Risk assessment of scientific sonars

• Main Authors: Burkhardt, Elke, Boebel, Olaf, Bornemann, Horst, Ruholl, Christoph
• Format: Conference Object
• Language: unknown
• Published: 2007
• Subjects: Alfred Wegener Institute; Antarc*; Antarctic
• Online Access: https://epic.awi.de/id/eprint/17624/; https://hdl.handle.net/10013/epic.27971

RISK ASSESSMENT OF SCIENTIFIC SONARSELKE BURKHARDT1, OLAF BOEBEL1, HORST BORNEMANN1 AND CHRISTOPH RUHOLL11 Alfred Wegener Institute for Polar and Marine Research, P.O. Box 12016, 27515 Bremerhaven, GERMANY. [e-mail]1. Introduction Scientific sonars form an important asset to conduct oceanographic, geophysical and biological research and are hence installed in many research vessels. Multibeam deep-sea echosounder map the sea-floor topography at high resolution, enabling researchers to identify sites of environmental importances such as cold water coral reefs and sea mounts, to locates suitable sites for oceanographic, geophysical and biological studies such as deep water passages and ice-berg grounding sites, and to develop navigational charts, also in the context of defining marine protected areas. Sediment echosounder explore the upper sediment layer stratification to determine location and thickness of sediment layers for coring sites for paleooceangraphic and sedimentological studies and to map the sediment distribution for paleo-oceanographic and paleo-biodiversity studies. Scientific fish finders are used to map the fish and krill distribution across large areas and at resolutions unachievable by catch data. This study analyses potential risks of these echosounders' usage with special emphasis on cetaceans present in the Antarctic Treaty region, i.e. the ocean south of 60° South. 2. Methods The study first presents a comprehensive description of the echosounders' technical parameters such as sound pressure level, effective pulse length and beam pattern, and continues by analysing three possible impact scenarios:a) Risk of direct damage due to immediate effects of sound;b) Risk of direct damage due to behavioural response;c) Risk of indirect damage due to changes to the habitat.3. Results For cruising ships (R/V Polarstern particularly), the study quantifies that the cumulative risk of type (a) (i.e. the risk of causing a temporary threshold shift, TTS) during simultaneous operation of ...