The researchers studied the benthic polychaetous communities in Deugryang Bay, Korea to see how they were distributed and how they changed over time. They found that the bay had a mix of different species living in different parts, with some areas having more species than others. The most common species were Lumbrineris longifolia and Heteromastus filiformis, which are indicators of organic enrichment in the water. The researchers also noticed changes in the types and numbers of species present, suggesting that the bay is relatively healthy but still needs careful environmental management.