DISCOL Megafauna Atlas

Introduction to the ONLINE version (2001)

Introduction to the preliminary version (1991)

This report is part of the project "Deep-sea environmental protection - Examination of existing (imagery) material" ("Tiefsee-Umweltschutz - Auswertung vorhandenen Materials") funded by the German Federal Ministry for Research and Technology (BMFT = Bundesministerium für Forschung und Technologie). Photo- and video-material of the first cruise (SONNE 61) of the DISCOL-experiment have been examined.
In 1989 the Institute of Hydrobiology and Fishery Science (Institut für Hydrobiologie und Fischereiwissenschaft) of the University of Hamburg started a "DISturbance and reCOLonization experiment in the South Pacific" (DISCOL) to contribute knowledge to the environmental effects of deep-sea-(manganese nodule)-mining (Foell et al. 1990, Schriever 1990, Thiel & Schriever 1989). The DISCOL experimental area (DEA) is located south of the Galapagos Islands near a mining claim of the German AMR (= Arbeitsgemeinschaft meerestechnisch gewinnbarer Rohstoffe) consortium. The DEA is circular with a diameter of ca. 2 nmi (= 3 754m), corresponding to an area of 3.14 nmi² (= 10.8 km²). The central position is 07o 04.4'S and 88o 27.6'W. The area and its surroundings were mapped by SEABEAM charting (8 x 12 nmi area). The water depth is between 3 950 - 4 500m.
The photos in this megafauna atlas were made by the 35mm camera unit of the Ocean Floor Observation System (OFOS) used by the DISCOL investigators to monitor the sea floor of the DEA during the experiment. The OFOS is built by the German firm PREUSSAG AG - Marine Technology. It is a towed unit equipped with real-time television and photo-on-command capabilities. The video and photo cameras are fixed to a metal frame, together with batteries, lamps, strobes and a navigation transponder.
The photo system contains a BENTHOS survey camera with a NIKONOS 28mm lens. The film used was KODAK Ektachrome 200 professional. During a single deployment, up to 800 photos can be taken before the battery package has to be recharged and the camera reloaded. Information about the time and the distance of OFOS above the sea bottom are added into the frame data chamber by a data encoder. The TV system contains a low level underwater camera, which sends black and white signals via coaxial cable to the shipboard unit. Aboard the ship the incoming signals are recorded on VHS tapes. On the videotapes the date and time are added. The OFOS is towed 3 - 5 m above the sea floor. The videosequences are used for better interpretation of the three-dimensional appearence of faunal individuals. Together with the 35mm slides, abundance values for the megafauna of this area can be determined.

Introduction to the print version (1998)