Sperm Whales: Magnificent Moby!
S.O.S.! The call came in to The Marine Mammal Center: a small whale had stranded by the marshes in Richmond, in San Francisco Bay. On arrival we stood, unbelieving: it was a newborn sperm whale, Physeter microcephalus, perhaps 14 feet long. We stabilized the calf, its fetal folds still intact, as the veterinarian administered Whale First Aid: B vitamins and steroids, and took blood and tissue samples. Unable to take it into captivity, we gently floated it towards open water, hoping its mother was nearby. Sadly, three days later it washed up dead beneath the Bay Bridge. The necropsy revealed severe scoliosis—a spinal malformation, and other problems. Sperm whales prefer very deep offshore waters; this remains the only recorded instance of a living sperm whale in San Francisco Bay.
A WHALE OF DISTINCTION: Immortalized in Melville’s “Moby Dick,” sperm whales embody magnificence. They are the largest toothed predator on the planet. Males achieve lengths of 62 feet, weighing upwards of fifty tons. They dive to over 7,300 ft., second only to the Cuvier’s beaked whale. Their huge “boxcar” heads contain the largest brain on Earth, although much of it goes to processing echolocation sounds. Giant squid, octopus, and fish comprise their diet. The California/Oregon/Washington sperm whale stock, estimated at 1,997 whales, is found mainly from April through mid-November, though some remain here year-round.
LOVING LEVIATHAN: Like most toothed whales, sperm whales have complex, highly structured societies. New mothers are attended by ‘aunties’ who share calf care-giving, remaining at the surface while Mom dives deep to hunt and replenish her energy stores; she has nursed her calf with incredibly fat-rich milk. Cows give birth at four- to ten-year intervals, sometimes caring for calves for a decade. After mating with the females, who remain in groups with immature males at temperate and tropical latitudes, bulls retire to high-latitude waters. They are cosmopolitan, found worldwide.
THE HUNT: Sperm whales were prized for their precious ambergris for pharmaceuticals and perfumes, their “ivory” teeth for carving, and their high quality spermaceti oil for specialized machinery. More mundane uses were as cattle feed and bone meal.
When the world whaling capital shifted from New Bedford and Honolulu to San Francisco around 1880, fast steam-powered boats with explosive harpoons proved lethally efficient. In 1919 there were sufficient gray, humpback and sperm whales to keep whaling stations active along the North-central California coast, including Crescent City, Humboldt, Pt. Arena, Bolinas, Pigeon Pt., Santa Cruz, Monterey Bay. The hunt continued, but with diminishing harvests, as stocks plummeted. Whalers were fishing themselves out of business.
FIDO FOOD: In the 20th century the development of plastics, the petroleum industry, and other whale product replacements made whaling increasingly unprofitable. However, the mid-20th Century gave rise to nuclear weapons and a burgeoning pet food industry. In the 1970s spermaceti oil was used in auto transmissions, and sold to the nuclear industry for weapons production. In December 1971, the KalKan pet food company commissioned a hunt into the Gulf of the Farallones off San Francisco, killing a sperm whale—the last whale to be hunted commercially under the U.S. flag.
PROTECTION: In 1946 the International Whaling Commission was established to regulate and keep whaling viable, but with the Marine Mammal Protection Act of 1972, American whaling was banned.
SURVIVAL! Killer whales (and humans) are their only natural enemies. Besieged sperm whales will use their big heads as battering rams, also wielding their jaws and flukes as weapons. Groups will surround their young or weak in a “marguerite daisy” rosette: heads-inward, powerful flukes pointed outwards towards attackers. These clashes may represent the most formidable battles of might, ferocity and wits ever to take place among creatures of the sea!
Human threats include vessel strikes, fishing gear entanglement, ocean noise, marine debris and pollutants. Climate change could affect prey availability, especially within Arctic and sub-Arctic ecosystems. But their extremely wide range – perhaps the greatest of any mammal – may confer resilience.
CONSERVATION: NOAA Fisheries and our national marine sanctuaries work to reduce these threats through protective legislation and other conservation efforts. Learn more about sperm whale biology, society, ecology and conservation at:
https://www.fisheries.noaa.gov/species/sperm-whale; sounds at https://swfsc.noaa.gov/textblock.aspx?Division=PRD&ParentMenuId=148&id=5776
https://www.youtube.com/watch?v=SkBpummjR5I & https://www.britannica.com/video/180340/diver-sperm-whale
