Basking sharks are the second largest fish in the world. They can reach lengths up to 10m, and have previously had a reputation for being slow and languid as they scour the sea for their staple diet of plankton. Hundreds of basking sharks live off the shores of Cornwall, Ireland and Scotland.

Researchers used video analysis for basking sharks and great white sharks to estimate vertical swimming speeds at the moment of leaving the water. They also fitted one large basking shark with a data recording device to measure speed and movement.

At one point during the deployment of the recording device, in just over nine seconds and 10 tail beats, the basking shark accelerated from a depth of 28m to the surface, breaking through the water at nearly 90 degrees. The shark cleared the water for one second and peaked at a height of 1.2 m above the surface.

Athletic speeds

To achieve this breach, the basking shark exhibited a six fold increase in tail beat frequency and attained a top speed of approx. 5.1 m/s. This is more than twice as fast as the average competitor in the Olympic men’s 50m freestyle swim.

The videos of basking sharks and great whites breaching showed similar speeds of breaching in other individuals. The basking shark videos were recorded in 2015 at Malin Head, Ireland. The white shark videos were recorded in 2009 at two sites in South Africa, during predation attempts on Cape fur seals using seal shaped decoys.

Lewis Halsey, a reader in the Department of Life Sciences at the University of Roehampton and one of the scientists involved, said: “The results of the research put the basking shark in a new athletic light.

“While there are no recorded incidents of them being of danger to swimmers or small boats, unlike the great white shark, we now know they do have an impressive ability to swim at great speeds and jump clear of the water.”

The research team comprised Queen’s University Belfast, University of Roehampton, Trinity College Dublin, University of Cape Town, Irish Basking Shark Study Group and the South African Institute for Aquatic Biodiversity.

This Author

Marianne Brooker is a contributing editor for The Ecologist. This story was based on a press release from the University of Roehampton.