Seatrack - "The Irish Seabird Passage Project"

The high ranking position of seabirds in marine trophic foodweb structures makes them excellent indicators of marine ecosystem health. They essentially ‘track’ their prey closely, timing their breeding & migration in order to follow seasonal abundances of food, often across large expanses of ocean. As such, any effects resulting from climate change or overexploitation of marine resources are likely to be reflected by changes in the distribution & status of seabirds inhabiting Irish waters.

One method of assessing any potential changes is to undertake land-based 'seawatching' surveys of migrating seabirds. Volunteer recording of seabird migration from Irish coastal headlands in late summer & autumn has been a long standing tradition since the 1960’s. Thus, there is already a significant recording effort in existence which could provide a means of gathering information & data for use in the scientific analysis of seabird movements around Ireland.

Seawatchers at The Bridges of Ross, Co. Clare  © Niall Keogh

Seatrack was initiated by BirdWatch Ireland in 2010 in order to try and coordinate Irish seawatching & collate records with the aim of following the seasonal distribution & movements of seabirds passing through Irish waters from late July to early November, potentially highlighting any key migration routes or favoured feeding areas which will be vital for designating future Marine Protected Areas. The project will run in conjunction with similar surveys being undertaken by BirdLife International partners in the UK, France, Spain & Portugal under the FAME (Future of the Atlantic Marine Environment) initiative. 

As a focal point for the survey, Seatrack also wishes to clarify the status & distribution of one seabird species visiting Ireland’s coastal waters in particular, the Balearic Shearwater.

Balearic Shearwater © Ricardo Guerreiro

The Balearic Shearwater (Puffinus mauretanicus) is a scarce but regular migrant to Irish waters, most often observed from coastal headlands between late July & early October during post-breeding dispersal from their nesting grounds in The Mediterranean Sea, where 2,000-2,400 pairs breed exclusively on The Balearic Islands from February to June. 'Balearics' are listed as Critically Endangered by the IUCN due to a recent, rapid decline of their small & range restricted breeding population. Factors such as predation by introduced mammals, increased development pressure at nesting sites & negative interactions with commercial fisheries have all been attributed as likely causes.

In recent years there has been an apparent northward shift in the non-breeding distribution of the Balearic Shearwater with an increase in numbers off northern France, in The English Channel & off the Irish coast. Some have suggested that this northward expansion has been facilitated by rising ocean temperatures as a result of climate change. Despite the increased presence of Balearic Shearwaters off Ireland in recent years however, our understanding of its ecological requirements & preferred destinations whilst inhabiting our waters remains quite poor.