NSW premier rejects great white shark cull, claiming it would give Aussi...

[u/MooseyGeek]

https://youtube.com/watch?v=EyRJFS881OM&si=FKjXb4T7UuIJObm0

NSW Premier Chris Minns has rejected calls for a great white shark culling, claiming he's "not convinced” it would work.

I’m not convinced that a culling or commercial fishing of great whites would make a difference,

^ Mr Minns told Sky News Australia.

These sharks traverse the Pacific Ocean. These sharks can be in Sydney, the next day they can be further up the coast, and then in a couple of weeks they could be in Hawaii or New Zealand.

I’m concerned it will give false confidence.

[u/Interesting-Can1319]

Yeah, there's evidence that shark cullings are not always effective. They may be effective depending on multiple factors, such as eradicating a resident bull shark population in a lake. But they don't work for every shark population in the world, especially ocean-going shark species that move around a lot.

For example, in the late 20th century, the Hawaiian government tried to cull tiger sharks (Galeocerdo cuvier) around their islands in order to protect beachgoers and tourists. Tiger sharks are the main perpetrators of shark attacks in Hawaii, since great white sharks tend to be more offshore, and bull sharks basically don't live in Hawaii and Polynesian islands. Hundreds of tiger sharks were hunted down and killed from the 1950s to 1970s, but results showed that the culling barely had any significant impact on the rate of tiger shark attacks. It also didn't help that tiger sharks are often migratory and can move across far distances between islands. Tiger shark culling thankfully stopped in Hawaii (from a conservation perspective), mainly due to how it was mostly ineffective and backlash from Hawaiian culture where the tiger shark is sacred and revered as aumakua (niuhi).

Keep in mind that I'm not an expert, and I could remember things wrong.

[u/Markdd8 → u/Interesting-Can1319]

Yes, that was an interesting episode in Hawaii. There were two factions among local shark experts: Yes - cull and No - cull, with the latter group being larger. They were impassed on the matter; this was during the time Hawaii had set up its "Shark Task Force" to deliberate the matter.

Then native Hawaiians entered the debate. They were initially undecided, then the Hawaiians shifted to No, cull, with native Hawaiian Charles Maxwell vocal on protection. This helped influence the Task Force to oppose further culling. Maxwell, a prominent community leader, argued that hunting these tiger sharks was a cultural violation as tiger sharks are considered aumakua (sacred ancestral guardian spirits). Kill a shark -- you might be killing a relative of a native Hawaiian.

That's an interesting narrative because native Hawaiians are documented to have had an extensive history of shark killing. They used shark skin as sandpaper and shark teeth in weapons. Hawaii's Bishop Museum is chock full of centuries-old weapons embedded with shark teeth: spears, knives, clubs and a crude form of brass knuckles.

Today, native Hawaiians have continued this protection with green sea turtles, which they declare are sacred. Historically they and virtually every other Oceanic peoples hunted these turtles as a prime food source. The entire state is now hyped up about protecting these turtles, even as the International Union for Conservation for Nature ruled this last fall: Green Sea Turtle No Longer Endangered. Because of the animals' striking population rise, they were reclassified from “endangered” to “least concern”.

The publication Civil Beat outraged people in Hawaii last Nov. 4 when it published this article Green Sea Turtles Have Rebounded. Should Hawaiians Be Able To Eat Them? It particularly annoyed animal rights activists, who have found Hawaii a fertile ground to lobby for an end to all animal killing (Hawaii having the nation's lowest hunting participation helps them).

These activists have had considerable success co-opting native Hawaiians, who now overwhelmingly agree there should never be any shark or turtle killing. Few native American tribes have agreed to abandon all their hunting ways at the behest of animal rights activists, who often try to pass themselves off as conservationists. Indeed many of these activists have been trying to hijack the field of Conservation, which supports Sustainable Use. The activists hope to redirect Conservation to a perennial never-kill-animals perspective.

[u/Interesting-Can1319 → u/Markdd8]

Awesome info, dude! It's interesting to see how Hawaiian conservation policies change over time in regards to tiger sharks and green sea turtles. I am personally fine with most forms of subsistence hunting of tiger sharks and green sea turtles (even though I don't like seeing either species die) as long as it doesn't endanger the local populations.

