Abstract
This report has been commissioned by Vattenfall A/S and constitutes an addendum to the previous assessment report (Tougaard & Mikaelsen 2018). The present addendum contains revised modelling of impact ranges prompted by changes in the project as specified by Vattenfall, recently updated information about efficacy of mitigation measures (air bubble curtains) and a request from Swedish authorities for a more thorough assessment of impact on harbour porpoise behaviour. The assessment of impact on harbour porpoises and evaluation of mitigation measures described in this report thus replaces the assessment in the previous report, but otherwise the two reports should be read as a whole.