The catching of a mature female tiger shark, driven to Exmouth for weigh-in during a major state fishing tournament, has outraged locals who allege it was brought to shore still alive and allowed to die slowly.
The week-long 39th annual Gamex is 'Western Australia's premier game fishing event', according to Exmouth Game Fishing Club's website.
The woman who photographed the shark near the boat ramp at Ningaloo on Wednesday was unavailable to speak with WAtoday on Thursday as she was offshore, but told friends it was still alive at the time.
"We could see it was a tiger shark just hanging off the back," her companion said.
"She went and took the photos and she came back and said it was moving.
"They told her it would be illegal to shoot it."
A representative of Gamex' host, the Exmouth Game Fishing Association, declined to comment.
WAtoday received further unconfirmed reports the shark, which the woman described as four metres long, was still alive when it arrived at the Exmouth town site weighing station, a 40 kilometre drive away.
It is unclear whether this would be possible - University of WA Centre for Marine Futures director Jessica Meeuwig consulted shark biologists who could not say for sure how long it would take the animal to die.
Whether it survived the trip back to shore could depend on whether there was water over its gills - researchers tagging tiger sharks generally had to demonstrate ability to demonstrate humane best practice which included correct handline techniques, a maximum of five minutes out of the water with seawater rushing past their gills throughout.
She said a neurobiologist's tentative opinion was that without this occurring the shark could potentially be brain dead within 15 minutes.
"I would be stunned if it were still alive [at the townsite]," she said.
She said regardless of how the fish died and continuing questions of whether fish felt pain, research into hormone levels had determined fish could become stressed and its journey to death would have been one of stress and anxiety.
She said as a mature breeding female this fish was exactly the type of animal that should be left in the ocean to reproduce.
"It comes back to the big old fat fish theory," she said.
"These animals are so valuable in terms of supporting healthy populations of apex predators in the ocean and the casual disregard, the treating them as trophies, has ecological implications.
"Tiger sharks, in particular, eat turtles, which helps maintain healthy seagrass systems, and those systems are important also for storing carbon that would otherwise end up in the atmosphere.
"These kinds of examples raise significant questions about how we treat ocean wildlife. You wouldn't drag a lion or a tiger through the Serengeti."
Another Exmouth local with a background in marine science said the incident jarred with Ningaloo's reputation as a pristine family ecotourism destination.
"This is the side people don't see," she said.
"They can't even use it for meat because they are full of ammonia. It is just pointless.
"These creatures are amazing. We are lucky to have this ecosystem up here and people are now realising the value of sharks to this ecosystem."
Tournament sponsors include the state government, Royalties for Regions, Recfishwest, Qantas, Australia Post and numerous local businesses.
It is sanctioned by the Western Australian Game Fishing Association, whose website states that its objects "focus strongly on conservation and promoting ethical game fishing practices". The Association did not respond to a request for comment.
Large whaler sharks, which include tiger sharks, with an interdorsal length of 700 millimetres or more are protected along the southwest and southern WA coastline but no restrictions, besides a bag limit of three, occur above the Kalbarri coastline.