Positive ocean news: August ’25 edition

A species of stalked jellyfish which was thought to be extinct has been spotted on South Uist in the Outer Hebrides. The Depastrum cyathiforme, which looks like a thistle, was last recorded off northern France in 1976 and in UK waters in 1954.

Six miles beneath the ocean’s surface, thousands of molluscs and worms have been discovered, making it the deepest colony ever recorded.

The creatures can survive at this depth by turning fluids that seep from the seafloor, which are rich in hydrogen sulfide and methane, into energy. Found in hadal trenches, the deepest region on the ocean, the recently discovered colony spanned more than 1.5 miles.

This suggests that there could be even more marine life yet to be found in the hostile environments of the deep ocean. Xiatong Peng, the study’s co-lead author, said: “These findings challenge current models of life at extreme limits and carbon cycling in the deep ocean.”

Read more on the Oceanographic website

This is because whales, like other marine animals, move up and down the water column, rather than simply across it. Previous tracking data therefore did not account for the additional distance covered by the diving behaviour of whales.

When dive speed and distance was included in tracking, scientists found that humpback whales travelled 16% further (over 1,000km) than standard surface distance tracking shows.

Read more on the Oceanographic website

A remotely controlled vehicle filming life 4,000 metres underwater in Mar de Plata's submarine canyon has captured the attention of millions and become a social media phenomenon.

Researchers are using the vehicle to map the underwater gorge, identify marine species and collect samples to learn more about the area’s little-studied biodiversity. The high-definition cameras have captured a vast array of marine life, from orange starfish and transparent-faced fish to sea cucumbers and deep sea crabs.

As well as amassing 1.6million views a day, the livestream has become popular on social media, with users comparing creatures to famous cartoon characters and creating quizzes.

Its popularity came as a surprise to the research team, with expedition leader Daniel Lauretta saying, "it’s something that fills our hearts because we want to spread the word."

Read more on the Independent website

Scientists have discovered that what was thought to be a single species of coral is in fact several distinct species.

Among these are five species which were previously unknown to science, some of which are are only found on Australian reefs, such as the Great Barrier Reef.

The discovery changes what we know about corals’ biodiversity and their ecological importance, and raises questions for coral conservation and restoration.

Andrew Baird, Professor of Marine Ecology at James Cook University said, “If we think a coral species is common and found everywhere, we might not worry too much about it. But if that ‘one species’ turns out to be ten different ones, each living in a smaller area with lower numbers, they could be at much greater risk of disappearing. We need to urgently rethink how we assess and protect coral species - because you can’t save something if you don’t even know it’s there.”

Read more on the James Cook University website

A recent study has confirmed that there is a third species of manta ray, 16 years after a study suggested that it was likely. Discovered in the western Atlantic, the newly described Mobula yarae has V-shaped white shoulder patches and a lighter face than the other two species.

The confirmation of a third species took years of analysis of manta rays from across the Atlantic, with genetic results proving what had been predicted by the 2009 study authors who confirmed the existence of a second manta ray species, known as the reef manta ray.

As the species has limited range, having only been recorded in the western Atlantic, and lives in more coastal habitats, it is at greater risk of extinction than other manta species. Formally describing the species, however, is the first step towards protecting it.

Read more on the Mongabay website

Researchers from Swansea University have captured footage of sliteye sharks in the Great Chagos Bank in the Indian Ocean, the first time the species has been recorded in the region.

The sharks were spotted in previously unstudied seagrass meadows, at a depth of 23-29 metres. It’s thought that their slit-like eyes, for which they’re named, enhance their vision in low light, meaning they’re well adapted to these deeper, dimmer environments.

The discovery furthers our understanding of the species geographic range and of the biodiversity in the Chagos Archipelago. With sliteye shark populations predicted to decline by up to 29% in the next 15 years, their presence in the region underscores the importance of its Marine Protected Area in safeguarding vulnerable species.

Read more on the Phys.org website