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.
In numeric or date/time fields, original data may contain 'X' which was replaced with Null.
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.
This section explains attributes included in the original dataset.
OBIS-SEAMAP restricts the attributes available to the public to date/time, lat/lon and species names/counts only.
Should you need other attributes described here, you are encouraged to contact the data provider.
Attributes described below represent those in the original dataset provided by the provider.
Only minimum required attributes are visible and downloadable online. Other attributes may be obtained upon provider's permission.
Attributes in dataset
Attribute (table column)
Unique ID number (generated by OBIS-SEAMAP)
Vessel role (Source or Monitoring)
Date and time (local time) of observation
Sighting identification number
Species name recorded
Taxonomic Serial Number added by OBIS-SEAMAP
Number of individuals observed.
Number of juveniles observed.
The location of the sighting on the clockface where forward is 12:00.
The clockface direction the animal is heading relative to the animal (not the vessel).
Reticle of sighting (degrees). Blank if observed by naked eye.
First cue that the observer identified.
First behavior observed.
Second behavior observed.
If the animal(s) were observed in Water or Ice (or both:IL).
Pace of animal.
Reaction of animal.
Secondary reaction, if applicable.
Vessel activity type
Latitude in decimal degrees based on sighting distance and bearing
Longitude in decimal degrees based on sighting distance and bearing
Depth at sighting position calculated in Mysticetus.
Initials of PSO that observed the sighting.
Initials of the PSO that recorded the data.
Reliability of the identification of the sighting.
Call time of mitigation, if applicable. Blank if not.
Time mitigation was implemented, if applicable. Blank if not.
Time of the animal
Calculated from fist and last record of same animal(s). Blank: if only seen once
Clock face position of the animal at its closest point of approach to the vessel.
Distance (meters) at closest point of approach to observer for the sighting
Distance (meters) at closest point of approach to observer for multiple sightings