Atlantic Bluefin tuna

SEASONAL AVAILABILITY

In the Mediterranean and the Eastern Atlantic, the period 26 May to 1 July marks the season where large vessels (purse seiners), are allowed to fish for bluefin tuna. Trapping in the Mediterranean starts in February and ends in July.

Overview

Atlantic bluefin tuna (Thunnus thynnus) are found in the entire North Atlantic and its adjacent seas, primarily the Mediterranean Sea. ICCAT recognizes two stocks: Western Atlantic, and Eastern Atlantic and Mediterranean bluefin. There is considerable mixing between the two.
Average size and age at maturity is 115cm (Fork Length) and 4 years respectively.
Bluefin Tuna are known to be highly migratory, with individuals making long migrations every year. These migrations correspond with their spawning behaviour and with their food needs.
Atlantic bluefin tuna spawn in two widely separated areas. One spawning ground exists in the western Mediterranean, particularly in the area of the Balearic Islands. Their other important spawning ground is the Gulf of Mexico.
This species reproduces via broadcast spawning, where several females and several males release millions of eggs and sperm into the water column at the same time. Female Atlantic bluefin tuna produce up to 10 million eggs a year. Eggs hatch 2 days after being fertilized.
Atlantic bluefin tuna are top predators, feeding on fish such as herring and mackerel as adults.
Atlantic bluefin tuna are the largest tuna species. The Western Atlantic stock reaches a maximum length of 13 feet (4 m) and weight of 2,000 pounds (907 kg), while the Eastern Atlantic stock reaches a maximum length of 15 feet (4.6 m).
Atlantic bluefin tuna can live for 35 years, possibly longer.

Catches of Eastern Atlantic and Mediterranean bluefin tuna in 2019 were about 28,800 tonnes. The latest catch data of the Western Atlantic bluefin tuna was about 1,200 tonnes, which is predominantly a sports fishery.
For the Eastern Atlantic and Mediterranean bluefin tuna stock, purse seiners take 61% of the catch, followed by traps (16%), longline (15%), and a variety of surface gears, including pole-and-line, handline and trolling.
In the Eastern Atlantic and Mediterranean, the period 26 May to 1 July marks the season when large vessels (purse seiners) are allowed to fish for bluefin tuna. Together with traps, purse seiners account, by far, for the biggest part of the EU quota (71 %).
Controls on gears that catch the fish alive for ‘grow-out’ purposes is in place. In 2018 the number of vessels authorized to fish bluefin tuna was 1,088 vessels (of which, 58 were purse-seiners) and 12 traps and the EU quota for 2018 was 15,850 tonnes.
Size limits are applied on catch of the species depending on the catch area. Catch limits on Western Atlantic bluefin tuna are set for different fish size classes.
Countries actively involved in the Eastern Atlantic and Mediterranean bluefin tuna fishery are Spain, France, Croatia, Italy, Greece, Portugal, Malta and Cyprus.
The bluefin tuna fishery is regulated by the ICCAT where the EU is a contracting party. In 2006, ICCAT adopted a multi-annual recovery plan for Bluefin tuna, which has been regularly modified based on stock assessment, control experiences and new technologies.
IUCN red list status of Atlantic bluefin tuna changed from Endangered (since 2011) to Least Concern in 2021. This is an indication of significant stock recovery of the species.
Bait is needed to catch the fish when using hooks. However, the baitfish fisheries can be substantial and are largely unmonitored and unmanaged.

Pelagic longline

Longlining, as the name suggests, involves long fishing lines which can be as long as 100 kilometres. Attached to them are shorter lines with baited hook tied at fixed intervals. Longlines can be set at different depths to catch different species. Pelagic longline is where the lines are set near the surface of the water to catch open water fish such as bluefin tuna, yellowfin tuna and swordfish. Bycatch is a major environmental issue in the longline fishery, especially impacting billfish, sea turtles, pelagic sharks, and seabirds. Also there are concerns about the baitfish* fisheries for the bait that is needed to catch the fish using hooks; these can be substantial and are largely unmonitored and unmanaged.

Pole and line

Hook and line is one of the best methods of fishing with regards to sustainability. This can involve one person and a rod, or alternatively using a basic winch with a line of hooks. The hook and line fishing method has little impact on the surrounding environment and the catch can be selective. For example, any fish too small, or not the right species can be placed back into the water, with limited harm. Problems with large-volume, yet unmanaged baitfish* fisheries are also associated with pole and line fisheries. *See general coverage on tuna baitfisheries: Gillett, R. E. (2012). Global study of the management of baitfisheries that support pole-and-line tuna fishing SPC Fisheries Newsletter #139 - September/December 2012

Purse seine

Purse seine nets are used as walls to encircle fish. After the fish are surrounded, the bottom end of the purse seine net is pulled up and closed to form a bag that traps the fish. Schooling fish such as sardine, salmon and yellowfin tuna are caught by this method. Can be unselective, particularly if used alongside Fish Aggregating Devices (FADs), where sharks, rays, turtles, dolphins and juvenile tuna can be caught.

Almadraba traps

The almadraba traps are big nets anchored or held by pegs, open on the surface and provided with different systems to direct and trap the fish. They are usually divided into different chambers, which have nets at the bottom. The fishing season for the pasotype of almadraba traps takes place in spring and ends at the beginning of summer, and for the “return” type almadrabas, it begins at the end of summer and ends in autumn. All almadraba traps currently belong to the pasotype, because the quota is reached within the first few months. Currently the almadraba season begins in February and ends in July. The crew for the almadraba is made up of 40-45 people hired during this period.

Evidence from the catch certificate showing the following:
- Latin species name,
- country sea area / RFMO area,
- vessel flag,
- name of vessel,
- Unique Vessel Identifier, such as an IMO number; note that as of 2017 vessels, including fishing vessels above 100 GT (which would include most tuna vessels) should have an IMO number. Ask supplier for a link showing the vessel identities. https://www.fao.org/global-record/background/unique-vessel-identifier/en/,
- capture method,
- landing port,
- required observers onboard vessels
- any knowledge of management of baitfish fishery that supplies target species (if pole and line or longline used) or any threatened species bycatch mitigation efforts by fishing operation
- If pole and line / longline, is bait sourced from a fishery undergoing fisheries improvement?
Are the supplier vessels included in the International Seafood Sustainability Foundation ProActive Vessel Register (ISSF PVR)? Ask supplier for a link showing the vessel identities.
Note if you are buying from vessels that are not on the PVR – you can get suppliers to apply for PVR status: https://iss-foundation.org/knowledge-tools/public-vessel-lists/proactive-vessel-register/
Is your supplier a member of the Global Tuna Alliance?

If all of this evidence can be obtained, this will provide some assurance that the product has been legally caught, and that your supplier is supporting responsible tuna fishery management practices.

Common Name(s)

Medium Risk

Traditional Chinese

Japanese

Simplified Chinese

French

Spanish

Certifications

Date of Assessments

Peer Reviewer

Assessment Organisation

SEASONAL AVAILABILITY

Overview

Pelagic longline

Pole and line

Purse seine

Almadraba traps

FISHERIES IMPROVEMENT PROJECTS

COUNTRY SPECIFIC RISK ASSESSMENTS

Eastern Atlantic and Mediterranean

OTHER Wild FISH

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Arapaima

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