Strategic Review of Offshore Wind Farm Monitoring Data Associated with FEPA Licence Conditions: Benthic Ecology

Abstract

All offshore wind farm (OWF) developments within the UK require a FEPA licence. To this licence, a number of conditions can be applied to ensure that environmental parameters determined as meriting observation during the application assessment are monitored. Specifically, concerns about the effects of OWFs on the benthic environment have been expressed and therefore require monitoring.

This report considers the licence conditions and benthic monitoring data for OWFs during and after their installation. Standard licence conditions and survey techniques are highlighted for operational OWFs and for those under construction, namely North Hoyle OWF, Barrow OWF, Kentish Flats OWF, Scroby Sands OWF and Burbo Bank OWF.

The monitoring surveys undertaken so far have provided a valuable insight into the immediate impacts of Round 1 wind farm construction and operation. The monitoring shows that no detrimental effects have been detected so far. However, detecting the extent of natural variability and the ability to draw conclusions from a short time-scale of three years post-construction data is limited. The monitoring reports also demonstrate that there is a need to tailor monitoring programmes specifically to the impacts predicted in the EIA, with monitoring objectives clearly stated at all stages, as this has not always been the case. The concept that monitoring surveys should not be perceived as a standardised ‘one survey fits all approach’ is emphasised.

The quality of statistical analyses across monitoring studies is variable, which restricts the effectiveness of cross-site reviews. There is no s ingle correct way of analysing data, however the use and reporting of QA/QC procedures would ensure that all datasets and results over space and time are compatible.

Epifaunal colonisation of monopiles can result in a localised increase in species diversity, whether this is a ‘beneficial’ impact as is often predicted, is debatable and highly subjective as the colonising species are different from the original community. However, it is worth noting that the species observed colonising monopiles are the same as those on other rocky substrates. The long-term effects of these changes are still unknown.

To address the limitations in obtaining detailed temporal baseline data and an understanding of natural variability, studies should collaborate with national monitoring programmes (such as National Marine Monitoring Programme -NMMP). Also, the potential of following the model set up by the aggregate industry to address regional issues should be considered (i.e., REAs), where the use of such a tool, independently or in collaboration, could be highly beneficial to the offshore wind farm industry in the future.

Longer term datasets are required to ascertain the long-term effects of OWF installation. The application of regional methods to address the highlighted limitations in existing monitoring strategies can allow site-specific monitoring to be considered in terms of the frequency of post-construction infaunal monitoring. In terms of infaunal monitoring, less frequent surveys over a longer period of time are recommended, with more frequent monitoring concentrating on the known ‘near-field’ and colonisation impacts.

Related Reports:

This document is related to the Scroby Sands Wind Farm Project Site.