The whales which have visited Scotland for 20 years

Andy Tait's image of minke whale Knobble

Conservationists have appealed for sightings of two whales they have been observing for 20 years.

Nicknamed Kasey and Knobble, the minke whales have appeared separately off Scotland's west coast each summer over the past two decades.

Hebridean Whale and Dolphin Trust (HWDT) said there was much to still learn about the species, including where the animals spend the winter.

Knobble has been seen more than 50 times since first being recorded in 2002, mostly around the Isle of Mull.

Minke are among the most common whale spotted off Scotland

Encounters with Kasey this year have included the whale surfacing next to a wildlife-spotting boat operated by Arisaig Marine.

Those on board were able to see the whale's distinct dorsal fin, which has three nicks along one edge.

First photographed in 2000, Kasey has been seen more than 30 times during the past 21 years.

HWDT has asked the public to send it images of the whales, as well as photographs of other whales and dolphins spotted off Scotland's west coast.

The pictures - provided they have been taken while following rules aimed at preventing any harm to the animals - can be used by scientists to better understand the movement and behaviour of marine creatures.

Knobble has been spotted more than 50 times of Scotland's west coast

HWDT said whales and dolphins have distinct dorsal fins that can be used to identify an individual, much like human fingerprints.

The trust said by curating catalogues of the individual whales and dolphins found off the west coast, it can build a "deeper understanding of these enigmatic creatures".

Pippa Garrard, of HWDT, said: “If you’ve got any photographs or videos of whales on the west coast of Scotland, past or present, please get in touch.

"Your photos help us to build a long-term picture of whale movements in Scotland and show if individuals favour particular areas."

She added: "They can also teach us about the health of individuals, and we can learn more about the threats that they face."

Scientists use photographs to identify individual whales and dolphins. This dolphin was photographed near North Berwick on Scotland's east coast

Minke are among the most common whales spotted around Scotland.

They can grow to 9m (29ft) in length and can live for up to 50 years.

The whales feed on fish, including herring, sand eels and sprat.