This document is the third in a series of reports on the environmental monitoring workstream of the EnFAIT project. It satisfies deliverable D8.7 of the EnFAIT project and summarises the key environmental monitoring activity of years 4 and 5 of EnFAIT. As the final report in the series, it sets out the key evidence and knowledge gained on the environmental effects of tidal turbines throughout the monitoring programme for the Shetland Tidal Array. It also shares critical learning in the development of cost-effective best practice monitoring for tidal turbines and arrays. As with the previous two EnFAIT environmental monitoring reports, it will be shared publicly on the project website.

The Year 1 environmental monitoring report (Nova Innovation, 2018) covered the key outcomes from surveys of marine mammals and birds at the Shetland Tidal Array project site in Bluemull Sound for the 12 months between May 2017 and April 2018. It also presented the results of subsea video monitoring of marine wildlife around the turbine observations gathered using underwater cameras attached to the turbines.

The Year 3 report (Nova Innovation, 2020) detailed the environmental monitoring activity carried out in years 2 and 3 of the EnFAIT project. This included results from a comprehensive analysis of the data gathered at the Shetland Tidal Array since the start of monitoring at the site in 2010. This analysis was completed during years 2 and 3 of EnFAIT, so key findings were presented in the Year 3 report along with recommendations for the environmental monitoring for the remainder of the EnFAIT project.

This final (Year 5) EnFAIT environmental monitoring report focuses on the contribution EnFAIT has made to the development of environmental evidence and best practice for cost-effective monitoring of tidal energy projects and the sustainable development of the sector. An overview of monitoring activity carried out over the duration of the project is provided, including details of how methods and approaches have evolved to ensure they remain fit for purpose and cost-effective as the Shetland Tidal Array has increased in size. Key evidence and knowledge on the environmental effects of tidal turbines gained through monitoring is summarised, along with details of how this learning has been shared and disseminated to maximise its impact. The forward plan for monitoring activity for the remainder of the EnFAIT project are presented, covering the period in which the remaining two turbines in the expanded array will be installed and the layout of turbines in the array reconfigured.