Tuna Species Research Articles

Global occurrence, bioaccumulation factors and toxic effects of polychlorinated biphenyls in tuna: A review

Polychlorinated biphenyls (PCBs) tend to accumulate in adipose tissue and induce toxicity due to their high lipophilicity and persistence. Tuna play an important role in the ocean food web and human diet. PCBs can damage the growth of tuna directly and have some adverse effects on human indirectly. This review aims to provide geographic variations, bioaccumulation factors and the toxic effects of PCBs in tuna. PCB levels found were varied significantly among the different regions and it showed a trend of offshore greater than pelagic, with the northern hemisphere higher than the southern hemisphere. The highest PCB concentration of tuna was in FAO area 37. Nearly all of the specimens presented similar domain configuration, while their concentrations varied significantly. PCB congeners and concentrations in tuna were affected by a vast of factors, such as geographical distribution, tissue types, trophic level and growth stage, gender, tuna species and physical and chemical properties of PCBs. They can damage reproductive, neurologic and development systems. This review gives a systematic insight into PCBs in tuna and highlights the more attention should be paid to the long-term changes of PCBs in tuna and oceans. There is also a need to strengthen the assessment of PCB impacts on tuna ecology.

Longtail tuna, Thunnus tonggol (Bleeker, 1851): a global review of population dynamics, ecology, fisheries, and considerations for future conservation and management

Longtail tuna (Thunnus tonggol) is a neritic species that supports commercial, artisanal and recreational fisheries throughout the Indo-Pacific region. Historically receiving little attention by commercial fisheries, the global annual catch of longtail tuna has steadily risen from around 30,000 t in the early 1980s to exceeding 200,000 t since 2004, reaching a peak of 291,264 t in 2007, and was 281,613 t in 2017. Catches of longtail tuna in the Indian Ocean now exceed catches of principal commercial target species, such as albacore and bigeye tunas. A sequence of stock assessments undertaken throughout the species’ range since the late 1980s persistently indicated that at least three of the four stocks defined in this paper are likely to have been, and most likely are currently, subject to overfishing and overfished as a result of excess fishing effort on this relatively slow-growing and long-lived tuna species. As the spawning biomass of principal tuna target species continue to decline in both the Indian and western and central Pacific Oceans, the increasing catches of longtail tuna, other neritic tunas, and seerfishes is worrisome. Few conservation and management measures (CMMs) are currently in place specifically for longtail tuna, although in recent years some coastal States, Regional Fishery Bodies, and tuna Regional Fisheries Management Organisations have begun to develop initiatives to improve the catch and biological data quality for longtail tuna and sympatric species of neritic tunas and tuna-like species. This paper provides a global review of biological, ecological and fishery information to provide researchers, fishery managers and policy makers with the most current information from which to begin to guide future stock assessment and the development of CMMs for longtail tuna.

The current state of fish market in Ukraine

The fishing industry is an important component of the economy of Ukraine at the present stage of development. The development and implementation of the innovative technologies in fish farming and fish processing require mandatory and ongoing analysis of a fish market infrastructure. The demand for food protein, which is characterized by a balanced amino acid content is provided by fish and seafood at 20–30 %. The aim of this work was to understand a current state of a fish products market in Ukraine, its pricing and consumption. Based on the specialized literature the evaluation of a current state of fish and fish products consumption in Ukraine and own studies of the price category of fish products in Ukraine in recent years were conducted. We studied fish and fish products consumption per year per capita in Ukraine over the last 20 years, assortment of fish in Ukraine, the import of fish and fishery products by species, the product prices in UAH per kg both in previous years and today. According to international medical standards the annual consumption of fish and seafood should be 20 kg per person. At the same time in Ukraine according to the State Statistics Committee on the 01.01.2019 14.5 kg of fish and seafood came out per capita. In 2018–2019 herring traditionally remained a leader of consumption in Ukraine. Ukraine also imported such species of fish: mackerel, hake, herring, salmon, pilchards, pollack, capelin, sardines, notating. In addition pangasius, shrimp, blue whiting, mussels, squid, saury, Jack mackerel, sea bass, tuna, flounder, anchovies, smelt, cod, salmon and other species of fish, caviar and seafood are imported in Ukraine. The investigated assortment of fish in Ukraine is represented both domestic and imported products. The domestic production are: carp, pike, capelin, herring, mackerel, sprat, the imported products are: flounder, perch, pangasius, salmon, butter, hake, Pollock, capelin, nototenia, herring, mackerel, cod, tuna, tilapia (sole), sea trout, whiting and so forth. It is established that the condition of a fish market in Ukraine is affected by an unstable economic and political situation in the country, low solvency of the population, corruption and the high payables of the enterprises. In Ukraine a tendency towards a decrease in the volume of fish and fish products consumption by the population of Ukraine is observed annually, which is a consequence of the decline in fish catch and fish production, depreciation of fixed assets and a lack of financial support to the fishing industry.

