Scottish sea anglers have tagged more than 20 of a critically endangered species of shark during a unique two-day marathon aimed at putting pressure on the government to create special marine reserves to help protect dwindling stocks in UK waters.

About 100 volunteers gathered in Loch Sunart in West Lochaber and Loch Etive in Argyllshire at the weekend to undertake the tagging of spurdog, a breed of small shark commonly called "rock salmon" and noted for its slow growth and longevity.

Among those captured, tagged and returned was a specimen weighing over 21lbs (9.5kg) - laying claim to a new Scottish boat record.

Steve Bastiman, chairman of the Scottish Sea Anglers Conservation Network, said yesterday: "The event was an outstanding success and is a testament to the commitment and dedication of sea anglers in Scotland."

The conservationists now plan to raise £25,000 to launch a satellite tagging study to monitor movements of the spurdog.