Researchers have made a surprising discovery: a lumbering barrel-shaped sleeper shark was filmed as it lazily sailed across an arid seabed, much deeper than sunlight can reach. According to experts, sharks were not thought to exist in these icy Antarctic waters until this specimen was thrust into the spotlight of a deep-sea camera and briefly stole the show.
In this regard, Jamieson said: “We went there not expecting to see sharks because there is a general rule of thumb that you don’t encounter sharks in Antarctica.”
Climate changes and warming oceans may be the main factors driving sharks to the cold waters of the Southern Hemisphere. Historically, data on range changes near Antarctica have been limited due to the extreme remoteness of the region.
According to expert observations, the population of sleeper sharks in the Southern Ocean is difficult to detect. This particular shark was observed at a depth of approximately 500 meters along a sloping seabed. It probably stayed at that depth to stay within the warmest water layer, where different thermal currents stack on top of each other.
The Antarctic Ocean is heavily stratified to a depth of about 1,000 meters (3,280 feet), resulting in conditions such as colder, dense water below that does not immediately mix with fresh water running off from melting ice.
The study is limited because cameras were only placed at that specific depth during the summer months.