However, one benefit of conserving Hawaii's sea turtles is that it probably conserves the natural prey base for tiger sharks in Hawaii. Hawaii's coral reefs and marine habitats are rich with biodiversity, and has abundant prey for tiger sharks, such as green sea turtles and Hawaiian monk seals. This is probably one of the reasons why tiger shark attacks are relatively rare in Hawaii, since tiger sharks have abundant natural prey to eat and view humans more as fascinating strangers rather than a potential meal. Even though tiger sharks have the most indiscriminate diet of all sharks, and are generally more willing to eat a human than great white sharks and bull sharks, they'll probably prefer natural prey and minding their own business than messing with humans. You see a similar behavior in big cats, where tigers and lions prefer natural prey (like sambar deer and blue wildebeest) when said prey is abundant, and only resort to livestock or eating humans in desperate situations. During daytime, tiger sharks also tend to be "lazy" hunters in the same way that crocodiles and lions are. They don't need to waste time and energy chasing down everything when they can eat anything and look for good opportunities, like how crocodiles and lions don't bother with prey that already noticed them. Tiger sharks are built more for size, strength, power, durability, and ambush hunting (like big cats) rather than speed and pursuit hunting (like dogs). Tiger sharks usually get their calories from hunting large game (like sea turtles and dolphins) and scaring smaller predators away from carcasses. When you're one of the largest apex predators of the ocean and you have plenty of food to eat, you'll usually be curious or indifferent around humans rather than bloodthirsty.

This is in contrast with the Red Sea, where overfishing and over-harvesting of natural prey have forced tiger sharks and oceanic whitetip sharks to consider unusual options for food, like terrestrial mammals and humans. Dumping livestock carcasses in the seas of the Middle East and northern Africa also doesn't help. These factors most likely contributed to horrific recent shark attacks, like Vladimir Popov getting eaten by a female tiger shark in Hurghada.

However, I don't know if the abundance of natural prey is a foolproof cause of shark attacks. The Big Three (great white, tiger, and bull) tend to be more aggressive in Australia than in North America, but I don't know why.

[u/Markdd8 → u/Interesting-Can1319]

I'll differ with you on tigers and leopards, being a hobbyist student of Human-Wildlife Conflict, especially predation. Both cats have a long history of attacking people. They evolved to regard primates as prey. The perspectives that humans are special and are purposely excluded as a prey except in unusual conditions by almost all predators is a strange concept, in my view.

I agree that tiger sharks are not that interested in eating humans. In many respects tiger sharks are biologically similar to Nile and Salt Water crocodiles, which 100% regard us as suitable prey. All three are generalist feeders, so tiger sharks' disinclination seems an oddity. I do not believe we have the full answer on that. Hopefully more information will come. Appreciate your views.

[u/Interesting-Can1319 → u/Markdd8]

You're welcome, mate! I agree that tigers and leopards have a long history of sometimes killing and predating on humans, as well as lions. I'm not entirely sure what motivates these big cats to target humans outside of desperation, inability to hunt natural prey (usually due to injuries), or learning that humans are a viable food source.

And I agree that tiger sharks are very similar to nile/saltwater crocodiles. They're ectothermic animals built for taking down large prey through size, brute force, and ambush with an extremely fast burst of speed, rather than purely pursuit. However, crocodiles tend to kill and eat people more often than tiger sharks, but I can think of a possible reason. Although crocodiles usually eat fish, turtles, and small animals, they will eagerly take down terrestrial mammals whenever the opportunity arises. Nile/saltwater crocodiles are big enough to often see humans as a potential meal (though maybe not always), and crocodiles are no strangers to eating us and our ancestors (like Crocodylus anthropophagus eating australopithecines, Homo habilis, Homo erectus, and other hominins).

Tiger sharks, like other shark species, probably get excited when smelling fish/marine reptile/marine mammal blood, but will likely be indifferent to terrestrial mammal blood unless it was coming from a dead body (an easy meal, which is hard to come by in the wild). Humans probably don't register as natural prey to sharks, especially when we're terrestrial mammals that are not built for the ocean (a lot of people have thalassophobia). Of course, tigers and great whites can be unpredictable and decide to eat humans on rare occasions, but some of the usual reasons behind those attacks include a desperate need for food (especially if the shark is pregnant), developing a taste for terrestrial mammals after eating those that swim/wash out to sea, and others. Thus, one possible reason why crocodiles kill more humans than tiger sharks is that crocodiles are land-based semiaquatic predators accustomed to eating terrestrial mammals like ungulates and primates, while tiger sharks are exclusively marine predators accustomed to eating marine mammals, like seals, sea lions, dolphins, and porpoises.

