TGS Seismic Survey Visual Sightings in Chukchi Sea 2013


Dataset credit

ASRC Energy Services, Inc.
TGS-NOPEC Geophysical Company


Primary contact Troy Nelson TGS-NOPEC Geophysical Company
Secondary contact Megan Blees ASRC Energy Services, Inc.
Data entry Ei Fujioka Duke University



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 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.



Supplemental information

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)Description
oidUnique ID number (generated by OBIS-SEAMAP)
vessel_nameVessel Name
vessel_roleVessel role (Source or Monitoring)
obs_datetimeDate and time (local time) of observation
sighting_idSighting identification number
sp_obsSpecies name recorded
scientificScientific Name
sp_tsnTaxonomic Serial Number added by OBIS-SEAMAP
obs_countNumber of individuals observed.
juv_countNumber of juveniles observed.
where_atThe location of the sighting on the clockface where forward is 12:00.
where_toThe clockface direction the animal is heading relative to the animal (not the vessel).
stg_methSighting method
reticleReticle of sighting (degrees). Blank if observed by naked eye.
stg_distDistance (meters)
visual_cueFirst cue that the observer identified.
behav_1stFirst behavior observed.
behav_2ndSecond behavior observed.
water_iceIf the animal(s) were observed in Water or Ice (or both:IL).
pacePace of animal.
react_1stReaction of animal.
react_2ndSecondary reaction, if applicable.
activity_typeVessel activity type
latitudeLatitude in decimal degrees based on sighting distance and bearing
longitudeLongitude in decimal degrees based on sighting distance and bearing
seaChukchi Sea
stg_depthDepth at sighting position calculated in Mysticetus.
observed_byInitials of PSO that observed the sighting.
recorded_byInitials of the PSO that recorded the data.
reliabilityReliability of the identification of the sighting.
mitigation_typeMitigation type
call_timeCall time of mitigation, if applicable. Blank if not.
time_implementedTime mitigation was implemented, if applicable. Blank if not.
cpa_timeTime of the animal
elapsed_timeCalculated from fist and last record of same animal(s). Blank: if only seen once
cpawhereatClock face position of the animal at its closest point of approach to the vessel.
cpa_to_obsDistance (meters) at closest point of approach to observer for the sighting
final_cpa_to_obsDistance (meters) at closest point of approach to observer for multiple sightings
notesAdditional details pertaining to the sighting.
geomGeometry field added by OBIS-SEAMAP
Marine mammals544
Sea turtles0
Rays and sharks0
Other species0
Non spatial3
Non species0
Date, Begin2013-08-26
Date, End2013-10-30
Temporal prec.111111
Latitude64.41 - 74.28
Longitude-168.61 - -158.76
Coord. prec.6 decimal digits
Data typeAnimal sighting
EffortYES (ID: 1111)
Traveled (km)85,464
Effort hours1,556
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