Collecting accurate data to assess seabird population impacts in offshore wind development

To meet renewable energy targets, the Australian Government has identified six priority areas for offshore wind development. For developers to gain project consent, a large amount of data on seabirds and other marine wildlife will be required. But with little or no data currently available, it is difficult to predict how seabirds and other marine wildlife in and around Australian waters will interact with offshore wind farms.

The need for precise and accurate data

Data that identifies which seabird species utilise the seas off Australia’s coast – as well as their abundance, seasonal usage and behaviour – will form the bedrock for determining baseline conditions. These data will be an essential component of robust impact assessments as part of project-specific development applications.

The two key potential impacts from offshore wind projects on seabirds are:

• Collision risk that may result in birds fatally colliding with wind turbine generators
• Displacement of birds from preferred feeding or roosting areas, the consequence of which may lead to increased mortality

Establishing the risk from these two potential impacts may be the most critical component of a developer’s permitting process. With high levels of scrutiny from Government and State level regulators as well as from conservation bodies, other consultees and the public, robust scientific data is key to providing confidence in these predictions.

Evolution of surveying techniques

Historically, bird surveys in the marine environment were dependent upon visual methods with boat-based surveys the go-to solution when it came to the collation and analysis of offshore ornithology data. As technology and the needs of offshore wind developers and regulators have evolved, digital aerial survey (DAS) methods have become the de facto standard for offshore wind and other major offshore developments.

Prior to the use of DAS, highly experienced field scientists braved every type of weather to visually identify birds from viewing towers on vessels, recording numbers and estimating flight heights before returning to shore to collate their findings.

Many of the vessels used were decommissioned fishing boats which naturally introduced inaccuracy into the data collection. Some seabirds, including gulls and shearwaters, instinctively flocked towards these boats with the hope discovering food. It is now known that other seabirds, including divers and auks, actively avoid vessels of any kind, either by moving away or by diving, again introducing unquantifiable bias into the data.

Boat-based methods also provide no audit trail, with results being recorded based on expert (time served) observers and data ‘corrected’ post survey for analysis.

Interim solutions came in the form of low altitude bird spotter planes fitted with viewing bubbles for species identification. However, the required altitude for these surveys is not safe for use once a wind farm has been built and causes disturbance to birds. Therefore, the development of state-of-the-art data collection rapidly evolved to use digital aerial still images from a higher altitude.

The benefits of Digital Aerial Surveys

The development of state-of-the-art data collection rapidly evolved to use digital aerial still images, which provide multiple benefits:

• Surveys are flown at a height of between 400 and 550m, ensuring that birds are not disturbed and their flight behaviour, height and distribution are a true representation of the ecology of the species
• Once an OWF is built, it is not possible to fly safely at lower altitudes, so ongoing monitoring can only be delivered safely at the altitudes flown for DAS
• Digital still imagery that is captured gives a permanent record that allows for review  and re-analysis later if required
• Imagery can be shared with independent analysts and colleagues, if required, for additional verification steps and Quality Assurance (QA)
• The orientation of birds in flight is routinely collected and provided for flight directional analysis

A World Leading Approach

Previous data collection methods relied on estimation of seabird populations and behaviour whereas the APEM Group approach is based on measurement, a fundamental difference that provides increased accuracy and precision.

Our methodology captures the most scientifically robust digital still data, reducing the uncertainty and likelihood of delay in the permitting process from other methodologies.

Our specialist team capture ultra-high resolution (1.5cm resolution) stills, using state-of-the-art cameras on stabilised camera mounts, mitigating any vibration issues and providing industry-leading image quality that is essential for species level identification.

By capturing the coordinates for each bird, we can delivery accuracy of ± 3 to 5 m as standard.

Our onboard camera technician constantly monitors the images captured, making immediate adjustments as required, ensuring the accuracy and precision of our data is maintained throughout the survey.

Our use of Global Positioning System (GPS) antenna and internal Global Navigation Satellite System (GNSS) and Inertial Measurement Unit (IMU). Only with these devices can accurate measurement occur allowing estimation of the survey coverage captured (a ‘precise survey measurement’) as well as informing ‘size-based’ bird flight height calculations

Data worth waiting for

The APEM Group have the benefit of over 15 years of planning and delivering DAS across the globe, surveying Australian waters for the last 4 years.

During this work, we considered the optimal period covered by a survey programme to capture seabird distribution and abundances across different seasons, as well as inter-annual variation between years. We established 24 months as global best practice, taking into account seasonal and inter-year variations.

Adherence to this format allows for greater buy-in from regulators in the final data sets, reducing the instance of data not being approved and having to retrospectively collect further data, resulting in significant project delays.

Following the APEM Group’s methods, our clients throughout Australia and around the world trust us to demonstrate global best practice and ensure that the data delivered meets the necessary legislation for the location surveyed.

We give global renewable developers the confidence that financial, environmental and delivery risk can be successfully mitigated first time, every time and on budget.

For more information on our DAS methods or how the APEM Group can help you, visit our APEM Group Australia website and complete the contact us form at the bottom of the page.

About the author, Sean Sweeney

Sean Sweeney is Country Manager for APEM Group in Australia and leads the company’s efforts in supporting renewable developers and regulators find the innovative solutions to ensure Australia can meet its ambitious targets for offshore wind capacity.

A global expert on offshore ornithology, Sean has designed and led innovative seabird surveys, behavioural studies and impact assessments at APEM Group for over 12 years. His contribution to advances in seabird science and how they interact with offshore wind developments is backed by multiple scientific papers and presentations at international conferences.

Sean brings significant experience in the process of gaining consent for offshore wind development projects, including the first project in the world to rely on Digital Aeriel Survey data to characterise its baseline for offshore ornithology assessments.

Acknowledgement of Country

We acknowledge the Traditional Owners of Country throughout Australia and recognise their continuing connection to land, waters and culture. We pay our respects to their Elders past and present.

About APEM Group

With locations across the globe, APEM Group provide independent environmental consultancy and expert scientific advice to a wide range of industries including water, renewables, infrastructure, power and utilities, ports and harbours as well as to regulators and governments around the world.

We provide a range of services to clients including our world leading digital aerial wildlife surveys, environmental impact assessments, marine, water & terrestrial ecology, geospatial insights, shipping and navigational risk assessments and landscape visualisation.

Find out more: www.apemgroup.com

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