The researchers studied the types of small creatures living in the coastal waters of Chagwi-do, Jeju-Island over a year. They found a total of 201 different species, with mollusks being the most common. Annelids were the heaviest, while gastropods were the most abundant. The number of species and individuals of mollusks and arthropods changed throughout the seasons, peaking in summer. The diversity of species varied between different locations, with the highest diversity in Gosan. Overall, the coastal waters of Chagwi-do have a diverse community of macrobenthic invertebrates that change with the seasons.