The situation came to a head recently, when eleven individual lifelines were taken, leaving no emergency aids in place from the Old Bridge at Christie Park to the Cutts at Castleroe.
Throwlines and buoyancy aids can make the difference between life and death, and there is a growing concern that a tragedy will occur if this type of mindless behaviour continues.
Mayor of Causeway Coast and Glens Council, Cllr Richard Holmes, said: “This vital equipment is provided for the simple purpose of keeping people safe, and it is beyond belief that it would be removed or destroyed.
“To those behind this – it must stop before it’s too late. An emergency can arise at any time. It could be your friend or family member in need and this equipment could save their live.
“To anyone who witnesses such irresponsible behaviour please make sure to report it immediately and help us address this grave situation.”
Sergeant Clare Sweeney said: “It defies belief that people are willing to put the lives of others at risk through such reckless action.
“We are appealing for anyone who witnessed the lines being taken or saw anything suspicious in the area to contact us on 101 quoting reference 537 of June 25th. A report can also be made www.psni.police.uk/makeareport Information can be provided to Crimestoppers anonymously on 0800 555 111 or online at www.crimestoppers-uk.org