NYSDEC aerial surveys

New York State Department of Environmental Conservation

The New York State Department of Environmental Conservation Division of
Marine Resources contracted Tetra Tech to conduct aerial whale monitoring in
the New York Bight (NYB). Monitoring consisted of 36 monthly line-transect
aerial surveys starting in March 2017 and ending in February 2020. The NYB
survey area is a 43,449 square kilometer area of ocean from the south shore of
Long Island to the continental shelf break. These surveys focused on six large
whale species: the blue whale (Balaenoptera musculus), fin whale (B.
physalus), humpback whale (Megaptera novaeangliae), North Atlantic right
whale (Eubalaena glacialis), sei whale (B. borealis), and sperm whale
(Physeter macrocephalus). This longitudinal multi-year study provides new
insight into the occurrence, relative abundance, behavior, and densities and
abundance of the six large whale species, as well as the occurrence other
marine species, in the NYB.

A total of 733.1 hours and 149,482 kilometers of flight time were completed
over 263 survey flights. Observations were conducted by two observers from a
high-winged, twin-engine Partenavia aircraft; one observer was positioned on
each side of the aircraft and looked through bubble windows. Data recorded
included all parameters required to estimate density and abundance using
distance sampling techniques. A total of 3,069 sightings of 37,410 estimated
individuals were recorded, including all six large whale species, other marine
mammals, sea turtles, and other marine species (i.e., sharks, rays, fish
schools, etc.).

Further details may be found in the Final Comprehensive Report at
www.dec.ny.gov/docs/fish_marine_pdf/mmaeran3.pdf and the associated
references.

The primary goals of the aerial surveys were:
(1) Determine the distribution and estimate relative abundance and density of
the six large whale species;
(2) Determine monthly and seasonal occurrence, and inter-annual variability
of the distribution and estimated abundance, density, and relative abundance
for the six species;
(3) Record data about the behavior of sighted large whales;
(4) Record opportunistic sightings of sea turtles and other marine species; and
(5) Record relevant environmental variables.

Environmental data are available and included in the downloadable zipped file.

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)
date_time	definition not provided
decl_angle	Declination Angle to Sighting
bearing_obs	Observed Bearing to Sighting (e.g. 320, R, L, 33R, 6:00)
species	Initial Species Identification
sp_tsn	Taxonomic Serial Number added by OBIS-SEAMAP
sgt_dist	Distance to sighting
init_grp_beh	Initial Group Behavior State: Fast Travel, Medium Travel, Mill, Other, Probable Foraging, Rest/Slow Travel, Surface Active Mill, Surface Active Travel, Unknown
beh_desc	Behavior Description SW = Norm Swim, CH = Charging, MI = Milling, BR = Breeching, FE =Feeding, LO = Logging, SA =SAG, DI = Diving, OT = Other
swim_dir	Initial Group Heading Observed (e.g. 320, L, R, 33L, 6:00)
min_disp	Minimum Dispersion (in body lengths)
max_disp	Maximum Disperson (in body lengths)
min_cnt	Minimum Count
max_cnt	Maximum Count
best_count	Best Count
min_calves	Minimum Number of Calves
leg_type	Type of leg currently being flown
lbft	Left beaufort (copied from Effort/Env)
rbft	Right beaufort (copied from Effort/Env)
photos	Whether or not photos were taken
circling	Whether or not this sighting was circled.
gps_alt_ft	GPS Altitude at time of sighting
bearing_abs	Absolute Bearing to Sighting
init_grp_hdg_abs	Initial Group Heading
latitude	Latitude in decimal degrees
longitude	Longitude in decimal degrees
psd_km	Perpendicular Sighting Distance
depth_ft	Depth (negative) or Elevation (positive) at Sighting Position
slope	Slope at Sighting Position
aspect	Slope Aspect at Sighting Position
shore_dist_km	Distance to nearest shoreline from Sighting Position
geom	Geometry field added by OBIS-SEAMAP