World Tuna Day

  The World Tuna Day aims to draw attention to the importance of conservation management and sustainable fishing.

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The United Nations Fish Stocks Agreement.

The United Nations 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 (UNFSA) is an international agreement that regulates key fisheries that, because of their transboundary nature, require international cooperation for their conservation and management. Its objective is to ensure the long-term conservation and sustainable use of straddling fish stocks and highly migratory fish stocks through effective implementation of the relevant provisions of the Convention. The Agreement sets out principles for the conservation and management of those fish stocks and establishes that such management must be based on the precautionary approach and the best available scientific information. 

The United Nations Agreement for the Implementation of the Provisions of the United Nations Convention on the Law of the Sea of 10 December

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Moving towards a more sustainable tuna fishing and biodiversity conservation.

The GEF-funded Food and Agriculture Organization of the United Nations (FAO) Common Oceans Tuna project aims to ensure that tuna stocks are fished at sustainable levels by 2027.

On this May 2nd; World Tuna Day, learn about its ambitious goals towards more sustainable tuna fishing and biodiversity conservation.

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Bluefin Tuna Index.

The Bluefin Tuna Index provides detailed information about bluefin tuna habitat to management bodies to inform decision making. The index tracks favorable habitat for the bluefin tuna in near-real time and is used by NOAA Fisheries in stock assessments. With better-informed catch limits and location information, commercial fishing operations are able to harvest their catch both successfully and sustainably.

Learn more Bluefin Tuna Index

AOML scientists use ocean observations to help protect species and understand and predict how environmental conditions change.

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Estimated size, weight and weight at size conversion factors for Atlantic bluefin tuna stocks.

Highlighted weight - size functions correspond to the annual equations representing overall mean for the population. Size measures are straight fork length (SFL), curved fork length (CFL), length 1st dorsal spine (LD1), head length straight line from snout to operculum (HeadL), preopercular length straight line from the snout to preoperculum (PreOP). Weight measures are round weight: weight of the whole fish (RWT); gutted weight: weight without guts and gonads (GWT); gutted and gilled: weight without guts, gonads and gills (GGWT); gutted gilled and tailed: weight without guts, gonads, gills and tail (GGTWT); and dressed weight: weight of fish gutted, head and tail off (DWT). All size units are centimeters (cm) and weight in kilograms (kg).

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Estimation of the weight of the bluefin tuna.

In 2021 the SCRS revised the length-weight relationships in use for estimating the catch weight for bluefin tuna destined farming for two eastern Atlantic areas (Atlantic coast of Morocco and southern Portuguese coasts).

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Length-weight relationships adopted by the SCRS for major tropical tuna species.

Length-weight relationships adopted by the SCRS for major tropical tuna species: Yellowfin (YFT) (Thunnus albacares), Bigeye (BET) (Thunnus obesus), Skipjack (SKJ) (Katsuwonus pelamis)

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Supporting an alternative perspective towards managing global fisheries.

Fisheries bycatch continues to drive the decline of many threatened marine species such as seabirds, sharks, marine mammals and sea turtles. Management frameworks typically address incidental catch with fleet-level controls on fishing. Yet, individual operators differ in their fishing practices and efficiency at catching fish. If operators have differing abilities to target, they should also have differing abilities to avoid bycatch. We analysed variations in threatened species bycatch among individual operators from five industrial fisheries representing different geographic areas, gear types and target species. The individual vessel is a significant predictor of bycatch for 15 of the 16 cases, including species that represent high or low costs to fishers or have economic value as potentially targeted byproducts. Encouragingly, we found high-target and low-bycatch operators in all five sectors, including gears known for high bycatch mortality worldwide. These results show that there is untapped opportunity to reduce negative environmental impacts of fisheries with interventions targeting specific performance groups of individuals, supporting an alternative perspective towards managing global fisheries.

