OND99 Quarterly Rpt. sidebar
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(Quarterly
Report for Oct-Nov-Dec 1999)
1999 On-Ice
Monitoring and Research Workshop
The National Marine Mammal Laboratory (NMML), in
cooperation with the NMFS Office of Protected
Resources, has hosted annual workshops for several
years with representatives from industry, federal
agencies, research groups, and other interested
parties to discuss and evaluate the potential
impacts of oil and gas exploration and development
in the Beaufort Sea on marine mammals. Prior
to 1998, the majority of these discussions focused
on monitoring and research associated with
industrial activities during open water periods in
the spring, summer, and fall. Most of the monitoring
efforts were related to possible impacts on bowhead
whales. However, in May 1998 and October 1999,
the NMML hosted workshops to specifically address
monitoring and research efforts associated
with industrial activities conducted on the sea ice
during winter. The main goals of the May 1998
workshop were to consider the status of on-ice
seismic activities and incidental harassment
authorization, to identify information needed to
conduct meaningful impact assessments of such work,
and to recommend future actions. Most of the
discussion at this workshop focused on
monitoring efforts related to possible impacts on
bearded and ringed seals. Objectives of the October
workshop were to review recent on-ice research and
monitoring programs, identify data gaps, and suggest
possible improvements for future short- and
long-term research that will assist in assessing the
impacts of on-ice industrial activities on marine
mammals. The workshop was chaired by Robyn
Angliss of NMML. A draft workshop report was
circulated to participants in November 1999; a final
workshop report is expected to be available during
the first quarter of 2000.
By Robyn P. Angliss
Alaska Scientific Review Group Meeting
The 10th meeting of the Alaska Scientific Review
Group (AKSRG) was held at the NMFS Alaska Regional
Office in Juneau from 6 to 8 October 1999. Staff
from both the NMML and the Regional Office presented
fisheries and marine mammal data and facilitated the
meeting. The purposes of the meeting were to
review the revised 2000 Stock Assessment Reports (SARs)
for marine mammal stocks in Alaska, to discuss
current data on Cook Inlet beluga whales, and to
review NMFS and U.S. Fish and Wildlife Service plans
for marine mammal research and management. Special
attention was given to updated assessment
information on harbor porpoise, Pacific white-sided
dolphin, Dall’s porpoise, and gray whale. Additional
discussions addressed a broader range of issues
including subsistence harvest monitoring strategy,
incidental take monitoring programs, ringed seal
incidental harassment authorizations, and progress
on the development of comanagement agreements with
Alaska Natives. The draft 2000 SAR is expected
to be available for public comment in January 2000.
By Rich Ferrero
The 13th Biennial Meeting of Society for
Marine Mammalogy
National Marine Mammal Laboratory scientists
participated in the 13th Biennial Meeting of the
Society for Marine Mammalogy held in Maui, Hawaii,
from 28 November to 3 December 1999. Oral
presentations and posters presented at the meeting
by NMML staff (in bold) are listed below.
Oral
Presentations
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Anne York — (cooperative work
Alexander Boltnev, Marine Mammal Laboratory,
Petropovlosk, Kamchatksky) presented “Maternal
investment in northern fur seals:
Interrelationships among mother’s age, size,
parturition date, offspring size, and sex-ratio.
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Bruce Robson — (cooperative
work with Rolf Ream, Mike Goebel and Jason Baker
of the Southwest Fisheries Science Center and
Robert Francis, University of Washington)
presented “Hydrographic influences on the
foraging location of female northern fur
seals.”
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Pat Gearin — presented “Prey
of Steller sea lions in Washington State.”
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Sharon Melin — presented “A
comparison of breeding and non-breeding season
foraging behavior of lactating California sea
lions.”
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Brad Hanson — presented
“Evaluating the relationship between small
cetacean tag design and attachment duration: a
bioengineering approach.”
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Bob DeLong — presented
“Archaeological investigations on San Miguel
Island, California: A view of 3,000 years of
pinniped community dynamics.”
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David Withrow and Jack Cesarone
— presented “An estimate of the proportion
of harbor seals missed during aerial surveys
over glacial ice in Alaska.”
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Sally Mizroch — presented
“Distribution and movements of fin whales (Balaenoptera
physalus) in the Pacific Ocean.”
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Dave Rugh — presented
“Timing of the southbound migration of gray
whales.”
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Jeremy Davies — presented
“Blue whale habitats in the North Pacific:
analyses of remotely-sensed data using a
Geographic Information System.”
- Rod Hobbs — presented “Abundance of beluga
whales in Cook Inlet, Alaska, 1994-98"
Poster Presentations
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Chuck Fowler — presented
“Marine Mammals: Examples of
Sustainability.”
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Kathryn Chumbley —
(cooperative work with John Sease and Rod Towell)
presented “Juvenile Steller sea lion (Eumetopias
jubatus) decline at Marmot Island, 1979
through 1996.”
