Deep discovery

Life in some of the deepest ocean trenches in the world is being revealed by a UK-built video system designed to withstand pressures that would cause any other device to implode.

The autonomous camera, developed at

, recently filmed fish at 7,700m beneath the surface of the Pacific Ocean — the deepest any fish have been captured on video — and it has the potential to explore even greater depths.

In laboratory tests the camera withstood pressure of 1,400bar, which would be found at sea depths of 14,000m. The Mariana Trench in the eastern Philippine Sea, the deepest part of the world's oceans, has a maximum depth of 11,000m.

The camera, which uses a light-sensitive digital image sensor called a charge-coupled device to form images, is housed inside a stainless steel case and attached to a PC and recorder card encased in a stainless steel tube. All this is plugged into a 12V lead acid car battery that is pressure compensated with oil so it can be dropped to any depth.