The actual act of culling is often inhumane and cruel. Drumlines with baited hooks can ensnare sharks for days at a time before they eventually die, causing extreme suffering and distress. Even shooting the trapped animals does not always result in a quick and painless death.

Slow-moving fish and turtles and shellfish beds are often decimated by the rough undercurrents and rapid changes in water temperature and salinity wrought by a hurricane. Sharks, whales, and other large animals swiftly move to calmer waters, however, and, generally speaking, are not overly affected by hurricanes.

Despite their scary reputation, sharks rarely ever attack humans and would much rather feed on fish and marine mammals. Only about a dozen of the more than 300 species of sharks have been involved in attacks on humans. Some of the larger shark species prey on seals, sea lions, and other marine mammals.

But even at the lower end of the estimates, a 272-year lifespan makes the Greenland shark the longest-lived vertebrate. One theory to explain this long lifespan is that the Greenland shark has a very slow metabolism, an adaptation to the deep, cold waters it inhabits.

It all comes down to the photoreceptors they’ve got in the retinas of their eyes. Like humans, sharks have both rods and cones in their retinas that are stimulated by light. But even species of shark which have quite high cone numbers, like the common black tip shark and the bull shark, can’t see colour.

Sharks don’t see red. A new study by scientists in Australia shows that sharks don’t see their world as we do. What’s the view like through the eyes of a shark? However, we found that sharks have only a single cone type and by conventional reckoning this means that they don’t have color vision.

Sharks have an acute sense of hearing and are sensitive to low-frequency signals. They’re able to track sounds and are particularly attracted to sounds made by wounded prey. Their ears are located on either side of their head, behind the eyes.

Since sharks see contrast colors, anything that is very bright against lighter or darker skin can look like a bait fish to a shark. For this reason, he suggests swimmers avoid wearing yellow, white, or even bathing suits with contrasting colors, like black and white.

Yes, shark meat is legal for consumption in the United States. That said, shark meat is not particularly popular in America because many species found off American shores are endangered and shark meat has also been known to contain high levels of mercury in some cases.

Shark species are nondescript in colour, varying from gray to cream, brown, yellow, slate, or blue and often patterned with spots, bands, marblings, or protuberances.

Dr Gruber had the shark’s vision analysed by experts at Cornell University and discovered that it can only see blue/green hues which he says is a perfect adaption for the environment it lives in.

The researchers suggest the sharks’ glowing underbellies may help them hide from predators or other threats beneath them. They say the bioluminescence is achieved through thousands of photophores (light-producing cells) located within the sharks’ skin.

Both it and the swell shark are the only sharks known to give off a green glow when exposed to light. When an atom of the element bromine tags along, this kynurenine releases a green glow when exposed to the blue light below the ocean’s surface, the team reports today in iScience .

The ocean has tons of blue light that can be absorbed and then turned into a lower energy green or red light, hence why these two sharks glow green. The brilliant research was recently published in the journal iScience.