Updated 6pm

A shark spotted in the sea off Sliema in a video shared on Friday sparked debate over whether it was a great white or a blue shark.

The footage shows a fin breaking the surface of the water, with the body of the shark visible below the surface in parts of the video.

The video was uploaded on Friday afternoon with the person who posted it saying it was shot close to 1926 La Plage Beachclub in Tigne.

Speaking to Times of Malta, National Aquarium curator Daniel De Castro said he believed it was most likely a great white shark.

"The way it comes out of the water from beneath is very typical of a great white. The wide triangular dorsal fin and notch on the tail are other tell-tale signs", he said, after inspecting the video.

Castro said there was a possibility that it was a mako shark, but the fact that it was so close to shore made it more likely to be a great white. Great white sharks can be dangerous to humans, but attacks are very rare.

The shark is shown maintaining a stationary position in the water, leading some to question whether the animal had become entangled under the surface and was unable to leave the area. However, Castro said the fish was not exhibiting any behaviour to suggest so.

Marine biologist Alan Deidun noted that while it was hard to ID a shark from such footage, he believes it is most likely a shortfin mako or, at most, a porbeagle. However, the former is more probable given its agility and ease of manoeuvre.

"Both candidate species are critically endangered in the Mediterranean, and hence we are a threat to them and not the other way round," Deidun warned.

Castro added that the shark could have picked up the scent of food, such as a dead tuna, and swum close to shore.

The scene where the video was taken was shark-free when a Times of Malta photographer arrived on Friday afternoon, but no one was daring a dip in the rough water. Photo: Jonathan Borg

Shark expert Alex Buttigieg, better known as the Shark Man, said he did not believe it was a great white, but was almost certain it was a blue shark or possibly a shortfin mako.

"What is interesting is the fact that it seems to be feeding on something. It's a pity there is no better footage," he said.

Greg Nowell, founder of Shark Lab Malta also said he believed it was a blue shark, which is not generally considered dangerous to humans.  

"I'm basing this on movement in the water, but more importantly, the shape of the upper part of the tail... It's a rare sight being so close to shore."

"We know people label great whites with a negative reputation. Bottom line is sharks are not interested in people. We should be grateful for the sighting. We need them in our seas maintaining balance," Nowell said.

The Meteorological Office forecast was showing south-westerly wind speeds of eight knots in Msida at the time of publication, meaning the currents could have helped push the fish towards the shore.

In January, Malta emerged as a significant contributor to shark conservation in the Mediterranean in a study on the subject. 

With 27 actions, policies and initiatives implemented to protect various species of sharks, rays and skates, Malta placed fifth behind Spain, Greece, Italy and Croatia. 

The most notable previous encounter with a great white shark occurred in April 1987, when fisherman Alfredo Cutajar caught what is believed to be the largest great white shark ever recorded, measuring approximately seven metres in length and weighing about 2,300 kilos.

This catch was made near Filfla.