ORJIP Offshore Wind Stage 1

Launched in 2012, Stage 1 has helped develop the evidence base to help inform consenting decisions.

Stage 1 overview

Stage 1 of ORJIP Offshore Wind was set up in 2012 by the UK Department for Business, Energy & Industrial Strategy (BEIS - previously DECC), The Crown Estate, Marine Scotland and 16 offshore wind developers. The programme invested over £1.8million into four key research projects.

Major studies included an investigation into the efficacy of Acoustic Deterrent Devices on different marine mammals and a pioneering, two-year study to record and quantify the avoidance behaviour of seabirds around offshore wind farms. 

This stage of the programme made a significant contribution to the evidence base around the impact of offshore wind on marine life, which has allowed for more informed consenting decisions to be made. 

Stage 1 partners

Bird Collision Avoidance Study

The ORJIP Bird Collision Avoidance Study aims to use innovative methodologies to understand how birds interact with offshore wind farms to provide a robust evidence base

The study included analysis of over 600,000 videos, of which only 12,131 contained evidence of bird activity and only six collisions with turbines were observed. The analysis revealed that collision risk of seabirds was much less than currently expected based on current understanding and during the study seabirds were observed to exhibited avoidance behavior and change their flight path to avoid the turbines.

This will encourage the use of proven, practical and cost-effective monitoring systems to gather an empirical evidence base to reduce uncertainty for developers, advisors and regulators during collision risk modelling for consenting applications.

The study completed in April 2018 and ORJIP hopes the conclusions from this research on collision risk will allow better informed wind farm design and consent decisions just as the next generation of more powerful offshore turbines are being tested and manufactured. As a result the research will support UK Government plans to rapidly and sustainably grow the offshore wind sector by 2030.

Niras and DHI were contracted to install state of the art monitoring equipment at Vattenfall’s Thanet Offshore Wind farm to monitor micro, meso and macro bird avoidance behaviours. The multimillion pound, collaborative study was commissioned by 11 leading offshore wind developers, The Crown Estate, The Crown Estate Scotland and Marine Scotland, was supported with funding from the UK Government and was managed by the Carbon Trust. The project was developed and run with the support and advice from the UK and Northern Europe’s leading ornithologists and environmental advisers such as Natural England and RSPB.

The project provides robust, substantive, empirical evidence on the levels of avoidance behaviour and collision to improve collision risk models and therefore give greater certainty on the true impact of offshore wind farms on marine birds. 

The study included analysis of over 600,000 videos, of which only 12,131 contained evidence of bird activity and only six collisions with turbines were observed. The analysis revealed that collision risk of seabirds was much less than currently expected based on current understanding and during the study seabirds were observed to exhibited avoidance behavior and change their flight path to avoid the turbines.

This will encourage the use of proven, practical and cost-effective monitoring systems to gather an empirical evidence base to reduce uncertainty for developers, advisors and regulators during collision risk modelling for consenting applications.

The study completed in April 2018 and ORJIP hopes the conclusions from this research on collision risk will allow better informed wind farm design and consent decisions just as the next generation of more powerful offshore turbines are being tested and manufactured. As a result the research will support UK Government plans to rapidly and sustainably grow the offshore wind sector by 2030.

Full report

Bird Collision Avoidance study, April 2018

Efficacy of Acoustic Deterrent Devices

ORJIP carried out a two phase project to investigate and understand the efficacy of mitigation methods that could deter mammals from an offshore wind construction site and in turn, protect them from piling noise.

During the construction of wind farms, turbine foundations are driven into the seabed using a hydraulic hammer which generates significant levels of underwater sound. At close range this could potentially be harmful to a number of marine mammals.

Currently if a marine mammal is detected close to an offshore wind construction site this delays piling until it is deemed that there are no longer marine mammals within the predefined injury zone. The current method for detecting the mammals is by using marine mammals observers posted offshore, or passive acoustic monitoring. These methods of detection are restricted by sea roughness and daylight hours meaning that visual and acoustic mitigation has limitations.

