Wylies Baths Coogee, Sam Camer. Thursday 3rd Jan 2013

Wylie's Baths regular ... Sam Camer. Photo: Danielle Smith

 IT WAS an unusual whodunit: a much-loved octopus found dead at Coogee's historic Wylie's Baths.

But it did not take long to find the likely perpetrator - an overzealous cleaner armed with chlorine.

''I've been swimming there for 11 years and I've never seen anything remotely like this,'' said Coogee resident Matthew Martin who described the scene at the tidal bath as a ''dead sea''.

Wylies Baths Coogee

Time will tell ... Sam Camer reckons the marine life will return with the tide. Photo: Danielle Smith

''Not only was every marine fibre bleached white and dead, so was every marine creature that usually lives in the pool.''

The Wylie's Baths Trust, which runs the site, has posted a mea culpa on its website about the death of its resident octopus ''apparently as a result of chlorine contamination''.

The notice said the ''success or otherwise of the cleaning process'' - to routinely remove slip hazards posed by algae growing around the pool - was dependent on a range of factors including ''frequency, volume, timing, tide, temperature and swell''.

''It appears in this instance, we got it wrong,'' it said.

But that was not enough for Randwick City Council, which said the pool must come up with another cleaning method to prevent slip hazards at the baths.

Although some Sydney councils use chlorine or another algicide to do this, all pools cleaned by Randwick - including the neighbouring ladies' baths - are cleaned using a hot-water pressure system.

''We are committed to safe maintenance practices which do not harm our local marine life,'' a council spokeswoman said.

A spokesman for the trust, Tony Cousins, said it had asked the Environmental Protection Authority to help it review its cleaning.

''If there's a good option for us to use other than chlorine, we'll be dead keen on using it, I can assure you,'' Mr Cousins said.

But he said he did not think the incident had stirred lingering disquiet about management changes last year, which were part of an attempt to make the pool more financially sustainable.

Regular swimmer Fiona Giles said the mishap was ''arguably a direct result of the communication problems that persist'' at the site.

Wylie's had recently returned to cleaning the pool with chlorine after using grit and a bristle brush proved ineffective.

Sydney Institute of Marine Sciences director Peter Steinberg, a professor at the University of NSW, said the effect of chlorine on marine life was localised and short-term, but its use had ''diminished significantly in recent years''.

''It's frowned upon by the agencies that worry about those kinds of things,'' he said.

Work was ongoing to develop non-toxic wax coatings to control algae, he said, but other experiments using small grazing snails have been abandoned.

''It was difficult to corral the snails in the end,'' he said.

A Coogee local, Reg Chappell, said management might have made an error cleaning the pool. But he and fellow regular swimmer Sam Camer said the marine life - which in the past has included bream and a Port Jackson shark - would return with the tide.

Less conventional methods have been deployed in the past to clear Wylie's of unwanted marine visitors: a persistent wobbegong was once hurled back into the sea by its tail.

''We threw him over the corner, but then he just came back in again,'' Mr Camer said.