In the Name of Sharks

In this stimulating primer, oceanographer Sarano (Oceans) reflects on diving with sharks and surveys the “scientific research on their biology and their exceptional sensory system.” Sarano recalls his most notable dives, including a 1987 voyage off the coast of Australia, where he became the first to observe that the small epaulette shark “uses its pectoral and pelvic fins as legs” to walk on the ocean floor, “a bit like a lizard.” Highlighting the diversity of the shark world, he notes that the 18-meter-long whale shark is “a hundred times the size of the dwarf lanternshark... which is only eighteen centimetres long.” Elsewhere, Sarano serves up fascinating trivia on shark reproduction (the Greenland shark only “reaches sexual maturity at around 150 years”) and “electrosensing,” or the ability to sense the electrical activity of neurons and heart muscle cells, allowing sharks to “easily detect an immobile organism buried in the sand, invisible to ordinary predators.” Sarano’s deep reverence for his subject undergirds his passionate account of how harvesting millions of sharks each year for their fins and liver oil (which is used in beauty creams) has put more than a third of all shark and ray (their close cousins) species at risk of extinction. Wide-ranging and accessible, this is worth diving into. Illus. (Jan.)