Patrolling the shores off the coast of Massachusetts is a conservation success story. Six great white sharks were recorded feeding on the carcass of a minke whale that was spotted this week floating belly up out at sea, prompting the state to close three of its most popular beaches as a precaution. By the next day, all that remained was in effect its skull and spinal column, with the sharks having feasted on the tongue, internal organs, and most of the muscle.
Researchers from the Center for Coastal Studies were impressed by the “rapid deterioration of the carcass” over just a 24-hour period, something that reflects the incredible rebound in great white shark numbers seen in the region over the last decade. Ranging from Newfoundland, Canada, to the Gulf of Mexico and northern Caribbean Sea, the sharks have benefitted from an increase in protection, as well as a boom in their main prey species, the grey seal.
Previous data, collected from accidental by-catch of the creatures spanning 210 years, has suggested that between 1986 and 2000, great white sharks suffered a rapid decline in numbers by as much 89 percent. In 1997, the animals were listed in the US as a “prohibited species”, protecting them from commercial and recreational hunting, although they are still reportedly caught in the controversial annual shark fishing competitions that occur along the Eastern seaboard. Either way, the protections seem to have broadly worked, with a massive increase in their sightings.
In fact, researchers now think they have established their migratory patterns along the coast for all age groups and sexes. The sharks seem to be spending their spring and summer in the cooler waters off the north-eastern states around Massachusetts, before heading south to the Gulf States for fall and winter. Research has suggested that the rebound in grey seal populations along the coast has helped boost their numbers, something that officials stress people should not be panicked by, but instead should be celebrating.
The good news coming from the coastal waters of the eastern United States is in sharp contrast to the conclusion of a recent study on arguably the most famous population of the sharks in South Africa. A comprehensive review of the creatures over a period of six years found that there were only between 350 and 520 great whites living in the waters surrounding Cape Town. “The numbers in South Africa are extremely low,” explained Sara Andreotti, who led the study published in Marine Ecology Progress Series. With only around 333 thought to be breeding adults, “the chances for their survival are even worse than what we previously thought,” concluded Andreotti.