ISSF Study Reports Increase in Purse Seine Vessels Overall, but Fewer Large Scale Purse Seine Vessels Fishing for Tropical Tuna Species Globally

Tuna Conservation Group Releases 2021 Snapshot of Large-Scale Tropical Tuna Purse Seine Fishing Fleets as of July 2021

The International Seafood Sustainability Foundation (ISSF) has updated its Large-Scale Tuna Purse Seine Fishing Fleets report as of July 2021. The total number of purse seine vessels, calculated based on data from the five tuna Regional Fisheries Management Organizations (RFMOs), has increased from 1,721 in 2020 to 1,855 today. 

The report also shows approximately 678 vessels (down 2.6 percent from last year) defined as large-scale purse seine (LSPS) vessels targeting tropical tuna species (skipjack, yellowfin, and bigeye), with a combined fishing capacity of over 865,000 m³ (cubic meters). 

Having an accurate estimate of active vessels is critical for managing tuna fishing capacity regionally as well as globally. Although purse seine vessels account for approximately 69 percent of the 5.0 million-tonne global tuna catch, multiple databases must be searched to compile a count of all authorized purse seine vessels.

To provide an annual best estimate — and to track capacity changes from year to year — ISSF analyzes and aggregates information from the five tuna RFMOs and other sources. As the report explains, these figures still may underestimate the total fleet, because many small-scale purse seiners or purse seiners operating in only one exclusive economic zone (EEZ) do not have to be listed on RFMOs’ records of authorized fishing vessels. 

Other report findings about the large-scale purse seine vessels targeting tropical tuna include:

• About 16 percent of these 678 large-scale vessels are authorized to fish in more than one RFMO, which should be taken into account in any efforts to manage fishing capacity at a regional level.

• Among the RFMOs, the Western and Central Pacific Fisheries Commission (WCPFC) still has the highest number of LSPS registrations (341), more than half of the total worldwide. 

• The majority of large-scale vessels (503) are registered on the ISSF ProActive Vessel Register (PVR); PVR-registered LSPS represent 74 percent in number and 81 percent in fish hold volume (FHV).

The report also covers purse-seine vessel construction, distribution, and FHV by national flag. It offers recommendations for vessel owners on registration for IMO numbers and for RFMOs on vessel-data collection and management, such as a recommendation to publish lists of active vessels. View the updated report here. View a related infographic here.