NOAA logo JFM 2001 Quarterly Rpt. sidebar

Resource Ecology &
Fisheries Management

(Quarterly Report for Jan-Feb-Mar 2001)

Socioeconomic Assessments Program:
Modeling the Effect of Fishery Attributes on Participation Rates and Angler Welfare

Changes in sportfishing trip attributes, such as cost, harvest regulations, environmental quality, and resource abundance, affect both the expected net benefits associated with a fishing trip and participation decisions.  The ability to estimate both of these is important for various types of policy analysis.  The study completed by Drs. Todd Lee, Mark Herrmann (University of Alaska, Fairbanks), and Keith Criddle (Utah State University) and Charles Hamel (University of Alaska, Fairbanks), uses hybrid stated preference questions of anglers who sport fished in the marine waters off the Kenai Peninsula, Alaska to estimate a nonlinear random effects probit model that expresses both participation rates and angler net benefits as functions of trip attributes.  The use of stated preferences data along with a nonlinear utility specification allows for the simulation of a wide range of policy scenarios.  The study design and nonlinear model permit the identification of substitution and complementary effects across attributes, as well as non-linear marginal utility.

Econometric Analysis of Stated Preference Ratings Data

Economic valuation and market research surveys often ask respondents to rate a set of multi-attribute alternatives.  Economic choice theory is based upon ordinal preferences, but standard estimation approaches for ratings data are based upon inter-personal utility comparisons.  Developing an ordinal model for ratings data has proven difficult due to “tied” ratings.  Drs. David Layton (University of California, Davis) and Todd Lee developed a new preference estimation approach based only upon the ordinal content of ratings data.  They showed how the ordinal content of any respondent’s set of ratings can be viewed as a censored ranking, developed a censored rank-ordered econometric model, and applied it to a ratings conjoint survey of recreational fishing.

Measurement of Capacity, Utilization, and Economic Performance in Alaska Groundfish Fisheries

Overfishing and excess capacity are two common, undesirable, and related characteristics of domestic, foreign, and international fisheries.  They are related in three ways.  First, they both are caused by the externalities stemming from the problem of common property.  These externalities provide incentives for fishermen to invest too much in fishing vessels and gear and to catch too much fish.  Therefore, if the fishery management regime is not able to block these perverse incentives or eliminate the externalities that generate them, excess capacity and overfishing often occur. Second, excess capacity can increase the risk and potential level of overfishing.  Third, overfishing decreases stock abundance and the target catch level and can, therefore, further increase excess capacity.

The adverse effects of excess capacity have become too severe to ignore, and there have been increased national and international efforts to address the problem of excess capacity.  As part of this effort, Congress passed the American Fisheries Act (AFA) in 1998, which was, in part,an effort to “rationalize” the Bering Sea-Aleutian Island (BSAI) walleye pollock fishery (the most valuable of the Alaska groundfish fisheries).  The AFA included regulations that restricted access to certain parties and allowed formation of cooperatives that instituted fishing rights which could be traded among the members of the cooperatives.  Initial reports indicate that there has been a decrease in fishing effort and an increase in season length for the pollock fishery since passage of the AFA. However, given that the quantity of pollock caught has not diminished and is still being taken in a few months time, it is unclear whether observed capacity reductions are sufficient to ease existing concerns. In order to further our understanding of the issues discussed above, Ron Felthoven estimated harvesting capacity and utilization in the catcher processor sector of the BSAI pollock fishery and analyzed the changes brought about by the AFA. Two methods for measuring fishing capacity – stochastic production frontiers (SPF) and data envelopment analysis (DEA)– were employed in multi-input, multi-output applications to that sector of the fishery.  The resulting capacity estimates from the models were then compared and used to characterize the degree of excess capacity in this fleet and to illustrate the substantial differences in capacity estimates that may arise when the stochastic aspects inherent in harvesting technologies are ignored.  And, because DEA and SPF models allow one to analyze technical efficiency in production, the frameworks were also used to compare pre- and post-AFA efficiency among individual vessels and the fleet as a whole.  Ron Felthoven completed this dissertation research as one of the first four Fellows in the NMFS/Sea Grant Graduate Fellowship Program in Population Dynamics and Marine Resource Economics.

