Posted on behalf of Tim Sands

The BBC is reporting the live capture of a fish from 2300m below the surface of the North Atlantic – that’s 900m deeper than the record for the catching a live fish. The unlucky creature was a Pachycara saldanhai, a species first described in 2004 (paper). It was hauled to the surface in a pressurised container. The scientists-cum-fishermen also caught shrimps of three species right down there, as well as at a slightly more modest 1700m.

Given their adaptation to the crushingly great water pressure and low temperatures at these depths, creatures recovered from the deep ocean rarely survive for long. Bruce Shillito from Université Pierre et Marie Curie in Paris and his team designed a pressurised capture chamber to bring samples to the surface for study. The chamber can hold the fish at the same pressure at which they’re hooked – at this depth it is around 230 atmospheres. They describe the finds and the new equipment in July’s edition of Deep-Sea Research Part 1 (paper).

Unfortunately for these particular sea creatures, the pressurised aquarium hasn’t been invented yet, and they did not respond well to life without pressure. According to the BBC, shrimp brought to the surface unpressurised: “…jerked violently, and after a few hours were dead.” Owners of pet shrimp may find some of the video footage disturbing.

The creatures were recovered from undersea vents, home to a remarkable and unique array of fauna. What the researchers would really like to get in their trap is a Pompeii worm, which can withstand temperatures of 80ºC in the waters around the vents.

It was reported last year that lights from undersea research could blind members of one of the same species of deep-ocean shrimp caught in this new trap. That research found that the blinding didn’t seem to damage the shrimp population.

Of course, what we would really like to see brought up alive from the bathyal depths is a colossal squid. You will recall fishermen in New Zealand trawled up a specimen in 2007 that didn’t survive and which was recently defrosted and examined (apparently it tastes like a cockle). Other candidates are pictured on a webpage aptly titled “10 Horrible Deep Sea Creatures”. For now we will have to settle for Pachycara saldanhai.