We use technology to provide pictures of life in the ocean and also to make measurements. These are quite different requirements. These days, underwater still and video cameras and lights are widely available from many companies. However, most instruments to quantify life in the oceans, particularly the plankton, bacteria and viruses, are still experimental, and have to be developed by research institutions.
Deep-sea cameras may be found on Remotely Operated Vehicles (ROVs) operated from ships, on landers placed onto the seafloor for long periods of time, or on robot submarines. ROVs are highly mobile and allow us to explore areas of the ocean where the terrain prevents us from using other survey and sampling methods - such as submarine canyons. The quality of image that can now be obtained with today's digital cameras is now superb, allowing scientists to film life at ocean depths beyond the reach of light in high definition. Using ROVs to take samples of deep-sea fauna and their surroundings also allows an exceptional degree of precision and accuracy.
Sonar can provide intriguing graphic 'pictures' of sound reflected from animal life in the oceans. They can provide insight into animal behaviour, such as the daily migration from deep to shallow depths. Unfortunately, understanding exactly what is being seen remains difficult; this remains a research challenge.
In the future, we will have instruments in the ocean that use microchips to identify and quantify species from their genetic material; this will be especially valuable for the smaller phytoplankton and laboratory research on prototypes is well underway. One day we hope to be able perform a range of biogeochemical analyses in situ in the deep ocean without the need to bring samples up to the surface for analysis.