Age and Growth Program

Estimated production figures for
1 January 2001 to 31 March 2001.

Walleye pollock




Pacific whiting


Northern rockfish


Light dusky rockfish


Total production figures were 10,605 with 2,055 test ages and 61 examined and determined to be unageable.


Other Research

Dr. Todd Lee has received a grant for $95,000 from the NMFS Office of Science and Technology to study the economic effect of bag limits and catch-and-release fishing regulations.  The study will measure the importance of harvest limits on angler participation decisions and the economic value anglers derive from a recreational fishing trip.  The data for the study will be gathered from a survey that will be administered this fall.  The final results are expected to be available by August 2002.

By Joe Terry.

U.S. North Pacific Groundfish Observer Program:
Training, Briefing and Debriefing Statistics

During the first quarter of 2001, 314 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 region.  They sampled aboard 270 fishing and processing vessels and at 22 shoreside processing plants.  These observers were trained or briefed in various locations. The University of Alaska Anchorage (UAA) Observer Training Center trained 38 first time observers and another 182 observers with prior experience were briefed at this site.  The AFSC  Observer Program in Seattle briefed another 86 observers who had prior experience.  Eight observers were excused from briefing because they had just completed a cruise successfully and were returning immediately to the field.  The first quarter 2001 observer workforce thus comprised 12% new observers and 88% experienced observers.

The Observer Program conducted a total of 51 debriefings during the first quarter of 2001.  Four debriefings were held in Kodiak, 17 in Anchorage, and 30 were held in Seattle.

Observer Program Hosts National Safety Training

Fishery observer trainers from each NMFS region gathered at the Center in March to attend a safety training  course, designed specifically for teachers of sea safety.  The purpose of the course was to ensure that NMFS staff, who are responsible for training fishery observers, have the expertise and resources necessary to provide the best possible safety training for the gear and vessel types they monitor. The 5-day course, taught by the Alaska Marine Safety Education Association, was intense, running well into the evenings, and packed with information on safety equipment, safety techniques, and ways to teach safety to observers.  On the sixth day, the NMFS observer trainers met for discussion about their own program’s training needs and ways to share resources.

Observer Program Cadre Opens

The Observer Program began full implementation of its cadre during the first quarter of 2001.  The cadre consists of five new employees hired in December 2000 along with two other staff members stationed in new office space in the Federal building annex in Anchorage. The cadre is an inherently flexible unit of employees that can be deployed as needed to ports throughout Alaska.  They help to increase the Observer Program’s presence in the field and allow for more “front line” communication between NMFS, observers, and the fishing industry.  Todd Loomis, the Anchorage field office manager, is responsible for leading the cadre.

By Bob Maier

Status of Stocks and Multispecies Assessment Program:
Korean Workshop on Large Marine Ecosystems

Jim Ianelli was invited to present a paper at the “Korean Yellow Sea Large Marine Ecosystem (K-YSLME) Workshop” on Jeju Island, South Korea.  Ianelli presented a paper titled:  “Fisheries management of eastern Bering Sea pollock in an ecosystem context.”  Representatives from several research and management organizations within Korea participated in the workshop, as well as invited speakers from the United States  and China.

Working group sessions were held in the areas of pollution, geographic information systems (GIS), fisheries management, and oceanographic productivity.  Guidelines for group discussion were to review findings of K-YSLME and point out where further developments and analyses were needed.  Recommendations specific to the fisheries working group were to

  • Continue trawl surveys with a view to establish a times series,

  • Increase the trawl survey sample stations in area (to the west, east and south) and density,

  • Contrast results from surveys with available historical surveys and commercial fishing information,

  • Continue to experiment with trawl gear (e.g., use of cover net with video for selectivity estimates), and hydroacoustic equipment (e.g., target strength measurements, adaptive sampling),

  • Add a midwater trawl to verify acoustic data used for echo-integration estimates of stock abundance,

  • Investigate methods for examining carrying capacity in the Yellow Sea, such as using ECOSIM and  comparing productivity in other similar ecosystems around the world,

  • Use separate vessels for fish surveys and the collection of oceanographic data.

