MIGRADROME: new study on impact of vessel sound pollution on fish behaviour

Sounds from shipping and boats can be harmful to aquatic species. An international consortium of experts (see frame) has teamed up to identify the sounds that are most harmful and how they are produced and propagated. The partners will investigate both short-term and cumulative long-term impacts of noise from shipping and boats on three representative groups of aquatic species in rivers and the sea: invertebrates, fish and marine mammals. The collaboration explores the most promising options for measuring and reducing the negative impacts of ship noise that can be applied to current and future vessels.

Swim tunnel technology

Associate professor Hans Slabbekoorn from the Institute of Biology Leiden (IBL) takes part in the consortium and leads at the IBL the MIGRADROME-project on migratory fishes. Many species are affected by noise pollution through disturbance, deterrence, and distraction, or masking of other biologically relevant sounds. Especially the locally experienced sound conditions may weigh heavily, together with other physical and chemical water conditions, in the decision-making process of where fishes prefer to swim. In MIGRADROME, fishes will be tested for the impact of sound conditions on movement decisions. The study will use the latest swim tunnel technology and an innovative combination with experimental exposure to underwater sounds.

Simulating estuaries and rivers

Slabbekoorn and the other researchers involved aim to find answers to several questions: do natural soundscapes affect where fishes prefer to swim and what migratory decisions they make moving up or down estuaries and rivers? And: at what levels do vessel sounds have a masking or disturbing impact and affect decision-making and swimming behaviour of migratory fishes? The project will likely start in February 2021 and a new PhD-student will be hired at the IBL (call open for applications on the 4^th of November 2020).