International cruise ships are feeding the algal blooms in the Baltic Sea | WWF
International cruise ships are feeding the algal blooms in the Baltic Sea

Posted on 08 July 2008

A majority of the international cruise ships visiting the Baltic Sea continue to discharge their sewage straight into the sea. A plea by WWF to the cruise ship companies to stop their discharges of waste water has been met with refusal by most companies.
A majority of the international cruise ships visiting the Baltic Sea continue to discharge their sewage straight into the sea. A plea by WWF to the cruise ship companies to stop their discharges of waste water has been met with refusal by most companies.

Already last year WWF contacted the ferry lines and cruise ship companies that are sailing in the Baltic Sea, asking for a voluntary ban on waste-water discharge. So far, most of the ferry lines have responded positively, but only three of the international cruising lines have signed up. The remaining 17 cruising lines that were contacted answered through their umbrella organization CLIA (Cruise Lines International Association) by saying: “at this moment signing the WWF petition without sensitivity to understand the variety of waste streams, port reception facilities, and environmental equipment would be premature”.

“We think it must be the responsibility of anyone operating a ship in the Baltic Sea to take care of their own wastes in a responsible manner and stop polluting the sea”, says Mats Abrahamsson, Program Director of the WWF Baltic Ecoregion Program. “If some companies can sign our agreement, why can’t the others?”

The Baltic Sea receives between 250 and 300 cruise ships each year. The waste-water produced in these vessels is currently estimated to contain 113 tons of nitrogen and 38 tons of phosphorus, substances that add to the eutrophication of the sea. Most of this is still discharged into the Baltic Sea, mainly in international waters. In addition to excess nutrients, the waste water also contains bacteria, viruses and other pathogens, as well as heavy metals.

Eutrophication is considered by many the main environmental problem of the Baltic Sea, causing both biological and economic damage to marine environment and coastal areas. It is caused by an overload of nutrients, such as phosphorus and nitrogen, into the ecosystem. Eutrophication causes many problems, including unusually strong and frequent blooms of algae such as the toxic cyanobacteria (also called “blue-green algae”).

“The international cruise ship industry claims that one of their biggest problems is the insufficient reception facilities in the ports receiving cruising ships. We know that there are improvements needed in many ports, and we have offered to work together with the cruising companies to demand better facilities. Still, there is no excuse for dumping the sewage in the sea”, says Dr. Anita Mäkinen, Head of Marine Programme for WWF Finland, who has been coordinating the WWF project.

“All ports have some sort of facility to receive ship sewage. Some big cruise ships are treating their waste waters onboard, but only according to the Alaska regulations, which do not regulate nutrients but only bacteria and organic content of the waste water. They don’t seem to understand that this is not enough in the Baltic Sea”, continues Dr. Mäkinen.

Ferry companies that have signed WWF’s voluntary agreement:
Birka Line (Finland)
Bornholmstrafiken (Denmark)
Colorline (Norway)
Eckerö Line (Finland)
Molslinien (Denmark)
Nordic Jetline (Finland)
Rederi AB Gotland and Destination Gotland (Sweden)
Seawind Line (Finland)
Tallink (Estonia)
Tallink-Silja Line (Finland)
Viking Line ABP (Finland)

Cruise ship companies that have signed WWF’s voluntary agreement:
Aida (Germany)
Hurtigruten (Norway)
Peter Deilmann Reederei (Germany)


For more information, please contact:


Mats Abrahamsson, Program Director, WWF Baltic Ecoregion Program, +46 705 821 499

Dr. Anita Mäkinen, Head of Marine Programme, WWF-Finland, +358-40 52 714 25

See also


Notes to editors:

Facts about the international cruise ships
  • A cruise ship with 1,100 crew members and more than 3,000 passengers produce altogether 1,000 m3 grey and black water per day. The amount of black water produced per day is 25 m3. (Black water is term used to describe water containing fecal matter and urine, while gray water refers to wastewater generated from processes such as dish washing, laundry and bathing)
  • This size of a ship can store waste waters for 4 days.
  • The American owned ships are following the Alaska discharge requirement which regulate TSS (Total Suspended Solids), BOD (Biochemical/biological Oxygen Demand), pH, residual chlorine and fecal coliform bacteria (FCB). The Alaska requirements for these parameters are higher than IMO requirements; however, they don’t regulate nutrients at all.

Facts about sewage water regulations in the Baltic Sea
According to the international convention MARPOL 73/78 and its Annex IV which is regulating discharge of sewage waters, ships are allowed to discharge black waters beyond 12 nautical miles from the shore line and grey waters beyond 3 nautical miles from the shore line.

The Baltic Sea states have agreed in the Baltic Sea Action Plan (BSAP) “to have in 2009 a joint submission by HELCOM Contracting States to IMO in order to elaborate relevant new regulations for ships covered by the existing Annex IV to MARPOL 73/78, including further consideration of designation of the Baltic Sea as a special area, with the aim to eliminate the discharge of sewage from ships, especially from passenger ships and ferries”. They further agreed “to encourage voluntary activities in ports and shipping companies to dispose of sewage to the port reception facilities and to undertake all the necessary improvements in the availability of these port reception facilities”.