Changes of the Avifauna in Sihwa Lake according to the Blackish Water Circulation and Agricultural Land Reclamation

Abstract

This study was conducted between October of 2004 and November of 2006 in the region of Lake Sihwa (Sihwaho) in order to study the area's avifauna and bird community change according to the seawater mixing and agricultural development. A total of 178,061 birds of 158 species were observed, with the Common Pochard as the dominant species. The avifauna of the Lake Sihwa region showed a high level of inhabiting species during the wintering season and the spring-fall migratory season, and the summer season showed a temporarily low number of species. Among the diving duck species, the Common Pochard and the Common Goldeneye showed stable wintering pattern, and in the case of the Greater Scaup and the Tufted Duck, there was low usage level during early winter and late winter passing period. Dabbling ducks displayed lower usage level in February and March, which is included in the late winter period, when compared to that of fall and early winter. Low water level correlated with high avian density, and such region included a high level of aquatic plants of the desalinated area. A total of 754 birds of 28 government-protected species were observed, alongside a total of 125 birds of 6 Class-I endangered species. The avifauna of the Lake Sihwa region has changed from the dominance of dabbling ducks, waders and plovers to the dominance of the diving duck community. Such change has been caused by the spread of aquatic plants (Chara spp.) during the desalination process of select areas under agricultural development and is also assessed to be the result of environmental changes following the seawater mixing into Lake Sihwa.