Researchers assess economic productivity for Hawaii longline fishery

image1 (1) (1)PIFSC Socioeconomics Program researcher Dr. Minling Pan, in collaboration with Northeast Fisheries Science Center economist Dr. John Walden, recently published a study measuring productivity changes in the Hawaii longline fishery in the journal Marine Policy. Fisheries productivity is the result of many factors, including exogenous and endogenous elements, such as regulation and stock condition. Understanding changes in productivity and the factors affecting that change is important to fishery management and a sustainable fishing industry. This work represents the first study to measure productivity change in the Hawaii longline fishery, the largest fresh bigeye tuna and swordfish producer in the United States.

A biomass quantity index is constructed to disentangle biomass impacts in a pelagic environment in order to arrive at an “unbiased” productivity metric. This is particularly important in the Hawaii longline fishery where catches rely mostly on transboundary (shared) stocks with little control on the total amount of extraction. As resource depletion of the transboundary stocks occurs, productivity losses may follow if less output is obtained from the same input usage, or more inputs are used to extract the same catch level from the fishery.

Using a Lowe productivity index, productivity change in the Hawaii longline fleet between 2000 and 2012 is measured in this study.Overall, unadjusted (“biased”) productivity in the Hawaii longline fishery showed a declining trend since 2005. However, once biomass change was used to adjust the index values, the negative productivity change turned positive (Figure 1).

Figure 1. Unbiased and biased Lowe index for tuna trips 2002 to 2012 (base year = 2005)

Figure 1. Unbiased and biased Lowe index for tuna trips 2002 to 2012 (base year = 2005)

While bigeye tuna biomass has trended down in recent years, fishing productivity has improved, as the unbiased productivity index (the adjusted Lowe index) went up steadily from 0.84 in 2009 to 1.36 in 2012. During the study time period, especially since 2010, analytical results show that tuna fishing became more productive in terms of endogenous productivity (e.g., fishing technology). Such an improvement of endogenous productivity has offset the negative impact of the bigeye stock depletion and kept the fishery stable in terms of output to input ratio. Without such an improvement in productivity, the tuna fishery would have had much poorer performance due to the depletion of the shared fish resources. Finally, the study compares productivity change under different fishing technologies and finds evidence that tuna fishing seems to be more efficient compared to swordfish fishing.

For more information about this and other research from the PIFSC Socioeconomics Program visit our websitebrowse recent blog posts, or contact us by email:  pifsc.socioeconomics@noaa.gov

How can an ecosystem approach be used to address climate change?

By Adel Heenan and Amanda Dillon
Figure 1. Potential pathways for climate driven impacts on fisheries systems. Projected changes in climate and ocean properties (top tier) in response to increased CO2 emissions will directly affect human and natural capital (bottom tier). Changes in these aspects of the ocean will affect fishes and their related ecosystems (second tier) which will amplify through the fishery system, affecting aspects of fishing catch and effort (third tier). This will in turn have national level societal and economic repercussions (forth tier), in addition to influencing the natural and physical capital of individuals and fishing related communities (bottom tier).

Figure 1. Potential pathways for climate driven impacts on fisheries systems. Projected changes in climate and ocean properties (top tier) in response to increased CO2 emissions will directly affect human and natural capital (bottom tier). Changes in these aspects of the ocean will affect fishes and their related ecosystems (second tier) which will amplify through the fishery system, affecting aspects of fishing catch and effort (third tier). This will in turn have national level societal and economic repercussions (forth tier), in addition to influencing the natural and physical capital of individuals and fishing related communities (bottom tier).

The Pacific Islands Fisheries Science Center’s Coral Reef Ecosystem Division (CRED), in collaboration with scientists from 16 international institutions, recently published a paper in the journal Marine Policy that discusses how coastal fisheries management can incorporate considerations of climate change.

The projected impacts of climate change and ocean acidification on fishes and fisheries in the Asia-Pacific region are being documented with increasing frequency. In turn, these impacts will directly and indirectly effect both natural and human capital (Figure 1). The risks posed by climate change need to be assessed in concert with efforts to address pre-existing threats to tropical fisheries—such as overfishing, habitat degradation, pollution, eutrophication, and invasive species. What is needed is an approach to management that can more effectively deal with these pre-existing stresses, while reducing the vulnerability to longer-term climate impacts. The challenges inherent in achieving this management approach is demanding, particularly in the Asia-Pacific, where coastal fisheries are characterized by a lack of data, limited human capacity for effective management, and weak governance.

This paper focuses on an ecosystem approach to fisheries management (EAFM), which is now widely accepted as a potential solution to the current deficiencies in existing management efforts. The activities required to harness the full potential of an EAFM as an adaptation to climate change and ocean acidification include:

  • provision of the necessary expertise to inform all stakeholders about the risks to fish habitats, fish stocks and catches due to climate change,
  • promotion of trans-disciplinary collaboration,
  • facilitating the participation of all key stakeholders,
  • monitoring the wider fisheries system for climate impacts,
  • and enhancing resources and capacity to implement an EAFM.

By using an “ecosystem approach” to address climate and ocean change, developing countries will build resilience to the ecological and fisheries effects of climate change, and will also address the habitat degradation and overfishing that damages the productivity of coastal fisheries.

For more detail, the full paper is available for download here.