Stunning footage has been captured of a critically endangered shark swimming at a gas field in the UK North Sea.
The large predator, known as a porbeagle, was seen on camera during a diving operation at Shell’s Shearwater field, around 140miles east of Aberdeen.
They are among a number of large sharks and rays which are endangered in Europe, primarily due to over fishing in the late 20th century.
A Subsea 7 diving operation spotted the shark earlier this month at Shearwater, a bridge-linked platform which serves as a production hub for a number of surrounding fields.
Professor Paul Fernandes, chairman of Fisheries Science at Aberdeen University, said these large structures can often act as good feeding grounds for predators.
He said: “As large three dimensional structures in the sea, oil platforms can act like reefs, providing opportunities for a variety of animals and plants to grow.
“This has given rise to the term ‘rigs to reefs’ whereby, in the United States for example, oil rigs are converted to artificial reefs. These support thriving underwater communities, culminating in large aggregations of fish, much as natural reefs do.
“It is no wonder then that large predators, such as porbeagles, then seek out these more productive areas for feeding opportunities.”
Professor Fernandes added that this provides further evidence that rigs could be beneficial to the marine environment, raising the “controversial” question of whether they should be cleaned and left in place as artificial reefs, rather than be fully decommissioned.
The Marine Conservation Society lists the porbeagle shark as “critically endangered” due to extensive fishing in the 1960s and 1990s which led to dramatic declines, particularly in the north-east Atlantic.
Despite this, however, there have been other recorded sightings of the porbeagle in waters off the UK.
A former student of professor Fernandes, Janne Haugen, earlier this month published a paper on the “unusual observation” of a minimum of 20 porbeagles being spotted circling the Alba platform in the central North Sea in 2014.
Last year subsea firm DeepOcean also spotted one of the sharks at the Skarv field off Norway.
Protections have been in place for the porbeagle since 2010.
Professor Fernandes added: “Sharks are particularly vulnerable to a number of threats, such as directed fishing or bycatch, because compared to fish they produce few offspring and only become mature at a relatively old age – up to 20 years old for females.
“This is the case for many of our sharks and rays, the so called megafauna.
“There has not been any commercial fishery for porbeagle in Europe since 2010, but they were fished fairly intensively in the late twentieth century, mainly by Canadian and French vessels; relatively small amounts are still caught in the North Atlantic by Norwegian and American fishing vessels.”