https://doi.org/10.82144/44da74dd https://seamap.env.duke.edu/dataset/651 https://www.gbif.org/dataset/abd1b4fd-d1ed-4728-87c9-4ba157484446 https://obis.org/dataset/b2412f4d-5988-4876-bc7c-954cbe192cc8 Marielle Thillet Encana Corporation Primary contact marielle.thillet@encana.com OBIS-SEAMAP Marine Geospatial Ecology Lab, Duke University

A328 LSRC building Durham NC 27708 US

seamap-contact@duke.edu https://seamap.env.duke.edu OBIS-SEAMAP Marine Geospatial Ecology Lab, Duke University

A328 LSRC building Durham NC 27708 US

seamap-contact@duke.edu https://seamap.env.duke.edu distributor Marielle Thillet Encana Corporation Primary contact marielle.thillet@encana.com owner 2025-07-31 eng Original provider: Encana Corporation Dataset credits: Marielle Thillet, Deep Panuke Project, Encana Corporation Abstract: We present marine mammal observation statistics, high-frequency seismic source characteristics, and example denoising of marine mammal acoustical recordings using data collected during the mitigation and monitoring program for a 3-D seismic survey by Encana Corporation, Calgary, Alberta, Canada, in the northwest Atlantic during 2003. Marine mammals were observed both visually and acoustically. No marine mammal incidents or adverse reactions were observed during the survey. Acoustical observations were made by the Seamap Passive Acoustic Cetacean Monitoring System (SPACMS), consisting of two hydrophones placed 50 m apart, towed ahead of and to one side of the seismic source. Visual and acoustical detections were uncorrelated, indicating the complementary nature of the two observational techniques. Visual detections were more common per hour of effort than acoustical detections. Acoustical detection rates showed no significant day–night difference. Marine mammals appeared to have avoided very close ranges (100 m) from the seismic array during seismic acquisition, but the overall number of marine mammals in the observable radius (1–2 km) did not change significantly when the seismic source was “on” compared to “off.” Marine mammals were observed in larger groups and appeared to have become less vocal when the seismic source was active. It should be noted however, that the results from this data gathering effort may be affected by potential sources of bias (such as the combination of data from toothed and baleen whales). Signal processing of seismic source signatures indicated some high-frequency energy content consistent with expectations from earlier work. This analysis confirmed that most of the seismic energy was concentrated at lower frequencies (500 Hz). No low-frequency comparisons with near-field data could be made due to the geometry of the SPACMS recording hydrophones and seismic source, which resulted in the Lloyd’s mirror effect obliterating low-frequency components in the SPACMS records. A wavelet-based denoising method was applied to improve the visibility of marine mammal vocalizations on a spectrogram display. Marine Biology Passive acoustic detection N/A Visual data collected in this survey are registered on OBIS-SEAMAP separately as the <a href=http://seamap.env.duke.edu/datasets/detail/650>Deep Panuke whale sightings 2003</a> dataset. This work is licensed under a Creative Commons Attribution Non Commercial (CC-BY-NC) 4.0 License. https://seamap.env.duke.edu/dataset/651 Oceans -57.84 -57.467604 44.384523 43.775861 2003-05-04 2003-05-23 Scientific names are based on the Integrated Taxonomic Information System (ITIS). order Cetacea Cetaceans family Delphinidae Dolphins species Hyperoodon ampullatus Northern bottlenose whale species Physeter macrocephalus Sperm whale notPlanned Marielle Thillet Encana Corporation Primary contact marielle.thillet@encana.com NA NA NA Marielle Thillet owner NA zd_651 2025-07-31T14:35:02-04:00 dataset Thillet, M. 2011. Deep Panuke whale Acoustic 2003. Version 1.0.0. Dataset published in OBIS-SEAMAP. https://doi.org/10.82144/44da74dd. OBIS-SEAMAP Dataset Page UTF-8 Interactive map https://seamap.env.duke.edu/dataset/651 FGDC Metadata UTF-8 XML https://seamap.env.duke.edu/dataset/651/fgdc EML Metadata UTF-8 XML https://seamap.env.duke.edu/dataset/651/eml OBIS-SEAMAP zd_651 zd_651 Potter, J.R., M. Thillet, C. Douglas and M.A. Chitre. 2007. Visual and passive acoustic marine mammal observations and high-frequency seismic source characteristics recorded during a seismic survey. IEEE Journal of Oceanic Engineering: 32:469-483.