What's lurking beneath the surface in the Wellington Harbour?
Hint: it's not a vicious sea monster. In fact, past experience shows it to be truck tyres, trolleys, and motor scooters, among other things.
Next weekend, volunteer divers in Wellington will be braving the depths to dredge up the rubbish coating the sea floor in the harbour. If last year's efforts are anything to go by, they might retrieve as much as three tonnes of junk.
The Wellington Harbour Spring Clean, an annual event to clear rubbish and raise awareness about protecting the marine environment, is set to go ahead on Saturday, November 19.
Nicole Miller is the president of the Wellington Underwater Club, which is one of the groups organising the event.
She said one of the big parts of the job was "decrittering". A team of 20-30 divers would bring the rubbish up from underwater, then volunteers would "look at each piece of rubbish, check if there's any fish or octopus or starfish" and return the critters to the sea.
Miller expected at least 50 volunteers to be involved in the cleanup, which included collecting litter on the shore as well.
A couple of weeks ago, the club joined in the Plastic Free Peninsular clean up at Miramar Wharf, in which about 70 children and adults gathered and decrittered the equivalent of about 27 council bags of rubbish.
The Underwater Club is joined in organising the Harbour Spring Clean by Ghostfishing NZ, which focuses on removing old fishing gear, such as lines and nets, from the sea.
The groups were also supported by the Wellington City Council, Sustainable Coastlines, and the Island Bay Marine Education Centre.
With more and more rubbish and large items finding their way into the water every year, much of it through the stormwater drains, Miller admitted the team felt "a little like the ambulance at the bottom of the cliff", but said it was important to raise awareness.
"There's still many, many tyres left, last year we couldn't bring up all the truck tyres . . . road cones unfortunately find their way in there as well.
"The main problem that we see is a lot of things that are coming through the stormwater drains . . . I see people's recycling blown around the roads on rubbish pick up day."
People wanting to volunteer could head to the Wellington Harbour Spring Clean 2016 Facebook page to sign up, or email firstname.lastname@example.org to get in touch.
Volunteers should start showing up to the Taranaki Wharf by The Boatshed about 8.30am, but for members of public wanting to come along and watch, 10am would be when the action started.
"We really want to make an impact with the event," Miller said.
"The main thing for us is really just putting a focus on marine pollution. We just want people to understand their domestic rubbish can end up in the sea. Any impact we do on land is also impacting on the ocean and our marine environment."