Why is the Baltic Sea the only sea area designated for Annex IV?

• A. The circulation of the water in the Baltic is very weak and any discharges there will remain for long periods of time. All ships in the area must discharge to a reception facility.
• B. It has the strongest currents that spread wastes quickly.
• C. It is geographically isolated with strict port controls only here.
• D. It has no reception facilities, making discharges necessary.

Answer: (A)

Special Areas under MARPOL Annex IV are chosen where discharges of sewage would cause disproportionate harm because the water doesn’t dilute pollutants well. The Baltic Sea fits this because its circulation is very weak, so sewage and other wastes linger longer and can accumulate, posing greater risk to the ecosystem. To protect the sea, ships in this area are required to handle sewage on board or discharge it only to reception facilities on land where it can be treated, rather than releasing it into the water. That combination of environmental sensitivity and the need for proper treatment is why the Baltic is designated as an Annex IV Special Area.

The other options don’t fit because strong currents would dilute pollutants, not justify stricter controls; the Baltic isn’t designated due to political isolation or unique port controls; and the situation isn’t that there are no reception facilities—in fact, reception facilities are part of the reason ships must use them to prevent at-sea discharges.