Non-Entangling & Biodegradable FADs Guide

ISSF’s Non-Entangling & Biodegradable FADs guide for tuna fishers, Regional Fisheries Management Organizations (RFMOs), governments, and vessel owners shows research-based best practices in Fish Aggregating Device (FAD) design — both to avoid bycatch and reduce marine pollution.

Four tuna RFMOs already require fleets in their regions that fish with FADs to use only non-entangling designs. Some RFMOs additionally encourage fleets to build those FADs with biodegradable materials. The guide, first published in 2012 and revised in 2019 to include the biodegradable recommendation, is available in several languages.

ISSF 2021-12: A Snapshot of the Large-Scale Tropical Tuna Purse Seine Fishing Fleets as of July 2021*

Date Added: September 8, 2021
Downloaded: 89 times
Tags: Capacity Management, Justel-Rubio, Purse Seine, Recio, RFMOs, Tuna
Authors: Ana Justel-Rubio, Lorena Recio
Language: English
Featured: False
Report Type: Technical Report


Purse seine vessels account for about 66% of the world’s tuna catch. However, the number of purse seiners operating in the various oceans is not available from a single source.

In this paper, we estimate the number and fishing capacity of authorized tuna purse seiners based primarily on information available from the five tuna Regional Fishery Management Organizations (RFMOs). After accounting for possible duplicate entries, we calculate that as of July 2021 there are at least 1,855 purse seiners fishing for tunas worldwide. This is surely an underestimate because many small-scale purse seiners or purse seiners operating in only one EEZ do not have to be listed on RFMO records of authorized fishing vessels.

Focusing on large-scale purse seiners (defined here as having 335 m3 fish hold volume or greater) that target tropical tunas (skipjack, yellowfin and bigeye), we calculate there are 678 such vessels with a combined fishing capacity of over 865,000 m3. The number of these vessels decreased by about 2.6% during the past year, however, the fishing capacity remained at a similar level decreasing just 1%.

Of those 678 large scale purse seine vessels fishing for tropical tunas, 503 are registered on the ISSF Pro Active Vessel Register (PVR), which represent 74% in number and 81% in fish hold volume (FHV). About 16% 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. 

See the related infographic.