NEFSC North Atlantic Marine Mammal and Turtle Aerial Abundance Survey 2007

NOAA Northeast Fisheries Science Center (NEFSC)

During 30 July to 29 August 2007, the Northeast Fisheries Science Center conducted an abundance survey using an airplane and ship in waters from Cape Hatteras, North Carolina to the Bay of Fundy, from the coast line to beyond the 2000 m depth contour. The shipboard survey (using the R/V Henry Bigelow) was concentrated in the coastal waters in the Gulf of Maine, and the aerial survey (using the NOAA Twin Otter) covered the rest of the area. The aerial results are reported in this document; while the shipboard results are reported in a companion paper. The primary objective for the aerial survey is to determine the spatial distribution and abundance of cetaceans and sea turtles in the study region. The airplane flew at 600 feet above the water surface at about 110 knots and the circle-back (Hiby) data collection methods were used, where circles were performed on groups of cetaceans and turtles that had 5 or less animals per group. There were about 8,900 km of on-effort track lines that were conducted in Beaufort 3 or less and will be used in the abundance estimates. On these track lines, there were 15 species of identifiable cetaceans, 4 turtle species detected. There were 98 circle-backs performed on 20 species/species groups that can be used to estimate g(0) for these species. The abundance estimates using these data are underway.

The primary objective is to determine the spatial distribution and abundance of cetaceans and sea turtles in the study region. The aerial survey was coordinated with a shipboard survey. Each platform covered separate regions, except for two small areas which were surveyed simultaneously by both platforms on the same day on the same track lines.

Perpendicular distance to the animal is not publicly available.

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)
cruise	Cruise ID
year	Year
month	Month
day	Day
time	Time of the sighing at local time zone
sightlat	Latitude at decimal degrees
sightlon	Longitude at decimal degrees
species	Species code
sp_tsn	Taxonomic Serial Number added by OBIS-SEAMAP
groupsize	Group size
transect	Transect No.
leg	Leg
sighting_number	Sighting number
beaufort	Beaufort sea state
perp_m	Perpendicular distance, measured in meters
effort	Effort (on/off)
quality	General sighting quality as seen by the port and starboard observers, where the first number is the port observer and the second number is the starboard observer
cloud	Percent cloud cover, usually rounded to 10 degrees
glare_mag	Glare code
geom	Geometry field added by OBIS-SEAMAP