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Carolyn Kurle — (cooperative
work with Graham Worthy, Texas A&M
University) presented “Stable isotope
assessment of temporal and geographic
differences in feeding ecology of northern fur
seals (Callorhinus ursinus).”
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Merrill Gosho — presented
“Gray whale research in northwestern
Washington waters.”
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Harriet Huber — presented
“Identification of salmonid bone from pinniped
scat using molecular genetics
techniques.”
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Peter Boveng — presented
“Relationships between sea ice, air
temperature, and recruitment of crabeater
seals.”
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Jack Cesarone, David Withrow and
John Jansen — presented “Capture techniques
for harbor seals hauling out on glacial ice.”
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Lisa Hiruki, John Bengtson, T.
Ichii, Peter Boveng, and J. Abrams
–(cooperative work with T. Ichii, National
Research Institute of Far Seas Fisheries, Japan
and J. Abrams, Redmond, Washington) presented
“Spatial analysis of Antarctic fur seal
foraging behavior at Seal Island, Antarctica.”
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John Jansen, David Withrow, and
Jack Cesarone — presented “Abundance
estimation of Alaskan harbor seals: assessing
the effects of tide and animal movement.”
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Janice Waite — presented
“Habitat preference of harbor porpoise and
Dall’s porpoise in the Gulf of Alaska and
adjacent inland waters.”
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Kim Shelden — presented
“Winter distribution of gray whales off the
northern Washington Coast.”
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Sue Moore — presented
“Arctic cetaceans on a warming planet.”
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Marilyn Dahlheim — presented
“Killer whale fishery interactions.”
In addition , the
presidential address was given by Doug DeMaster,
president of the Society for Marine Mammalogy and
the financial report was presented by John Bengston,
treasurer of the Society.
By Anita Lopez.
Low Frequency Active (LFA) Noise and Marine
Mammals
The significant increase of noise in the
world’s oceans has been a subject of concern among
marine mammal scientists for the last two decades.
Vessel traffic, geophysical exploration,
long-range sonar, and other sources of underwater
anthropogenic noise are often regarded as a source
of potential disturbance to aquatic animals. Of
particular concern is the U.S. Navy’s use of the
SURTASS LFA (Surveillance Towed Array Sensor System
Low Frequency Active sonar). SURTASS
broadcasts low frequency sounds (100-500 Hz) at
levels often in excess of 200 dB re 1 uPa.
On 5 October 1999, the NMML and the Navy
cohosted a meeting in Seattle at which Navy
representatives and scientists demonstrated
the LFA program to interested public. The Navy
has also drafted an Environmental Impact Statement (EIS)
to document the potential effects of this project
(Navy DEIS, 1999).
There have been a number of studies addressing the
impact of LFA on selected species of mysticete
whales (e.g., blue whales, fin whales, humpback
whales, and gray whales). Recently researchers
from the NMML undertook a study to determine if
sperm whale signals changed in the presence of LFA
broadcasts. The call rates of specific sperm
whale underwater vocalizations (referred to as
“clicks”) were compared prior to, during, and
after the projection of LFA signals. Although
statistical analysis yielded no significant change
in the structure of sperm whale clicks during the
projection of LFA, the overall pattern
documented decreased calling rates during LFA
transmissions followed by periods of silence and
then a notable increase in calling immediately
following LFA broadcasts. An experiment with
an adequate number of treatments and replications
along with concurrent surface behaviors and acoustic
monitoring is required prior to making final
conclusions on the effect of LFA on sperm whale
behavior.
By Marilyn Dahlheim and Sue Moore.
Gray Whale Strandings: January -
October 1999
Gray
whale strandings by region |
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Alaska
Canada
Washington
Oregon
California
Mexico |
73
10
28
2
42
118 |
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The NMML in
conjunction with other NMFS research centers is
preparing a report summarizing available information
on gray whale (Eschrichtius robustus)
strandings in 1999. A total of 273 gray
whale strandings were reported from 1 January to 15
October 1999, roughly five times higher than the
total reported for any year since 1995. Strandings
were documented all along the gray whale migration
route, with highest numbers reported for Mexico and
Alaska. The northernmost stranding was
reported at the mouth of the Yukon River in Alaska,
while the southernmost was in Bahia de Banderas,
Mexico.
Most strandings
occurred during late spring and summer, with a peak
in number (72 whales) in March. Sex of the
stranded animals often could not be determined due
to inaccessibility or decomposition. Of the
109 whales (40%) of known sex, 74 (68%) were
females and 35 (32%) were males. Similarly,
age at death based on length could not be determined
for many of the strandings, particularly in Alaska
where carcasses were seldom measured. Of the
178 whales where age class was assigned, 94 (53%)
were adults, 34 (19%) were juveniles/subadults, 36
(20%) were yearlings, and 14 (8%) were calves.