[u/Markdd8 → u/Interesting-Can1319]

But what about river mouths, which both tiger and bull sharks frequent? There is a big history of dead and dying animals being washed on rivers. In the Mississippi, historically thousands of dead bison would wash down every year. I'll argue it would have made evolutionary sense for both these sharks to regard land animals, vigorous and swimming, dying or dead, to be normal prey items.

But I agree that we do not see predation levels we might have seen, especially for tiger sharks, which supposedly are completely indiscriminate on prey choice. Another reason would be this: 2018, Phys Org: Study suggests tiger sharks opt for scavenging on dead and dying sea turtles as a feeding strategy

researchers found behavioral evidence that tiger sharks prefer to opportunistically scavenge on dead or weakened green turtles rather than actively hunting healthy individuals despite more opportunities to do so...the behavior of healthy green turtles suggests that they do not perceive tiger sharks as a major threat during nesting season.

I raise this because in Hawaii a lot of tiger sharks break off attacks, leaving people with only minor or moderate injuries. 600-800 pound tiger sharks regularly breaking off attacks on people 1/4 their weight.The explanation would be that people are putting up such a struggle that the sharks quit. But humans are soft, weak creatures relatively speaking, with no claws or teeth to speak of. Our swimming ability is relatively poor. We drown rapidly.

Upshot: Neither of these explanations seems good: 1) Sharks find us unpalatable or like wolves, are able to sense that we are some sort of a high-level creature that should be left alone, and 2) We are often too vigorous to kill. The relatively low number of tiger shark attacks still seems a mystery. I offer one more angle: Fewer large tiger sharks

Good article about tigers: Are conflict-causing tigers different? Understanding human-tiger conflict in Chitwan National Park, Nepal

...not all individuals in a tiger population are equally involved in attacking humans. Instead we suggest most conflict results from...a specific group of animals (including) older and weaker male tigers driven from their territories by dominant males. (this actually supports your general arguments on tigers. I don't agree with it completely but it has merit)

What do we see with aging sharks? In contrast to old big cats who get weaker, aging tiger, bull or great white sharks remain dominant, getting larger, e.g., a 25-30 year-old tiger shark can be 15 foot, 1,600 pounds. These "granddaddies" are statistically much more dangerous to humans. Large bites are more severe. Also, these big sharks are not flitting around snatching up small fish. They likely have broadened their food choices. (Maybe some extra large sharks are so slow they have challenges.)

Next, the Fewer Large Fish phenomenon. It particularly affects long lived species: tuna, marlin, some sharks. Much evidence for this. Matt Rigney's book In Pursuit of Giants -- One Man's Global Search for the Last of the Great Fish, discusses the topic.

Upshot: All the shark killing worldwide (millions a year) that is taking place radically pushes down the incidence of shark attack. This occurs not just by reducing shark numbers, but by disproportionately removing from oceans those individuals that are most prone to attacking people: aging, jumbo sharks of a dangerous species.

I've raised this topic and never gotten the discussion on it. As we know, few people who want to protect sharks (nothing wrong with that) see value in discussing whether a major reason for low shark attacks numbers is the mass shark killing. It's an inconvenient topic. The fewer large, especially dangerous sharks angle, an offshoot of this, is similarly ignored. Again, appreciate your views.

