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Article

A Crusade Throughout the World’s Oceans: Genetic Evidence of the Southern Bluefin Tuna Thunnus maccoyii and the Pacific Bluefin Tuna Thunnus orientalis in Brazilian Waters

by
Rafael Schroeder
1,2,*,
Rodrigo Sant’Ana
1,
André O. S. Lima
3,
Juliana A. Dallabona
3,
Gabriela S. Delabary
3,
Lucas Gavazzoni
1,
Luciana de Oliveira
3,
Yan de O. Laaf
3 and
Paulo Travassos
4
1
Laboratório de Estudos Marinhos Aplicados, Escola Politécnica, Universidade do Vale do Itajaí (UNIVALI), Rua Uruguai 458, Itajaí 88302-901, Brazil
2
Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos S/N, 4550-208 Matosinhos, Portugal
3
Laboratório de Genética Molecular, Escola Politécnica, Universidade do Vale do Itajaí (UNIVALI), Rua Uruguai 458, Itajaí 88302-901, Brazil
4
Laboratório de Ecologia Marinha, Universidade Federal Rural de Pernambuco (UFRPE), Rua Dom Manuel de Medeiros S/N, Recife 52171-900, Brazil
*
Author to whom correspondence should be addressed.
Biology 2025, 14(4), 340; https://doi.org/10.3390/biology14040340
Submission received: 21 February 2025 / Revised: 19 March 2025 / Accepted: 25 March 2025 / Published: 26 March 2025
(This article belongs to the Special Issue Progress in Wildlife Conservation, Management and Biological Research)
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Simple Summary

This study highlights the presence of large pelagic species in distant marine ecosystems in the waters of southeast–south Brazil. Important commercial species were identified, such as Southern bluefin tuna (Thunnus maccoyii) and Pacific bluefin tuna (Thunnus orientalis). The presence of the cold-water T. maccoyii and the warm-water T. orientalis suggests a long migration from common species ranges that could be influenced by climate change. These results imply a readjustment of the spatial management structures for these species.

Abstract

The large pelagic species play an important role in transferring energy in vast distant marine ecoregions. Results obtained report on extraordinary findings of important commercial species in southeast–south Brazilian waters, including the Southern bluefin tuna Thunnus maccoyii and the Pacific bluefin tuna Thunnus orientalis, an endemic species from the Pacific Ocean. These specimens were identified within the genomic description of 10 individuals randomly selected from the catch to evaluate the catch composition of pelagic longline fisheries off Brazilian waters. Most of the records were from T. maccoyii (6), followed by the Bigeye tuna T. obesus (2), Yellowfin tuna T. albacares (1), and T. orientalis (1). Yellowfin and Bigeye tuna are expected to be captured in the vicinity of the longline fishing areas. However, the unlikely presence of the cold-water T. maccoyii and the warm-water T. orientalis suggests a long migration from common species ranges that could be influenced by climate change. These results imply a readjustment of spatial management structures for these species.

