An investigation has been launched to determine why thousands of dead fish washed up on the reef in Bundoran yesterday.
The bizarre scenes have shocked people in the area who witnessed the large-scale cull of scad, which are a type of mackerel.
The shoals of fish have washed up near the promenade at the roadside, so it is not believed to affect the beach areas.
Such incidents have occurred in South Donegal areas in recent years, which were linked to algae bloom. However, the cause of this week’s killing has not yet been found.
Chairman of Bundoran Tidy Towns Micheal McMahon said he cannot recall so many fish washing up before.
He said: “There are hundreds and hundreds of fish and we are all wondering what is the cause.
“It is an unusual sight, and now the seagulls are picking them up. It’s a feast for the birds.
“Some people think it was caused by some other wild fish coming after them and leading them to the shore. But we really don’t know the cause yet.”
The Sea Fisheries Protection Authority is investigating the incident today.