Trends in tuna carbon isotopes suggest global changes in pelagic phytoplankton communities.

Considerable uncertainty remains over how increasing atmospheric CO2 and anthropogenic climate changes are affecting open-ocean marine ecosystems from phytoplankton to top predators. Biological time series data are thus urgently needed for the world's oceans. Here, we use the carbon stable isotope composition of tuna to provide a first insight into the existence of global trends in complex ecosystem dynamics and changes in the oceanic carbon cycle. From 2000 to 2015, considerable declines in δ13 C values of 0.8‰-2.5‰ were observed across three tuna species sampled globally, with more substantial changes in the Pacific Ocean compared to the Atlantic and Indian Oceans. Tuna recorded not only the Suess effect, that is, fossil fuel-derived and isotopically light carbon being incorporated into marine ecosystems, but also recorded profound changes at the base of marine food webs. We suggest a global shift in phytoplankton community structure, for example, a reduction in 13 C-rich phytoplankton such as diatoms, and/or a change in phytoplankton physiology during this period, although this does not rule out other concomitant changes at higher levels in the food webs. Our study establishes tuna δ13 C values as a candidate essential ocean variable to assess complex ecosystem responses to climate change at regional to global scales and over decadal timescales. Finally, this time series will be invaluable in calibrating and validating global earth system models to project changes in marine biota.

Survivorship of species caught in a longline tuna fishery in the western equatorial Atlantic Ocean

Longlines bearing “hook timers” (HTs) and alternating circle (15/0 and 17/0) and “J” (10/0) hooks were employed off the coast of Brazil to measure differences in fishing mortality associated with hook type and on-hook time between capture and boarding. A total of 431 HTs were activated, revealing a clear pattern of the increased mortality rate of fishes associated with increased on-hook time. Swordfish had high mortality rates, unlike blue sharks, which had low mortality rates regardless of hook type and the location in which the hook was transfixed. The six species of tunas and billfishes examined in this study showed a strong association between hooking location and the animal’s release condition, with reduced mortality associated with individuals hooked externally. Results suggest that knowledge of factors affecting the survival of pelagic fishes caught in longline fisheries may enable the development and adoption of fishing methods to reduce mortality of longline bycatch.

Accumulation of halogenated polycyclic aromatic hydrocarbons by different tuna species, determined by high-resolution gas chromatography Orbitrap mass spectrometry

Halogenated polycyclic aromatic hydrocarbon (HPAH) concentrations in tissues from three tuna species Thunnus albacares (yellowfin tuna), Katsuwonus pelamis (skipjack tuna), and Auxis thazard (frigate tuna) were determined by high-resolution gas chromatography Orbitrap mass spectrometry. The tuna samples were collected from the Indian Ocean. The instrument conditions gave high mass accuracy at 0.9 m/z isolation width of the mass filter and a mass error of <±1.0 ppm for many HPAHs. A total of 29 of the 30 targets chlorinated PAHs (ClPAHs) and 20 of the 21 targets brominated PAHs (BrPAHs) were detected in the tuna muscle samples. The mean total ClPAH, BrPAH and PAH concentrations for tuna were 127.2, 156.6 and 682.8 ng/g lipid weight, respectively. The mean total ClPAH and BrPAH concentrations (ng/g lipid weight) in the tuna were considerably lower than that of PAH concentrations. The mean total ClPAH, BrPAH and PAH concentrations in T. albacares respectively were 185.8, 249.2 and 784.1 ng/g lipid weight, irrespective of the body sizes. The mean total ClPAH, BrPAH and PAH concentrations in K. pelamis respectively were 45.1, 24.8 and 555.6 ng/g lipid weight. The mean total ClPAH, BrPAH and PAH concentrations in A. thazard respectively were 34.09, 4.73 and 433.24 ng/g lipid weight. The total ClPAH concentrations and body weights significantly positively correlated for T. albacares. The mean total ClPAH concentration in white muscles was significantly higher (p < 0.05) for large than for small T. albacares. This suggests ClPAHs could bioaccumulate in T. albacares, possibly because they are poorly metabolized. The chlorinated phenanthrene and pyrene concentrations indicated tuna accumulate these compounds increasingly effectively as the tuna grow. This was the first time large numbers of HPAHs were found in biological samples. HPAHs may adversely affect the health of humans consuming tuna.

