The mammals were found close to the old bridge over the Ratty River in Bunratty on Sunday.
Concerned for their wellbeing, members of the public raised the alarm and volunteers from Bunratty Search and Rescue launched their boat to investigate.
Rescuers confirmed the presence of three dolphins in the murky waters close to Durty Nellys pub just yards from Bunratty Castle. Team members attempted to coax them back under the bridge but the mammals were reluctant to move.
As more onlookers gathered, there were fears people would enter the river to help the dolphins.
As a result, the coastguard marine rescue co-ordination centre at Valentia, Co Kerry, mobilised the Killaloe unit to the scene.
It had been thought the mammals were common dolphins, an open-water species, and that they would become stranded and die on the river bank.
However, the Irish Whale and Dolphin Group (IWDG) now believes they are bottlenose dolphins which have been known to forage for food in rivers.
Co-ordinator Simon Berrow said the dolphins “are likely to belong to the resident population of Shannon Estuary bottlenose dolphins. They should be left to swim back into the Shannon Estuary catchment on their own”.
“The Shannon Estuary is a special area of conservation for bottlenose dolphins and thus they and their habitat is fully protected,” he said.
“Although it is very unusual to see dolphins this far up a muddy creek, recent acoustic monitoring carried out by the Shannon Dolphin and Wildlife Foundation [SWDF] has recorded bottlenose dolphins on 15% of days off Shannon Airport and 25% of days off Aughinish; thus bottlenose dolphins are upriver much more than we previously thought.”
Crowds have been gathering on the bridge in recent days, however the dolphins have not attempted to pass beneath since they arrived on Sunday.
“SDWF and& IWDG recommend that the dolphins are left alone to swim back down the creek on their own terms. Obviously if they become stressed [as determined by breathing rate] then some intervention may be required,” said Dr Berrow.