PIFSC, Cetacean Survey, MACS 2018, Cruise 1803, NOAA Pacific Islands Fisheries Science Center

NOAA Pacific Islands Fisheries Science Center

[2023-09-06] Some of the sightings got their group sizes estimated incorrectly. These are fixed.

The 2018 Mariana Archipelago Cetacean Survey (MACS) was a shipboard line transect survey aboard the Oscar Elton Sette that operated in the island waters from Guam to Pagan and west out to the West Mariana Ridge (9 July - 1 August). During 22 days of surveys there were 66 cetacean sightings including 12 identified species.

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Data were collected under NMFS permit 20311.
The data included here are the sightings and on-effort tracks recorded within WinCruz survey software and extracted from the QA/QC'd DAS file using the R package swfscDAS (https://smwoodman.github.io/swfscDAS).

Attributes for fields within the trackline files:
Cruise - see description in attribute table below
segnum - segment number for continuous on-effort line
Date - Local date m/dd/yyyy
TimeStart - Local time at start of on-effort segment
LatStart - Latitude in decimal degrees at starting point of on-effort segment
LongStart - Longitude in decimal degrees at starting point of on-effort segment
TimeEnd - Local time at end of on-effort segment
LatEnd - Latitude in decimal degrees at end point of on-effort segment
LongEnd - Longitude in decimal degrees at end point of on-effort segment
Mode - see description in attribute table below
EffType - see description in attribute table below
avgSpdKt - average speed (knots) of the ship over the on-effort segment traveled
avgBft - average Beaufort Sea State over the on-effort segment

Other data not included here:
Photos and biopsy samples were collected during some sightings. Acoustic detections were recorded from a towed hydrophone array. Sonobuoys were deployed opportunistically.
High-frequency Acoustic Recording Packages (HARP) were recovered and redeployed off Saipan, Tinian, and Pagan. Drifting Acoustic Spar Buoy Recorders (DASBRs) were deployed and recovered opportunistically (McCullough et al. 2021). Oceanographic data were collected (CTD).

Overview

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.
All attributes are included in the downloadable file (CSV or ESRI File Geodatabase) for "Complete Set of Dataset".

Attributes in dataset

Attribute (table column)	Description
oid	Unique ID number (generated by OBIS-SEAMAP)
line	Line No.
sightno	Sighting No. (continuous numbers incrementing from 1)
datetime	Date and time of the sighting at local time zone
lat	Ship Latitude in decimal degrees
lon	Ship Longitude in dcimal degrees
cruise	Cruise No.
mode	C = closing (observer team went off-effort when a cetacean group was sighted to focus on species identification, group-size estimation, or other data collection); P = passing (search effort was continuous even after a sighting was made; rare - generally occurring only when the ship was required to be somewhere at a specific time)
efftype	Effort Type: S = standard/systematic (search effort while following predetermined parallel transects); N = Non-standard/non-systematic (search effort during transit between transect lines, to & from port, or circumnavigating islands); F = fine scale (when the ship was following standard data collection protocols within the study grid, but was headed toward or away from a DASBR deployment so not on the pre-determined trackline))
oneffort	Effort status assigned in the field: TRUE = on-effort (the 3-person observer team was on the flying bridge actively searching for cetaceans); FALSE = off-effort (the observer team had suspended active searching; e.g., during another sighting or inclement weather). Depending on analysis assumptions, some on-effort sightings could be considered off-effort (e.g., made by a non-primary observer or past a specified truncation distance). For more information on additional data attributes or considerations, please contact the data provider.
nsp	Number of cetacean species present during an encounter (sighting)
spcode	Numeric species code by provider
sciname	Scientific name
commonname	Common name
sp_tsn	Taxonomic Serial Number added by OBIS-SEAMAP
gsspbest	Best estimate of species group size (the arithmetic mean of all observers)
gssphigh	High estimate of species group size (the arithmetic mean of all observers)
gssplow	Low estimate of species group size (the arithmetic mean of all observers)
perpdistkm	Perpendicular distance (km) of the sighted group from the trackline
bft	Beaufort sea state
swellhght	Swell height (height of predominant swell in feet)
vis	Visibility (distance in nautical miles at which a dolphin could be seen surfacing with the water (not sky) as background)
geom	Geometry field added by OBIS-SEAMAP