Deep-sea grenadier fish, Nezumia sp. (© NOCS 2006) Deep-sea grenadier fish, Nezumia sp. (© NOCS 2006)
Deep-sea grenadier fish, Nezumia sp. (© NOCS 2006)
Deep-sea grenadier fish, Nezumia sp. (© NOCS 2006)
Deep-sea grenadier fish, Nezumia sp. (© NOCS 2006) Deep-sea grenadier fish, Nezumia sp. (© NOCS 2006) Deep-sea grenadier fish, Nezumia sp. (© NOC 2006)
Deep-sea grenadier fish, Nezumia sp. (© NOCS 2006)
 

Deepsea Photography

The seabed was first photographed in 1893 in the Mediterranean. Underwater photography then developed at a fast rate in shallow waters and photography of the deep-sea environment began with the design of special cameras with the ability to reach almost 5000 m depth – designed by Maurice Ewing and Allyn Vine (USA) in 1941. Photography is now well established as an important tool for studying the deep-sea environment.

Early explorers of the deep sea would lower equipment over the edge of the ship and were totally oblivious to what kind of environment and animals they may sample with their nets and grabs. They could only guess at the nature of the seabed, the extent of the particular environment type or the behaviour of the animals. Modern day deep-sea scientists use photographic technologies which can enable quantitative data collection on the spatial and temporal abundances and distribution of the larger seabed dwelling animals. Photographic surveys may be small scale, with photographs being taken by free-fall cameras ‘bounced’ along the seabed or deployed on the seabed for long periods, taking photographs at regular intervals (time-lapse photography – e.g. Bathysnap). Larger scale surveys are made using camera sleds, towed over the seabed using acoustic telemetry to fly at a set altitude (e.g. Wide Angle Survey Photography – WASP); manned submersibles; Remotely Operated Vehicles (ROV) and Autonomous Underwater Vehicles (AUV) e.g. Autosub. Video is an additional tool used for exploring the deep-sea environment.

Photographic techniques

Free-fall cameras

ROBIO lander, a free-fall camera system, waiting to be deployed

Free-fall camera systems were the first photographic tools developed for deep-water ecological assessment. They have been used extensively in the deep sea with the more recent models typically depicting a small area of seabed and allowing identification of organisms down to 1mm in size. They provide a quantitative quadrat type sample, although the area covered, even by systems bounced along the seabed is typically very small. On the left is a picture of the ROBIO lander developed by Oceanlab, Aberdeen. See here for examples of the type of cameras now being used.

Time-lapse cameras

Bathysnap - the NOCS time-lapse camera system

Time-lapse cameras are deployed on a frame that sits on the seabed and provide a quantitative photographic sample of a small area of seabed over a typically long time period. Previously unknown important temporal variations in animal abundance have been discovered using this method, for example using the NOCS ‘Bathysnap’ time-lapse camera, Bett et al. (2001) reported a radical change in the abundance and activity of animals on the Porcupine Abyssal Plain, northeast Atlantic.

Towed cameras

WASP - Wide-Angle Seabed Photography system

Towed camera systems provide a quantitative picture of a relatively large area of the seabed environment and can be used for transect-type biological studies. They lack the resolution of the free-fall cameras although good results have been obtained from these cameras. Towed camera platforms are used particularly for geological studies and were instrumental in the location of hydrothermal vents, biological studies are less common. Most biological studies concentrate on the distribution and abundance of organisms.

The majority of photographs on this website were taken using the NOCS WASP (Wide-Angle Seabed Photography) system. WASP is an off-bottom towed camera platform, typically operated 3-6 m above the seafloor at a speed of approximately 0.5 knots (1 km per hour). Vehicle performance is monitored in real time via an acoustic telemetry system; the data telemetered includes pressure (depth), temperature, altitude and camera operation. The vehicle carries an Ocean Instrumentation Ltd (UK) Mk7 still camera and 1200J flashgun. The camera is mounted in the nose of the vehicle and aimed directly downwards at the seafloor, the flash is mounted in the tail (some 2.5 m from the camera) and aimed at the camera's focal point (for an altitude of 5 m).

Submersibles

Maria Baker preparing for descent in the manned submersible 'Johnson Sealink' (HBOI)

Manned submersibles have been used extensively for the study of deep-sea fauna. Many of these studies have included some photographic sampling of the animals along the submersible track. In one of the most comprehensive submersible photographic studies to date, the distribution of seabed animals along the well-studied Gay Head-Bermuda transect was investigated and provides detailed descriptions of the highly variable fauna. The US submersible “ Alvin” is frequently used in the investigation of deep-sea hydrothermal vents and thousands of impressive photographs of bizarre creatures have been taken at these sites.

ROVs

ISIS the NERC ROV

Remotely Operated Vehicles are becoming increasingly used in deep-sea research and industry. All are equipped with video systems and often stills cameras that can be used in ecological studies of the seafloor. Real-time control of the vehicle allows different survey strategies to be employed and verification of species and observations of behaviour to occur. An increasing number of biological studies are made using ROVs to undertake structured seabed surveys. On the left is a picture of ISIS the UK's first full-ocean depth research ROV. The SERPENT project based at NOCS has vastly increased the availability of ROV technology to scientists.

AUVs

Autosub - an autonomous underwater vehicle

Several Autonomous Underwater Vehicles have been fitted with camera systems and although the technology is not fully developed for imaging, the potential of AUVs for biological survey is impressive. AUVs will be able to cover large distances and conduct detailed biological surveys in the open ocean as well as in habitats that were previously inaccessible, such as the seafloor environment under ice the ice shelves.

Video

Video has been used as an important tool for the study of deep-sea fauna. It is used more widely in shallow water, particularly in the study of seabed communities on coral reefs as it allows a wide swathe of seabed to be recorded quickly and by operators with limited identification skills. Despite the continuous coverage of video it has an inherently lower resolution than photographs. It is often combined with photography in the deep sea to provide a combination of detail and aerial coverage or to direct the camera to the most suitable location.

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