Análisis de la pesca española en el Atlántico noreste 1980-2012: Papel de Galicia en la explotación de las principales especies marinas

The Spanish fishing fleet is one of the most important in the European Union and is exploiting marine resources in the FAO area 27 (North-eastern Atlantic Ocean). The Galician Region has a relevant role in the fishing industry. The number of boats decreased significantly between 1980 and 2012. But the landing quantities of the main marine species exploited (small pelagic fishes and tuna species mainly) decreased faster that the fleet during the same period. In contrast, landing quantities of Elasmobranchs (sharks and rays) and Cephalopods increased. This analysis shows the overexploitation of the Atlantic fishing grounds.

Targeted mutagenesis of the ryanodine receptor by Platinum TALENs causes slow swimming behaviour in Pacific bluefin tuna (Thunnus orientalis)

In bluefin tuna aquaculture, high mortalities of hatchery-reared juveniles occur in sea cages owing to wall collisions that are caused by high-speed swimming in panic due to changes in illuminance. Here, we report that targeted gene mutagenesis of the ryanodine receptor (RyR1b), which allows the sarcoplasmic reticulum to release Ca2+ in fast skeletal muscle, using highly active Platinum TALENs caused slow swimming behaviour in response to external stimuli in Pacific bluefin tuna (PBT) larvae. This characteristic would be a useful trait to prevent wall collisions in aquaculture production. A pair of Platinum TALENs targeting exons 2 and 43 of the PBT ryr1b gene induced deletions in each TALEN target site of the injected embryos with extremely high efficiency. In addition, ryr1b expression was significantly decreased in the mutated G0 larvae at 7 days after hatching (DAH). A touch-evoked escape behaviour assay revealed that the ryr1b-mutated PBT larvae swam away much less efficiently in response to mechanosensory stimulation at 7 DAH than did the wild-type larvae. Our results demonstrate that genome editing technologies are effective tools for determining the functional characterization of genes in a comparatively short period, and create avenues for facilitating genetic studies and breeding of bluefin tuna species.

Non-Targeted Identification of Brine Covered Canned Tuna Species Using Front-Face Fluorescence Spectroscopy Combined with Chemometric Tools

The most common frauds of tuna cans supply chain concern the substitution or mixing of valuable tuna species with cheaper ones, which is strictly forbidden. The objective of the present study was to determine the potential use of front-face fluorescence spectroscopy (FFFS) as a rapid tool to authenticate species in canned tuna: skipjack tuna (Katsuwonus pelamis), yellowfin tuna (Thunnus albacares), Albacore tuna (Thunnus alalunga), and bigeye tuna (Thunnus obesus). Different spectra (tryptophan residues, aromatic amino acids, and nucleic acids (AAA + NA), riboflavin, nicotinamide adenine dinucleotide (NADH), and vitamin A) were recorded on 256 canned tunas, produced at the pilot scale, that were used for the establishment of models. The robustness of the established models was tested on 40 commercial canned tunas. According to the label tunas, the percentage of correct classification reached 75% allowing us to conclude that FFFS may represent a promising tool to be used by both canning industry and governmental control agencies to ascertain correct labeling of canned tuna.

Simple PCR-RFLP detection method for genus- and species-authentication of four types of tuna used in canned tuna industry

A simple method for authentication of processed tuna products is not only for testing against fraudulent practices in the tuna industry but being a promising tool for enhancing traceability. Here, a method of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) had been developed using a part of the mitochondrial cytochrome c oxidase subunit 1 (COI) gene as a key region for genus-and species-identification. The analysis was based on the different RFLP patterns of TaqI and HaeIII digested COI DNA from the four tuna species; i.e. Kasuwonus pelamis, Thunnus alalunga, Thunnus albacares, and Thunnus obesus, respectively. While the conventional PCR-RFLP worked effectively in raw tuna meat, a method of semi-nested PCR had to be developed in order to increase efficiency in the detection in cooked meat from canned product. The semi-nested PCR-RFLP pattern of COI DNA allowed the detection of 10% contamination of K. pelamis in canned tuna of other higher-valued species.

