St Aidan’s CBS, Dublin – Assessment of importance of loss of foraging habitat to light-bellied brent geese

Background

St Aidan’s Christian Brother School is located in Dublin 9, Republic of Ireland. On behalf of the Board of Management of St. Aidans Christian Brothers School, Sports Labs Ltd. submitted a planning application in 2014, for a new artificial turf pitch for multi-sport use. The development site is located on the grass playing fields to the rear of St Aidan’s CBS on Collins Avenue in the Whitehall area of Dublin. These are located within 3km of North Bull Island Special Protection Area (SPA) (004006) and within 6km of South Dublin Bay and River Tolka Estuary SPA (004024). Light-bellied brent goose is listed as a qualifying interest for both of these SPAs and is a species known to use the parks and sports pitches in Dublin city for grazing.

Dublin City Council issued a Request for Further Information (RFI) in April 2014 and, further to Sports Labs Ltd. submitting the additional information, Dublin City Council granted permission for the development, subject to five conditions (none relating to ecology) in July 2014. The permission was subsequently appealed to An Bord Pleanala by local residents in August 2014.

BSG Ecology’s Role in the Project

BSG Ecology was commissioned to address a key element of the objection from the local residents group which was the potential for effects on supporting habitat (grazing land) of light-bellied brent geese that are potentially part of the flocks listed as qualifying interests for the two aforementioned SPAs.

The approach taken included a habitat and desk-based appraisal of the likely situation as far as non-breeding birds, such as light-bellied brent geese, were concerned. The limited timescale, two weeks from appointment to submission, required a swift and efficient response to the commission.

St Aidans_Brent Geese_smallApproach

BSG Ecology undertook a desk study to inform the field surveys and assessment of potential migrating bird interest. The desk study included a review of available existing documentation on the development site and immediate area in addition to accessing available online resources, such as National Biodiversity Data Centre, for information on flora and fauna, including migratory bird species, within or close to the development site. Liaison was also undertaken with a local bird recorder about general bird movements and land use in the area.

A walk-over survey of the development site was carried out in September 2014 to both describe the habitats present on the site and evaluate them in terms of their potential suitability to support migratory bird species particularly light-bellied brent goose. Areas of potential suitable habitat for light-bellied brent goose within 1-2km of the proposed development site were also visited, where access permitted, or scanned from accessible locations during the field survey. Nearby land and its wintering bird potential put the proposed development site in a wider context and assisted with assessment of the development site’s relative importance.

A short report was prepared describing the existing environment of the site and detailing methods, the findings of the site visit survey, and any limitations. The report presented the information gathered during the desk and field studies. The existing environment was described and the habitats on site were classified, mapped and evaluated in terms of their suitability for use by migratory bird species. The report made particular reference to the potential use of the site by migratory bird species and the site’s likely importance locally.

Findings in brief

The review of available information indicated that light-bellied brent goose will preferentially use sites as close to their roost site as possible and that their preferred ranging distance is to foraging areas within 3km of their roost sites. The Dublin flock are known to use the Dublin Bay coast and particularly North Bull Island SPA for roosting. The playing fields at St Aidan’s, at ca. 3km from the North Bull Island SPA boundary and ca. 5km from Bull Island, are on the edge of their preferred ranging area.

Light-bellied brent goose is considered likely to use the playing fields at St Aidan’s CBS for grazing at least occasionally during some of the winter months. A single visit to the development site outside of the winter season cannot confirm how many and how often the playing fields are used for feeding by the geese. However, if it assumed that light–bellied brent goose do use the playing fields at St Aidan’s then the conversion of the western pitch to artificial turf will result in the loss of ca.1.21 ha of feeding habitat. The geese may continue to use the eastern pitch as it will be retained as a grass pitch in the same condition as present i.e. short managed turf.

The total area of potentially suitable habitat for light-bellied brent goose within a 2km radius of St Aidan’s CBS was estimated using ArcGIS as 180.85ha. The loss of half the playing fields to artificial turf will result in a loss of ca 0.7% of potentially suitable light-bellied brent goose habitat within this area.

The location of St Aidan’s playing fields on the edge of the preferred ranging grounds for light-bellied Brent Goose and the noted widespread and increasing use of a variety of different types of amenity grasslands by the species in and around Dublin city, suggest it is unlikely that the loss of 1.21 ha of playing field in this location will result in a negative impact on the wintering population.

Outcome

An Bord Pleanala (ABP) issued their decision on 2 December 2014, deciding in favour of the proposed development. Permission was granted subject to five conditions none of which related to ecology. In making their decision ABP referred to the report prepared by BSG Ecology for the proposed development.

Light-bellied brent geese, Dungarvan, Co. Waterford. © Ciaran Cronin

St Aidan’s CBS, Dublin – Project Profile

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