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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