Missing Nemo from tropical island highlights threat of illegal poaching to Great Barrier Reef

It was a flicker in the water, only 2 centimetres long, but bright and distinct, darting into the protection of a carpet anemone.

The 2003 film Finding Nemo made clownfish and the Great Barrier Reef international icons.

When the species known as a "true nemo" — Amphiprion percula — turned up in a bay on Magnetic Island, just 20 minutes off the coast of Townsville in 2022, locals were excited.

"It was called 'Island Nemo' because we finally have a Nemo now," local diver and marine biologist Lawrence Scheele said.

Mr Scheele said it was the first recorded sighting of a true Nemo on Magnetic Island because the fish were typically found further north or off the coastline.

"Locals have been enjoying it."

For four years, Mr Scheele would regularly dive at Geoffrey Bay, watching through his snorkelling mask as his fish friend grew up.

Then one day, Island Nemo disappeared.

Finding Nemo

Just two weeks earlier, unbeknown to Mr Scheele at the time, two snorkellers had pinpointed the fish's location when they uploaded a photo to the citizen scientist app iNaturalist.

Island Nemo has not been seen since.

Locals fear their special little fish has been poached.

"The timing is the most suspicious thing," Mr Scheele said.

"Because there were two instances of him being online at the time he disappeared, the community thinks it's too coincidental."

'The go-to fish'

James Cook University's Morgan Pratchett said the commercial harvest of clownfish was low because the fish could be bred in captivity, adding that Island Nemo was in fact "worth very, very little" in economic terms.

But Dr Pratchett said Island Nemo had symbolic value.

He said clownfish were not likely to relocate, so "if it wasn't poached, it succumbed to natural mortality … but the rates of natural predation are quite low."

"There's every possibility a recreational person with a home aquarium may have taken it," he said.

"The go-to fish is absolutely a true Nemo."

Scale of the problem

Dr Pratchett said more work needed to be done to understand the extent of the illegal poaching of fish and coral.

He said the threat to coral was "far more serious" because it was easier for poachers to access and take more valuable corals.

And while European countries have banned specific corals being exported from Australia, Dr Pratchett said some coral species that turned up overseas could only have come from Queensland.

A useful tool

Marine scientist Adam Smith has made more than 20,000 observations on iNaturalist and leads an annual citizen scientist push encouraging people to log species on the Great Barrier Reef.

Professor Smith said iNaturalist had an in-built failsafe that blurred the geolocation to around the nearest kilometre for species listed as endangered, vulnerable and threatened by the International Union for Conservation of Nature.

"That's to stop people taking advantage of those rare sightings and harvesting," he said.

That list does not include Amphiprion percula, so the geolocation block was not activated automatically on Magnetic Island.

"Every tool has its advantages and disadvantages," Professor Smith said.

Fears for the future

Mr Scheele loves iNaturalist's citizen-sourced data sets but wants people to know the power of the information they share.

When he reached out to the people who posted Island Nemo's location, they were distraught.

"They said: 'I had no idea anyone would even do that', but it was too late. It had been up for weeks," Mr Scheele said.

"If someone posts the coordinates for sensitive or vulnerable species, what else is going to go missing?"