The JCG strives to understand the state of marine pollution through surveillance by patrol vessels and aircraft, investigation and crackdowns based on reports to the emergency call phone number "118," and investigations by hydrographic survey vessels. The number of marine pollution cases confirmed by the JCG in 2019 was 432, an increase of 18 cases from the previous year. Looking at the number of confirmed cases of marine pollution in recent years by type, the number of cases of oil pollution is the highest, followed by the number of cases of pollution by waste. By the cause of pollution, the causes of oil pollution include refueling of fuel oil, inadequate confirmation of valve opening and closing when transferring fuel oil on board, or "overflow" due to negligence in measuring fuel tanks in the ship. Many of them are due to elementary carelessness that can be prevented by checking at the beginning of work. Pollution by substances other than oil is often due to intentional acts.

The JCG is implementing comprehensive efforts to conserve the marine environment, such as surveillance and crackdown on violations of maritime environment-related laws, investigating the marine environment, and conducting guidance and awareness-raising activities to the public.