The Relationship Between Surface Macrofauna and Sediment Nutrients in a Mudflat of the Chuwei Mangrove Forest, Taiwan

The importance of sediment nutrients to the surface macrofaunal abundance in a mudflat of the Chuwei Mangrove forest, Taiwan was determined. Macrobenthic abundance fluctuated seasonally. Most benthic activities occurred within top 3 cm of sediment. Three dominant deposit feeders were found: the oligochaetes, Paranais litoralis and Monopylephorus parvus, and the polychaete, Capitella sp. P. litoralis appeared only from late winter till early summer, and its distribution was correlated with sediment temperature. The abundance of Capitella sp. was correlated with surface sediment organic content. M. parvus recruited mainly in the springtime. Although the detritus can provide most of the carbon needs for benthic animals, the availability of labile materials, especially nitrogen-containing material, was limited. A pulse of available nitrogen in October and December 1993 might have provided additional nutrients and stimulated animal abundance from late falls till early winter.