Bycatch rates in fisheries largely driven by variation in individual vessel behaviour - Nature Sustainability

Fishing practices and efficiency at catching fish vary across individual operators with implications about the operators’ ability to avoid b

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Despite considerable logistical challenges, at-sea dFAD recovery offers promising options for reducing the ecological footprints of purse-seine fisheries.

Tropical tuna purse-seine fishing vessels contribute to abandoned, lost or discarded (ALD) fishing equipment by deploying large numbers of drifting Fish Aggregating Devices (dFADs). Here we analysed more than 80,000 dFAD trajectories (56,263 tracking buoys) in the Indian and Atlantic oceans from 2012 to 2018. We found that more than 40% of dFAD trajectories ultimately drifted away from fishing grounds, becoming ALD. About 20% of these lost dFADs passed within 50 km of major ports, indicating that port-based programmes could be effective in collecting ALD dFADs at sea. We also identified areas within the fishing grounds where most dFADs exit and where high-seas recovery could be valuable. For example, most dFADs leaving Indian Ocean fishing grounds along their eastern border at ~70° E, particularly in October–December, do not return to fishing grounds. Despite considerable logistical challenges, at-sea dFAD recovery offers promising options for reducing the ecological footprints of purse-seine fisheries.

Recovery at sea of abandoned, lost or discarded drifting fish aggregating devices - Nature Sustainability

Nearly half of drifting fish aggregating devices in the Indian and Atlantic oceans becomes abandoned, lost or discarded. However, a substant

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Electronic tags that archive or transmit stored data to satellites have advanced the mapping of habitats used by highly migratory fish in pelagic ecosystems.

Here we report on the electronic tagging of 772 Atlantic bluefin tuna in the western Atlantic Ocean in an effort to identify population structure. Reporting electronic tags provided accurate location data; that show the extensive migrations of individual fish (n = 330). Geoposition data delineate two populations, one using spawning grounds in the Gulf of Mexico and another from the Mediterranean Sea. Transatlantic movements of western-tagged bluefin tuna reveal site fidelity to known spawning areas in the Mediterranean Sea. Bluefin tuna that occupy western spawning grounds move to central and eastern Atlantic foraging grounds. Our results are consistent with two populations of bluefin tuna with distinct spawning areas that overlap on North Atlantic foraging grounds. Electronic tagging locations, when combined with US pelagic longline observer and logbook catch data, identify hot spots for spawning bluefin tuna in the northern slope waters of the Gulf of Mexico. Restrictions on the time and area where longlining occurs would reduce incidental catch mortalities on western spawning grounds.

Electronic tagging and population structure of Atlantic bluefin tuna - Nature

The Atlantic bluefin tuna is at the centre of an international debate in fisheries conservation. Last summer the western Atlantic bluefin tu

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Stocks of prized bluefin in danger of collapse.

Atlantic bluefi tuna are huge marine predators that can weigh up to 650 kilograms and are prized for their flesh. They are the most valuable fish in the ocean — in Japan, single fish can command prices of up to US$100,000. In recent decades, fishing boats have scrambled to catch as many as possible by trap, net, harpoon or long line, and as a result bluefin numbers have fallen by 80% or more since 1970. The migration patterns of giant Atlantic bluefin tuna have been unravelled through satellite tagging — and the results suggest that policies for managing the overfished species require an urgent rethink.

Satellite tags give fresh angle on tuna quota - Nature

The Atlantic bluefin tuna is at the centre of an international debate in fisheries conservation. Last summer the western Atlantic bluefin tu

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Promote sustainable fisheries management.

Overfishing has reduced numerous fish populations to remnants of their historical levels, yet we have a poor understanding of what impact this has had on their evolutionary potential and resilience. This information is crucial to predict future demographic changes and thus promote sustainable fisheries management. Studies of historical marine ecology offer an opportunity to learn and heed these past lessons. In particular, genetic/genomic studies can infer past history from contemporary samples, or directly test archaeological and archival samples for losses in genetic diversity, population restructuring, or adaptive responses to natural factors e.g., climate, or anthropogenic ones e.g., fisheries-induced evolution (FIE). A decade ago, the first to investigate temporal demographic changes in the key species Atlantic bluefin tuna (Thunnus thynnus, hereafter BFT) using archival early-20th century samples and microsatellite markers. Here, we build on this work by genotyping archival and archaeological samples to extend investigations into the pre-industrial era, when fishing may have also had the potential to impact BFT.

