How underwater robots shine a light on sharks

Deep in the waters of the Gulf of Mexico, sunlight cannot permeate and temperatures are close to freezing. Perhaps it’s unsurprising that little has historically been known about the creatures living there.

But with help from the energy industry, marine scientists are gradually unveiling more secrets about underwater life.

Shell and other energy companies have offered access to underwater robots known as Remote Operating Vehicles (ROVs), which are controlled from the surface and equipped with cameras, powerful beams of light and robotic arms. The machines are capable of exploring life thousands of metres below sea level, and have led to the discovery of new species.

“These underwater vehicles are our eyes in the sea,” says Mark Benfield, Professor in the Department of Oceanography and Coastal Sciences at Louisiana State University in the USA. “They enable us to explore the largest habitat on the planet, most of which is still unknown to science.”

Their sightings include sleeper sharks, which can lurk at depths as low as 2,700 metres (9,000ft). Benfield believes many sightings may be of one of six such species, the Greenland shark. Because the species are similar in form, the only certain way to identify them is through DNA testing.

Greenland sharks are thought to live up to 200 years. They swim very slowly, reaching a top speed of about 2.6 kilometres per hour (1.6 miles per hour). In cold latitudes, they are usually seen close to the surface, but in the warmer Gulf of Mexico they swim close to the seabed where the water temperature is about 4° C.

Studying deep-sea marine life

Gaining access to ROVs can be challenging for marine scientists. The vehicles are expensive and only a few are owned by academic institutions. Oil and gas companies, however, have many, and allow scientists like Benfield to borrow them whenever the vehicles are not otherwise in use.

This collaboration between academia and the deep-water oil and gas industry is known as SERPENT, which stands for Scientific and Environmental ROV Partnership using Existing Industrial Technology.

Educational institutions benefit from free access to the vehicles and the help of the operators, whom they train to observe and monitor marine life over long periods of time at offshore production sites. And companies like Shell get a better understanding of how their operations and sea life coexist near the ocean floor.

Thousands of dives

Since 2007, Benfield’s Gulf SERPENT project has received data and images from thousands of underwater vehicle dives at Shell as well as other oil and gas facilities in the area. This has led to the discovery of a new species of octopus and observations of creatures rarely seen in their natural environment.

“It’s a highly successful collaboration,” Mark says. “Without it, deep water in the Gulf of Mexico would remain largely unknown.”