Phase 1

Acoustic deterrent devices could enable exclusion zones to be created around the turbine helping to actively mitigate any harmful impact, thus avoiding the need to spot marine mammals from the sea surface and increase certainty that marine mammals are protected when operating in deep water conditions where visibility can be poor.

Phase 1 of the ORJIP study identified and reviewed 34 acoustic deterrent devices and their effectiveness on different marine mammals. The work identified a basic understanding of efficacy of acoustic deterrent devices for harbour porpoise, grey seal, harbour seal, bottlenose dolphin and minke whale and little evidence or no understanding of:

  • Deterrence in offshore environments
  • Long term responses to deterrence
  • Flexibility of effective range

Outputs

Efficacy of acoustic deterrent devices -  phase 1 research summary report (pdf)

Phase 2

Stage one
This phase focused on Harbour porpoise, Grey seal and Harbour seal. A literature review gathered evidence on the effectiveness of acoustic deterrent devices using existing evidence.

The outcome of this work, accepted by regulatory bodies, demonstrated that previous studies demonstrated effective deterrence beyond 500m for Harbour porpoise, Grey seal and Harbour seal. As a result acoustic deterrent devices could be used for these species during construction.

Read the reports

The use of Acoustic Deterrents for the mitigation of injury to marine mammals......... (pdf)

Joint Statutory Nature Conservation Bodies Position Statement (pdf)

Stage two
ORJIP commissioned RPS and Marine Conservation Research to carry out in-field testing on the efficacy of acoustic deterrent devices on Minke whale to provide recommendations on their use during construction. Recommendations on the use of Acoustic Deterrent Devices (ADDs) in the offshore wind industry have been made to inform government guidance on mitigating injury to marine mammals. 

Read the press release

New research builds confidence in wider use of Acoustic Deterrent Devices (Dec 2017) ....  

Read the full report

Understanding the Effectiveness of Acoustic Deterrent Devices on Minke Whale

Impacts on fish from piling at offshore wind sites

A study to improve understanding and acceptance of the risk of offshore wind construction on fish spawning grounds.

Offshore wind construction activities, such as pile driving, generate noise which can disturb marine life. Due to potential impacts, restrictions and conditions are placed on UK offshore renewables developers during their construction activities when marine mammals and fish are considered to be most vulnerable to disturbance, such as during spawning and migration. It is important to ensure that the established controls are appropriately formulated to deliver a protection benefit without unnecessarily burdening development.

The  ORJIP ‘Impacts on Fish from Piling at Offshore Wind Sites’ project analysed annual fish spawning data in UK waters over the past 10 years to better define fish spawning grounds and to evaluate the potential impacts of new offshore wind sites on Atlantic herring and other fish.

The main spawning sites for the different Atlantic herring stocks in UK waters are well known. However, due to the specific habitat and environmental conditions that herring need to spawn successfully, there are discrete pockets of spawning bed areas that are less easy to identify as they can change from year to year. Currently the exact location of spawning beds can only be identified if they are recorded through grab sampling or by drop down video surveys.  This study aims to address the uncertainty of the accuracy of fish spawning information and the impacts of piling activity on fish species.

The objectives of the study were:

  • Review and consolidate available data and information to define (where possible) UK populations, spawning areas, and periods for key species of concern.
  • Identify any gaps in our understanding of fish populations, spawning areas and periods.
  • Define and gain acceptance with consenting authorities and experts on fish populations, spawning areas and periods.
  • Discuss and understand how the current mitigation approaches are agreed by consenting authorities with the aim to understand what is required to support a change in construction restrictions.

The study launched in Summer 2017 is the first ORJIP study to look in detail about the important subject of fish and wind farm consenting. Below is an example of an Atlantic herring heatmap - an output of the study.

The analysis shifts the focus of studies from abandoned spawning sites and highlights those regions that have shown recent spawning activity. The techniques and methodology of heat mapping demonstrated the final report study provides clearer information of the areas of spawning and their proximity to offshore wind developments. If considered in the consenting process this could lead to a reduction in construction times, potentially lowering cost to consumers, and reducing operational disruption for offshore wind farms.

ORJIP Piling Study Final Report Aug 2018 (pdf)