Evidence review of harbour porpoise disturbance ranges in the context of the assessment and management of impulsive noise in Special Areas of Conservation

Invitation to tender documents for project reference C24-0619-1913 - Evidence review of harbour porpoise disturbance ranges in the context of the assessment and management of impulsive noise in Special Areas of Conservation. In 2020, JNCC, Natural England and DAERA, published guidance on noise management in harbour porpoise Special Areas of Conservation (SACs). This guidance recommends area-time thresholds within harbour porpoise SACs. A plan or project, individually or in combination, is considered to result in significant disturbance if it excludes harbour porpoises from more than:

1. 20% of the relevant area of the site in any given day, or
2. an average of 10% of the relevant area of the site over a season.

This management approach ensures that within those particularly important habitats for harbour porpoise i.e. the SACs, disturbance is kept low so that animals can utilise and access those habitats in order for the sites to continue to contribute to the species Favourable Conservation Status. To assess the area of a site that may be affected by the noise disturbance, the guidance recommends the use of Effective Deterrence Ranges (EDRs), as being the area around an impulsive noise event from which harbour porpoises are disturbed/deterred, equivalent to the mean loss of habitat per animal (Tougaard et al. 2013). The EDRs in the guidance are not equivalent to 100% disturbance/deterrence in the associated area, instead they represent the area over which the bulk of the effect occurs. Most EDRs have been informed by matching a suite of generic activity categories (e.g., monopiles, pin-piles, seismic surveys) to the empirical evidence described in studies covering an activity with the most similar characteristics and sound levels, with values chosen on the precautionary end of the spectrum. To review evidence (empirical and modelled) on harbour porpoise disturbance ranges from impulsive noise sources and recommend updated Effective Deterrence Ranges for activities that use such sources. To meet the overall aims of this project the objectives are:

Additional information: You are invited by JNCC Support Co (JNCC) to submit a tender for the supply of works or services required under the above project. If interested, you should download and carefully read the documents contained within the zip file.