The Netherlands organisation for applied scientific research, TNO, is involved in various tasks in the SATURN project. TNO acoustic experts have supported the acoustic design of laboratory facilities for testing the response of fishes and invertebrates when exposed to ship sound, and the studies in which the response of marine mammals to ship sound is determined from tagged animals in the wild. In an initial study, we have identified the main characteristics of ship sound. The relevant spectral and temporal features are represented in well-described synthesized sound signals for use in future laboratory exposure studies. The availability of harmonized sound signals is an important step forward towards standardization of exposure studies. TNO is also actively contributing to the standardization of ship radiated noise measurements. With support from SATURN, TNO has taken a leading role in the ISO working group that will be developing a standard procedure (ISO 17208-3) for measurements of ships in shallow water, over the coming years.
A core expertise of TNO is the development of underwater acoustic models. With such models, maps of underwater sound caused by shipping and wind can be made. The monthly statistical maps of the sound of ships and wind in the North Sea, developed in the JOMOPANS project, give a useful insight in the dominance of shipping sound pressure with respect to ambient noise. The use of modelled sound maps was demonstrated in a seminar of the potential effects of slow steaming on shipping underwater sound and air emissions, after a study for the Belgian government. In SATURN, this modelling capability is being extended to represent the particle motion component of the sound as well. This is relevant for evaluating the impact of shipping sound on fish and invertebrate species, that are sensitive to particle motion. Together with SATURN partner JASCO, models for sound particle motion are now being verified through a process of benchmarking, as was done for the models for sound pressure in JOMOPANS. The next step will be to validate these models against field data. We are preparing a measurement campaign of the Dutch coast, near The Hague, in May 2022.
We at TNO are excited about the great opportunity to work with so many esteemed colleagues in this very relevant project, addressing the many knowledge gaps that hamper the management of shipping sound in the oceans.
