Payment for ecosystem services - paying mussel producers for nitrogen mitigation

Mussel production is an alternative measure to reduce excess nutrients in fjords causing unwanted eutrophication, and mussel production and removal (harvest) can improve the utilisation of nutrients wasted to the sea. The basic principle of mussel farming as a mitigation tool is that by harvesting cultured mussels, the unidirectional flow of mineral nutrients from land to sea is returned by bringing back the nutrients bound in the mussels from sea to land.

Mitigation mussel production can be carried out at lower costs compared to consumption mussel production, and a pilot study in Skive Fjord in Denmark has demonstrated that using mussels to remove nutrients from the coastal environment can be a cost-effective means of mitigation of excess load of nutrients compared to many agricultural measures.

Many agricultural measures have a restricted capacity for additional reduction of nutrient load to the marine environment, and the costs of implementing these abatement measures for nutrient load reductions are increasing at the margin. The nutrient uptake by the mussels can be regarded an ecosystem service, that might be utilized, but which need motivation and incentives for the mussel producers.

If the provision of this ecosystem service is dependent on market conditions it will be uncertain, and Payment for the ecosystem service – i.e. the nutrient uptake and removal from the sea – a regulating service – can be justified. The sales prices of mussels have been low for a long time, and conventional mussel production has not been profitable.

Research is ongoing to develop the possibilities of using mussels for fodder and fertilizers in agriculture, but still the markets for mussel productions are vulnerable. A Payment for Ecosystem Services (PES) is a voluntary transaction where a well-defined environmental service (ES) is being “bought” by minimum one ES buyer from minimum one ES provider, if and only if, the ES provider continuously secures ES provision (conditionality).

The PES can be arranged as a payment from the state or the municipality to the mussel producers, or it could be arranged as a transferable development right where farmers buy the right to continue current fertilizer practices by paying for N retention in another location (here in the water bodies). It is also possible to learn from the GHG policy where it is possible to pay for abatement elsewhere, where it’s more cost-effective.

The paper and presentation discuss the cost-effectiveness of mitigating nitrogen in fjords by mussel production compared to agricultural measures, and possibilities and barriers of paying mussel producers for the ecosystem services they provide.