Impacts of underwater noise induced by offshore windfarms on marine mammal underwater noise effects (UWE)
Project code: 3515 82 2000
Contract period: 01.09.2015 - 31.08.2018
Purpose of research: Applied research
Keywords: harbour porpoise, seal
The potential impacts of underwater noise on marine mammals are to be investigated in several work units during this project. Underwater noise, which is emitted during construction and service of offshore windfarms, is able to have negative impacts on marine mammals, according to hitherto existing studies. Particularly the impulse noise, which is created during the foundation ramming, but also the continuous and background noise accompanying the increased shipping traffic for example, possess the potential to harm and/ or disturb marine mammals like harbour porpoises and seals sustainably.During this project the potential effects of underwater noise on marine mammals are to be analysed and the necessary knowledge concerning mitigation of damages is to be expanded in several work units in cooperation with the main project partners (University of Aarhus (DK) and DW ShipConsult (GER)):The effects of underwater noise, created by construction and service of offshore windfarms as well as the associated shipping noise, on harbour porpoises, grey seals and harbour seals will be investigated. For this purpose up to ten harbour porpoises and ten seals will be equipped with D-tags.The effects of seal scarers applied as protective measure for harbour porpoises, grey seals and harbour seals during the construction of offshore windfarms are to be analysed via playback experiments on animals kept in Kerteminde (DK). These analyses enable an examination of the animals´ behavioural pattern regarding the scarers´ acoustic signals. Impacts of the offshore windfarm construction and service on habitat utilisation and hearing ability of harbour porpoises. Continuative investigation of wild harbour porpoises´ hearing sensitivity regarding a potential hearing threshold shift via multiple noise exposition as well as the application of C-PODs and sound recorders at the location of already completed offshore windfarms. These data shall be incorporated in statistic models including already conducted investigations from previous projects and be evaluated („synergistic investigations“). Analysis of harbour porpoise energy balance disturbances caused by shipping noise and quantification of potential impacts on the population via application of D-tags. Maintenance ships operating in the offshore windfarms are suspected to provide a relevant contribution to the background noise. In order to estimate the noise emissions, the acoustic source levels of different offshore windfarm providers are to be measured. Stationarily anchored hydrophones as well as trailed systems shall be applied for the measurements.