AGE AND GROWTH PROGRAM
Estimated production figures for 1 January through 30 June 2003.
Northern rock sole
Pacific ocean perch
Light dusky rockfish
Dark dusky rockfish
Total production figures were 15,393 with 5,844 test ages and 260
examined and determined to be not ageable.
The Age and Growth Program has begun to provide age data for species that are not normally aged
including skates, some new rockfish species, and some minor species such as
eelpouts, sculpins, and snailfish.
More details will be provided as this work progresses.
By Dan Kimura.
RESOURCE ECOLOGY AND
ECOSYSTEMS MODELING PROGRAM
Laboratory analysis was performed on 1,272 groundfish stomachs from the
eastern Bering Sea and 3,173 from the Gulf of Alaska. Observers collected
and returned 1,273 stomachs from their Bering Sea cruises.
Groundfishes in the Aleutian Islands Region
REFM scientists have completed a study describing the diets of the important
groundfishes collected in the Aleutian Islands in 1994 and 1997. A total
of 31 groundfish species were included in the investigation. The general
diet, variations of the diet by different predator sizes, geographic distribution
of main prey, and size of important prey consumed by each species were
analyzed. When applicable, diets of certain species from 1994 and 1997
were compared with those from 1991 samples.
The study emphasized groundfish predation on commercially important fish,
crab, and shrimp species. The data indicate that Atka mackerel was the
dominant prey fish and was consumed by Pacific cod, arrowtooth flounder,
Pacific halibut, Greenland turbot, Alaska skate, whiteblotched skate, great
sculpin, and big mouth sculpin. Walleye pollock was another important
prey and was consumed mainly by Pacific cod, arrowtooth flounder, Pacific
halibut, Alaska skate, and whiteblotched skate. Pollock cannibalism was
not found in this study. In the Aleutian Islands area, myctophids were
important prey of many fish. The main predators of myctophids were arrowtooth
flounder, Greenland turbot, Pacific ocean perch, pollock, giant grenadier,
shortraker rockfish, and rougheye rockfish. Other forage fish such as
Pacific herring, osmerids, and Pacific sand lance were consumed by Pacific
cod, arrowtooth flounder, and Pacific halibut. However, each of these
species comprised no more than 5% of the stomach contents weight. Some
mesopelagic fish, like bathylagids and viperfish, were found in groundfish
stomachs. Tanner crabs were mainly consumed by Pacific cod, Pacific halibut,
and great sculpin, though they were also consumed by Alaska skate and flathead
sole. Many predators preyed on pandalid shrimp, which includes all the
Pandalus and Pandalopsis species. The diets of Pacific cod, arrowtooth
flounder, shortspine thornyhead, rougheye rockfish, shortraker rockfish,
Bering skate, darkfin sculpin, and Aleutian skate contained the most pandalids.
The study was published as
AFSC Processed Report 2003-07.
By Mei-Sun Yang.
Pat Livingston organized a meeting in May for researchers working on composite
ecosystem indicators for the Ecosystem Considerations Chapter, which accompanies
the annual stock assessment and fishery evaluation reports to the North
Pacific Fishery Management Council. Participants came from the University
of Washington (UW), University of Alaska, Pacific Marine Environmental
Laboratory (PMEL), and AFSC. Attendees included: Wiebke Boeing, Jennifer
Boldt, Janet Duffy-Anderson, Pat Livingston, Nate Mantua, Bern Megrey,
Franz Mueter, Jim Overland, Sergei Rodionov, and Shannon Tribble.
The purpose of the Ecosystem Considerations Chapter is to provide scientists
and fishery managers with information on the status and trends of various
ecosystem components and to evaluate the effects of climate and fishing
on the ecosystem. The use of aggregate indicators, which bring together
time series data on climate, fishing, and biology, is an important part
of the chapter but still is in early stages of development. Presently,
the regime shift analysis pioneered by Steve Hare (International Pacific
Halibut Commission) and Nate Mantua (UW) is part of the chapter. Future
enhancements to this type of analysis could include time series of human
influences on the system.
The meeting served to promote discussion among the different groups working
on similar indicators, to determine what would be available for this year's
ecosystem chapter, and to begin discussion about how to expedite these
composite analyses to provide an annual aggregate assessment of the main
climate drivers and human influences on historical ecosystem change.
PMEL is working on a web page to providing climate time series for the
Bering Sea that will provide detailed information about the time series,
such as geographic extent and how the index was actually calculated. A
description of its relevance to the ecosystem will also be included along
with information on recent trends and references used in interpreting the
recent trends. The web page will make the physical time series data more
available to biologists who have difficulty accessing and interpreting
such time series. Some of these time series would also be presented in
the Ecosystem Considerations Chapter. The Ecosystem Considerations Chapter
will provide a structure for annually updating and reporting on individual
ecosystem components and facilitating the aggregate analysis of these time series.
By Pat Livingston.
