RPubs – SACGB Blue Shark tagging returns

The great ocean wanders, the travels of Blue Sharks tagged by boats from Looe.

Blue Sharks are known as great travellers, one satellite tagged specimen travelled over 18,000 mile in 952 days, and fish captured from Looe in the summer may be off the west coast of Africa by the winter. Results from a tagging study carried out from Looe between 1998-2010 reveal just how far these fish can move during their annual migrations. One female blue shark captured on Aries was recaptured over 4000 miles away, nearly two years later off the south coast of Venezuela. Another female fish caught by Morning Glory travelled nearly 30 miles per day before being recaptured 89 days later on the seamounts SE of Maine. Both these values are straight line distances, so the actual distance travelled by these fish would be far greater.

Blue sharks are estimated to live for somewhere between 20-25 years and one mature fish, captured on Aires in 1999 was recaptured 16.5 year later between the Canary Islands and the Azores. As the fish was already five years old when first captured, this grand old lady was probably over 22 years old when recaptured!

The information gathered by a simple tagging study has produced both scientifically important and interesting information on the travels of the great ocean wanderer that is the blue shark.