BirdWatch Ireland and Dublin Port are working together to investigate how waterbirds use Dublin Bay. A three-year monitoring programme will identify key feeding and roosting areas, and studies of the movements of colour-ringed birds will help us better understand the ecological requirements of the birds using Dublin Bay.
Dublin Bay and neighbouring estuaries Baldoyle Bay, Malahide Estuary and Rogerstown Estuary are internationally recognised for their year-round importance for waterbirds and are each designated as Special Protection Areas under the European Birds Directive.
In winter, tens of thousands of waterbirds congregate at these sites from their Arctic and boreal-nesting areas, indicating that opportunities for feeding (largely shellfish, worms and algae) are good, and that there are suitable and secure roosting areas. In summer, platforms at Dublin Port support an increasing colony of terns that migrate from as far away as West Africa and perhaps even beyond. Later in August and September, the strand at Sandymount plays host to thousands of post-breeding terns and their newly fledged young, not just from the Port Colony, but from other internationally recognised Irish colonies such as Rockabill Island off north County Dublin, Lady’s Island Lake in Wexford, and no doubt other colonies from further afield. At this time, when these terns are preparing to head south, they are joined by incoming migrants from the arctic once again. So the cycle continues, despite the levels of disturbance resulting from a bustling city supporting 1.5 million people.
|Post-breeding terns congregate on Sandymount Strand. Dick Coombes|
During this project, we will be undertaking a comprehensive programme of monthly waterbird counts and observations within Dublin Bay that will help us to better understand how waterbirds are using the bay, to define the most important areas used and to examine their ecological requirements. These counts and observations began in late summer 2013 and will continue through to spring 2016. They take place at varying tidal states and at different times of the day to help us build an accurate representation of the birds’ distribution and abundance.
We are also running a colour-ringing scheme for a selection of wader species. Since we started the project in 2013, we have colour-ringed 262 Oystercatchers Haematopus ostralegus, 99 Bar-tailed Godwit Limosa lapponica, 36 Redshank Tringa totanus and 278 Common Terns Sterna hirundo in Dublin Bay. Through dedicated fieldwork and the collation of colour-ring re-sightings by us (with lots of help from the wider public) we will build a re-sightings database, which will allow complex ecological questions on the birds’ usage of Dublin Bay and the surrounding areas to be answered. Over 1,600 re-sightings have already been submitted, with birds turning up at 14 different locations in Dublin and in 4 countries (Scotland, Norway, Iceland and the Faroe Islands). Results from this work will inform on measures that may reduce the impacts of disturbance, development and climate change, and facilitate decision-making regarding such activities around the wider Dublin Bay area.