YouTuber Drops Camera Into London’s River Thames, Finds Invasive Species

The River Thames is one of the most famous rivers in the world, but what goes on beneath its waters? A YouTuber recently dropped a few cameras into the deep to find out.

However, the River Thames in Central London is notoriously brown and murky because it is a tidal river, meaning water is constantly moving sediment around from the riverbed and estuary. In other words, it’s a terrible place to drop a camera.

So, YouTuber Barny Dillarstone, who previously dropped cameras in the Indo-Pacific region, turned his attention to the many dock systems that run adjacent to the River Thames.

After spotting a large pike, he tried dropping his camera. But even in the Thames basins, there is sedimentation. And all Barney managed to film was a freshwater mussel jetting water, which it does for reproduction, feeding, and waste removal.

Barny headed further upstream, outside of the city. It’s where he came across his first invasive species: signal crayfish.

The Secrets of Big Rivers

“They were first introduced to Europe in the 1960s after being bred on farms for restaurants to serve as a delicacy,” Barny explains.

“But like the mitten crabs, they possess a number of behavioral traits that make them bad news for British water systems.

“Firstly, they can burrow deep into the riverbank, causing erosion and collapse. They also predate native species and outcompete them for food and space, like the native crayfish, the white-clawed crayfish.”

Barny says that while it’s rare to find white-clawed crayfish in the same area as signal crayfish, he might have filmed the two species together, but the infrared light spectrum makes it hard to tell.

However, what Barny didn’t film was large river fish. He speculated that his infrared lighting system might be putting off the larger species, as it emits some visible red light.

“I wonder if those big fish can see it and stay away,” he says. So, Barny installed a camera during the day to see if big fish approach without the light.

During the day, he captured pikes, a barbel, river chub, silverfish, perch, and an enormous Thames carp.

As night fell, Barny glimpsed his second invasive species: a Chinese mitten crab, a furry, clawed crustacean that found its way to Europe from Asia and is “silently eroding riverbanks and outcompeting native species.”

But eventually Barny did record a massive river fish up close, a large barbel. It was a relief, as now he knows that the “infrared cameras are discreet enough to film big freshwater fish at night.”

The YouTuber plans to keep discovering the secrets of big rivers. For more of his adventures, check out Barny’s YouTube channel.