Researchers document seasonal migration in deep-sea

First time scientists have documented this phenomena

Date: March 26, 2020

Source: Nova Southeastern University

We've all seen the documentaries that feature scenes of mass migrations on land. Those videos are pretty impressive showing all sorts of animals -- birds, mammals and other creatures -- on the move. What wasn't known was to what extent this was taking place in the deepest parts of our oceans.

That was until now.

Scientists have, for the first time, documented seasonal migrations of fish across the seafloor in deep-sea fish, revealing an important insight that will further scientific understanding of the nature of our planet.

"We are extremely excited about our findings, which demonstrate a previously unobserved level of dynamism in fishes living on the deep sea floor, potentially mirroring the great migrations which are so well characterised in animal systems on land," said Rosanna Milligan, Assistant Professor at Nova Southeastern University, who started the work at the University of Glasgow.

The study -- published today in the Journal of Animal Ecology and led by Nova Southeastern University (NSU) and the University of Glasgow -- analysed more than seven years of deep-sea photographic data from West Africa, linking seasonal patterns in surface-ocean productivity with observed behavioural patterns of fishes at 1,500 metres.

The deep sea -- greater than 200-meters water depth -- covers most of the world's surface. Recent advances in technology and computational power have hugely improved our ability to access and study deep sea ecosystems, but there are still many basic questions that we simply don't have answers to.

This study now provides evidence of cycles of movement across the seafloor in deep-sea fish, with the study authors believing these movements could be happening in other locations across the world's sea floor too.

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Deep-Sea Explorers Find Rare Shapeshifting Jellyfish with a Prize Inside

By Brandon Specktor - Senior Writer

Part ghost, part plastic bag, all amazing.

What in the name of Neptune's beard is that thing? A ghost? An alien? The ghost of an alien?

Such were the questions that vexed a team of deep-sea scientists aboard the Nautilus research vessel earlier this month, when their underwater recon robot encountered a limp, limbless creature hovering like a ghostly lantern over the Pacific seafloor. As the team watched, the bell-shaped blob suddenly transformed, ballooning into a long, translucent windsock with a mysterious red splotch stuck to its innards.

The blob, the researchers revealed in a recent video of the encounter, was no alien (it's never aliens), but one of the rarest-seen and least-studied jellyfish in the sea. 

It's called Deepstaria (named for the research vessel that first discovered the genus in the 1960s), and has been seen only a dozen or so times in the last half-century. Researchers don't know much about the armless, shapeshifting sack, but they do know it has a habit of expanding its body to engulf any prey trusting enough to swim nearby.

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More than 12,000 marine creatures uncovered during West Java deep-sea exploration

Over a dozen new species of crabs, prawns and lobsters discovered; over 40 new records for Indonesia

Date:  April 17, 2018

Source:  National University of Singapore

Despite a stormy start thanks to Cyclone Marcus, scientists who participated in the South Java Deep Sea Biodiversity Expedition 2018 (SJADES 2018) had collected more than 12,000 creatures during their 14-day voyage to survey the unexplored deep seas off the southern coast of West Java, Indonesia.

The expedition team, consisting 31 researchers and support staff, were led by Professor Peter Ng, Head of the Lee Kong Chian Natural History Museum of the National University of Singapore (NUS), and Professor Dwi Listyo Rahayu, Senior Research Scientist at the Research Center for Oceanography (RCO) of the Indonesian Institute of Sciences (LIPI). The NUS research team comprises scientists from the Lee Kong Chian Natural History Museum and the Tropical Marine Science Institute.

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‘Alien' Shark with Goblin-Like Jaws Hauled Up from the Deep Sea

By Laura Geggel, Senior Writer | January 12, 2018 04:00pm ET

Imagine this fearsome sight: an ink-black shark with gnarly, needle-like teeth; creepy, glass-like eyes; a glowing belly and a potentially extendable jaw. That's what scientists saw when they pulled up this rare creature, along with four of its pals, from the deep sea — so, naturally, it gave them quite a jolt.

Indeed, they were not expecting to meet these alien-like creatures during a routine fish survey off the Taiwanese coast, according to news reports.

Four of the sharks — known as viper dogfish (Trigonognathus kabeyai) — died immediately, but one survived its capture for 24 hours, until it, too, perished, according to Taiwan News.

Read on 

Ocean Worm Wriggles Back Into View after 140 Years

In 1873, an unknown species of deep-sea worm was dredged up from the bottom of the ocean. Further analysis showed that the animal, collected from almost 3.5 miles (5.5 kilometers) beneath the surface, turned out to be a new type of acorn worm. It was dubbed Glandiceps abyssicola.

For nearly 140 years, that was the last that humans would see of this type of acorn worm. Acorn worms are a group of animals that live on the seafloor eating pieces of sediment and detritus that float down from above. And the single specimen that was collected in 1873 by the HMS Challenger found its way to Germany, where it was destroyed by bombs in World War II.

Then, in 2009, a small chunk of yellow flesh turned up in a sample of sediment collected near the same spot as the original, in the equatorial Atlantic near South America. An anatomical and genetic study of the material, published last month in the Journal of the Marine Biological Association of the United Kingdom, found that it was part of aGlandiceps abyssicola worm's body.

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