Arctic Climate Impact Assessment
REFM scientists Pat Livingston and Tom Wilderbuer are contributing to an
effort to assess the effects of climate change on the Arctic. The Arctic
Climate Impact Assessment (ACIA) (http://www.acia.uaf.edu) is an international
project of the Arctic Council and the International Arctic Science Committee
(IASC) to evaluate and synthesize knowledge on climate variability, climate
change, and increased ultraviolet radiation and their consequences. The
aim is to provide information to governments, organizations, and peoples
of the Arctic on policy options to meet such changes. The National Science
Foundation and NOAA are providing funding for the ACIA Secretariat, which
is located at the International Arctic Research Center at the University
of Alaska Fairbanks. Pat Livingston is contributing to the assessment
on Marine Systems, and Tom Wilderbuer is contributing to the chapter on
Fisheries and Aquaculture with focus on climate change in the Bering Sea.
A workshop was held in 2003 to bring chapter authors together and to provide
a means for synthesizing results from the assessment. As a result of preliminary
reviews and suggestions from the synthesis workshop, a revised draft of
the assessment is being prepared and will be available for expert review
around July 2003. The peer-reviewed scientific volume will be completed in 2004.
By Pat Livingston.
Climate / Fish Relationships Science Workshop
Jennifer Boldt and Anne Hollowed of the REFM Division participated in a
climate/fish science workshop in San Jose, California, on 28-29 April 2003.
The climate/fish science project is part of the NOAA-funded Marine Fisheries
Stock Assessment Improvement Plan. The project consists of basinwide,
coordinated research to improve stock assessments and other scientific
evaluations needed for management. The goals of the project are to 1)
deliver time series of ecological indicators to be used in assessment models,
2) develop climate-sensitive ecological indicators, 3) maintain time series,
4) examine them for climate trends, and 5) facilitate their incorporation
into models used for fisheries and ecosystem management.
The purpose of the April workshop was to present and discuss progress on
funded research projects. Jennifer presented 1) results of a study conducted
by Tom Wilderbuer and others on flatfish recruitment response to decadal
climatic variability and ocean conditions in the eastern Bering Sea, and
2) plans for developing an index of spawning pollock biomass anomalies,
which incorporates water temperature and the amount and complexity of flow
through Shelikof Strait. Other NOAA researchers presented progress on
their indices/time series, and plans to incorporate these into stock assessments
were discussed. The next workshop is planned for late September.
By Jennifer Boldt.
U.S. NORTH PACIFIC GROUNDFISH OBSERVER PROGRAM
During the second quarter of 2003, 165 observers were trained, briefed,
and equipped for deployment to fishing and processing vessels and shoreside
plants in the Gulf of Alaska, Bering Sea, and Aleutian Islands. They sampled
aboard 205 fishing and processing vessels and at 16 shoreside processing
plants for a total of 5,696 days. The observers were trained or briefed
in three locations: the AFSC Observer Program in Seattle briefed 41 observers
with prior experience and another 19 first-time observers were trained
there; the University of Alaska Anchorage (UAA) Observer Training Center
briefed 81 observers; 11 observers were briefed at the Observer Program's
field office in Kodiak during the second quarter of 2003, and 13 observers
were excused from briefing because they had just completed a cruise successfully
and were returning immediately to the field. The second quarter 2003 observer
workforce thus comprised 12% new observers and 88% experienced observers.
The Observer Program conducted a total of 221 debriefings during the second
quarter of 2003. One debriefing was held in both Kodiak and Dutch Harbor,
76 in Anchorage, and 143 were held in Seattle.
Plans for Restructuring
At its April 2003 meeting, the North Pacific Fishery Management Council
reviewed a draft schedule and analytical outline to restructure the design
and funding mechanism of the Observer Program to address data quality and
disproportionate cost issues resulting from the current program structure.
The analytical outline contained a list of decision points that were reviewed
by the Council and will become the basis for formal alternatives and options
for analysis. The Council decided that the primary alternative would
include a funding mechanism that combines a user fee-based system with
Federal funding. This alternative would be developed for all vessels and
processors operating in the Gulf of Alaska, with a suboption to extend
the fee-based program to all vessels with currently less than 100% coverage
requirements in the Bering Sea and Aleutian Islands. A preliminary analysis
should be ready for Council review in October 2003, with initial review
scheduled for February 2004 and final action in April 2004.
Deployments of NMFS Staff
With new regulations effective this year, NMFS was granted the authority
to place NMFS staff and other authorized individuals as observers on fishing
vessels that currently are required to carry observers. This will enable
the Observer Program to deploy staff on two vessels during the third quarter
2003, with the purpose of developing vessel-specific sampling protocols.
This will result in improved sampling conditions and support for observers,
more effective observer sampling and catch and bycatch monitoring, and
a better working relationship with vessel personnel. In addition, Observer
Program staff already have been deployed to a catcher processor in the
Pacific cod longline fishery to conduct research designed to evaluate the
accuracy of catch accounting methods currently used by observers and longline
catcher processor operators. Also, Observer Program staff trained and
certified two NMFS staff members who were deployed to longliners that participate
in fisheries with a high bycatch of shortraker and rougheye rockfish.
The observers are attempting to develop new observer sampling protocols
that will allow for more accurate differentiation of shortraker and rougheye rockfish.
Bill Karp Returns to Lead Observer Program
Dr. William Karp was chosen as the new Observer Program Leader in June
2003. He will be returning in August to a job he knows well, as he served
in this position from 1993 to 1999. Dr. Karp served as leader of the RACE
Division's Midwater Assessment and Conservation Engineering program from 1999 to July 2003.
By Bob Maier.
Quarterly April-June 2003 sidebar
April - June 2003
Auke Bay Lab