It came ashore close to Scrabster, near Thurso.
The Scottish Marine Animal Stranding Scheme (SMASS) is to investigate the animal's death.
It is the latest incident of its kind in about a month with photographer Gavin Bird, who is based in Caithness, capturing the latest fatality.
Fishing gear, including a buoyancy aid and a piece of rope, can be seen wrapped around the animal.
SMASS said entanglement in fishing gear is a global problem.
Scottish waters offer a world-class fishing ground for creel and trawl fishermen as well as a habitat for a diverse range of large marine animals, the organisation said.
It added: "Unfortunately these animals sometimes become entangled in fishing gear, and the consequences of these interactions can have conservation, welfare and economic implications.
"Entanglements can impair an animal’s ability to breath, feed, swim and reproduce, and have been recognised as the main cause of death of minke whales in Scottish waters.
"Other species including orca, humpback and northern bottlenose whales have also died in our waters as a result of interactions with fishing gear."