Beach Buddies has criticised the ‘lazy and thoughtless’ dumping of a bag of rotten whelks in one of its coastal bins after volunteers were met with a ‘putrid stench’ while carrying out collections this week.

The charity said the incident happened at Glen Mooar, south of Kirk Michael, when volunteers emptied one of the organisation’s sponsored bins as part of their regular rounds around the island’s coastline.

According to Beach Buddies, the bin itself being full was ‘fine’ and reflected the efforts of people who regularly clean the area and use the facility responsibly.

However, volunteers said a strong smell was noticeable from up to 30 yards away before they even opened their truck.

The source of the odour was discovered at the bottom of the bin - an orange net bag filled with decomposing whelks, a species of sea snail.

In a social media post shared on Thursday, the charity said it believed the shellfish had been left there for at least a week.

Beach Buddies questioned why the whelks had not simply been returned to the sea, which was only a short distance away.

The group said: ‘What is going through someone’s head to make them think that this sort of action is OK?

‘It’s not the most pleasant of jobs emptying the Beach Buddies bins, even if they are just full of normal rubbish, but we know it is really important.’

The charity added that while the vast majority of beach users support its work, the incident showed how some people ‘simply don’t care’.

Founded in 2004, Beach Buddies has become internationally recognised for its environmental work and for helping maintain the Isle of Man’s reputation for having some of the cleanest beaches in the world.

The charity now maintains more than 50 sponsored bins around the island and also carries out litter picks in plantations, car parks, play areas and along walking routes.