Coordinates of tagged seals in the San Juan Islands are reported. Seals were captured and tagged during 2007 to 2009 at several sites in Padilla Bay and the Rosario Strait of the Pacific Northwest coast. Seals were tagged with satellite-linked time-depth recorders (TDR's) and GPS receivers.

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Archival Copy

Version Date	Archive	Persistent Identifier	Date Assigned
2012-11-28	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.1575/1912/bco-dmo.3704.1	2019-03-01

Description

Data are in the PRV format, which means that there are time and location duplicates because all uplinks to the satellite are included.

Methods & Sampling

Seals were captured and tagged in April or May of 2007 and 2008 following the methods of Jeffries et al. (1993) at three sites: Padilla Bay, Bird/Belle Rocks, and Protection Island. In 2009, seals were captured on Protection Island. In 2007-2008, animals were tagged with time-depth recorders (TDR; Wildlife Computers, model Mk-9 or Mk-10F) and satellite tags. The TDR tags were placed on the dorsal midline of the animals and the satellite tags were placed on top the head. In 2009, animals were tagged with a combined satellite-linked TDR and Fastloc GPS receiver (Wildlife Computers, model Mk10AF). These instruments were epoxied to the animals on the dorsal midline so that satellite tags would be exposed to the air when the back of the seal reached the surface.

Position transmissions were received via the ARGOS satellite network. Tags transmitted locations daily. TDR sensors were programmed to sample every 10 seconds. TDR tags were equipped with a VHF transmitter to allow for the device to be recovered when it was shed during the animal's annual molt.

The Argos system provides 2 position estimates (lat/lon and lat2/lon2). Argos usually picks the correct lat/lon pair (of the two it generates), but occasionally it does not. When working with these data, one of the first steps is to check the lat/lon pairs to see if swapping out the lat/lon pair for the lat2/lon2 pair improves the data and is more biologically reasonable.

The Argos positioning system uses the following system for classifying location quality. These codes are used in the loc_q_flag column. Standard locations are those with > 4 uplinks from the tag; auxiliary locations are those with 4 or less uplinks from the tag.

loc_q_flag codes (according to Ward et al.):
Standard locations:
3 = 68th percentile predicted accuracy < 150 m
2 = 68th percentile predicted accuracy 150 - 350 m
1 = 68th percentile predicted accuracy < 1,000 m

Auxiliary locations:
0 = 4 uplinks, with > 1,000 m predicted accuracy
A = 3 uplinks, with no predicted accuracy
B = 2 uplinks, with no predicted accuracy

Data Processing Description

BCO-DMO made the following edits to the dataset:
- blanks were replaced with 'nd' to indicate 'no data';
- parameter names were modified to conform to BCO-DMO conventions;
- day, month, and year were separated from the original date column.

Data Files

File
seal_location_tracking.csv (Comma Separated Values (.csv), 4.59 MB) MD5:89c95c9b89d5f95b120867d2fe0c974d Primary data file for dataset ID 3704

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-0550443

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
Seal_Captures		2007-04-04	shoreside San_Juan_Islands	Alejandro Acevedo-Gutierrez (Chief Scientist)	data info

Instruments

SPOT5 Argos Transmitter

Supplied Description:

In 2007-2008, SPOT5 transmitters were epoxied to the tops of seals heads. Satellite locations were obtained daily.

Instrument Type

Generic Name: SPOT5 Argos Transmitter

Acronym: SPOT5

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/POS17/

Generic Description:

The SPOT5 is an Argos transmitter manufactured by Wildlife Computers (Redmond, WA) and designed for deployment on marine mammals, fish, or seabirds. SPOT5 devices use the Argos satellite network to transmit locations of animals with an accuracy of +/- 350-meters. See more information from the manufacturer.

Wildlife Computers Time-Depth Tag (TDR)

Supplied Name: Wildlife Computers TDR

Supplied Description:

TDR's were epoxied to seals along the dorsal midline. All TDR tags were equipped with an Eco-tech floatation pack and a VHF radio transmitter to allow for tracking and retrieval of the device once it became detached from the animal. TDR sensors were set to sample every 10 seconds and record only dives >2 m in depth or >30 s in duration. In 2009, the TDR's used contained an MK10-AF Argos transmitter.

Instrument Type

Generic Name: Wildlife Computers Time-Depth Tag (TDR)

Acronym: TDR

Generic Description:

Time depth recorders (TDR's) manufactured by Wildlife Computers, Redmond WA) are designed for studies of seals, penguins, fish, and marine mammals. Standard TDR's are mounted externally on the animal's body, where they record temperature and depth. See more information from the manufacturer.

Parameters

Date and time formats are described in python strftime() syntax.

Supplied Name	Supplied description	Supplied Units	Standard Name
seal_id	Unique seal identification.	unitless	sealname
pttno	PTT tag number.	unitless	tagid
inst	Name of the instrument (MK10 or SPOT 5; both manufactured by Wildlife Computers).	unitless	inst_model
lat	Primary latitude. (See Acquisition Description.)	decimal degrees	lat
lon	Primary longitude. (See Acquisition Description.)	decimal degrees	lon
lat2	Secondary estimate of latitude provided by Argos. (See Acquisition Description.)	decimal degrees	lat
lon2	Secondary estimate of longitude provided by Argos. (See Acquisition Description.)	decimal degrees	lon
month	Month of year (01 to 12).	mm	month
day	Day of month (01 to 31).	dd	day
year	4-digit year. in yyyy format	unitless	year
date	Date, in mm/dd/yyyy format.	unitless	date
time	Time, 24-hour clock.	HHMM	time
satellite	Identification of the Argos satellite transmitting the signal: A = METOP-A (MA); K = NOAA-15 (NK); L = NOAA-16 (NL); M = NOAA-17 (NM); N = NOAA-18 (NN); P = NOAA-N (NP). See more information.	unitless	no_bcodmo_term
loc_q_flaq	Location quality flag. The Argos system classifies points with decreasing precision: 3 > 2 > 1 > 0 > A > B. See Acquisition Description for code definitions.	unitless	q_flag