Resource Ecology and Ecosystems Modeling Program

A total of 1,018 fish stomachs were collected from the eastern Bering Sea and 992 from the Gulf of Alaska. Laboratory analysis was performed on 1,009 groundfish stomachs from the eastern Bering Sea, 47 from the Gulf of Alaska/Aleutian Islands, and 626 from the Washington-Oregon-California area. No observers returned stomach samples during the quarter.

North Pacific Basin Models

Kerim Aydin was a key participant in a workshop sponsored by the Basin Ecosystems (BASS) Task Team of the North Pacific Marine Science Organization (PICES), held on 5-6 March  2001, in Honolulu, Hawaii. The workshop was hosted by the NMFS Honolulu Laboratory.  Twelve scientists from five countries, the United States, Canada, Russia, Japan, and China, attended the workshop.  The purpose of the meeting was to exchange data and develop two food web models of the eastern and western North Pacific subarctic gyres for the purpose of examining ecosystem structure and function, climate impacts, and the historical effects of fishing on the pelagic community of the two ecosystems.

The model focused on the subarctic Pacific, north of 45°N and south of the continental shelf, divided into eastern and western sections by the narrowing of the subarctic Gyre along the Aleutian Island chain.  This area is high in primary production relative to the adjacent subtropical waters and represents extremely important feeding grounds for Pacific salmon (Oncorhynchus spp.), many large squid species, and marine mammals.  Changes in the circulation and production of the gyres are linked to regime shifts as typified by the Pacific Decadal Oscillation, which is considered to have a large impact on salmon growth and survival and is important to evaluate relative to other impacts of climate change.

Extensive data exchange occurred between countries in the month before the workshop.  Previously unavailable data was assembled, including fishing rates, biomass, production rates, and diet habits of over 60 distinct species or guilds of organisms living in the region, representing the entire trophic web.  The preliminary estimation of the overall flow of biomass within the system was assembled by Kerim Aydin using this data and presented at the workshop.

At this stage, the results were aimed at identifying key species for which little data were available.  These species included micronektonic squid, forage fish, and mesopelagic fish, species which provide the primary conduits of energy from primary production to salmon and higher trophic levels.  Methods for linking fish and mammal production to climate via lower trophic-level (plankton) modeling was also discussed.  Based on this preliminary information, the model was distributed to allow researchers to focus on specific data-gathering and refinement tasks, to be presented at the 10th Annual PICES Meeting in October 2001.  At that point, the final product will be evaluated as a tool for investigating the effects of climate change on the North Pacific gyre ecosystems.

Climate Change and Biodiversity

Pat Livingston organized and chaired a workshop, sponsored by PICES, the Sloan Foundation’s Census of Marine Life (CoML), and the International Pacific Research Center (IPRC), held 7-9 March  2001 at the East-West Center in Honolulu. The workshop, “Impact of Climate Variability on Observation and Prediction of Ecosystem and Biodiversity Changes in the North Pacific,” gathered 63 marine scientists including physical, chemical, and biological oceanographers, atmospheric scientists, and fish, marine mammal, and bird researchers from Canada, China, Japan, Korea, Russia and the United States.

The workshop focused on reviewing the goals and strategies for observing North Pacific marine ecosystems and their biodiversity and improving our ability to predict ecosystem change.  This was accomplished by  1) defining our existing observation and prediction system (regional and basin-scales), 2) identifying needed improvements to the existing system for increasing our understanding of biodiversity and climate-linked changes in biodiversity, and 3) nominating existing time series and predictions for inclusion into a PICES Ecosystem Status Report.  Workshop participants were primarily representatives of various national monitoring and prediction programs or members of various PICES groups or programs.  Existing time series observations on physical and chemical oceanography and climate; phytoplankton, zooplankton, and micronekton; fish and crustaceans; and marine mammals and birds from the eastern, western, and open North Pacific were presented at the workshop by participants.  Although the workshop’s primary emphasis was on time series information, candidate predictive models (from purely physical to coupled biophysical models) were also identified for use in forecasting future climate changes and their effects on biota.

Major workshop recommendations included adding these time series data to a North Pacific ecosystem metadatabase that was originally started by NOAA researchers Allen Macklin and Bern Megrey to facilitate Bering Sea research and to begin work on structuring and compiling a North Pacific Ecosystem Status Report. The final workshop report is being prepared and is targeted for completion by fall 2001.

By Pat Livingston.