Ancient DNA SNP-panel data suggests stability in bluefin tuna genetic diversity despite centuries of fluctuating catches in the eastern Atla

Atlantic bluefin tuna (Thunnus thynnus; BFT) abundance was depleted in the late 20th and early 21st century due to overfishing. Histori

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 Four commercially fished tuna species have shown signs of recovery; thanks to countries enforcing fishing quotas albacares). 

 

Tuna conservation is working, says Red List; Four commercially fished tuna species have shown signs of recovery thanks to countries enforcing fishing quotas: Atlantic bluefin tuna (Thunnus thynnus), southern bluefin tuna (Thunnus maccoyii), albacore (Thunnus alalunga) and yellowfin tunas (Thunnus albacares). 

Tuna conservation is working — but Komodo dragons are endangered, says Red List. Plus, freak cold snaps are linked to Arctic warming and why we write letters of recommendation for ourselves.

Daily briefing: These tuna species are no longer endangered

Tuna conservation is working — but Komodo dragons are endangered, says Red List. Plus, freak cold snaps are linked to Arctic warming and why

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The IUCN Red List now includes 138,374 species of which 38,543 are threatened with extinction.

Four commercially-fished tuna species are on the path to recovery thanks to the enforcement of regional fishing quotas over the last decade, according to today’s update of the IUCN Red List of Threatened Species™ released at the IUCN World Conservation Congress in Marseille. However, the recovery comes in the midst of growing pressures on marine species, with 37% of the world’s sharks and rays now threatened with extinction primarily due to overfishing, compounded by loss and degradation of habitat and climate change.

Tuna species recovering despite growing pressures on marine life - IUCN Red List

Marseille, France, 4 September 2021 (IUCN) – Four commercially-fished tuna species are on the path to recovery thanks to the enforcement of

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The Pacific bluefin tuna is distributed throughout the Pacific Ocean and displays wide-ranging movements and population connectivity throughout its range.

Tropical and temperate tunas are essential components of marine ecosystems and play important ecological roles by influencing the structure and dynamics of pelagic food webs. Many species of tunas are highly migratory and regularly cross international borders or management boundaries, often traversing oceans to complete their life cycles. Migration activities and resulting shifts in spatial distributions of tunas complicate management efforts for targeted populations because fishing pressure varies spatially within an individual’s home range. In response, efforts to better understand movement pathways and the intrinsic drivers that facilitate or initiate spatial shifts are critical, and resource managers readily acknowledge that a species’ migratory history is important to developing reliable population models and management plans. While our understanding of the movement ecology of tropical and temperate tunas has increased significantly in the past two decades, data on directed migrations during early life when juveniles leave spawning or nursery areas are lacking for many populations and species.

Natal origin and age-specific egress of Pacific bluefin tuna from coastal nurseries revealed with geochemical markers - Scientific Reports

Geochemical chronologies were constructed from otoliths of adult Pacific bluefin tuna (PBT) to investigate the timing of age-specific egress

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Netting Billions: A Global Valuation of Tuna

Taken together, the seven most commercially important tuna species are among the most economically valuable fishes on the planet. Collective

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Podcast: Two tunas and a tale of managed extinction

Today we discuss the tales of two tuna: yellowfin in the Indian Ocean, and bluefin in the Atlantic. These are two tales of overfishing and p

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Fishing Aggregating Devices (FADs) in Responsible Tuna Fisheries

World Tuna Day is observed on 2nd May every year; it was officially established by the United Nations General Assembly (UNGA) by adopting resolution 71/124, in December 2016.

A visual stimulus and optical void (Hunter, JR and Mitchell CT, 1966)