At a meeting on Wednesday night, Ards Borough Council’s development committee agreed to recommend the closure of the Exploris Aquarium in Portaferry.
It came after a private venture deal by Livingstone Leisure to buy the aquarium on a 25 year leasee fell through when agreement could not be reached on staff pension provisions.
Strangford Alliance MLA Kieran McCarthy said: “There were a number of options on the table but the DUP has recommended its closure.”
Committee chair counciillor Trevor Cummings said they were proposing the closure with deep regret.
“This is not a recommendation we make lightly, knowing that it will impact directly on our staff, the town of Portaferry and the wider tourism base,” he said.
“However, the level of expenditure required is not sustainable in this economic climate when we face so many financial pressures, and regrettably, we feel this is the only realistic option.”
The aquarium, on the shores of Strangford Lough, employs 18 permanent staff and houses a seal sanctuary.
The development committee’s closure proposals will be put before a meeting of the full council next week.
If councillors agree to shut the facility and sell it off, they will begin a consultation with staff and trade union representatives, lasting a minimum of two months.
The site would then be placed on the market for sale.