The State of World Fisheries and Aquaculture 2020

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PART 2 
SUSTAINABILITY IN ACTION
Fisheries resources of importance in ABNJ are 
deep-sea fisheries and highly migratory species 
such as tunas. The International Guidelines for 
the Management of Deep-sea Fisheries in the 
High Seas apply where the total catch (including 
bycatch) includes species that can only sustain 
low fishing rates and where fishing gear is used 
that is likely to contact the sea floor during 
operations. Deep-sea fishing (DSF) occurs over 
continental slopes, seamounts, ridge systems and 
banks on soft muddy sediments and hard, rocky 
substrates, mostly between 400 m and 1 500 m, 
although some specialized vessels may fish down 
to 2 000 m.
While DSF can be traced back 450 years, major 
expansion began with the deployment of 
factory-freezer trawlers in the mid-1950s, leading 
to huge catches. However, since 1980, only three 
major developments in DSF have taken place: 
orange roughy trawling; longlining for toothfish; 
and bottom trawling for Greenland halibut 
(Hosch, 2018).
Many deep-sea living resources have low 
productivity and are only able to sustain 
low fishing rates. Moreover, once depleted, 
their recovery is long and not assured. 
However, concerns associated with DSF extend 
beyond the potential impact on the targeted 
stocks to wider impacts on associated species and 
marine biodiversity.
In contrast, tuna are highly migratory species, 
typically crossing many EEZ boundaries and 
moving into ABNJ. Tuna fisheries produce a yield 
of about 7 000 000 tonnes (although only about 
40–50 percent is estimated to be caught in ABNJ). 
Apart from these widely distributed and highly 
migratory pelagic fish stocks, other species 
of conservation importance also traverse 
ABNJ and the territorial waters of numerous 
countries, or spend most of their annual cycle 
in ABNJ (Harrison 
et al
., 2018). In contrast, DSF 
produces only about 220 000 tonnes, mainly by 
industrial vessels, but these vessels interact more 
profoundly with the habitat (operating on or close 
to the seafloor), including vulnerable ecosystems. 
Both fisheries are of major interest in terms of 
biodiversity conservation, as well as interactions 
with other users of the same marine space.
Overarching rules governing the use of oceans 
and seas and their resources were established 
by UNCLOS. However, during the UNCLOS 
negotiating process, fishing in ABNJ was not 
perceived as a major problem requiring priority 
attention. Therefore, with respect to fishery 
resources occurring partly or entirely in ABNJ, 
UNCLOS limited itself to providing general 
principles for their conservation, optimal 
utilization and management, calling upon 
all States to cooperate towards the further 
development and implementation of these 
general principles. 
Other international instruments adopted in 
the last 20 years for the conservation and 
management of world fisheries resources, 
including in ABNJ, impose legally binding 
obligations on their Parties, such as: the 
Agreement for the Implementation of the 
Provisions of the United Nations Convention 
on the Law of the Sea of 10 December 1982 
relating to the Conservation and Management 
of Straddling Fish Stocks and Highly Migratory 
Fish Stocks; the FAO Agreement to Promote 
Compliance with International Conservation 
and Management Measures by Fishing Vessels 
on the High Seas; and, most recently, the FAO 
Agreement on Port State Measures to Prevent, 
Deter and Eliminate Illegal, Unreported and 
Unregulated Fishing.
Concerns regarding DSF led to specific guidance 
from the United Nations General Assembly (e.g. 
through UNGA Resolutions 61/105 and 64/72), 
principally aimed at improving the management 
of high seas fishery areas. This has helped 
promote measures to protect benthic habitats and 
VMEs in particular, especially at the regional 
level – implemented by RFMOs. FAO has also 
been central in developing international policy 
frameworks for DSF. It adopted the International 
Guidelines for the Management of Deep-Sea 
Fisheries in the High Seas in 2008 and created 
the VME Database.
