Mussels heralded as saviour for Auckland's polluted Waitematā Harbour

Tens of thousands of tiny living mussels may hold the key to cleaning up Auckland's polluted Waitematā Harbour.

Auckland Council and local iwi on Thursday unveiled their unique "weapons on a rope" which have been barged in to improve water quality in a new public space opening on the city's waterfront.

Mussels are being heralded as a saviour for downtown Auckland, with 38 laden ropes stretching over half a kilometre placed in the harbour.

"The health of the harbour is not as good as it should be," Nga Puhi Marine Scientist Dr Jarrod Walker said.

"Mussels can filter up to 200 litres of seawater per day so the idea is to use those mussels like a filter to remove some of those contaminants, sedimentation, bacteria. "

Divers have begun fixing the living eco-gifts to special floats which will bob up and down with the tide in Auckland's ferry basin.

Water quality there is murky at best with discharge from the city's pipes not helping.   

But before they can be put to work they have to be thoroughly dipped in cold water as a biosecurity measure to get rid of any hitchhiking pests that may have come up from the Firth of Thames, like fan worm or sea squirt. 

The newly-homed mussels will hang from the underside of a soon to be opened public waterfront space, known as Te Wānanga, which downtown Auckland Council transport director Eric van Essen described as "a really special, unique space".

It's a space with kelp-like nets Aucklanders can look through to see thousands of mussels below, cleaning up the water.

Dr Walker said its intention is to "educate people so they understand the importance manawhenua has in terms of the connection in this area but ultimately to start to improve our marine environments".

And with living mussels now on the job filtering away the muck, Aucklanders may soon appreciate once again why Waitematā translates to sparkling waters.