Researchers Drop a Camera Into the World’s Second-Deepest Marine Trench. A Rare Encounter Occurs

Some of the deepest corners of the world, like the Marina Trench, have long sparked curiosity among marine researchers. The latest feat to discover new creatures in the unexplored depths of the Pacific uncovered a rare encounter with a Pacific Sleeper Shark, scientifically known as Somniosus pacificus. In a recent experiment conducted by the University of Western Australia and The Minderoo-UWA Deep-Sea Research Centre, a camera dropped into the Tonga Trench, the second-deepest marine trench in the world, captured the sleeper shark attacking the equipment as prey. 

Located in the southwestern Pacific Ocean, the Tonga Trench is the deepest trench in the Southern Hemisphere. At about a depth of 1,400 meters, researchers observed a female sleeper shark searching for prey at the bottom in September 2024, as per the documented video shared on YouTube (@deepseauwa) a month later. Sleeper sharks are described to be benthopelagic species, which means they live and feed near the bottom of the oceans along with the midwaters and surfaces (pelagic). These species generally feed on benthic and free-swimming organisms, per FishBase. They grow up to an average length of 4.4 meters and can grow more than 7 meters at maximum. 

“Due to the lack of observable claspers on the pelvic fins, we’ve identified it as female,” Dr. Jessica Kolbusz, Oceanographer & Chief Scientist, said in the narration for the video. The sleeper shark was identified to be about 3.5 meters in length. Thirty seconds into the documentary, the shark attacked the camera equipment and provided a distinct picture of the inside of her mouth. The shark was probably not impressed by the camera’s taste and went for the previously ditched bait attached to the camera equipment. The video further added that the water temperature was 2.5 degrees Celsius, ideal for sleeper sharks' survival, and are found in the northern Pacific waters. There are reports of their sightings near the Solomon Islands and the Chapman Islands. 

After chomping up on the bait, the sleeper shark swam away from the camera. According to the video, these species have a highly adaptable diet and can feed on fish, squid, octopus, crabs, and prawns. Reports suggest that there is scarce information about these slow-moving shark species, regarding their population sizes, the distance they cover, and areas of reproduction. Sleeper sharks are often caught by commercial fish vessels as unwanted bycatch, mostly juvenile in age while adult sleeper sharks are rarely spotted. An Instagram video by OceanX (@oceanx) explained that the sharks are related to Greenland shark species that have the longest lifespans of any invertebrates. 

Sleeper shark meats are often consumed and said to impart a similar effect to being drunk. As a result, the species are reportedly witnessing a population decline in the United States, according to NOAA Fisheries. This has sparked concerns about their conservation efforts particularly because sleeper sharks have low commercial value, and are difficult to spot given their deep habitats and poor handling by fishing vessels due to their massive size. 

You can follow @deepseauwa on YouTube for more fascinating videos and information about marine life and aquatic environments.