William McKeever

I'm giving up on this one. It's interesting, and I was enjoying it quite a bit but I got to the spot where there's a pretty upsetting description of people torturing a shark (it's made clear that what they did is animal cruelty, not simply fishing/killing for food or even sport) and given my current tolerance for things that are Bad right now I kind of put it down and haven't wanted to pick it up again. I may try it again in the future, as I was enjoying it, but for now I'm moving on to something a bit lighter.… (plus d'informations)

It is quite remarkable that in 2019 we still don’t know much about sharks. We know little of their mating habits, their territories, their abilities,their lifespans, their value in ecology and in dollar/ecotourism terms. William McKeever goes a long way to filling in the gaps in Emperors of the Deep.

There are about 400 species of shark left that we haven’t totally obliterated. At 400-600 million years, sharks are among the oldest survivors. They have come in a literally unbelievable variety of shapes and sizes, including one with an upright buzzsaw of teeth in its mouth, and of course the hammerhead, with one eye at each end of the T. Some work in packs, some are loners. McKeever examines them closely, giving an entire chapter to each of the Big Four.

The great white shark is a traveler, a nomad. Scientists attach trackers to their dorsal fins, and find them crossing the Atlantic or from California to Hawaii and back like it was a stroll. Another was tracked in a straight line from South Africa to Australia and back, racking up about 70 miles a day. Tens of thousands of miles are in their territories. They go deep. Great whites think nothing of swimming at a mile of depth, and can rise or dive with total comfort and ease and dizzying speed.

The mako is the top predator. It is a speed demon with extraordinarily sharp senses of smell and electro-sensitivities. From its pointed head to its powerful body, it is a streamlined predator. It can track prey for hours, making a final sprint at up to 45 mph. Tuna, the bullet of the seas, is its main target. McKeever tells the story of a gigantic 1323 pound mako, caught (and tortured to death). It had an entire sea lion in its stomach, which it had fought and swallowed whole a couple of days earlier. Fighting for its life on a line, a mako will jump 20 feet out of the water, several times. Makos have such a large range they can run afoul of 19 different jurisdictions in their territory, and the chance of a mako being killed in the north Atlantic in any year is a worrying 30%.

Hammerhead sharks are possibly the most unusual of animals. Their T-shaped heads have eyes on the ends. The bigger they are, the more their vision overlaps, giving them better and better depth perception. The front of the head also contains a series of noses. As the shark swims, it passes water through the sensors, giving it not just recognition but direction for the source. To maximize the tool, the hammerhead sweeps its head back and forth as it swims, like a blind person with a cane. With such good vision, it prefers the shallows, where the bottom is visible. Others, like the great white, rely on other senses, and swimming through total blackness is no bother.

Tiger sharks are the clever ones. They track, corner and ambush prey. They like to see, but not be seen. Their teeth are a sort of A or Y shape, differentiating them from all other sharks. The force of their jaws is rated at 3 tons per square centimeter, which McKeever says is the weight of two cars applied to one spot. Combined with the serrated teeth, this is a killing machine.

Shark numbers are down 75-80% over the past 15 years. They are roadkill, called bycatch in fishing terms, of nets and hooks meant for others. They are also caught illegally 24 hours a day by mostly Asian fish processors, simply for their fins, used in a largely tasteless soup that can go for up to $25,000 a bowl in China. The still-living tubes that are their bodies are dumped back into the ocean where they fall to the bottom and drown.

There is a dramatic chapter on slavery, in which Asian men are kidnapped for fishing vessels that may not put to shore for years at a time. They are regularly beaten, kept awake with drugs, and worked 20 hours a day, while being fed next to nothing outside of fish scraps. When necessary, they are simply dumped overboard. The boats can fish for years not just because labor is free, but because there are gigantic reefer ships – floating fish freezers and processing plants, that they can transfer their catch to when their little boats fill up. It’s an evil system that is rapidly depleting the oceans of sharks, tuna and numerous other species. They like to carry flags of multiple nations in case they are inspected, which is quite illegal itself. They like to export to Western countries, which put all kinds of legal restrictions on fishing, for sustainability reasons. Odds are high you have bought fish (even just canned tuna) caught by slaves.

A real problem is some sharks’ remarkable range. A few countries protect them, some simply welcome them, and some have nothing to say. Passing from jurisdiction to jurisdiction, sharks are terrifically at risk. A hundred million are killed each year. Unlike other fish however, sharks don’t spread a million eggs out for sperm to fertilize. They nurture 12-20 young in pregnancies that last nearly two years. Some give birth to just two at a time. The math says this cannot go on much longer.

Sharks sense movement with their sight when possible, with smell, and with electrosensors that receive signals of movement. Any sort of disturbance under water will bring them to investigate. They don’t simply attack anything that moves, either. They know what they want and when they want it. There are legions of stories in which men faced sharks, and the sharks simply wheeled and left the scene. The number of shark attacks of swimmers is so tiny as to be meaningless, especially considering how many more millions of people flock to the beaches and seas today. Culling sharks does nothing to lessen the number of attacks. It just unbalances the ecological matrix of the oceans, McKeever says.

There is an excellent chapter on the cascading effects and unintended consequences of shark reduction around the world. In example after example, McKeever shows that the reduction or removal of the top predator has results that ricochet right down to sea grass, which feed and shelter innumerable species in the food chain. By keeping the middle-sized predators in check, sharks prevent them from clearing out the coral reefs, mangrove swamps and shore grasses which nurture life in the oceans. They are the vultures of the deep, cleaning up whale carcasses, picking out the diseased and the weak fish, and so helping other species to improve and increase. Taking sharks out of the equation upsets the whole balance, making coral reefs barren dead zones. Their role is critical.

McKeever has done a remarkable job of assembling this knowledge, traveling the world, and seeing for himself. Sharks have been his passion since childhood, and it shows. Emperors of the Deep is both respectful and personal. He ends with the sadly obligatory calls for greater vigilance, tighter laws, more co-operation and better appreciation to save the shark from extinction and the planet from having to go on without them. After half a billion years, they deserve better.

David Wineberg… (plus d'informations)