp. 159-185 in Weinstein & Kreeger, Concepts and Controversies in Tidal Marsh Ecology, Kluwer.