Although Guleopdo is small island of only 1.71 ㎢, the endangered butterfly species, Argynnis nerippe, is abundant there. This study was carried out to estimate the abundance of A. nerippe in Guleopdo, using quadrate, mark-recapture, and line-transect methods. Although the study was insufficient, the population size was estimated at 4,467 to 6,700 larvae and approx. 1,000 adults. A. nerippe was the most abundant among butterfly species in Guleopdo, and it comprised 32% of the total butterflies. A total of 28 butterfly species were observed in this study, and 3 species of these species were migrating species. When the abundance of A. nerippe throughout the country during the period from 1938 to 2010 was studied, we found that it decreased abruptly in the 2000s. Presently, A. nerippe inhabits a few locations in the mid-northern region and western islands. The relatively high numbers of A. nerippe in Guleopdo was due to conservation of natural grasslands and grazing of livestock, which provides adequate habitat for this species.

Coastal dune wetland has an important ecological implication in that it could be closely related to the coastal dune ecosystem by providing various ecological habitats as well as ecological corridor. This paper aims to investigate the hydrological characteristics and aquatic biota of Mokgimiyeonmot (pond), coastal dune wetland in Gulupdo (island). Mokgimiyeonmot located in the lowland dune flat areas has six months long hydro period a year and can be categorized into wet dune slack type coastal dune wetland. As a result of this study, two species of freshwater fishes, two species of amphibia, and 35 species of benthic macro-invertebrates are recognized. Talitridae sp. belonging to Amphipoda also recognized in this survey for the first time from Korea. The results of this study are expected to be basic data necessary to understand the aquatic ecosystems and manage the ecological function of coastal dune field.

The natural environment of Gulup-do should be preserved due to its unique ecological characteristics. A recent report stated that CJ group, one of Korea’s major business conglomerates (chaebols), plans to construct golf courses and resort facilities in Gulup-do. Such projects will destroy the delicate animal habitats of the island. The harmful chemical runoff from golf courses will also significantly damage the ecosystem. The purpose of this paper is to show that the development of Gulup-do will adversely affect the ecology of the island.