Russia stepping up security at Black Sea base with spy dolphins, says UK intelligence

New defences near the Sevastopol Black Sea fleet base include at least four layers of nets and booms across the harbour entrance, says British intelligence. Photograph: Russian Black Sea Fleet Press Service/Reuters

Russia is stepping up security at its Sevastopol Black Sea fleet base by deploying trained dolphins meant to detect and “counter” enemy divers, British intelligence has said.

A report made by the UK defence intelligence agency says that the Russian navy is investing in major enhancements to the Black Sea fleet’s main base in Sevastopol, a port on the occupied peninsula of Crimea.