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Economics and Social Sciences Research Program

Improving the Usefulness of Logbook Data in the North Pacific Groundfish Fisheries

Economics and Social Sciences Research (ESSR) Program researchers Stephen Kasperski and Alan Haynie are currently conducting research exploring the feasibility of using logbook data to improve fisheries management in Alaska. Logbooks are a major data reporting requirement for fishers in the North Pacific groundfish fisheries, yet the logbooks are not verified for accuracy nor digitized to make them available to fishery managers or analysts.

While NMFS has implemented a substantial observer program in the North Pacific to monitor the activities of large vessels, the majority of catcher vessels have only partial observer coverage. As smaller catcher vessels have an observer on board for 0%–30% of their days at sea, it is possible that vessels’ harvesting strategies differ depending on whether they are observed. This could include changing fishing locations, altering the species composition harvested, or taking shorter trips when observed.

To explore the potential observer effect and the potential usefulness of logbook data in the North Pacific groundfish fisheries, we have merged data from fish tickets, observer data, and a set of digitized logbooks for all trawl vessels operating in the Gulf of Alaska in the year 2005. Preliminary results suggest that for trips in which there is full coverage (a fish ticket accompanied by a record of observer and logbook hauls), the total harvests by species in the fish tickets are generally close to the totals derived from the logbook records, except for some flatfish species.

We are in the process of exploring how total catch of prohibited species such as halibut and Chinook salmon, fishing location choice, species composition, and trip length differ across datasets. We also hope to explore whether there are any quantifiable differences in the characteristics of observed and unobserved trips.

By Stephen Kasperski and Alan Haynie

Optimal Multispecies Harvesting in the Presence of a Nuisance Species

ESSR Program researcher Stephen Kasperski is currently conducting research relating to the multispecies bioeconomic models of groundfish in the Bering Sea. Specifically, he is examining models that account for biological and technological interactions among species to determine the optimal quotas and subsequent stock sizes for each species in the presence of a nuisance species. The nuisance species lowers the value of the fishery by negatively affecting the growth of the other species in the ecosystem and has little harvest value of its own.

The model also allows for technological interactions by estimating gear- and class-specific cost functions which allow for bycatch and combined harvesting of multiple species that varies across target species. As approaches for ecosystem-based fisheries management are developed, results demonstrate the importance of focusing not only on the species with harvest value but also on species which may have no harvest value on their own but affect the productivity and availability of higher value species. Ignoring the role of these nuisance species can result in a less productive and lower value fishery if the nuisance species replaces some of the exploited species and its population remains unchecked because it is not economically valuable.

This study uses the arrowtooth flounder, Pacific cod, and walleye pollock fisheries in the Bering Sea/Aleutian Islands region of Alaska as a case study and finds the net present value of the fishery is decreased from $16 billion to $3 billion dollars by ignoring arrowtooth's role as a nuisance species on the growth of Pacific cod and walleye pollock. To account for the negative impact of arrowtooth flounder on the profitable harvesting of cod and pollock, the model solves for an optimal subsidy on the harvest of the nuisance species. Aggregated over all vessels and time periods, the total subsidy on the harvest of arrowtooth is $49 million dollars, which increases the net present value by $111 million dollars after accounting for the subsidy, which results in a 126% rate of return on the subsidy for the nuisance species.

By Stephen Kasperski

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