More than a dozen herring gulls have been rescued after being coated in what appears to be fish oil in Peel, prompting fresh calls to identify the source of the pollution.

Manx Wild Bird Aid says it has received reports of oiled gulls in the area over the past three weeks, with the contamination believed to have originated near the Food Park on Mill Road.

At least 13 gulls have been recovered for treatment, while reports of both partially and heavily oiled birds continue. Many others remain able to fly, making them impossible to catch.

Although the substance does not appear to be toxic, the effects on birds can be devastating.

Oil destroys the waterproofing of feathers, leaving birds unable to keep warm or stay afloat. Once they enter the sea, they become waterlogged, rapidly lose body heat and can succumb to hypothermia or even drown.

The charity says during the breeding season, the loss of an adult gull may leave chicks without a parent to feed and protect them. In some nests, both adults may have been contaminated, leaving young birds with little chance of survival.

A spokesperson for Manx Wild Bird Aid said: 'The authorities have never been able to find the source of the oil - hopefully this year will be different. We should be ashamed that this is happening to birds year after year, and nothing is ever done. It makes a mockery of our biosphere status and gives a terrible impression of our island's attitude towards wildlife.'

The charity says the incident is part of a recurring problem in the west of the island.

Oiled birds have been reported in Peel repeatedly over a number of years. In 2022, rescuers recovered an oiled peregrine falcon from the same area.

Despite previous investigations, Manx Wild Bird Aid says the source of the pollution has never been identified.