NMML 1999 Bering Sea Shelf Cetacean Survey
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seamap123
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Summary
Abstract:
Visual line-transect surveys for cetaceans were conducted in the central-eastern Bering Sea (CEBS) from 5 July to 5 August 1999, in association with a pollock stock assessment survey aboard the NOAA ship Miller Freeman. Observers scanned for cetaceans with 25x (Big Eye) binoculars form the flying bridge (platform height = 12m) at survey speeds of 18.5-22 km h-1 (10-12 knots). Transect survey ... effort was 1761 km, in a study area 196,885 km2. An
additional 609 km of trackline was surveyed, respectively, while in transit to
or from Pollock survey way points. Fin Whales (Balaeoptera physalus) were the
most common large whale, and Dall's porpoise (Phocoenoides dalli) the most
common small cetacean. In the CEBS (1999), uncorrected cetacean abundance
estimates were: 3368 (CV = 0.29) fin whales, 810 (CV . 0.36) minke whales (B.
acutorostrata), 14,312 (CV = 0.26) Dall's porpoise and 693 (CV = 0.53) harbor
porpoise (Phocoena phocoena). Non-pollock echosigns observed near cetaceans,
some of which may have been cetacean prey, were not routinely identified during
trawl sampling because the research focus was on pollock abundance assessment.
© 2002 Elsevier Science Ltd. All rights reserved. Clearly, additional surveys
and concomitant assessment of cetacean prey are needed to define their role in
the Bering Sea ecosystem better. Such surveys, combined with measures of local
hydrography and prey field should be the goal of future cetacean assessments. 
Purpose:
Cetacean distribution and abundance in the Bering Sea is poorly described, with even recent reviews of cetaceans' role in the ecosystem reliant on data from the commercial whaling era (e.g. Springer et al., 1999; Springer, McRoy, & Flint, 1996). Commercial harvests of baleen whales (mysticetes) were extensive in the North Pacific and Bering Sea (Miyashita, Kato, & Kasuya, 1995), especially between ... 1835 and 1850 for North Pacific right whales (Webb,
1988) and between 1965 and 1979 for fin and humpback whales (Wada, 1981). The
effect of these large-scale removals on the marine ecosystem is largely
unknown. Similarly, some species of toothed whales (odontocetes) are sometimes
killed in the course of commercial fishing operations. Pelagic dolphins and
Dall's porpoise were especially vulnerable during high seas driftnet fishing in
the North Pacific in the 1980s (Hobbs & Jones, 1993), and once again the
long-term ramifications of these removals are unknown. One reason for this
uncertainty is the lack of data on current cetacean distribution and estimates
of abundance in pelagic environments. Surveys to determine distribution and
abundance are costly and, therefore, often confined either to coastal waters
where the logistics are most practical (e.g. Barlow, 1995), or to areas of the
ocean where marine mammal mortality associated with commercial fishing is
particularly high (e.g. Hobbs & Jones, 1993). The pelagic waters of the Bering
Sea have not met either criteria and so are comparatively undersampled for
cetaceans. Cruises were undertaken in association with the Alaska Fisheries
Science Center/Resource Assessment and Conservation Engineering (AFSC/RACE)
division to conduct visual surveys for cetaceans during the semi-annual
acoustic trawl surveys for walleye pollock (Theragra chalcogramma) on the
Bering Sea shelf (Tynan, 1999). Biologists from the AFSC/National Marine Mammal
Laboratory (NMML) were able to join surveys in the central-eastern Bering Sea
(CEBS) in 1999 providing an opportunity to describe cetacean distribution and
calculate abundance over a broad area of the Bering Sea shelf.
SUPPLEMENTAL INFORMATION: Provisional results of the 1999 survey in the CEBS
were presented in Moore, Waite, Mazzuca and Hobbs, 2000), but without clear
reference to the three hydrographic domains (Coastal, Middle Shelf, and Outer
Shelf) that delineate oceanographic and productivity patterns in the Bering Sea
(Coachman, 1986). Here, we present the first estimates of cetacean abundance
that can be compared between two broad pelagic zones, as well as cetacean
distribution and sighting rates relative to hydrographic domains and fronts
commonly referred in papers describing oceanographic processes in the eastern
Bering Sea (e.g. Hunt, 1997; Napp, Kendall, & Schumacher, 2000; Springer et
al., 1996; Stabeno, Bond, Kachel, Salo, & Schumacher, 2001).
CURRENTNESS REFERENCE: ground condition
SPATIAL REFERENCE INFORMATION -
GEODETIC MODEL
Horizontal Datum Name: D_WGS_1984
Ellipsoid Name: WGS_1984
Semi-major Axis: 6378137.000000
Denominator of Flattening Ratio: 298.257224
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Geographic Coverage
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Spatial coordinates
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N: 63.01
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S: 53.96
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E: -163.46
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W: -178.87
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Data Set Citation
Dataset Originator/Creator:
National Marine Mammal Laboratory
Dataset Title:
NMML 1999 Bering Sea Shelf Cetacean Survey
Dataset Series Name:
OBIS-SEAMAP
Dataset Release Date:
2004-06-23 19:57:14.4825-04
Dataset Release Place:
http://seamap.env.duke.edu/
Dataset Publisher:
OBIS-SEAMAP
Data Presentation Form:
vector digital data
Online Resource:
http://nmml.afsc.noaa.gov/
Parent DIF
This data set description is a member of a collection. The
collection is described in
OBIS-SEAMAP
Temporal Coverage
Start Date:
1999-07-07
Stop Date:
1999-08-04
Data Resolution
Latitude Resolution:
0.000167 Decimal degrees
Longitude Resolution:
0.000167 Decimal degrees
Horizontal Resolution Range:
1 meter - < 30 meters
Access Constraints
ACCESS CONSTRAINTS: Open public unless otherwise noted.
DISTRIBUTION LIABILITY: Not to hold OBIS-SEAMAP liable for errors in the data.
While we have made every effort to ensure the quality of the database, we
cannot guarantee the accuracy of these datasets. Also please refer to Use
Constraints.
Use Constraints
Not to use data contained in OBIS-SEAMAP in any publication, product, or
commercial application without prior written consent of the original data
provider. To cite both the data provider and OBIS-SEAMAP appropriately after
approval of use is obtained. Also please refer to Distribution Liability.
Data Set Progress
COMPLETE
Distribution
Distribution Format:
Shapefile
Personnel
Role:
TECHNICAL CONTACT
Role:
DIF AUTHOR
Phone:
919-613-8021
Fax:
919-684-8741
Email:
efujioka at duke.edu
City:
Durham
Province or State:
NC
Postal Code:
27708
Country:
USA
Role:
TECHNICAL CONTACT
Phone:
206-526-6554
Email:
Janice.Waite at noaa.gov
Contact Address:
NATIONAL MARINE MAMMAL LABORATORY
7600 Sand Point Way N.E.
City:
Seattle
Province or State:
Washington
Postal Code:
98115-6349
Country:
USA
Publications/References
Cetacean distribution and relative abundance on the central-eastern and the
southeastern Bering Sea shelf with reference to oceanographic domains. 2002.
Progress in Oceanography. 55: 249-261.
Creation and Review Dates
DIF Creation Date:
2007-01-22
Last DIF Revision Date:
2008-01-13
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