Seabirds have adapted to life in marine environments. More than 25% of the bird species observed in South Korea are seabirds, using the coast area of Korean peninsula as a stop-over and wintering, and breeding site. The aims of this review are to provide information about migratory and resident Korean seabirds and to discuss the methods that are currently employed to monitor the marine environment. In Korea, it has been reported that more than 400,000 individuals of seabirds breed on Nando Islet, Chilbaldo Islet, Guguldo Islet, Sasudo Islet, Hongdo Islet and Dokdo Islet. In 2010, approximately 160,000 seabirds also visited South Korea during the winter. Two of the main treats were introduced wildlife and habitat destruction by humans. Seabirds are monitored mainly at the population and individual levels. The assessment of population sizes and biomagnifications of pollutants are performed preferably at the community and population levels. Behaviour, growth, morphological characteristics, and breeding success is analyzed at the individual level and employed to gauge the health of the marine environment. In addition, we could suggest that molecular technique of seabirds successfully adopted to investigate the effects of pollutants and toxins in the marine environment.