1. Introduction

Knowledge of the spatial distribution of species is a fundamental requirement for managing and conserving marine biodiversity [1,2,3]. Pelagic longline fishing off the Brazilian coast has low selectivity, and includes target species, such as highly migratory pelagic fish (e.g., Thunnus spp. and swordfish Xiphias gladius) but also a considerable list of bony fish and elasmobranchs as accompanying fauna [4], including some species of high commercial value, such as the Atlantic bluefin tuna Thunnus thynnus [5,6,7]. Some of these species, however, are difficult to identify when they are landed in ports, so accurate methodologies need to be used to accurately identify the organisms caught, such as mitochondrial genetic analysis [8,9,10].
In the southeast–south region of Brazil, the Yellowfin tuna Thunnus albacares, Albacore Thunnus alalunga, and Bigeye tuna Thunnus obesus, along with the Blackfin tuna Thunnus atlanticus, are frequently found in longline catches, with other tuna and tuna-like species occurring in smaller volumes [11]. These species have a widely known distribution [12,13,14,15] and are managed by the International Commission for the Conservation of Atlantic Tuna (ICAAT). In recent years, however, relatively frequent catches of a temperate-water tuna species have been recorded, referred to as the Southern bluefin tuna (Thunnus maccoyii) [11]. These recent appearances of species of important commercial value prompted a study investigating the catch composition of these larger, commercially important specimens, using genetic markers [16].
The Southern bluefin tuna occur in southern seas, off the Antarctic continent, mainly between the latitudes of 30° and 50° S to nearly 60° S [17], with a thermal preference for water between 19 and 21 °C, but can withstand much colder (3 °C) and warm temperatures (30 °C) during the spawning season [18]. Despite its predicted distribution in Brazilian waters, its participation in pelagic longline catches remains unknown. In addition, this species is managed by the Commission for the Conservation of Southern Bluefin Yuna (CCSBT) and already faces intense fishing efforts. As indicated by the CCSBT T. maccoyii stock is overfished, but overfishing is not currently occurring [19].
Another extraordinary record involves a species of tuna not yet known in the Atlantic [20], the Pacific bluefin tuna Thunnus orientalis, which is widely distributed in the Pacific Ocean and seasonally inhabits subarctic, temperate, and tropical waters in the North Pacific Ocean and temperate waters in the Southern Hemisphere around Australia and New Zealand, marginally entering the eastern Indian Ocean [21,22,23,24,25]. The species is evaluated by the International Scientific Committee for Tuna and Tuna-like Species in the North Pacific Ocean (ISC) and placed as Near Threatened on the International Union for Conservation of Nature (IUCN) Red List Category and Criteria. The current population trend is decreasing [25].
The fact that population studies involving complementary methodologies, such as morphological, molecular and otolith chemistry analyses and tag-return data, show that both species of bluefin tuna consist of panmictic stocks for T. maccoyii [17,26,27] and for T. orientalis [28,29,30], and their occurrence in the South Atlantic may increase fishing mortality and spatial overlap of management units with implications for the management of these species [31]. Thus, this study aimed to identify tuna specimens, especially concerning possible occurrences of southern bluefin tuna caught by the longline fleet based in southern Brazil, through the genetic analysis of samples collected. The paper reports recent astonishing records of tuna species known previously from the North Pacific in locations in the Southwest Atlantic. The study hereby discusses how these might have appeared thousands of kilometers from their previously known species ranges.

2. Materials and Methods

2.1. Origin of Samples and Fishing Data

The Industrial Fisheries Monitoring Program (PMAP) conducted by UNIVALI/LEMA has been carrying out analyses of commercial catches and biological samples in southeast and south Brazil since 2000 [11]. In more recent years (2018–2022), data included landed catches, fishing efforts, and areas of operation of 5869 fishing trips conducted by vessels operating pelagic longlines (Figure 1). A total of 39 species have been identified from the landed catch, together with some bluefin tuna of unknown identification. By 2020 and 2022, biological tissue samples had been collected from specimens of 10 large-sized bluefin tuna, commercially caught. Samples were collected from distinct specimens that could not be identified onboard. The samples were stored in alcohol and sent to the Laboratory of Molecular Genetics (LMG) at the University of Vale do Itajaí, where they were stored in a freezer (−20 °C) for further processing.

2.2. DNA Extraction and COI Gene Amplification and Sequencing

Genomic DNA was extracted from muscle tissue samples using the DNeasy Blood and Tissue Kit (Qiagen, Hilden, Germany) according to the manufacturer’s instructions. After extraction, both the DNA quality and concentration were assessed simultaneously by measuring the absorbance ratio at 260 nm/280 nm using 2 µL of the sample on the NanoQuant Plate (Tecan, Männedorf, Switzerland) with a Tecan Infinite® 200 Pro microplate reader (Tecan, Männedorf, Switzerland). The absorbance ratio confirmed the absence of significant protein contamination, ensuring that the DNA purity was suitable for downstream applications.
The DNA samples were then subjected to polymerase chain reaction (PCR) to amplify the cytochrome c oxidase I (COI) gene, a mitochondrial marker commonly used for species identification. The PCR followed the protocol by [32], utilizing the primer pair VF2_t1 (5′-TGTAAAACGACGGCCAGTCAACCAACCACAAAGACATTGGCAC-3′) and FR1d_t1 (5′-CAGGAAACAGCTATGACACCTCAGGGTGTCCGAARA AYCARAA-3′), both of which included an M13 tail to facilitate sequencing. The PCR reaction mixture (25 µL total volume) consisted of 50 ng of genomic DNA, 1x Taq DNA polymerase buffer (Sigma-Aldrich, St. Louis, MO, USA), 0.2 mM of each dNTP, 0.5 µM of each primer, 2 mM MgCl2, 1 U Taq DNA polymerase (Sigma-Aldrich, USA), and ultrapure water to reach the final reaction volume.
PCR amplification was conducted using the Veriti® Thermal Cycler (Applied Biosystems, San Francisco, CA, USA) with the following cycling conditions: an initial denaturation at 94 °C for 2 min, followed by 35 cycles of 94 °C for 30 s, 52 °C for 40 s, and 72 °C for 1 min, with a final extension at 72 °C for 10 min. The success of the PCR amplification was confirmed by agarose gel electrophoresis. A 1% agarose gel was prepared, and PCR products were mixed with loading buffer and stained with Diamond Nucleic Acid Dye (Promega, Madison, WI, USA). The amplified DNA fragments, approximately 700 base pairs in size, were visualized using a UV transilluminator, with their molecular weight determined against a λ Hind III marker. Electrophoresis was performed at 50 V and 120 mA for 90 min, and the gels were documented using the EOS Utility 2 software (v2.14.20.0, Canon, Japan). The amplified COI genes from the ten (10) samples were sequenced to confirm species identification. Sequencing was performed using the Sanger chain termination method on the Applied Biosystems ABI 3500 X Genetic Analyzer, producing sequences of approximately 700 base pairs. The sequencing was conducted by GoGenetic (Curitiba, PR, Brazil), ensuring accurate and reliable identification of the amplified products.

