The Contingent Valuation Method (CVM) aims at the assessment of people's willingness to pay (WTP) for a public project. The sum of the individual WTPs is interpreted as the social benefits of the project under consideration and compared to the project costs. If the benefits exceed the costs the...

Harmful algal bIoom species are the cause of important damages to marine living resources and human beings. These marine species are primarily introduced in North-European waters through ballast water, i.e. water trans-ported across the oceans so as to keep a vessel in balance. Port authorities...