Researchers at the University of Hawaii’s Joint Institute for Marine and Atmospheric Research (JIMAR) and the National Oceanic and Atmospheric Administration (NOAA) Pacific Islands Fisheries Science Center (PIFSC) examined “spillover effects” and “market transfer effects” resulting from fishing regulations instituted to protect endangered/threatened sea turtles. Swordfish and sea turtles co-occur in the North Pacific which enables spillover effects: when one fishery reduces activity on a resource, foreign fleet activity changes in ways that have adverse effects on the protected species. This study provides an empirical model to estimate spillover effects in terms of the change in sea turtle interactions associated with production displacement between U.S. and non-U.S. fleets. The study demonstrates strong spillover effects, resulting in more sea turtle interactions when Hawaii swordfish production declines.
Background: The Hawaii-based longline swordfish fishery was closed by the National Marine Fisheries Service (NMFS) in 2001 after a Federal court ordered reduction in incidental sea turtle bycatch. The fishery reopened in 2004 after incorporating measures including a hard cap on annual turtle interactions. In 2011, the NOAA Pacific Islands Regional Office requested PIFSC’s assistance with the analysis of potential market transfer effects after regulation of Hawaii-based shallow-set longline fishery, in support of Endangered Species Act consultations on the Hawaii-based longline fishery biological opinion (BiOp). Our study shows that if certain fishing regulations are removed, Hawaii swordfish production might increase and induce positive spillover effects of fewer turtle interactions. The study was used as a supportive document for the January 2012 BiOp on the continued operation of the Hawaii-based longline fishery.
Significance: This research supports NOAA’s strategic goal to protect, restore, and manage the use of costal and ocean resources. In November 2012, NMFS implemented the incidental take statement of the 2012 BiOp and increased the number of incidental interactions allowed between the Hawaii-based shallow-set longline fishery and leatherback and loggerhead sea turtles, from 16 to 26 and from 17 to 34, respectively.
Contact: Hing Ling Chan, JIMAR, University of Hawaii at Manoa
Figure 1. Conceptual Diagram of Spillover Effects Between Fisheries
Figure 2. U.S. Swordfish Production vs. Other Countries’ Production in the North Pacific Ocean, 1991-2009
Figure 3. Estimation Results if Hawaii Shallow-set Longline Fishery Increases to Historical High of 5,500 Sets