https://doi.org/10.82144/3b35bb0f https://seamap.env.duke.edu/dataset/1110 https://www.gbif.org/dataset/582edcfc-922c-43eb-b480-63971c425f2d https://obis.org/dataset/4b394534-8a6b-4bdb-bf1b-f07f983f9e37 Troy Nelson TGS-NOPEC Geophysical Company Primary contact Tnelson@arcis.com Megan Blees ASRC Energy Services, Inc. Secondary contact Megan.Blees@asrcenergy.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 Troy Nelson TGS-NOPEC Geophysical Company Primary contact Tnelson@arcis.com owner Megan Blees ASRC Energy Services, Inc. Secondary contact Megan.Blees@asrcenergy.com originator 2025-07-31 eng Original provider: TGS Dataset credits: ASRC Energy Services, Inc. TGS-NOPEC Geophysical Company Abstract: TGS-NOPEC Geophysical Company (TGS) conducted a 2D marine seismic survey along predetermined lines in U.S. Federal and international waters of the Chukchi Sea during the open-water season from 25 August to 30 October 2013. Two vessels were involved including 1) a seismic vessel (Geo Arctic) towing a 3,280 cu.in. seismic array and 8,100 m long solid streamer cable and 2) a marine mammal monitoring vessel (Norseman) which operated in advance of the seismic vessel. Both vessels had teams of visual protected species observers (PSOs) trained to monitor and implement seismic mitigation according to regulatory permits from U.S. Agencies. A combined-vessel total of 480 visual sightings occurred over 30,798 km of combined-vessel observer effort (both on and off effort). In addition to visual observers, the monitoring vessel also employed a towed passive acoustic monitoring (PAM) system. This dataset includes visual sighting data and acoustic data is presented separately. Occurrence GBIF Dataset Type Vocabulary: http://rs.gbif.org/vocabulary/gbif/dataset_type.xml Observation GBIF Dataset Subtype Vocabulary: http://rs.gbif.org/vocabulary/gbif/dataset_subtype.xml Marine Biology Visual sighting Marine Animal Survey Marine mammals Visual Sighting Vessel N/A In numeric or date/time fields, original data may contain 'X' which was replaced with Null. This work is licensed under a Creative Commons Attribution (CC-BY) 4.0 License. https://seamap.env.duke.edu/dataset/1110 Oceans,North Pacific Ocean,Arctic Ocean,Chukchi Sea -168.609283 -158.759196 74.278408 64.412343 2013-08-26 2013-10-30 Scientific names are based on the Integrated Taxonomic Information System (ITIS). species Balaena mysticetus Bowhead species Balaenoptera acutorostrata Common minke whale suborder Caniformia Pinnipeds order Cetacea Cetaceans species Erignathus barbatus Bearded seal species Eschrichtius robustus Gray whale species Histriophoca fasciata Ribbon seal class Mammalia Mammals species Megaptera novaeangliae Humpback whale suborder Mysticeti Baleen whales species Odobenus rosmarus Walrus species Phoca largha Spotted seal species Phocoena phocoena Harbor porpoise species Pusa hispida Ringed seal notPlanned Troy Nelson TGS-NOPEC Geophysical Company Primary contact Tnelson@arcis.com NA NA NA Troy Nelson owner Megan Blees originator NA zd_1110 2025-07-31T16:30:59-04:00 dataset Nelson, T. and M. Blees. 2014. TGS Seismic Survey Visual Sightings in Chukchi Sea 2013. Version 1.0.0. Dataset published in OBIS-SEAMAP. https://doi.org/10.82144/3b35bb0f. OBIS-SEAMAP Dataset Page UTF-8 Interactive map https://seamap.env.duke.edu/dataset/1110 FGDC Metadata UTF-8 XML https://seamap.env.duke.edu/dataset/1110/fgdc EML Metadata UTF-8 XML https://seamap.env.duke.edu/dataset/1110/eml OBIS-SEAMAP zd_1110 zd_1110 Cate, J.R., M. Smultea, M. Blees, M. Larson, S. Simpson, T. Jefferson and D. Steckler. 2014. 90-Day Report of Marine Mammal Monitoring and Mitigation during a 2D Seismic Survey by TGS in the Chukchi Sea, August through October 2013. AES Doc. No. 15416-04 13-185. Prepared by ASRC Energy Services, Smultea Environmental Sciences, Clymene Enterprises and Entiat River Technologies for TGS-NOPEC Geophysical Company, National Marine Fisheries Service and U.S> Fish and Wildlife Service: 122 p. + Appendices.