GulfCet II: Visual Surveys of Cetaceans and Sea Turtles from Aircraft
Entry ID:
usgsbrdcr_d_GulfCetII_4visair
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Summary
Abstract:
The visual survey of cetaceans and sea turtles from aircraft data set is part
of the overarching GulfCet II study, Cetaceans, Sea Turtles and Seabirds in the
Northern Gulf of Mexico: Distribution, Abundance and Habitat Associations,
which provides synoptic data and analyses on the species diversity, abundance,
and habitat characteristics for ... cetaceans, sea turtles and seabirds in the
northern Gulf of Mexico. In the EPA slope, a total of 18,788 km of transects
were sampled during the four seasonal aerial surveys. All of the proposed
transect lines (84 lines) were completed during summer surveys (10,440 km).
The primary objectives of the GulfCet II visual aerial and ship surveys were as
follows: (1) obtain a minimum abundance estimate for each cetacean and sea
turtle in the northeastern Gulf to establish a baseline for monitoring trends
in abundance over time. (2) to study the seasonal abundance and distribution
patterns of cetacean and sea turtle species in the northeastern Gulf. (3)
compare spring abundance estimates of cetacean species in continental slope
waters of the north-central and northwestern Gulf (GulfCet I study area) to
those made by Hansen et al. (1996) for the same area fro 1991-94 data.
Methodology: The GulfCet II aerial surveys were a continuation of aerial
surveys reported by Hansen et al. (1996) from Gulf Cet I. Seasonal sampling
intensity in the EPA shelf and slope study areas was similar to that expended
during GulfCet I. Systemic transects with a random start that generally
crossed isobaths orthogonally were uniformly spaced throughout the aerial
survey area. This design ensured that transects were randomly situated with
respect to cetacean density and allowed examination of cetacean distribution
throughout the study area. Each season the goal was to survey 58 transect
lines (spaced every 13.5 kilometers) totaling 6,133 km of transect effort. They
included 42 transect lines (total of 5,220 km) on the continental shelf (waters
< 100 m deep). Aerial surveys were conducted during summer 1996 and 1997, and
winter 1997 and 1998. As in GulfCet I, effort was based on projected
availability of acceptable survey conditions and flight times to the study
area.
Information for this metadata was taken from the report Cetaceans, Sea Turtles
and Seabirds in the Northern Gulf of Mexico: Distribution, Abundance and
Habitat Associations. Editors Randall W. Davis, William E. Evans and Bernd
Wursig. Prepared under the U.S. Geological Survey, Biological Resources
Division by the GulfCet Program, Department of Marine Biology, Texas A & M
University at Galveston, Galveston, Texas.
Geographic Coverage
Spatial coordinates
| N: 30.0 |
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S: 24.0 |
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E: -84.0 |
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W: -90.0 |
Data Set Citation
Dataset Creator:
Keith D. Mullin, and Wayne Hoggard
Dataset Title:
Visual Surveys of Cetaceans and Sea Turtles from Aircraft
Dataset Release Date:
1999-01-01
Dataset Release Place:
Galveston, Texas 77843
Dataset Publisher:
USGS, BRD by the GulfCet Program, Dept. of Marine Biology, Texas A&M U
Data Presentation Form:
spreadsheet
Online Resource:
http://www.gomr.mms.gov/homepg/whatsnew/techann/000002.html
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Temporal Coverage
Start Date:
1996-07-11
Stop Date:
1996-07-30
Start Date:
1997-02-07
Stop Date:
1997-03-20
Start Date:
1997-07-15
Stop Date:
1997-08-06
Start Date:
1998-02-08
Stop Date:
1998-03-14
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Location Keywords
Science Keywords
ISO Topic Category
Platform
Project
Quality
During the aerial surveys, cetaceans and sea turtles were identified to the
lowest taxonomic level possible based on descriptions in field guides and
scientific literature (e.g., Leatherwood and Reeves 1983, Carwardine 1995).
The ability to make an identification was dependent upon water clarity, sea
state and animal behavior. Identifications to species level were ... not always
possible for some genera or groups of species. For example, dwarf and pygmy
sperm whales could not be distinguished from each other from aircraft and could
not be reliably distinguished from each other from ships, and were identified
as dwarf/pygmy sperm whales. In some cases, cetaceans could only be identified
as large whales (> 7 m long), small whales (non-dolphin, <7m), dolphins,
odontocetes, and turtles as unidentified chelonids.
In the EPA slope, a total of 18,788 km of transects were sampled during the
four seasonal aerial surveys. All of the proposed transect lines (84 lines)
were completed during summer surveys (10,440 km). During winter aerial surveys,
poor weather prevented all of the transects from being surveyed, and 8,348 km
(80%) of the proposed effort was completed (66 lines). In total, 271 cetacean
groups were sighted (154 summer, 117 winter).
Access Constraints
None
Use Constraints
Dataset credit required
Ancillary Keywords
Data Set Progress
Data Center
Distribution
Distribution Format:
Excel spreadsheet
Fees:
none
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Personnel
KEITH
MULLIN
Role:
TECHNICAL CONTACT
Phone:
228 762-4591
Fax:
228 769-9200
Email:
kmullin at triton.pas.nmfs.gov
Contact Address:
National Oceanographic and Atmospheric Administration
National Marine Fisheries Service
Southeast Fisheries Science Center
Mississippi Laboratory
City:
Pascagoula
Province or State:
Mississippi
Postal Code:
39568
Country:
USA
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Related URL
Publications/References
Eds. Davis, R.W., W.E. Evans, and B. Wursig, eds. 1999, Cetaceans, Sea Turtles
and Seabirds in the Northern Gulf of Mexico: Distribution, Abundance and
Habitat Associations. Galveston, Texas. Prepared under U.S. Geological Survey,
Biological Resources Division by the GulfCet Program, Department of Marine
Biology Texas A&M University at Galveston. In cooperation with ... the U.S.
Department of Interior, Minerals Management Service. Prepared under U.S.
Geological Survey, Biological Resources Division Contract Number
1445-CT09-96-0004 and 1445-IA09-96-0009. This report was prepared under
contract between the U.S. Geological Survey, Biological Resources Division
(BRD), Texas A&M University, and the National Marine Fisheries Service. This
report has been technically reviewed by the BRD and the Minerals Management
Service (MMS), and has been approved for publication. Approval does not signify
that the contents necessarily reflect the views and policies of the BRD or MMS,
nor does mention of trade names or commercial products constitute endorsement
or recommendation for use. It is, however, exempt from review and compliance
with the MMS editorial standards. Copies of the report may be obtained from the
Public Information Office at U.S. Department of the Interior, Minerals
Management Service, Gulf of Mexico OCS Region, Public Information Office (MS
5034), 1201 Elmwood Park Boulevard, New Orleans, LA 70123-2394, Telephone (504)
736-2519 or (800) 200-GULF.
Creation and Review Dates
DIF Creation Date:
1999-10-29
Last DIF Revision Date:
2005-02-10
Future DIF Review Date:
2000-10-29
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Links
