In the foreground is a red mangrove (Rhizophora mangle) tree, extending its proproots out onto tidal flats. Mangrove trees drop their dying leaves into the inter- and sub-tidal ecoystem. In the mangrove ecosystem, oomycotes appear to be the predominant eukaryotic mycelial decomposers of leaves that fall into seawater and decay while submerged. While true fungi can be found in submerged decaying mangrove leaves, the amount of true-fungal mass produced there appears to be quite low compared to the fungal productivity within standing-decaying saltmarsh grasses. It may be, however, that true fungi can compete successfully with oomycotes in intertidal zones where decaying leaves dry out periodically. When fallen mangrove leaves are quickly swept away from sources of oomycotic zoospores (e.g., batches of submerged decaying leaves), it may be that prokaryotic decomposers win the battle for all of the leaf resources. See Newell & Fell, 1997, Aquat Microb Ecol 12:21-28; Newell, 1996, J Exp Mar Biol Ecol 200:187-206.