NEFSC Marine Mammal Abundance Cruise 2004 Passive Acoustic Monitoring - Porpoise Detections

Sofie Van Parijs

The primary objectives of the NEFSC Marine Mammal Abundance Cruise were to:
(1) determine the spatial distribution and abundance of cetaceans and turtles in the study region,
(2) determine the spatial distribution and relative abundance of sea birds in the same region, and
(3) use passive acoustics to record vocalizing cetaceans that will hopefully be used to improve the abundance estimates derived from the visual surveys.
A secondary objective was to compare the distribution of these species with each other, physical characteristics, such as depth contours and water temperature, and biological characteristics, such as relative plankton distributions.

During the NEFSC Marine Mammal Abundance Cruise 2004, no detections of harbor porpoise were made, although automated detections of echolocating dolphin species were made as groups passed directly by the hydrophone. A single porpoise-like event was attributed to a sighting of Kogia simus.

The Porpoise detector was developed by Douglas Gillespie and Olly Chapple for the International Fund Welfare (IFAW). It uses analog envelope tracing and software detectors; two narrow bandpass filters centered around 50 and 72 kHz and one broadband filter (100 kHz - 150 kHz). These are used to detect the broadband click ultrasonic vocalizations of dolphins, and the narrow band clicks produced by the harbor porpoise (Phoceona phocena), Vaquita (Phocena sinus) and Kogia spp. The detector was extensively trialled in the Baltic (Gillespie et al. 2005; OBIS-SEAMAP dataset: Baltic Porpoise Acoustic Surveys 01-02) and upper Gulf of California.

References:
Gillespie, D., P. Berggren, S. Brown, I. Kuklik, C. Lacey, T. Lewis, J. Matthews, R. Mclanaghan, A. Moscrop and N. Tregenza. 2005. Relative abundance of harbour porpoises (Phocoena phocoena). Journal of Cetacean Research and Management: 7(1):51-57.

Additional attributes caveat: The ranges and bearings associated with these data have not been validated or corrected in any way so they may vary from fairly accurate to completely wrong.

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	observation ID number
obs_date	observation date
obs_time	observation start time (UTC)
latitude	ship latitude when observation is abeam
longitude	ship longitude when observation is abeam
sp_obs	observed species
sp_tsn	ITIS number of species
obs_count	number of animals
index
number
gpsindex
gpstime
filename
duration
confidence
nporpoiseclicks
nbroadbandclicks
notherclicks
minbearing
maxbearing
comment
startsection
endsection
backgrounddc
backgroundac
porpoisebearing
otherbearing
startadctime
endadctime
automatic
timeabeam
secsoffbeam
rangeoffbeam
initialbearing
initialrange
sigtimeabeam
sigsecsoff
chi2
fitprob
storeclicks
block
acoustic
aframe
mast
acousticvisual
dualvisual
allthree
seastate
engine
ontrackhp