Call for seaweed on Louth coastline to be tested to ensure it is not 'toxic'

Seaweed masses that appeared on Louth beaches last summer raised concerns due to foul odours. Similar material in France was tested and found to emit sulphur, leading authorities to remove the seaweed before it dies off. The rotting process was linked to harm, including deaths reported in France. Louth County Council was asked to test any seaweed that appears again this year and to consider lifting it to reduce risks to animals and people. Unprecedented levels were reported at Clogherhead in summer 2025, and residents in Blackrock reported foul-smelling seaweed washing ashore in the north of the county.

"Seaweed which has washed up on the Louth coastline should be tested to ensure it isn't "toxic", a meeting of Louth County Council heard."

"Cllr. Michelle Hall said she had concerns about some of the foul smelling seaweed which appeared in large masses on beaches in Louth last summer. Speaking at the monthly meeting of Louth County Council, she explained that authorities in France had tested similar material and found it was emitting sulphur. The decision had been taken there to remove the seaweed before it dies off."

""It caused several deaths there," said Cllr Hall. "Because it is fine while it is alive, but when it rots it gives off sulphur." In an appeal to the council, she said: "If it happens again in Louth this year, can we get it tested?""

"She asked if the council could look at "lifting the seaweed as well, as when it dies that's when it causes problems for both animals and people too." The summer of 2025 had seen "unprecedented levels" of seaweed reported along the beach at Clogherhead. Residents of Blackrock had also reported "foul-smelling" seaweed which had washed up on the shore in the north of the county."

Read at Irish Independent