A new study has documented unexpected consequences following the decline of great white sharks from an area off South Africa.
A new study has documented unexpected consequences following the decline of great white sharks from an area off South Africa. The study found that the disappearance of great whites has led to the emergence of sevengill sharks, a top predator from a different habitat. A living fossil, sevengill sharks closely resemble relatives from the Jurassic period, unique for having seven gills instead of the typical five in most other sharks.
These findings are part of a long-term collaborative study between shark researcher Neil Hammerschlag from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, and wildlife naturalist Chris Fallows from Apex Shark Expeditions.
The research focused on the waters surrounding Seal Island in False Bay, South Africa, a site well known for its “flying” great white sharks that breach out of the water when attacking Cape fur seals. Since the year 2000, the research team has spent over 8,000 hours observing great whites from boats, during which they recorded 6,333 shark sightings, and 8,076 attacks on seals.These data revealed that for more than a decade, great white numbers were relatively stable, but in 2015 sightings began to drop off steeply.
Read more at Rosenstiel School of Marine and Atmospheric Science
Image: The waters surrounding Seal Island in False Bay, South Africa, are known for great white sharks breaching out the water in pursuit of seals (left image), but the recent disappearance of great whites from here has led to the emergence of another apex predator, sevengill sharks (right image) that now dominate the area. CREDIT: White shark image by Chris Fallows; Sevengill shark image by Neil Hammerschlag.
