SWFSC Marine Mammal Survey, PODS 1993, Cruise 1509
NOAA Southwest Fisheries Science Center (SWFSC)
Dataset credit
NOAA Southwest Fisheries Science Center (SWFSC)
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Contacts
Role | Name | Organization | |
Primary contact |
Jeffrey Moore |
Southwest Fisheries Science Center, NOAA |
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Secondary contact |
Dave Weller |
NOAA Southwest Fisheries Science Center |
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Data entry |
Benjamin Best |
Duke University |
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Citation
Gerrodette, T. 2004. SWFSC Marine Mammal Survey, PODS 1993, Cruise 1509. Data downloaded from OBIS-SEAMAP (http://seamap.env.duke.edu/dataset/215) on yyyy-mm-dd. Halpin, P.N., A.J. Read, E. Fujioka, B.D. Best, B. Donnelly, L.J. Hazen, C. Kot, K. Urian, E. LaBrecque, A. Dimatteo, J. Cleary, C. Good, L.B. Crowder, and K.D. Hyrenbach. 2009. OBIS-SEAMAP: The world data center for marine mammal, sea bird, and sea turtle distributions. Oceanography. 22(2):104-115.
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Abstract
This 1993 line-transect survey was designed to make abundance estimates of the northern stock of common dolphin, Delphinus delphis, in the eastern Pacific. This stock of dolphin is taken in the tropical tuna fishery. The index of relative abundance for this stock, computed from sightings on tuna vessels, has declined substantially in the last decade. However, because tuna vessels cover only the southern portion of the stock's range, the declines in the index may be due to a northward shift in distribution, rather than an actual decline in abundance. The 1993 survey was designed to produce the first range-wide estimates of abundance for the northern common dolphin and its recently described congener, Delphinus capensis. This survey was conducted by the NOAA Southwest Fisheries Science Center aboard NOAA Ships McArthur and David Starr Jordan for a combined total of approximately 32,000 kilometers surveyed from late July to early November 1993. This dataset provides the time-date and geographical coordinates, by species/stock, of all cetaceans detected during the survey, as well as the daily and intra-daily start and end points of the line-transect survey by the NOAA Ship David Starr Jordan.
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Purpose
The primary objective of the cruise was to survey the area inhabited by the northern stock of common dolphins, and to make an estimate of its absolute abundance in order to assess the impact of the dolphins killed by the United States and international yellowfin tuna purse seine fleet in the eastern tropical Pacific.
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Supplemental information
[2021-04-12] Updated with additional attributes.
SWFSC MMTD Cruise Number: 1509 Perpendicular distance will be released upon permission by the contributor. Please contact the contributor if needed.
Attribute descriptions for effort data: dist: Length of the segment (km) Mode: Effort mode type (C = closing mode; P = passing mode)
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References
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Attributes
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) |
event | Event code. S = cetacean sighting, t = sea turtle sighting, p = pinniped sighting |
datetime | Date and time of sighting (local time) |
lat | Latitude (decimal degrees) of vessel when sighting was made |
lon | Longitude (decimal degrees) of vessel when sighting was made |
cruise | SWFSC Marine Mammal and Turtle Divison Cruise number |
sightno | Sighting number (within Cruise) |
nsp | Number of species observed in the sighting |
mixed | TRUE for a multi-species sighting (nSp >= 2); FALSE otherwise (nSp = 1) |
spcode | Species code |
sp_tsn | Taxonomic Serial Number added by OBIS-SEAMAP |
gsspbest | The mean of all observers |
gssphigh | The mean of all observers |
gssplow | The mean of all observers |
perpdistkm | Perpendicular distance (km) to sighting from trackline; Available upon permission. |
bft | Beaufort sea state, as assessed by looking upswell with the naked eye |
swellhght | Average swell height from trough to crest of typical swells (estimated in feet, by eye) |
vis | A measure of air/atmospheric clarity only, as affected by observational conditions such as fog, rain, etc. |
groupsize_sightno | Running count ID of all cetacean groups recorded |
groupsize_count | Number of observers that provided a group size estimate |
groupsize_count_obs | Number of unique observer codes per sighting for S events |
geom | Geometry field added by OBIS-SEAMAP |
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OBIS-SEAMAP ID | 215 |
Seabirds | 0 |
Marine mammals | 1,039 |
Sea turtles | 108 |
Rays and sharks | 0 |
Other species | 0 |
Non spatial | 0 |
Non species | 0 |
Total | 1,147 |
Date, Begin | 1993-07-29 |
Date, End | 1993-11-05 |
Temporal prec. | 111111 |
Latitude | 18.69 - 32.09 |
Longitude | -120.10 - -105.50 |
Coord. prec. | 6 decimal digits |
Platform | Boat |
Data type | Animal sighting |
Effort | YES (ID: 216) |
if ($show_effort_stat) {
?>
Traveled (km) | 11,173 |
Effort hours | 585 |
}
if ($sources != null and $sources != "" and $dataset_id != 427) { // Do not show ESAS
?>
Contr. through | |
}
?>
Registered | 2004-09-16 |
Updated | 2021-04-29 |
Status | Published |
Sharing policy |
CC0 no rights reserved |
Shared with |
OBIS
GBIF (via DOI) |
See metadata in static HTML |
See metadata in FGDC XML |
See download history / statistics |
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