@article {53305, title = {Assessing vessel slowdown as an option for reducing acoustic masking for Arctic cod in the western Canadian Arctic}, journal = {The Journal of the Acoustical Society of America}, volume = {144}, year = {2018}, month = {Jan-09-2018}, pages = {1662 - 1662}, abstract = {

Noise from this shipping traffic can lead to acoustic masking, reducing the ability of marine animals to detect and use biologically important sounds. Vessel-slow down may be an alternative mitigation option in regions where re-routing shipping corridors to avoid important habitat for fish and marine mammals is not possible. We investigated the potential relief in masking from a 10 knot speed reduction of container and cruise ships. Based on ambient sound measurements and real shipping data, the percentage reduction in the available listening space for fish as a container or cruise ship passes under varying speeds and ambient sound conditions was shown. The mitigation effects from slower vessels (travelling at 15 knots compared to 25 knots), in terms of auditory masking, was equal between ambient sound conditions, but not equal between the type of vessel. Slowing vessels led to a substantial decrease in the listening space reductions, with the amount of reduction varying by distance away from vessels. Vessel slowdown through sensitive habitat could be an effective mitigation strategy for reducing the extent of auditory masking.

}, issn = {0001-4966}, doi = {10.1121/1.5067412}, url = {http://asa.scitation.org/doi/10.1121/1.5067412}, author = {Pine, Matthew and Hannay, David E. and Stephen J. Insley and William D. Halliday and Juanes, Francis} } @article {53282, title = {Spatio-temporal modelling of underwater noise related to an arctic exploration drilling program}, journal = {The Journal of the Acoustical Society of America}, volume = {144}, year = {2018}, month = {Jan-09-2018}, pages = {1733 - 1733}, abstract = {

One concern related to oil and gas industry activities in the arctic is the potential impact of anthropogenic noise on marine mammals. To gain understanding of the temporal evolution of the acoustic noise footprint from such activities, and to quantify the geographic extent at which sound levels remain within regulatory thresholds for marine mammal injury and behavioral disturbance, this work presents a comprehensive monitoring and modeling study of anthropogenic noise resulting from an exploration drilling project in the northeastern Chukchi Sea, conducted from July to October, 2015. Measured acoustic source levels of multiple vessels and drilling equipment were used to generate time-dependent wide-area noise fields. Model validation was carried out by comparing simulated results with high-resolution acoustic data acquired at multiple stations in the area. The study shows that noise radiating from up to 19 supporting vessels is usually dominant, but noise from certain drilling-related activities occasionally rises above vessel noise within a radius of 8 km from drillsites. Modeled scenarios also show that by constraining vessel positions to within a few kilometers of the drilling location, simultaneous construction of two oil well top holes results in minor increment of the aggregate acoustic footprint\’s extent relative to single-well drilling.

}, issn = {0001-4966}, doi = {10.1121/1.5067686}, url = {http://asa.scitation.org/doi/10.1121/1.5067686}, author = {Quijano, Jorge E. and Hannay, David E. and Melanie E. Austin} } @article {53025, title = {Acoustic characterization of exploration drilling in the Chukchi and Beaufort seas}, journal = {The Journal of the Acoustical Society of America}, volume = {144}, year = {2018}, month = {Jan-07-2018}, pages = {115 - 123}, abstract = {

This paper characterizes underwater sound levels produced by three drilling units during offshore exploration drilling at three sites in the Beaufort and Chukchi seas. Received levels and spectra are reported as functions of distance during drilling and excavation of mudline cellars (MLCs). Sound levels emitted during MLC excavation exceeded those during drilling at all three sites, although this operation was much shorter in duration. Drilling sounds exhibited tones below 2\ kHz, with harmonics present to 10\ kHz, while MLC excavation sounds were broadband in character. Drilling sounds varied substantially between the three operations, whereas MLC excavation sounds were more consistent in amplitude and spectral distribution. Estimates of broadband and 1/3-octave band source levels were computed from measurements at 1\ km range. The broadband drilling source levels were 168.6\ dB re 1\ \μPa m for the Kulluk drilling unit, 174.9\ dB re 1\ \μPa m for the drillship Noble Discoverer, and 170.1\ dB re 1\ \μPa m for the semi-submersible Polar Pioneer. The received levels measured at 1\ km during MLC excavation yielded source level estimates that were more consistent among sources: 191.8, 193.0, and 193.3\ dB re 1\ \μPa for the Discoverer, Kulluk, and Polar Pioneer, respectively.

}, issn = {0001-4966}, doi = {10.1121/1.5044417}, url = {http://asa.scitation.org/doi/10.1121/1.5044417}, author = {Hannay, David E. and Br{\"o}ker, Koen C.} }