Indications of strong adaptive population genetic structure in albacore tuna (Thunnus alalunga) in the southwest and central Pacific Ocean.

Albacore tuna (Thunnus alalunga) has a distinctly complex life history in which juveniles and adults separate geographically but at times inhabit the same spaces sequentially. The species also migrates long distances and presumably experiences varied regimes of physical stress over a lifetime. There are, therefore, many opportunities for population structure to arise based on stochastic differences or environmental factors that promote local adaptation. However, with the extent of mobility consistently demonstrated by tagged individuals, there is also a strong argument for panmixia within an ocean basin. It is important to confirm such assumptions from a population genetics standpoint for this species in particular because albacore is one of the principal market tuna species that sustains massive global fisheries and yet is also a slow‐growing temperate tuna. Consequently, we used 1,837 neutral SNP loci and 89 loci under potential selection to analyze population genetic structure among five sample groups collected from the western and central South Pacific. We found no evidence to challenge panmixia at neutral loci, but strong indications of structuring at adaptive loci. One population sample, from French Polynesia in 2004, was particularly differentiated. Unfortunately, the current study cannot infer whether the divergence is geographic or temporal, or possibly caused by sample distribution. We encourage future studies to include potentially adaptive loci and to continue fine‐scale observations within an ocean basin, and not to assume genome‐wide panmixia.

Factors linked to interannual variation in the metazoan parasite communities of black skipjack, Euthynnus lineatus (Pisces: Scombridae)

AbstractMarine parasite communities can exhibit temporal and spatial changes in response to seasonal and local variations in several biotic and abiotic environmental factors. Limited attention has been given to the influence of abiotic factors, so their effects on parasite community structure remain unclear. A total of 496 specimens of Euthynnus lineatus were collected over a 7‐year period (2012–2018) from Acapulco Bay, Mexico. Their parasite communities were analyzed to determine if they experience interannual variations due to local biotic and abiotic factors. Thirty‐three metazoan parasite species were recovered and identified: four species of Monogenea (adults); 16 of Digenea (one larvae and 15 adults); two of Acanthocephala (adults); two of Cestoda (larvae); three of Nematoda (two larvae and one adult); and six of Crustacea (three Copepoda, and three Isopoda). Species richness was greatest among the digeneans, which represented 48% of the total species recovered, followed by the crustaceans (19% of total species). Species richness at the component community level (14–24 species) was similar to reported richness in other small tuna species. The component communities and infracommunities of E. lineatus exhibited a similar pattern: high species richness and diversity, and numerical dominance by a single species, mainly by one of the didymozoids Allopseudocolocyntotrema claviforme or Pseudocolocyntotrema yaito. Parasite community structure and species composition varied among sampling years. Variations were possibly caused by a combination of abiotic and biotic factors which generated notable changes in the infection levels of several component species during the study period. These communities may therefore be unpredictable in terms of structure and species composition, as has been suggested for other communities of marine parasites.

Selenium intake from tuna in Galicia (Spain): Health risk assessment and protective role against exposure to mercury and inorganic arsenic

