"What a waste of a majestic tiger shark in its prime all concerned should be ashamed," another said. "Like the shark ever had a chance."
"Catching this huge tiger and killing it is no different that shooting a lion or a Bengal tiger," one wrote. "Why not just tag it and let it go?"
The fishermen posted a photo on Facebook, boasting about the prize after the Australia Day activities in Swansea, a town near Tasmania island's east coast, according to the Newcastle Herald. The picture shows three men smiling alongside a strung-up tiger shark — weighing a reported 625.5 kilograms (about 1,379 pounds) and reeled in with a 15-kilogram (33-pound) line.
Offshore Fishing NSW, the group that posted the photo online late last month, said the massive catch is a "pending" world record. According to the International Game Fish Association, the world record for a tiger shark caught on a men's 15-kg line is 619 kilograms; 625.5 would be a new record.
Offshore Fishing NSW did not respond to a request for comment.
The catch drew comparisons to the controversial practice of trophy hunting — a sport that was thrust into the international spotlight last year when American dentist Walter Palmer helped hunt and kill a beloved lion, Cecil. Female hunters in particular have felt the Internet's anti-hunting wrath, with photos showing their most prized big-game kills often engendering scorn.
Conservationists argue that wild animals — and fish — should be left alone and allowed to replenish their populations.
Tiger sharks — known for their dark stripes and healthy appetites — live in warm waters around the world and usually don't stray very far from the coast.
Experts call them opportunistic eaters because their teeth — wide and serrated — allow them to bite and pull pieces from prey they cannot fit in their mouths, meaning they can cut through turtle shells, swallow shellfish and catch birds.
Tiger sharks have been known to bite humans, but experts say shark attacks in general are usually a case of mistaken identity. Once they realize humans are not prey, they swim away.
But it was a human "attack" on the potentially record-breaking tiger shark that has people talking.
A typical tiger shark can grow 10 to 14 feet long and weigh between 850 and 1,400 pounds, according to National Geographic. Experts point out that because it takes years for tiger sharks to begin breeding, removing large, mature sharks from the ocean impacts the species' ability to reproduce.
Jennifer Schmidt, director of genetic studies at the U.S.-based Shark Research Institute, said sharks' breeding populations need to be protected.
"Big, mature animals should be breeding; it takes a long time for the bigger sharks to mature — depending on the species 10, 15, 20 years before they’re able to breed," said Schmidt, an associate professor in the department of biological sciences at the University of Illinois at Chicago. "Taking out a big breeding-age fish like this one is unfortunate because it could have helped replenish tiger shark populations."
The tiger shark, known as Galeocerdo cuvier, is considered "near threatened," according to the International Union for Conservation of Nature's Red List, which ranks threatened species around the world.
It notes: "There is evidence of declines for several populations where they have been heavily fished, but in general they do not face a high risk of extinction. However, continued demand, especially for fins, may result in further declines in the future."
"If his reported weight is correct," Schmidt said of the tiger shark caught in Australia, "that's an absolutely massive tiger shark, which shows it is an older, mature fish. It makes me really sad to see him on a hook like that."
Fishing is the greatest threat to shark populations, according to the Australian Marine Conservation Society. The group estimates that 73 million sharks are killed per year — mostly for their fins, which are considered to be a delicacy.
In recent years, shark finning has become a lucrative business, particularly in China. It involves removing a shark's fin and discarding the body in the ocean.
"Shark fins are considered status symbols," Schmidt said. In China, she noted, serving shark fin soup "says you’re important; it says you’re wealthy."
The National Oceanic and Atmospheric Administration (NOAA) allows recreational fishermen to take one shark per boat per trip in U.S. territorial waters; but the fish must have its "head, tail, and all fins naturally attached. The shark may be gutted and bled at sea."
But, Schmidt said, enforcing U.S. and international laws is difficult. "The ocean is a hard place to police," she said.
Jack Vitek, world records coordinator for International Game Fish Association (IGFA), an organization that promotes responsible recreational fishing, said recreational fishing is a multi-billion dollar global industry.
Vitek said people have an "inherent right to fish." By doing so lawfully through organizations like IGFA, he said, they help expand the industry, promote international economies and still work to protect natural environments.
Indeed, the controversial tiger-shark catch has cast a spotlight on the longtime struggle between conservationists and sportsmen.
"I often wonder why people who hate fishing and fishermen troll such sites," a man in Newcastle commented on the Offshore Fishing NSW photo. "If it offends you move on or better still embrace diversity, some people believe in different ideals to you."
Others called the catch a "ridiculous waste of life for two minutes of ignorant glory."
"This most definitely is NOT fishing," a woman wrote. "This is all about insignificant people trying to make themselves feel significant by taking the life of a magnificent creature instead of tagging and releasing in a sustainable way! Sorry guys this action hasn't given you any credibility or significant just shows you up for the small minded people you clearly are. By your actions you will be judged as lacking humanity!"
The IGFA, which tracks world records, said the tiger-shark catch could result in a world record, but the organization has not yet received any documentation of the catch.
A previous version of this post misstated the NOAA's shark-fishing regulations. The post has been updated.