Good governance for migratory species

Eastern Pacific yellow-fin tuna.

Eastern Pacific yellow-fin tuna off of Cocos Island, Costa Rica. (© Conservation International/photo by Sterling Zumbrunn)

Editor’s note: The following letter originally appeared in the journal Science in response to the article, “Preparing ocean governance for species on the move.” 

In their Policy Forum “Preparing ocean governance for species on the move” (15 June, p. 1189), M. L. Pinsky et al. discuss the need to cooperatively govern fisheries affected by climate change. This idea is not new to Pacific Island states, which supply 30% of the global tuna catch. The Parties to the Nauru Agreement (PNA) provide a shining example of how to equitably share the benefits from fishing for skipjack tuna, which move not only among the exclusive economic zones (EEZs) of the island countries but also in response to climate. The PNA’s “vessel day scheme” (VDS) was developed explicitly to cooperatively manage these highly migratory tuna species within the combined EEZs of the PNA members.

The cap and trade VDS sets the total annual purse-seine fishing effort at ~45,000 days (i.e., fishing by all vessels must add up to no more than the ~45,000 days mandated for the year) and allocates the days to PNA members based on the past 7 years of catch history. The VDS provides a trading mechanism among PNA members, allowing them to respond to the profound effects of the El Niño Southern Oscillation on the prime fishing grounds for skipjack tuna. During La Niña episodes, the best catches are made toward the west of the region. During El Niño events, fishing is most efficient up to 4000 km to the east. During La Niña events, countries in the west buy days from members in the east to enable fleets to keep fishing in their EEZs. The reverse occurs during El Niño episodes. Thus, regardless of where the fish are caught, all PNA members receive license revenue. The stock for skipjack tuna has remained robust under this cooperative arrangement.

The VDS is also designed to govern the fishery as skipjack tuna redistribute to the east due to climate change. Over time, PNA members located in the east will progressively accumulate a greater catch history and receive more days. Cooperative arrangements will need to be more common as climate change drives shifts in species distribution, and the Pacific Islands are leading the way.

The letter was co-authored by Johann Bell, senior director of tuna fisheries for Conservation International; Jack Kittinger, senior director of Conservation International’s Global Fisheries and Aquaculture program; and Transform Aqorau, CEO and founding director of iTUNA Intel and Pacific Catalyst. 


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