Temporal pattern of colonization process of the benthic macrofauna in Seonjae-do tidal flat, Incheon, Korea

초록

A field experiment was conducted at the middle tidal flat of Seonjae-do, Incheon, Korea, from January to November 2004. We examined the temporal settlement patterns of macrobenthic invertebrate larvae in the absence of biotic interactions, especially predation from epi- and infaunal predators, and biogenic disturbances associated with other biological activities. Accomplishing the purpose, we used plastic bottles (10㎝ wide and 20㎝ deep) filled with defaunated sediments on which larvae to settle and survive and sealed their openings with 2-mesh screens. As a result, the species number was high on May and August and the abundance peaked on February and May. The Manila clam Ruditapes philippinarum occupied about 26 percent of the total number of settlers. This species occurred nearly all the year round and especially showed high settlement rates on February, May and September. In terms of the entire benthic community level, May was the most thriving period not only in species richness but also their abundance. The manila clam Ruditapes philippinarum played an important role in temporal variation of larval settlement in the experimental area. The overall settlement pattern was presumed to be related to differences in food conditions derived from environmental changes over time and this may be partly explained by 'the settlement-timing hypothesis' (Todd and Doyle 1981). The results of this experiment will provide useful information for coastal management and habitat restoration.