How underwater robots shine a light on sharks
Discover how marine scientists are borrowing technology from the energy industry to explore the ocean depths and widen scientific knowledge.
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.”
The preferred habitat of the sleeper shark, which can grow up to 7m (23 feet) long, was thought to be cold, shallow northern waters. This one was filmed in the Mississippi Canyon at a depth of about 2,300m (7,500 feet), much deeper and farther south than previously known
Many sightings may be Greenland sharks, a sleeper shark species, which are hard to identify without DNA samples. In 2013, a Florida State University team captured the first Greenland shark in the Gulf of Mexico, but Mark Benfield believes he saw a large one there in 2008
Up to 8 metres (26 feet) in length, the oarfish is one of the world’s longest fish. It is thought to be the origin of sea serpent myths told by early seafarers. Before the use of ROVs it was rarely seen alive
The deep-sea lizardfish lives on the ocean bottom at depths as low as 3,500m (11,500 feet). It has a large mouth full of sharp teeth which curve backwards. Once caught, its prey cannot escape
This rarely seen giant deep-sea jellyfish had been filmed twice before in the Pacific Ocean, but had never been sighted in the Gulf of Mexico. Its disc-like bell can be 1 metre (3 feet) wide and its tentacles 7 metres (23 feet) long
This is a close-up of a cirrate octopus, thought to be a new species. It was filmed at Shell’s Perdido spar at a depth of around 2,280 metres (7,500 feet). If it can be collected and examined in a lab, it will be given a new scientific name
A remotely operated vehicle at a Shell drilling site. The vehicle is lowered to its target depth in a cage, and then released. It drives with its lights and cameras on looking for animals to film at depth intervals of 150m (500 feet)
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.”
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