Digital video aerial surveys of seabirds and marine megafauna in the Gulf of Maine from May 2023 to January 2024

Biodiversity Research Institute
HiDef Aerial Surveying Limited
Bureau of Ocean Energy Management (BOEM)

In April 2023, the Biodiversity Research Institute (BRI) commissioned HiDef
Aerial Surveying Limited (HiDef) to conduct high-resolution digital video
aerial surveys in the Gulf of Maine. The surveys aimed to record marine
megafauna, seabirds, and human activity. The designated survey area is
approximately 5 km off the coast of Maine

A total of four surveys were conducted between May 2023 and January
2024. HiDef designed the survey using 2.5 km- and 5 km-spaced transects
across the Gulf of Maine survey area, covering approximately 6,673 km².

Surveys were undertaken using an aircraft equipped with four HiDef
cameras with a sensor package designed and calibrated to achieve a
resolution of 1.5cm Ground Sample Distance (GSD). Each camera sampled
a strip of ~ 104m width, separated from the next camera by ~ 17m, to
provide a combined sampled width of 416m within a 467m overall strip. All
four cameras were analyzed, achieving approximately 10% coverage of the
survey area during each flight.

Data analysis followed a two-stage process in which video footage was
reviewed (with a 20% random sample used for audit) and detected objects
were identified to species or species group level (again with 20% selected
at random for audit). The audit of both stages requires 90% agreement to
be achieved.

The surveys recorded a total of 7,248 birds of 33 species and 534 non-avian
animals of 12 species, in addition to two dead birds. A further 409 birds and
58 non-avian animals were recorded which were not assigned to a species.
An identification rate to species level of 94% was achieved throughout the
survey period.

In April 2023, the Biodiversity Research Institute (BRI) commissioned HiDef
Aerial Surveying Limited (HiDef) to conduct high-resolution digital video
aerial surveys in the Gulf of Maine. The surveys aimed to record marine
megafauna, seabirds, and human activity. The designated survey area is
approximately 5 km off the coast of Maine A total of four surveys were
conducted between May 2023 and January 2024. HiDef designed the
survey using 2.5 km- and 5 km-spaced transects across the Gulf of Maine
survey area, covering approximately 6,673 km².

Survey effort (points) is included in the download.

The dataset has been updated over time as outlined below. Each entry includes the version number, release date, type of change, and a short description.

Overview

This section explains attributes included in the original dataset. The availability of the attributes depends on the share policy. When "Minimum attributes" is selected, only date/time, lat/lon, species identification and group size are available. Should you need other attributes described here, you are encouraged to contact the data provider. When "All attributes" is selected, all attributes are available in download.

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)
data_owner	Owner of the data
survey	Survey identifier
survey_date	Date of survey
camera	The camera ID (1-4)
cam___gsr	Image ground spatial resolution in cm.
reel_ref	Video segment identifier.
time	Time of observation
frame_ref	Frame number in video file the object was observed.
broad_category	Broad category of observed object or location.
species_group	Organism species group
group_confidence	Confidence in group identification (possible, probable, definite).
species	Species identification.
species_confidence	Confidence in speciesidentification (possible, probable, definite).
bto_code	Abbreviated species code
sp_tsn	ITIS Taxonomic Serial Number added by OBIS-SEAMAP
obs_count	Number of animal added by OBIS-SEAMAP (always 1)
behaviour	Animal behavior observed in imagery.
submerged	Whether the animal was observed below the water surface or at the surface. For marine mammals, surfacing behavior was classified into four categories: Surfacing - Any part of the animal visible above the water surface. Surfacing at red line (snapshot surfacing) - The dorsal fin breaking the surface at the frame nearest to the
age	Age of animal.
sex	Sex of animal.
measurements	Length measurements of animal for ID purposes.
additional_comments	Ancillary comments.
latitude	Calculated latitude of object or point based on position of cameras.
longitude	Calculated longitude of object or point based on position of cameras.
strip_width__m_	Width of effort (meters) at that location.
seastate	Beaufort sea state estimated by the imagery.
turbidity	Turbidity category (1-4).
air_clarity	Air clarity category (1-4).
cam1___gsr	Image ground spatial resolution in cm for camera 1.
cam1___valid	Validity of data on camera 1. Is the quality of the image good enough for use in final data.
cam1___glare	Glare estimate value for camera image.
cam2___gsr	Image ground spatial resolution in cm for camera 2.
cam2___valid	Validity of data on camera 2. Is the quality of the image good enough for use in final data.
cam2___glare	Glare estimate value for camera image.
cam3___gsr	Image ground spatial resolution in cm for camera 3.
cam3___valid	Validity of data on camera 3. Is the quality of the image good enough for use in final data.
cam3___glare	Glare estimate value for camera image.
cam4___gsr	Image ground spatial resolution in cm for camera 4.
cam4___valid	Validity of data on camera 4. Is the quality of the image good enough for use in final data.
cam4___glare	Glare estimate value for camera image.
center_of_effort_latitude	GPS latitude for camera image center.
center_of_effort_longitude	GPS longitude for camera image center.
geom	Geometry field added by OBIS-SEAMAP