This study aims to quantify the selenium contribution from tuna to the Spanish diet and evidence the Se protective role against mercury and inorganic arsenic toxicity. Selenium concentrations in tuna were determined by ICP-MS spectrometry (expressed as mg kg−1), and the risk assessment was evaluated joined to Hg and iAs contrasting criteria of regulatory agencies with those that consider the Se protective role. Differences between Se average concentrations in fresh (1.24) and preserved (1.17) tuna were not statistically significant. In canned tuna species, Se presented higher mean levels in Thunnus albacares (1.28) than Thunnus alalunga (1.01) with statistically significant differences (p = 0.002), and among canned preparations a decreasing sequence was observed in different preparation-packaging media: oil (1.42) > natural (1.01) > pickled (0.92). Statistical study showed Hg-iAs as the only pair significantly correlated in all samples. The HI (sum of individual target hazard quotients –THQs-) on the consumption of tuna in Spain, due to exposure to Se, Hg and iAs, revealed the possibility of risk of adverse chronic effects in the six-year-old children group (1.09). According to the maximum allowable tuna consumption rate in meals/week (CRmw) and the THQs obtained, tuna intake, especially in children, should be moderated. The health benefit values (HBVSe) were positive in all samples, 14.53 and 15.65 in fresh and preserved tuna, respectively, which allows tuna to be considered safe. The benefit-risk value (BRV) evidenced the Se molar excess with respect to Hg that reached a surplus of 14.32% on Se AI in adults. Since iAs reduces the Se bioavailability, applying a new BRV criterion, the aforementioned percentage decreased to 13.49% of Se AI. In conclusion, tuna offers high levels of selenium to counteract adverse effects by the presence of Hg and iAs, and to provide consumers an important source of this essential element safely.

In situ target strength of bigeye tuna (Thunnus obesus) associated with fish aggregating devices

Abstract Bigeye tuna (Thunnus obesus) is an important commercial fish species, which aggregates around fish aggregating devices (FADs) together with other tropical tuna species. Acoustics is the main technology used by fishers and scientists for the location and quantification of tunas at FADs. However, currently it is not possible to reliably discriminate between the different tropical tuna species that are found together at FADs using acoustic methods, which hampers the development of selective fishing needed to preserve some of the tropical tuna species for which overfishing is occurring. One of the prerequisites for species discrimination is to know the target strength (TS) of each species at different frequencies. This paper measures in situ TS values and explores the frequency response of bigeye tuna at FADs in the central Pacific Ocean using three different acoustic frequencies. For the range of body length caught (40–100 cm), the obtained b20 values were −65, −66, and −72 dB for 38, 120, and 200 kHz, respectively. The decreasing frequency response pattern obtained for this swimbladder bearing species contrasts with the opposite pattern previously observed for skipjack tuna (bladder-less), the most abundant tuna species found at FADs, hence allowing the potential for discrimination between the two species.

CHARACTERISTIC OF SMALL SCALE TUNA FISHERIES ASSOCIATED WITH FADs IN LABUHAN LOMBOK, WEST NUSA TENGGARA-INDONESIA

Fish aggregating devices, or FADs are used extensively in developing countries to attract and to collect pelagic fish and give positive impacts on fish production. Use of FADs has started in early 20th century with different names among the countries and regions. This study investigated the design, deployment, distribution, density and the number of FADs used by small scale tuna fisherman in Labuhan Lombok, including characteristics of fishing boat, fishing gear, catch composition, catch per unit of effort (CPUE), fish diversity and species richness. There were 65 FADs identified in this study and 47 of them were in normal distribution. Type of the FADs used was anchored FADs, spreading between 56.63 to 267.70 NM from Labuhan Lombok fishing port. The placement of FADs were arranged in such a way as to resemble a fence, in which the distance from one to another was close. It is expected to disrupt tuna movement towards the strait in the small islands around West Nusa Tenggara. The dimensional size of vessels used to catch fish was small boat (&lt; 7 GT) with handline as fishing gears. Fish catches were dominated by skipjack (40.30%) followed by yellowfin tuna (30.90%), tuna juvenile (13.44%), frigate tuna (4.19%), albacore (3.41%), bigeye tuna (2.71%) and others (5.03%). The highest nominal CPUE occurred in January and February, accounted for 278 kg and 285 kg per day at sea respectively. The average diversity of fish and species richness in FADs area were 1.07674 and 1.3573 correspondingly. Overall results inform that diversity of fish, productivity and ecosystem were at sufficient condition and mid ecological pressure but species richness was in low condition. If this continues, it is possible that tuna diversity will decrease and endanger the survival of tuna species and others species related to the tuna.

