Passenger numbers at Ireland's regional airline Aer Arann tumbled by 32pc over the year.
The company, which has just signed a franchise agreement with the national carrier Aer Lingus, saw the amount of travellers on its flights to Dublin falling from 480,230 in 2008 to 326,400 within the year.
The total amount of traffic through Dublin Airport dropped by 12.6pc in 2009 to just over 20.5million from nearly 23.5million in 2008.
Meanwhile, Aer Lingus passenger numbers at Dublin declined nearly 7pc in 2009 to just under 7.46million.
Low-cost airline Ryanair suffered a 11.7pc fall back in figures from just over 9.9million in 2008 to 8.75million last year.
Ryanair has outlined plans to slash the number of aircraft based at Dublin in the coming summer season to 15 from 18.
Earlier, Aer Lingus chief executive Christoph Mueller said that he would boost passenger numbers by offering more pre-flight and in-flight services, turning away from "pure" low-cost models preferred by Ryanair.
Mr Mueller also said that the airline would consider taking delivery of deferred aircraft, once Ireland's economy starts to expand again, but added financing options are available to the Irish airline.
And it is believed that Aer Lingus will explore the possibility of launching new short-haul routes from Shannon airport, which has seen its traffic numbers collapse in the recession.
Mr Mueller indicated that any new short-haul routes would be operated by its regional service, run by Aer Arann, and could involve flights to Britain and other airports in Ireland.
He said that they have identified that the Heathrow route to Shannon works "quite well".
"We will try to increase connectivity to and from Shannon, not only to the United States but also intra-Ireland and from Shannon to the UK because there is a strong market to Manchester and Birmingham," he said.
The western airport faces a steep decline in traffic this year as Ryanair downgrades its base to one aircraft. Chief executive Michael O'Leary has predicted that its traffic at Shannon would decline to 400,000 this year from a peak of 1.9million.
Shannon handled 3.2million passengers in 2008, but its expected that this figure will have fallen back by 12pc last year.