New Report Explores Spillover Effects of Regulations in Hawaii's Shallow-set Longline Fishery

In addition to having direct effects on the fish stock, fishers, and fishing community of primary interest, fishery regulations may generate external impacts or "spillover" effects on other entities, such as the ecosystem, social groups and economic competitors. It is useful to assess spillover effects as part of a regulatory impact analysis. A recent NOAA Technical Memorandum examines whether, and to what extent, limits on the Hawaii-based shallow-set longline fishery, instituted to protect endangered species, can cause changes in foreign fleet activity that ultimately have adverse effects on the very species intended for protection. The report, "Spillover effects of environmental regulation for sea turtle protection: the case of the Hawaii shallow-set longline fishery" was authored by PIFSC Economists Hing Ling Chan (employed by the University of Hawaii Joint Institute for Marine and Atmospheric Research) and Minling Pan.

Swordfish production by non-U.S. fleets in the central Pacific and North Pacific is inversely related to production by U.S. 
               fishing fleets. This suggests a spillover effect could result from reductions in U.S. swordfish catch.
Swordfish production by non-U.S. fleets in the central Pacific and North Pacific is inversely related to production by U.S. fishing fleets. This suggests a spillover effect could result from reductions in U.S. swordfish catch.

To protect sea turtles, federal fishery managers temporarily closed the Hawaii swordfish (shallow-set) longline fishery during 2001-2004. When the fishery reopened, it was subject to federal limits on annual fishing effort and interactions with sea turtles. The globalized (pelagic) resources of swordfish and sea turtles allow for "spillover effects": when one swordfish fishery reduces activity, other fisheries may increase activity to satisfy the unmet demand for swordfish. Likewise, constrained by a fixed demand, if one fishery expands, another may reduce its activity. The new study estimated the possible spillover effects resulting from the aforementioned regulations in the Hawaii swordfish fishery from two perspectives. First, the study estimated the spillover effect resulting from market replacement assuming U.S. swordfish consumption shifted from domestic production to foreign imports as a result of the domestic fishery closure. Because U.S. swordfish imports are harvested by other countries, and even in other oceans, the spillover effects are estimated on a global scale (the sum across all oceans). Second, the study estimated the spillover effects resulting from displacement of swordfish production by competing fleets in the specific ocean area where the Hawaii shallow-set longline fishery operates. The analysis suggests strong spillover (market transfer effects) from regulation of the Hawaii shallow-set longline fishery for swordfish, resulting in more sea turtle bycatch by foreign fleets as Hawaii swordfish production is reduced. The prediction of differential effects on sea turtles between U.S. and foreign fleets assumes that U.S. shallow-set longline vessels achieve lower turtle bycatch rates than their foreign competitors, as a result of the requirement that U.S. vessels use circle hooks.