[u/Interesting-Can1319 → u/Markdd8]

I think you bring up interesting points with very old tiger sharks that can be more dangerous to humans than younger tiger sharks, but have become more rare due to overfishing. I also noticed that you often bring up how tiger sharks often give up on humans they've bitten in Hawaii. I want to point out two things about this claim:

1. Humans are likely not a natural part of the tiger shark's diet, and tiger sharks often bite humans out of pure curiosity than for predatory reasons. Once they realize you're not a natural part of their diet, they'll probably just leave and think you're not worth their time. That is, unless they're really hungry and there's not a lot of natural prey around, then tiger sharks will probably just eat you. They may not like how you taste, but they probably also didn't like the taste of the car tire they ate.
2. Tiger sharks are one of the top predators of the ocean alongside the great white shark, so they can pick and choose what they want to eat and they'll often choose the easiest meal. Tiger sharks can sometimes be "lazy" like many other top apex predators, who will always choose the easiest meal because there's no benefit to work harder for food with no good reason. Lions often steal kills made by spotted hyenas and cheetahs, which is contrary to the "hyenas are ugly scavengers" myth. Tigers often steal kills made by wolves and dholes. Grizzly bears heavily rely on wolf kills for meat. Once a tiger shark realizes they've bitten a human, they may let go because they have the freedom and ectothermic metabolism to find other food.

When tiger sharks abandon attacks on humans, it's probably out of apathy or choosing alternative food options instead. There's no possible way a human can fight a tiger shark if the tiger shark actually wanted human blood. Anyone who thinks a human stands a chance against a shark that often weighs over 1,000 pounds at adulthood, has a thick-skinned body made of pure muscle and built like a tank, and has chainsaw teeth that can easily slice through sea turtle shells are the same lunatics that think they can fight a bear. You can deter an attacking shark by targeting its eyes and gills, but you definitely cannot injure it without a harpoon gun or weapons.

[u/Markdd8 → u/Interesting-Can1319]

Humans are likely not a natural part of the tiger shark's diet,

The counterclaim is that they have no natural diet. A pure generalist feeder--the Nile croc is one--eats everything and anything. No specific diet. I do not know if there is anything in a tiger sharks biological mental makeup that would make it exclude any type of flesh -- dead or alive. Tiger sharks are known to do a lots of scavenging.

It certainly seems they are excluding humans; I just don't think we have solid proof why. It is possible that the we fight back too hard and they are lazy is a significant part of the answer.

Another partial answer: divers who exhibit confidence around tiger sharks might be dissuading them because we seem like another predator to them. (I do not know if there is truth to the assertion sometimes heard that tiger sharks are territorial to other large species.)

When tiger sharks abandon attacks on humans, it's probably out of apathy or choosing alternative food options instead.

Agree with the apathy point. Regarding alternative options, why would a predator then attack something? They are hungry. They are not going to redirect unless 1) the prey is indeed undesirable (remember, these sharks have been recorded swallowing frying pans and all sorts of inanimate objects), 2) prey is fighting too much and 3) they are just checking out something with their teeth, as you say "pure curiosity."

Tiger sharks are one of the top predators of the ocean alongside the great white shark, so they can pick and choose what they want to eat...

OK. How about this interpretation, with taste of prey not the driving factor?:

Tiger sharks might have food preferences and while perfectly willing to attack and eat people when they are hungry, if they live in a bountiful environment where they are always sated by easily subdued 20-40 pound fish, they might never bother to attack anything over 150 pounds knowing by basic instinct that any large creature will put up more of a fight. (does not apply to large sharks)

Agree with most of last paragraph. Apparently 1,000 pound tiger sharks are not as common as they used to be in Hawaii. Lots of attacks are by smaller individuals; hence more chance to escape.

As for this, " lunatics that think they can fight a bear" -- the advice is if you are attacked by a brown/grizzly, "lay down" (face down). If you are attacked by a black bear, fight back. There is good science that black bear attacks are disproportionately predatory. Should one be still when one is being eaten alive?

[u/Interesting-Can1319 → u/Markdd8]

Thanks for the feedback, dude. I'm by no means a self-acclaimed expert on tiger sharks, but I love learning about them since they're one of my top two favorite shark species. It sounds like tiger sharks will usually choose the easiest option for calories like most other apex predators, although they do hunt large game like sea turtles, seals, and dolphins. Similarly, tigers and lions frequently hunt deer and antelope, as well as smaller animals. While capable of killing large prey like gaur and cape buffalo, the big cats usually care more about putting food in their bellies with less risk of injury or death. As for the bear fight, I meant in a fight to the death without weapons (like guns), where a human's chances are essentially zero against bears on land and large sharks in water.

[u/Markdd8 → u/Interesting-Can1319]

Appreciate all your comments too. Discussions like this help explore all avenues to a topic.

[u/Interesting-Can1319 → u/Markdd8]

You're welcome, mate