Delivering Ecoacoustic Net Gain in the UK

Ecoacoustics is the use of sound to understand more about the nature of ecosystems and how they function. The scientific field and practical applications are rapidly developing as new hardware and analytical techniques, in particular AI methods, make the methodologies more accessible and the results more actionable. A broad spectrum of taxa produces sounds which can be used to infer presence, activity, behaviour, and in some cases abundance. The supervisory team has experience using ecoacoustics methods to monitor birds, bats, orthoptera, small mammals, amphibia and a range of habitat types.

Biodiversity Net Gain (BNG) is an approach to development adopted by the UK government and implemented in the forthcoming Environment Act and National Planning Policy Framework. The policy aims to leave the natural environment in a measurably better state than before development - and this gain is assessed through a 30 year monitoring programme. As a consequence of this policy there is a significant interest in methods for monitoring biodiversity that can be used to evidence net gain and which can be deployed at scale.

Ecoacoustics has the potential to address the needs of BNG policy by providing measures of biodiversity at low cost over large scales, but key questions still remain. 1) Are ecoacoustics methods capable of detecting changes in biodiversity across habitat quality gradients with sufficient power to be of use for measuring biodiversity net gain, 2) do the same results hold for linear habitats, inherently valued to support connectivity, 3) what errors and biases are inherent to an ecoacoustics approach, and how do these impact on its effectiveness as a tool for measuring biodiversity net gain? How can these issues be designed/modelled away? and 4) can we define reference baselines to benchmark what 'good' and 'poor' quality habitats sound like?