He Efficacy and Safety of Using ω−3 fatty acids to reduce the Incidence of Breast Cancer

Background: ω−3 fatty acids are essential fatty acids through our bodies cannot make them. The main source of ω−3 fatty acidsis fish especially Tuna, Salmon and Halibut species. Omega -3 fatty acids also play a vital role in brain function. It is very important to have the right ratios of ω−3 fatty acids in the diet. This study has established that consumed in the right quantities fish oil supplements containing high levels of Omega-3 fats mainly DHA and EPA had a 30 percent reduced risk of developing breast cancer. The project aims is to investigate and seek from many of the numerous studies that have linked Omega-3 supplementation with a decreased risk of invasive ductal breast cancer. Methodology: The data in this study was collected via University Library as an electronic database by accessing another database such as Web of Science, ProQuest, PubMed, Medline, and Science Direct databases. Results: The result part is composed of an analysis of five different studies conducted on the influences of fatty acids on breast cancer. Conclusion of this studythe ω−3 fatty acids does fight against breast cancer especially among women who have been diagnosed with the disease. Omega-3 fatty acids can shrink the breast cancer cells preventing metastasizing

Towards acoustic discrimination of tropical tuna associated with Fish Aggregating Devices.

Tropical tuna support some of the largest and most valuable artisanal and industrial fisheries worldwide, conducted to a large degree with Fish Aggregating Devices (FADs). Yellowfin, bigeye and skipjack are the main tuna species found in mixed aggregations around FADs and they are simultaneously encircled by the purse seining operation. One of the key challenges that purse seine fleets fishing with drifting FADs face in all oceans is to be able to target species in healthy condition such as skipjack, while reducing impacts on bigeye and yellowfin in areas where there is a need to reduce fishing pressure on these species. The present paper explores a technical solution for selective fishing at FADs by means of acoustic equipment used by purse seiners. Acoustic frequency response of skipjack and bigeye tuna were determined at 38, 120 and 200 kHz. Skipjack showed stronger response at higher frequencies. On the contrary, bigeye showed stronger responses at lower frequencies. The robust pattern shown in frequency responses of the two species demonstrates the potential to predict abundance and species proportions based on purely acoustic measures. The paper also addresses the conditions that need to be met to successfully apply this technology for selective fishing as well as other uses of direct acoustic observations to support tuna conservation.

Stable isotope analysis indicates resource partitioning and trophic niche overlap in larvae of four tuna species in the Gulf of Mexico

Stable isotope analysis indicates resource partitioning and trophic niche overlap in larvae of four tuna species in the Gulf of Mexico

Identifying the species of harvested tuna and billfish using deep convolutional neural networks

AbstractFish catch species provide essential information for marine resource management. Some international organizations demand fishing vessels to report the species statistics of fish catch. Conventionally, the statistics are recorded manually by observers or fishermen. The accuracy of these statistics is, however, questionable due to the possibility of underreporting or misreporting. This paper proposes to automatically identify the species of common tuna and billfish using machine vision. The species include albacore (Thunnus alalunga), bigeye tuna (Thunnus obesus), yellowfin tuna (Thunnus albacares), blue marlin (Makaira nigricans), Indo-pacific sailfish (Istiophorus platypterus), and swordfish (Xiphias gladius). In this approach, the images of fish catch are acquired on the decks of fishing vessels. Deep convolutional neural network models are then developed to identify the species from the images. The proposed approach achieves an accuracy of at least 96.24%.

Large-scale distribution of tuna species in a warming ocean.

Tuna are globally distributed species of major commercial importance and some tuna species are a major source of protein in many countries. Tuna are characterized by dynamic distribution patterns that respond to climate variability and long-term change. Here, we investigated the effect of environmental conditions on the worldwide distribution and relative abundance of six tuna species between 1958 and 2004 and estimated the expected end-of-the-century changes based on a high-greenhouse gas concentration scenario (RCP8.5). We created species distribution models using a long-term Japanese longline fishery dataset and two-step generalized additive models. Over the historical period, suitable habitats shifted poleward for 20 out of 22 tuna stocks, based on their gravity centre (GC) and/or one of their distribution limits. On average, tuna habitat distribution limits have shifted poleward 6.5km per decade in the northern hemisphere and 5.5km per decade in the southern hemisphere. Larger tuna distribution shifts and changes in abundance are expected in the future, especially by the end-of-the-century (2080-2099). Temperate tunas (albacore, Atlantic bluefin, and southern bluefin) and the tropical bigeye tuna are expected to decline in the tropics and shift poleward. In contrast, skipjack and yellowfin tunas are projected to become more abundant in tropical areas as well as in most coastal countries' exclusive economic zones (EEZ). These results provide global information on the potential effects of climate change in tuna populations and can assist countries seeking to minimize these effects via adaptive management.