So I asked leading shark ethologist and behaviourist, Professor Samuel 'doc' Gruber to elaborate. After pointing out how much pain women feel when they give birth, making the point that suffering has no effect on reproduction, he reminded me that sharks evolved their mating behaviours and the physical structures involved, separately from other animals.
Researchers from James Cook University's ARC Center of Excellence for Coral Reef Studies examined stomach contents of reef sharks and conducted chemical analyses of shark body tissue to find out what they had been eating.
Somewhat surprisingly after pumping sharks' stomachs to identify the contents of the last meal, the most common thing to find was in fact, nothing. "These results suggest that reef sharks eat small meals infrequently and opportunistically," Lead author, Dr Ashley Frisch said.
The paper presents the reasons why large predators of great ecological importance cannot supply the rising demand for shark fins, which is driven by profits that rival the drug trade and involves the fisheries of nations around the globe. They have essentially run out of fish so are targeting sharks now that the shark fin trade has made them valuable.
Development of a vaccine against Covid-19 could come at the expense of sharks, researchers warn; A key ingredient used in vaccines to enhance immune response and increase effectiveness, squalene — an oily substance found in plants and even human skin — is particularly concentrated in shark livers.
Many divers dream of the day they find themselves swimming beside a whale shark. Its gentle demeanour and huge size presents a unique humbling experience that is second to none.
Yet, there is much we still do not know about whale sharks.
Today, one of their hidden mysteries have been unlocked–their age.
Until recently, it was hard to fix a number to their age, as they do not have bony structures (otoliths) which are traditionally used to calculate the age of fish.
What we see is that sharks are being targeted by international factory fleets around the world who trail millions upon millions of baited hooks through their realm, trawl the sea floors for rays, skates and other bottom dwellers to 4,000 metres, and slaughter them by the millions. Sharks are the only profitable prey remaining, now that ninety percent of the original (fish) fisheries are fished out.
For the study, an international team led by researchers at KAUST's Red Sea Research Center collected a total of 88 mucus samples from the back and gill skins with lesions as well as from healthy skins of 44 wild-caught blacktip reef sharks caught in the wild around the Seychelles Islands.
Researchers sequenced the samples to identify the bacteria present in them, then compared the samples from the different sharks and tested them to detect changes in response to injuries.
The shortfin mako shark fishery of the north Atlantic is one of those that fisheries scientists have claimed to be potentially sustainable. It has been used to promote the idea that all shark fisheries can become sustainable, with the United States in the lead.
But in the meantime, the species has become globally endangered, and now, when other countries are urgently fighting for protection for the shortfin mako shark, the United States and the European Union have blocked it at the annual meeting of the International Commission for the Conservation of Atlantic Tunas (ICCAT).
Standing on the swim step, trying to time my entry with a gap in the dozen or more lemon sharks circling directly below me was a bit daunting the first go around. Of course, the sharks knew this routine well and skillfully avoided my clumsy splash into the water. The reward waiting beneath the surface was an assemblage of sharks that cannot be collectively encountered anywhere else in the world.
Tiger Beach in the Bahamas is firmly established as one of those global dive destinations of which almost everybody has heard. Its fame is largely derived from the many published images of its most celebrated visitor—Galeocerdo cuvier, the tiger shark.
“You’re crazy; I don’t get in the water with bitey things!” The announcement of my impending great white shark trip drew a variety of such responses from horrified friends. The undisputed bad boys of the shark world, great whites are the largest of all predatory sharks, reaching lengths of up to 6m and weighing in at over 2,000kg.
