EU request on alternative measures to prevent bycatch of the harbour porpoise (Phocoena phocoena) in the Baltic Sea

ICES considers that the implementation of dynamic closures as a mitigation tool to reduce harbour porpoise bycatch in the Baltic Sea is not optimal. The reason for this is that this management tool does not appear to be appropriate to mitigate the interaction between highly mobile elusive species and fisheries withhigh site fidelity. In addition, dynamic closures are particularly problematic to implement in small-scale fisheries where the technology to monitor porpoise and transmit information to fishers on a timescale to have a practical effect on fishing closures is not readily available.

The most efficient way of preventing porpoise bycatch is to use fishing gears that pose less risk for porpoises. These include traps and pots, longlines, and seines, which have all shown not to catch porpoises.

Several mitigation measures involving gear modifications are currently at an experimental stage, and further thorough testing would be required to prove their efficacy before they could be recommended for applications.

Other management strategies such as economic compensations or bycatch quotas might not be currently viable for reducing bycatch of harbour porpoise