Celebrities are losing their attraction. Once a turn-on for viewers, they're now proving a turn-off. The ratings disaster of Celebrity Wrestling could signal the end of entertainment shows in which D-list celebs attempt to extend their 15 minutes of fame.

The show has failed to force viewers into a submission despite massive pre-launch hype. The opening episode fared badly, drawing under four million viewers in a time slot where Ant And Dec's Saturday Night Takeaway had been achieving between seven and eight million. The Geordie duo's final show even beat Doctor Who for the first time since the two series went head-to-head.

Celebrity Wrestling fared even worse in the second week, luring a meagre three million viewers. The following programme, Celebrity Stitch Up, a variation on Candid Camera with pranks being played on sort-of-famous people, managed an audience of 3.2m.

Together, they helped ITV to its third lowest ever Saturday night audience. Executives have denied they're thinking of dropping the show but, if this weekend's ratings don't improve, expect to see it dumped into an earlier or later-night slot.

Celebrity Wrestling was a bad idea from the start. The format has little to do with wrestling and more to do with something that's a cross between Gladiators and It's A Knockout.

This mistake was compounded by the low level of celebrity enticed into the ring - the usual mix of ex-soap stars, sportsmen, presenters, singers and the obligatory pin-up girl with a face to which you can't put a name. James Hewitt, for instance, seems to make a living out of going on reality shows and Big Brother winner Kate Lawler shouldn't be encouraged to prolong her TV career. Former tennis star Annabel Croft should simply know better.

All of this means a lot of people at ITV headquarters are keeping their fingers crossed over the fate of Celebrity Love Island, which debuts on May 16. They'll be praying the show isn't washed away by a tsunami of public indifference.

The concept is as follows: "Twelve gorgeous celebrity singletons are thrown together on a fantasy island in ITV1's star-studded search for love". And there's more: "They will be whisked off to one of the most beautiful settings on Earth where they will be pandered and pampered to get them in the mood for romance".

They'll have to play "cut-throat competitions" to win over viewers and share a £100,000 prize. The audience will be asked to pair up castaways while also deciding who'll pack their bags and go home. This all sounds dangerously like I'm A Celebrity...Get Me Out Of Here, but with sea, sun and sex instead of jungle, creepy crawlies and Bushtucker Trials.

Much will depend on the singles persuaded to take a free sunshine holiday. Somehow, I can't see Orlando Bloom or Julia Roberts volunteering. We're more likely to end up watching some faded EastEnders star, a pop star looking to revive their career and the obligatory pin-up girl with a face to which you can't put a name. And James Hewitt too, if we're not careful.

The novelty of watching celebrities endure hardship was starting to wear thin before Celebrity Wrestling put the nail in the coffin. Celebrity versions of Big Brother and Fame Academy have produced diminishing returns in terms of ratings and entertainment value with each series. Even the template for such shows, I'm A Celebrity, didn't fare as well last time round.

The people at five seem undeterred. Even the low point in celebrity reality shows, known as Back To Reality, failed to stem the channel's enthusiasm for such entertainment. Monday sees the return of The Farm, which may not have the word celebrity in the title but will feature a selection of them working down on the farm.

Whether the series will produce a moment to outdo Rebecca Loos' close encounter with a pig on the previous series is debatable. What the makers will do is try to justify all the mayhem on the farm as educational.

At least C4's The Games was a relatively serious attempt by the celebrities - even if they did include James Hewitt - to prove themselves at sporting endeavours. It's more honourable than Celebrity Fit Club, which doesn't even have the guts to call itself Celebrity Fat Club.

Before the genre bites the dust, we have Celebrity Shark Bait to look forward to. This may sound like the idea for a comedy sketch but is a factual programme lined up in ITV1's spring/summer schedule to mark the 30th anniversary of Steven Spielberg's shark movie Jaws.

Four celebrities will be thrown into the waters of Shark Alley - no prizes for guessing which creatures swim there - in South Africa. They'll be in cages and, to ensure the Great Whites don't miss them, they'll be lured towards the celebrities with a foul-smelling mixture of fish and blood called chum.

"Underwater cameras," we're informed, "will capture all the action as the celebrities come face to face with the sharks". For once, these famous folk will have a valid reason to say, "I'm a celebrity, get me out of here".

* Celebrity Wrestling continues on ITV1 tonight at 6.30pm, followed by Celebrity Stitch Up at 7.45pm. Celebrity Love Island begins on ITV1 on May 16 at 9pm.