Baltic Marine Environment
Protection Commission

 

Baltic Marine Environment
Protection Commission

HELCOM Expert Interview: Sari Luostarinen on nutrients, eutrophication and agriculture

Sari Luostarinen is a Senior Research Scientist at the Natural Resources Institute of Finland (Luke) and is the current Chair of the HELCOM Agri group

Aren’t nutrients supposed to be good? What’s wrong with nutrients? 

Nutrients are vital for humans, animals and the environment as a whole. They are also vital for agriculture and food production. No crops can grow without nutrients. But as with most other compounds, too much in the wrong place causes problems. In our region for instance, the excess of nutrients has led to the eutrophication of the Baltic Sea.

In terms of eutrophication and nutrients, what is the current status in the Baltic Sea region?

The Baltic Sea is a vulnerable sea for many reasons. The nutrients it has received in the past are bound in the sediments and released under certain conditions, causing internal nutrient loading. At the same time, nutrient runoff from current human activities is adding to the problem. Of the latter, many point sources have been reduced, for example due to improved wastewater treatment. But it is more difficult to restrict diffuse loading such as from agriculture. Depending on the weather conditions and due to increasing temperatures, eutrophication and its consequences are worsening. More actions to control the nutrient load are needed.

In general, what would need to be done to curb eutrophication and nutrient inputs, especially in regard to agriculture?

As said, crops cannot grow without nutrients. Both phosphorus and nitrogen need to be available for crops on the fields to achieve good yields. Good yields also mean that most nutrients given as fertilizers end up in the harvested crop and little is lost to the environment. The amount of nutrients spread as fertilizers should be adequate, for instance adjusting quantities depending on the crop, the soil type and its nutrient content, as well as the timing of the spread. The use of animal manure as a fertilizer is the traditional way to recycle nutrients in food production. However, due to segregation of animal and crop production it may be either available in excess or in deficit depending on the region. More precise utilisation of manure nutrients, including replacing mineral fertilization with manure, is important for reducing agricultural nutrient load. Also, other measures, such as reduced tillage, catch crops, water protection zones, are also needed to manage nutrient losses.

What concrete steps is HELCOM currently taking on the nutrient issue from the agriculture perspective?

HELCOM is efficiently driving several measures to reduce agricultural nutrient losses to the Baltic Sea. As an example, HELCOM is preparing the introduction of recommendations for national manure standards. The aim is to ensure the availability of updated, scientifically proven data on manure quantities and nutrient contents in the Baltic Sea countries so that the manure data used in fertilization planning and thus the amount of manure spread on fields becomes more precise. This is expected to reduce nutrient runoff from the fields. Furthermore, on resource efficiency, HELCOM is also preparing a strategy for nutrient recycling in the Baltic Sea Region. Again, the aim is to introduce more efficient measures to make better use of the nutrients already available and to reduce the need to introduce new mineral nutrients into the cycle. For example, this could be achieved by processing manure, different wastes and their by-products into recycled fertilizers.

Handling of wastewater from ships in ports of the Baltic Sea is facilitated by new guidance

The handling of wastewater from ships in ports of the Baltic Sea just got easier with the newly published Technical Guidance for the handling of wastewater in Ports of the Baltic Sea Special Area under MARPOL Annex IV.

Intended for shipowners, port operators, local administrations as well as municipal wastewater companies, the Technical Guidance was developed to facilitate the management of wastewater from ships to better comply with IMO regulations on wastewater handling in the Baltic Sea region. 

In 2011, the IMO designated the Baltic Sea a Special Area for sewage discharges from passenger ships, directing passenger ships operating in the Baltic Sea and not equipped with an on-board sewage treatment facility to discharge their sewage – or black water – at port, in a so-called port reception facility (PRF). 

“Initial experiences show that there is no ‘one size fits all’ solution,” said Susanne Heitmüller, the Chair of HELCOM Maritime, the HELCOM working group that deals with shipping-related topics. “Almost each port, with its own, specific infrastructure requirements, needs a tailored solution,” she added.

The current lack of experience with sewage handling in ports requires the development of new and innovative approaches to manage these new challenges. The Technical Guidance for the handling of wastewater in ports was produced to fill this gap and offer a wide range of possible options to several scenarios ships and ports may face. 

“The Technical Guidance sets out probable problems a port may encounter, and presents possible solutions on the different aspects of the management of wastewater from ships,” said Heitmüller.

Under the IMO regulations, all newly built passenger ships after June 2019 are required to comply to stricter rules on wastewater discharges, while older passenger ships will have to comply to the same rules by June 2021, with some exceptions until June 2023 for ships en route directly to or from a port located outside the Baltic Sea and to or from a port located east of longitude 28˚10′ E.

According to the rules, passenger ships which carry more than 12 passengers will have to either discharge sewage into port reception facilities, or alternatively at sea – provided that nutrients have been reduced by 70% for nitrogen and 80% for phosphorus through on-board treatment. 

Untreated wastewater has been identified as an important source of both hazardous substances and nutrients, the main cause of eutrophication leading to unwanted growth of blue-green algae that upset the Baltic Sea’s biodiversity.

Published by HELCOM, the Technical Guidance was developed by the Development and Assessment Institute in Waste Water Technology at RWTH Aachen University (PIA) on behalf of the Federal Maritime and Hydrographic Agency of Germany (BSH) and in collaboration with the German Federal Ministry of Transport and Digital Infrastructure (BMVI).