The State of World Fisheries and Aquaculture 2020

YEAR
PERCENTAGE
Sustainable
Unsustainable
Overfished
Maximally sustainably fished
Underfished
0
1980
1974
1990
2000
2010
2017
SOURCE: FAO.
| 48 |

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THE STATE OF WORLD FISHERIES AND AQUACULTURE 
2020
Tunas are of great importance because of their 
high catches, high economic value and extensive 
international trade. Moreover, their sustainable 
management is subject to additional challenges 
owing to their highly migratory and often 
straddling distributions. The seven species of 
tunas of global commercial importance are 
albacore (
Thunnus alalunga
), bigeye (
Thunnus 
obesus
), skipjack (
Katsuwonus pelamis
), yellowfin 
tuna (
Thunnus albacares
) and three species of 
bluefin tuna (
Thunnus thynnus
, 
Thunnus maccoyii
and 
Thunnus orientalis
). Their combined landings 
were 5.03 million tonnes in 2017, a 5 percent 
increase from 2015 but 1 percent below the 
historical peak of 2014. 
In 2017, among the seven principal tuna species, 
33.3 percent of the stocks were estimated to be 
fished at biologically unsustainable levels, while 
66.6 percent were fished within biologically 
sustainable levels. Three stocks have seen 
their status improve from unsustainable to 
sustainable, including Eastern and Western 
Pacific bigeye tuna and Eastern Pacific 
yellowfin tuna.
Tuna stocks are generally well assessed, and 
very few stocks of the principal tuna species 
are of unknown status. In contrast, most 
minor tuna species and/or tuna-like species 
remain unassessed or assessed under high 
uncertainty. Market demand for tuna remains 
high, and tuna fishing fleets continue to have 
significant overcapacity. Effective management, 
including the implementation of harvest control 
rules, is needed to restore overfished stocks 
and to maintain others at sustainable levels. 
Moreover, substantial additional efforts on data 
collection, reporting and assessment for minor 
tuna and tuna-like species are required. 
FIGURE 20
PERCENTAGES OF STOCKS FISHED AT BIOLOGICALLY SUSTAINABLE AND UNSUSTAINABLE LEVELS,
BY FAO STATISTICAL AREA, 2017
Biologically sustainable
Biologically unsustainable
0
20
40
60
80
100