Incredible invention will safely reveal mysterious creatures of the deep

5 Jun 2018

A scientific diver descends into the twilight zone in Grand Cayman. Image: Luiz Rocha/California Academy of Sciences

Being able to catalogue and discover a huge number of new marine species just got a whole lot easier thanks to a new invention that sucks them up to the surface safely.

It is incredible to think that we arguably know more about interstellar objects light years away than we do about what goes on in the deepest parts of our planet’s oceans, but this could be about to change thanks to a new invention revealed by the California Academy of Sciences.

Described in the journal Frontiers in Marine Science, the device is called the Submersible Chamber for Ascending Specimens, or SubCAS for short.

The ingenious pressurised chamber measures less than a metre long and can be used by divers to collect and safely surface charismatic reef residents for further study and public display.

Consisting of a custom-designed inner collecting jar that fits into a larger chamber housing, the SubCAS has a hinged door capable of letting water flow over the ascending fish collected by the transparent tube.

This allows divers to monitor fish for signs of stress and to keep an eye on the chamber’s submersible depth gauge and thermometer.

Because a fish’s bladder could rupture when exposed to a rapid change of pressure as a result of a quick ascent, the fish’s journey starts at around 150 metres below sea level and, at approximately 55 metres, the jar part of the SubCAS is inserted and an air bubble is blown into the chamber lid, which is subsequently sealed. This air bubble is crucial because it expands during the ascent, helping to maintain the pressure inside.

At approximately 30 metres, the device is handed off to another team of divers who will take the samples away for controlled decompression, and they are then flown to California for study.

Bart Shepherd holding the SubCAS

Bart Shepherd collects fish in the decompression chamber. Image: California Academy of Sciences

Important for conservation

This is a major game-changer for the field of marine biology as it shows it is now possible to take previously undiscovered fish from depths of 150 metres below sea level to more than 10,000m above sea level and down again with a near-100pc success rate.

“Before the SubCAS, hand-collecting and surfacing live fishes involved the invasive process of needling a hole in their gas-filled swim bladders to prevent over-expansion,” said the study’s lead author, Bart Shepherd.

“The chamber now allows us to eliminate this step and surface precious species in a non-invasive way for closely monitored care, research and public display.”

He also said that the device will play an important part in the conservation of our oceans’ most precious areas.

“In a time of global crisis for coral reefs, discovering strange and beautiful fishes from unexplored reef habitats is critical to our understanding of how to protect them,” he said.

“These species are ambassadors of important environments that are rarely included in marine protected areas or sanctuaries. Our goal is to remind the public of the ocean’s vast and unexplored wonders and to inspire its conservation for future generations.”

Colm Gorey was a senior journalist with Silicon Republic