Norfolk/VA Beach Bottlenose Dolphin Photo-ID Surveys

The U.S. Navy Marine Species Monitoring Program

A combination of visual line-transect survey, photo-
identification (photo-ID), and automated acoustic
monitoring methods was used to gather important baseline
information on the occurrence, distribution, and density
of marine mammals near Naval Station Norfolk (NSN) and
adjacent areas. The study area was designed to cover areas
where United States Navy activity is substantial,
including Chesapeake Bay waters near NSN and Joint
Expeditionary Base Little Creek-Fort Story, as well as a
Mine Exercise (MINEX) Area (W-50) in the Atlantic Ocean
off the coast of Virginia Beach, Virginia. Sixty-one line-
transect surveys were completed in two zones (INSHORE and
MINEX) between August 2012 and August 2015, with 6,550
kilometers (km) and 349.6 hours completed on-effort. The
majority of sightings were of bottlenose dolphins
(Tursiops truncatus), although humpback whales (Megaptera
novaeangliae), harbor porpoises (Phocoena phocoena), and
short-beaked common dolphins (Delphinus delphis) were also
sighted in the study area on occasion. In addition,
loggerhead sea turtles (Caretta caretta), leatherback sea
turtles (Dermochelys coriacea), and a Kemp’s ridley sea
turtle (Lepidochelys kempii) were sighted during surveys.
Conventional line-transect analysis of bottlenose dolphin
sightings showed both spatial and seasonal variation in
density and abundance, with greatest density in the
INSHORE zone during fall months. Densities in the INSHORE
zone were calculated as 3.88 individuals per square
kilometer (km2) (abundance[N]=1,203) in fall, 0.63
individuals per km2 (N=195) in winter, 1.00 individuals
per km2 (N=311) in spring, and 3.55 individuals per km2
(N=1,101) in summer. Densities in the MINEX zone were
calculated as 2.14 individuals per km2 (N=1,277) in fall,
0.06 individuals per km2 (N=37) in winter, 1.53
individuals per km2 (N=913) in spring, and 1.39
individuals per km2 (N=829) in summer. Twenty-seven photo-
ID surveys were completed, and a photo-ID catalog was
created using photos taken during both dedicated photo-ID
and line-transect surveys through May 2014; it contains
878 identified individuals to date. Subsequent photos will
continue to be added and analyzed. One hundred ten
individuals were re-sighted; however, most re-sightings
were less than 4 months and 30 km apart. Additional survey
effort and further analysis will be required before any
clear movement patterns can be determined. C-POD acoustic
data-loggers were initially deployed at four sites
throughout the study area to cover areas of high United
States Navy activity. Bottlenose dolphins were detected in
each deployment location during all deployments from
August 2012 to December 2015. Though deployments did not
provide consistent coverage in all seasons for all sites
due to loss of gear, results from two deployment sites
nearest to NSN showed a greater level of occurrence during
fall months, and a diel pattern of occurrence with
increased detections during nighttime hours for three
deployment sites.

The HDR Marine Species Monitoring (MSM) Team was tasked to
initiate a monitoring project in coastal waters around
NSN, JEB-LC, JEB-FS, and the Virginia Beach waterfront,
including the VACAPES MINEX W-50 training area. The main
objective is to provide quantitative data and information
on the seasonal occurrence, distribution, and density of
marine mammals. Effort was dedicated to working with local
researchers and employing proven marine mammal monitoring
and research techniques to accomplish the following:

1. Conduct monthly systematic line-transect surveys to
determine distribution of marine mammals in the vicinity
of NSN, JEB-LC, JEB-FS, and the MINEX W-50 area.

2. Conduct monthly photo-identification (photo-ID) surveys
during summer months to determine the site fidelity and
distributional patterns of marine mammals utilizing the
areas listed above.

3. Supplement visual surveys by deploying and retrieving
four C-POD acoustic recording devices to monitor for
dolphin echolocation clicks in specific locations.

[2019-08-27] New data were appended and some columns with
empty values were removed. The dataset name is changed by
dropping the time period part.

This dataset includes sightings from photo-id surveys. No
images and information on individual animals are provided.

This dataset includes a subset of the data collection for
the Norfolk-VABeach Vessel surveys.
Other data of the collection are available in the
following datasets:
target="_blank">Norfolk/VA Beach Inshore Vessel Surveys
Nov 2012- Nov 2013
target="_blank">Norfolk/VA Beach MINEX Vessel Surveys

All the US Navy-funded survey datasets are found in the href="http://seamap.env.duke.edu/partner/NAVY"
target="blank">OBIS-SEAMAP US Navy page.

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)
behavior	Initial behavioral state of the animal or group when first observed. Examples: Travel, Mill, Rest
beaufortscale	Beaufort sea state (0-12)
countcalves	The number of calves in the sighting
counttotmax	The highest estimate of the number of animals in the sighting
counttotmin	The lowest estimate of the number of animals in the sighting
cue	The sighting cue that initially drew the observers attention
depthsounding	Depth as determined in situ via sounding in meters
effortstatus	The effort status of the platform. Options: On-effort (systematic), on-effort (focal follow), on-effort (circling), on-effort (random), off-effort (connector lines), off-effort (transiting), off-effort (other)
headingplatmagnetic	Heading of the observation platform relative to magnetic North in degrees
headingplattrue	Heading of the observation platform relative to true North in degrees
latplatform	The latitude of the platform in decimal degrees
longplatform	The Longitude of the platform in decimal degrees
observer	The name of the observer who first sighted the animal
observerright	Name of the observer on the right (starboard) side of the platform
ocean	The ocean where the survey took place (Pacific, Atlantic, Indian, etc.)
photoframes	The photo frames used for the sighting; or total frames taken
photogapher	Name of the photographer
photos	Were photos taken as part of the sighting? (Y/N)
pic	Pilot in command
platformmodel	Model of a/c or vessel (e.g. Partenavia Observer, RHIB, etc.)
platformtype	Type of survey platform (e.g., "aerial", "vessel")
rangecomplex	The Range complex (or complexes) associated with the survey (JAX, SOCAL, Cherry Point, etc.)
sightingnotes	Notes field to capture information not covered by existing attributes or other information of interest
sightingnumber	The sighting number for the particular survey day
spcsnmcom	Common name of the sighted species. Output should be singular (e.g. bottlenose dolphin)
sp_tsn	Taxonomic Serial Number added by OBIS-SEAMAP
sightingtimeend	The time at which the sighting was discontinued
surveyid	A survey identifier consisting of data collector, range complex, platform, year, month, and day. (Data Collector/Source)_(Range Complex)_(Platform Type or Details)_(Year)(Month)(Day) (eg. SES_SOCAL_Aerial_20120417)
geom	Geometry field added by OBIS-SEAMAP