Mapping of nutrient emissions into the Baltic Sea from shipping

Eutrophication is an extensive and intractable problem in the Baltic Sea. While the supply of new nutrients from sewage on land as well as from agriculture has declined in recent years, a new source of nutrient emissions has been on the increase – namely that from the cruise shipping industry.

Looked at overall, shipping in the Baltic Sea is extensive. Furthermore, cruise shipping traffic is at its height during the summer and in the areas of the Baltic Sea that are most affected by eutrophication. There are a variety of sources of emissions of nutrients from ships – from toilets (black water), showers, laundries, kitchens and restaurants (grey water) and from food waste. Future regulation under the International Maritime Organization (IMO) requires that sewage from passenger ships is purified or dumped ashore, but these regulations only cover water from toilets and not the other significant sources of nutrient. Increased vessel size also means that many ships are too large to lay alongside a quay where possibilities exist for connection to a sewage system or access to waste disposal systems. Smaller ports also continue to lack the capacity to manage sewage from ships and the time for sewage management at the dock is often limited. Another source of nutrient from shipping is the discharge of washing water from so-called scrubbers. A scrubber is an exhaust gas cleansing technology wherein exhaust emissions are washed, and the used water is subsequently pumped out into the sea. Currently, no surveys exist to indicate either how many vessels in the Baltic Sea use scrubber technology or the nitrogen concentrations contained in a typical washing water discharge.

Purpose and goal
To achieve an effective reduction of nutrients from shipping vessels, this project is intended to identify and describe the major sources of such emissions from them. The goal is to compile existing data on nutrient loads in various water emissions from shipping (black water, grey water, scrubbing discharges, food waste and NOx, i.e. mono-nitrogen oxide emissions*), and:

• identify any knowledge gaps and the need for and methodologies used in improved data collection;
• collect additional data to conduct a comprehensive survey;
• describe the sources and shipping segments accounting for the largest contributions; and
• take part in the development of decision support for effective action.

Part of the project will deal with the compilation of existing data from ports, authorities and shipping companies, both nationally and internationally, but it will also involve the assemblage of additional data from existing networks, such as the BONUS project and the Sustainable Shipping and Environment of the Baltic Sea Region (SHEBA) project, together with that from ports, shipping companies and interest groups in the Baltic Sea region. The project will carry out a detailed examination and description of the sources and the maritime segments that account for the largest proportions of emissions of nutrients. It will ultimately be able to contribute in the development of effective measures able to reduce local nutrient pollution from shipping in the Baltic Sea.

The project is being led by: Chalmers University of Technology – PhD Magda Wilewska Bien, Associate Professor Lena Granhag, and Professor Karin Andersson.

The project is funded by Thurséus forskarhem and will continue during 2017.

* mono-nitrogen oxides (NOx), include both nitrogen monoxide (NO) and nitrogen dioxide (NO2).

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Photo: Folke Rydén Production

Project status

Start: 2018-01-01
End: 2018-06-30

Project manager

Chalmers University of Technology – PhD Magda Wilewska Bien, Associate Professor Lena Granhag, and Professor Karin Andersson.