The maritime shipping sector continuously produces sounds across a wide range of frequencies and is the largest contributor of low-frequency anthropogenic underwater radiated noise (URN) in the marine environment. URN can have a negative impact on both marine habitats and marine life.
Currently there are limits on noise levels to prevent adverse effects of airborne noise on human health. There are, however, no mandatory limits for noise levels to prevent adverse effects of URN from ships on the marine environment.
There are different technical and operational options available for reducing URN in the shipping sector. Ideally, URN should be taken into account when designing new ships, but so far this is seldom the case. Technical retrofit measures are also available, but reducing an existing ship’s URN is more difficult and expensive than taking it into account at the design stage. For existing ships, reducing speed is a very effective measure to reduce URN over the entire frequency range.
The focus of this report is on ‘Blue Speeds’ – ship speed levels that protect the marine environment from the negative impact of URN and are associated with co-benefits for marine life and humans by reducing the hazards of ship strikes on whales, GHG emissions and air pollution.
There are various policy options to ensure that ships engaged in EU-related maritime transport operate at Blue Speeds. This report analyses these options and presents preferred options, taking into account environmental effectiveness, political and legal feasibility.
In addition, the social costs and benefits of Blue Speeds, implemented as mandatory speed limits, are analysed together with options for the implementation of Blue Speeds.