risso's dolphins

Historically, bird and marine mammal surveys have been dependent upon visual survey methods, however as technology and the needs of developers and regulators have evolved over the last ten years, the move towards digital aerial survey methods has increased.

So, which is the best method or is there a case for both?

Boat-based surveys

For years, and until camera technology was refined and tested, boat-based surveys were the go-to solution when it came to the collation and analysis of ornithology data.

Highly experienced field scientists often 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. The benefits of this approach include the ability of the expert to identify the nuances between similar-looking species and record other environmental factors ‘in the flesh’.

However, often many of the vessels used were decommissioned fishing boats which the birds instinctively flocked towards with the hope of food, giving unreliable data. It is also now well known that other species actively avoid vessels of any kind, either by moving away or by diving, again introducing unquantifiable bias into the data.

This method provides no audit trail, the results were recorded based on expert (time served) observers, and data needed to be “corrected” post survey for analysis.

Aerial survey evolution

From low altitude bird spotter planes fitted with viewing bubbles so that experts could see species, the industry has now evolved to digital aerial still images. The benefits of a digital aerial solution are many and include:

  • The altitude flown is much higher than that of a visual survey, ensuring that marine wildlife is not disturbed.
  • Once a windfarm 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 digital aerial surveys
  • Still imagery that is captured gives a permanent record that allows effortless review later if required
  • Imagery can be shared with independent analysts and colleagues if required for additional verification steps and QA

The specialist APEM team capture ultra-high resolution (1.5cm resolution) stills for wildlife survey projects, using state-of-the-art cameras. These are mounted inside the aircraft using stabilised camera mounts, mitigating any vibration issues, and provides industry-leading image quality, essential for species level identification.

Each survey flown has an onboard camera technician, who constantly monitors the images captured, making immediate adjustments as required.

APEM deliver digital stills aerial surveys and work with clients to ensure that they understand their needs, getting the design of a survey right first time.

Our technical experience is second to none and over the years we have fine-tuned our methodologies to ensure that we can provide the best possible advice that will deliver exactly what a client requires. Our experience in providing data suitable for the consent / permitting process is unrivalled.

To find out more visit our marine wildlife and ornithology survey page or if you have a specific question or requirement, please contact us.

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APEM are a global environmental consultancy providing independent advice and guidance to support government and environmental regulatory guidelines.