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All areas of distribution and all fleets catching 
tuna and tuna-like species are under the mandate 
of five tuna RFMOs (which encompass more 
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The VME Database can be accessed at: www.fao.org/in-action/
vulnerable-marine-ecosystems/en
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THE STATE OF WORLD FISHERIES AND AQUACULTURE 
2020
than 80 countries). This reflects the importance 
of tuna fisheries for the economies of countries 
along the supply chain, as well as in providing 
nutrition to many coastal communities.
Eight deep-sea RFMOs and other organizations 
exist with the competence to manage small 
pelagic and demersal fisheries in the high seas, 
covering about 77 percent of ABNJ. Their remit 
includes bycatch mitigation and the wider 
protection of the environment from significant 
adverse impacts. In all areas, flag States are 
responsible for the activities of their fishing 
vessels when utilizing fishery resources in the 
high seas. In addition, port States and coastal 
States also contribute to the verification of 
compliance with regulations. 
While recognized current best practice is 
to manage all associated species within 
ecosystem-based management frameworks, 
such frameworks can be complex and difficult 
to operationalize (Tingley and Dunn, 2018). 
Therefore, often, the ecosystem considerations 
in RFMOs have been implemented through 
the adoption of actions to mitigate the impact 
of fishing on non-target species, or on the 
ecosystem structure and function. In deep-sea 
RFMOs, in which the fisheries involve a 
higher level of interaction of fishing gear with 
the habitat, protocols have been adopted to 
cease fishing when a VME is encountered. 
Tuna fisheries have seen improved mitigation of 
incidental catch of important associated species 
such as turtles, birds, sharks and small tuna.
Minimum standards for “best available” 
science to support fisheries management have 
been developed and published (MFish, 2008). 
A high degree of transparency in science 
and management is fundamental to enabling 
fishers, NGOs, other science and management 
organizations, processers and retailers to have 
confidence in fisheries management.
Current guidance for managing impacts on 
benthic habitat proposes area closures to mobile 
demersal fishing gear, but these may also 
extend to static gear. The South Pacific Regional 
Fisheries Management Organisation, which 
manages the largest high seas orange roughy 
fishery, has closures amounting to more than 
95 percent of its convention area, and about half 
of the fishable depth within that area (Tingley 
and Dunn, 2018).
The effectiveness of area-based management 
measures depends on the mobility of the species 
involved. Marine protected areas (MPAs) will 
be less effective for highly migratory species in 
comparison with deep-sea species that are almost 
resident in a particular area (for example, those 
associated with a seamount), especially so in 
ABNJ, where pelagic species may occupy large 
geographical areas.
The aims of area closures are diverse. Many are 
for the protection of specific benthic areas of 
interest, such as seamounts and deep-water coral 
reefs, or for the protection of demersal species. 
Other closures aim to reduce impacts on pelagic 
species, including both adults and juveniles 
(Davis 
et al
., 2012). In general, closures are 
accompanied by other more targeted management 
arrangements, including regulation of fishing 
effort and catch quotas, adopted under the 
RFMOs. The role of pelagic MPAs in conservation 
and management is likely to remain controversial 
until more documented studies become available. 
The seabed and water column are inextricably 
linked. Emerging research increasingly links 
upper-ocean communities and processes to 
seabed ecology and biogeochemistry (O’Leary 
and Roberts, 2018).
Sustainability cannot be achieved without 
biodiversity conservation, and sustainable 
utilization of fisheries resources in ABNJ is 
compatible with biodiversity conservation. 
This realization is reflected by many RFMOs 
adopting the EAF, recognizing the need to 
manage fisheries more holistically. An additional 
challenge is to implement sufficient 
cross-sectoral coordination among the multiple 
users of ABNJ to ensure that biodiversity impacts 
from any user, and overall, are monitored and 
mitigated. Action should be taken to minimize 
the impact of fishing operations on biodiversity, 
building on the RFMOs’ existing mandate, 
and ensuring appropriate communication and 
coordination with other initiatives and users.
Since 2014, FAO, in close cooperation with many