While the number of
stranded gray whales reported in 1999 was higher
than previous years, the total number may have been
influenced upwardly by increased aerial surveys in
Alaska and greater research efforts in Mexico, both
areas where high stranding numbers were reported.
Of note, the total number of stranded
animals represents only about 1% of the Eastern
North Pacific population, estimated to number 26,635
(CV = 10.06%) whales from a census done during
winter 1997/98. As reported in the
recent Status Review of the Eastern North Pacific
Stock (Rugh et al. 1999; NOAA Tech. Memo
NMFS-AFSC-103), this stock appears to be approaching
carrying capacity and therefore may be reaching the
limits of available resources. The gray whales’
annual migrations along the coastline of western
North America make them particularly vulnerable to
potential impacts from offshore human activities or
catastrophic events. As recommended in the
Status Review, continued monitoring and research on
potential human impacts to critical habitats is
required to aid interpretation of mortality rates
such as those reported in 1999.
By Sue Moore.
Depths at Sighting Sites of Harbor
Porpoise and Dall’s Porpoise in Gulf of Alaska and
Adjacent Inland Waters
Harbor porpoise (Phocoena phocoena) and
Dall’s porpoise (Phocoenoides dalli) occur
in Alaskan waters but appear to occupy different
habitats, as indicated by differences in
distribution. For example, water depth can
indicate habitat preference. The NMML
conducted 19,335 km of line-transect aerial survey
for small cetaceans in June and July of 1997 and
1998. Surveys included Gulf of Alaska waters
out to a water depth of 1,830 m from Dixon Entrance
to just west of Kodiak Island, and adjacent inland
bodies of water. Surveys were flown in a
DeHavilland Twin Otter aircraft at 152.5 m (500 ft)
and 185 km/hr (100 kts). Porpoise sighting
locations were determined from GPS (geographic
positioning systems) locations and plotted. Depths
at sighting locations were subsequently obtained
from NOAA nautical charts. A significant
difference (t-test, p < 0.0001) was found between
the mean depths of harbor porpoise (mean = 99 m, SE
= 4.8 m, n = 220) and Dall’s porpoise (mean = 258
m, SE = 8.6 m, n=287) sightings. Depth
comparisons were also made among five regions:
1) inside southeastern Alaska, 2) offshore
southeastern Alaska, 3) inside southcentral Alaska,
4) offshore southcentral Alaska, and 5) Shelikof
Strait and inlets of Kodiak Island and Kenai
Peninsula. Mean depths for both porpoise
species varied by region, but differences in all
regions were highly significant with harbor porpoise
always in shallower water. Logistic regression
showed that the point where equal numbers of harbor
porpoise and Dall’s porpoise were present was 125
m. Eighty-eight percent of harbor porpoise
were found at depths shallower than 125 m, and 73%
of Dall’s porpoise were found at depths deeper
than 125 m. Although harbor porpoise and
Dall’s porpoise are both found in inside and
offshore waters of Alaska, they appear to occupy
different habitat, which may be related to
differences in diving capabilities or preferred
prey. This difference in habitat preference might
also be reflected in the degree to which these two
porpoise species interact with various commercial
fisheries in Alaska.
By Janice Waite
U.S.-Russian Marine Mammal Cooperative
Agreement
Tom Loughlin attended the 15th annual
meeting of the U.S.-Russian Marine Mammal
Cooperative Agreement on the Environment (Project
.02.05-61 “Marine Mammals” under Area V of the
U.S./Russia Environmental Agreement”) in
Petropovlosk Kamchatsky, Russia, during 6-17
November 1999. He presented
results of U.S.-Russian cooperative research on
Steller sea lions and northern fur seals. Dr.
Loughlin is the co-chairman of this working group
By Tom Loughlin.
California Current Ecosystems
The California Current Ecosystems program is
responsible for assessing the status and trends of
marine mammals in Washington waters and the
ecological impact of their involvement with
fisheries along the coasts of Washington, Oregon,
and California.
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Gray whale surveys: Gray whale
surveys were conducted in the western Strait of
Juan de Fuca and northern Washington coast
during October and November. Gray whales
were photographed for individual identification
and five whales were biopsied.
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California sea lion captures and
marking:California sea lions were captured and
marked at Shilshole Bay in support of Northwest
Region- funded studies of predation of coho
salmon and steelhead at the Hiram Chittenden
Locks in Ballard. Between 2 September 1999 and 5
January 2000, 51 California sea lions were
captured at Shilshole Bay, including 16 new
animals and 35 recaptured animals.
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Sea lion surveys: Surveys for
Steller and California sea lions were conducted
on the northern Washington coast in October and
November. Record numbers of sea lions were
counted including over 5,000 California sea
lions and 1,500 Steller sea lions.
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Lake Ozette surveys- Lake Ozette,
Washington, was surveyed by boat four times
during October-December to document the presence
or absence of harbor seals near the Lake Ozette
sockeye salmon spawning grounds.
By Robert DeLong.
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