Forewind

Detailed field data on the behaviour of harbour porpoise in response to underwater noise has been collected for the first time as part of an ambitious international project to better understand the impacts of wind farm construction on the North Sea harbour porpoise population.

Forewind is a partner in the Vattenfall-initiatied project, along with SMart Wind, East Anglia Offshore Wind and Eneco Luchterduinen.

Researchers from Aarhus University have gathered initial data about the harbour porpoise, a very small whale species widely distributed in the North Sea and subject to strict protection. Harbour porpoise is a challenging species to study due to its size, shyness and the fact it spends all its time at sea, so there is little basic knowledge about its life and how it copes with human activities in the North Sea.

Like other toothed whales, harbour porpoise rely on sound for communication, locating prey and navigation - therefore loud anthropogenic sound sources may interfere with these abilities. One noise source, pile driving during offshore wind farm construction, has been found to temporarily disturb porpoises at large distances leading scientists to question the consequences for the affected porpoises and whether it impacts the population. The Disturbance Effects on the Harbour Porpoise Population in the North Sea (DEPONS) project was established to look for answers to these questions.

DEPONS is a unique industry-funded research project gathering new knowledge and insights on basic porpoise behaviour, movement patterns and responses to underwater noise. The data gathered is fed into a scientific simulation model which, once fully developed, will serve as an evidence-based tool to assess the consequences of individual and multiple North Sea wind farm developments on harbour porpoise population.

The results from the preliminary data collection have been used to develop a first version of the DEPONS model and a report with initial results for a number of scenarios for North Sea wind farm development has been published.

DEPONS project manager from Vattenfall, Jesper Kyed Larsen said initial indications are that the North Sea harbour porpoise population may be less susceptible to pile driving noise than previously believed, however further work will be undertaken to substantiate the early findings and the model will be updated by the end of 2015.

“The DEPONS project demonstrates the commitment of the offshore wind industry to addressing the environmental impacts of offshore wind development. It is our hope that the results of this project will facilitate cost-effective and timely development of offshore wind in the North Sea in balance with a viable harbour porpoise population”.