Water quality test results are due today from the canal in Tralee.
Kerry County Council took samples of the water following the washing up of thousands of small silver fish in the Basin in recent days.
The sprat were brought in on the high tide.
This is a natural phenomenon with a lack of oxygen in the water killing the fish but it will mean Kerry County Council will have to embark on a clean up operation to remove them.
A council spokesperson said it is prudent not to open the lough gates until tests are back to determine the quality of the water in the canal before releasing it into Tralee Bay.