APEM Ltd undertook environmental monitoring for the London Array offshore wind farm, including aerial ornithology (bird) surveys and aerial surveys covering birds and marine mammals across multiple phases. The Tethys project page lists APEM-led aerial surveys for the proposed site and control zones (Nov 2009May 2010), winter aerial bird surveys during construction (2010/11, 2011/12, and 2012/2013), and operational-phase aerial bird surveys in 2013 and 2014, with reports published in 2010, 2012, 2013 and 2016.