Thanks to satellite tracking technology, we now know how Britain's basking sharks spend their winters.
Basking sharks often spend most of their time far from land and little time at the surface of the ocean, so little is known about where they migrate to during winter. A study by University of Exeter has shed some light on this, revealing that some of them stayed in the waters off Spain, Portugal and North Africa, while others headed for the Bay of Biscay or remained near the UK or Ireland.
The results of the study have been published in the latest issue of Scientific Reports.
"Knowing where these animals are all year round allows us to understand the threats they face," said lead author Philip Doherty, of the Environment and Sustainability Institute at the University's Penryn Campus in Cornwall.
The researchers also noticed that the basking sharks that swam south left in the late summar and returned in spring and early summer.
"We don't yet know whether individuals make the same migration each year or alter their behaviour based on factors such as body condition, reproduction and food availability," said senior author Dr Matthew Witt, also from the University of Exeter.
Dr Suzanne Henderson, of Scottish Natural Heritage, co-funder of the research, added: "This is shedding new light on their seasonal residency and winter migration, which is key to their conservation."
A total of 70 basking sharks were tagged in the research. The results were gleaned from the 28 tags that continued transmitting after five months.