Interest in underwater noise is growing in Sweden, and two recent stakeholder events showed how relevant this topic has become. At both meetings, IVL Swedish Environmental Research Institute presented ongoing work within the DEMASK project and discussed how new knowledge can support future policy, management and mitigation measures.
The first event took place on 23 January, when IVL organised a roundtable with the Swedish Agency for Marine and Water Management and the Swedish Transport Agency. IVL presented the overall progress of DEMASK, with particular attention to its work on underwater noise mapping for recreational boats and on ecosystem-based risk assessment.
One focus area was the development of underwater noise maps for recreational boats, using Koster Marine National Park as a case study area. IVL also presented its work to support an ecosystem-based approach to underwater noise risk assessment, including efforts to identify invertebrate species in the North Sea that are especially sensitive to underwater noise and could be used as indicator species.
The discussion covered possible mitigation measures and future scenarios for recreational boating in the case study area. These included both developments without mitigation, such as more vessels or larger engines, and locally relevant measures such as reduced speed and restricted boat traffic in particularly sensitive areas and seasons. Other options, such as propeller changes, cleaning of hull and propeller, and electrical propulsion, were also discussed, although these cannot yet be fully assessed because of limited data on their effects on underwater noise levels.
Stakeholders emphasised that underwater noise from recreational boats and other non-AIS vessels is receiving increasing international attention, while major knowledge gaps still remain. They also noted that new results from projects such as DEMASK could provide valuable input for ongoing discussions in HELCOM, OSPAR, TG Noise and IMO.
This strong interest was visible again on 16 and 17 March, when IVL joined a seminar on underwater noise in Stockholm organised by the Swedish Transport Agency. One day focused on recreational boats and the other on commercial shipping. Around 85 participants joined each day, on site and online, including researchers, policymakers, authorities, NGOs, shipping and boating organisations, operators and businesses.
During the seminar, Anna-Sara Krång, Senior Researcher in marine ecology and ecotoxicology at IVL, introduced DEMASK to this broad audience. She presented IVL’s work in work package 2 on methods for underwater noise mapping for recreational boats, as well as its contribution to work package 3, including a trait-based framework to reflect noise vulnerability across mammals, fish and invertebrates.
Together, the two Swedish stakeholder events confirmed the relevance, timing and value of DEMASK in supporting both research and policy on underwater noise.