FOWL play is suspected for the failure of a Dublin beach to qualify for a Blue Flag.
Fingal County Council has revealed bird droppings may be costing Burrow Beach in Sutton, north Dublin, the coveted status for cleanliness.
Seawater quality at the beach has been rated as "poor" over the past two years.
It is now the worst performing strand in terms of water cleanliness among Fingal's nine designated beaches.
The other beaches at Balbriggan, Skerries, Loughshinny, Rush, Portrane, Donabate, Malahide and Portmarnock were all rated either "sufficient" or "good" last year.
However, Fingal believes a factor in the Burrow's less than impressive results may be the flocks of birds which fly over the beach.
The council said 26 samples were taken during the bathing season in 2010 and just two samples failed the mandatory limits.
This indicated the limits "were largely complied with throughout the bathing season and the water was safe for bathing through most of the season", the local authority insisted.
It said the "non-compliant" results may be due to a number of factors, including "faecal matter from large numbers of birds in the area".
Other factors may be overflows from three pump stations within the vicinity of the beach and the activities in Howth harbour located in close proximity to the beach. Fingal said dog and horse waste could also have played a role.
"Upgrading of the pump stations is part of the Portmarnock Sewage Scheme, formerly the Dublin Bay Project, which is included on the Water Services Investment Programme (WSIP) 2010-2012," it pointed out.
The information was provided to Fine Gael councillor Kieran Dennison who asked WHY Burrow Beach "failed to meet basic water cleanliness standards in 2010".
The local authority said that, based on the sampling results, it applied for Blue Flags at Portmarnock and Portrane beaches.