2.3. Sequence Processing, Identification, and Phylogenetic Analysis

Following sequencing, the raw reads from the amplified COI genes of the nine (9) samples were processed using CLC Genomics Workbench (v6.7, CLC bio, Aarhus, Denmark). Each sample was sequenced twice, generating reads from both the forward and reverse primers. The initial step in data processing involved trimming the terminal sequences based on a quality threshold of Q30 to ensure high accuracy.
The trimmed sequences from both directions were then aligned and merged to create a consensus sequence for each sample. These consensus sequences were saved in FASTA format for subsequent analyses. Each FASTA file was uploaded to the Barcode of Life Data System (BOLD) for species identification and compared against the Species Level Barcode Records database [33]. This extensive database includes 5,040,349 COI sequences representing 246,329 species and 120,909 interim species. By comparing our sequences to this comprehensive reference, we achieved precise species identification based on the highest similarity matches with known entries in the BOLD database.
The consensus sequences obtained were further analyzed to explore phylogenetic relationships. All consensus sequences were aligned using MEGA 11 (Molecular Evolutionary Genetics Analysis, v. 11) software. This alignment process ensured that the sequences shared a common start and end point, allowing for uniform comparison across samples. To enhance the phylogenetic analysis, additional sequences were retrieved from the BOLD database, given its higher level of curation and consistency with the species identification step. Specifically, mitochondrial DNA sequences from all Thunnus species were downloaded from BOLD, along with Katsuwonus pelamis sequences, which were used as an outgroup. A custom script was employed to extract between 5 and 10 sequences per Thunnus species, focusing on those that matched the COI gene region obtained from our samples. The combined dataset, including both the new sequences from this study and the reference sequences from BOLD, was aligned using the ClustalW algorithm in MEGA. This comprehensive alignment formed the basis for the subsequent phylogenetic analysis. The phylogenetic relationships were inferred using the Maximum Likelihood (ML) method, employing the Kimura 2-parameter model with a gamma distribution (G) to account for rate variation among sites [34]. The number of discrete gamma categories was set to 5, and the robustness of the phylogeny was tested with 1000 bootstrap replicates. The initial tree was automatically generated using the Nearest-Neighbor-Interchange (NNI) heuristic method. The final phylogenetic tree was carefully analyzed to interpret the evolutionary relationships among the Thunnus species represented in the dataset.

3. Results

3.1. DNA Extraction and COI Amplification

DNA was successfully extracted from all fish muscle samples, with concentrations ranging from 21.95 ng/µL to 179.5 ng/µL and 260 nm/280 nm absorbance ratios between 1.96 and 2.19, indicating high purity suitable for downstream analyses (Table 1). PCR amplification of the COI gene was also successful for all samples, producing amplicons of approximately 720 base pairs. The expected band sizes confirmed successful amplification in each case. The amplified COI sequences were processed and compared against the Barcode of Life Data System (BOLD) database for species identification. The identification results showed four species within the Thunnus genus. Six samples were identified as Thunnus maccoyii, two samples were identified as Thunnus obesus, one sample identified as Thunnus albacares with 100% identity, and one sample matched Thunnus orientalis with 99.85% identity (Table 1). These results confirm the efficiency of DNA extraction, amplification, and sequencing processes, reflecting the reliability of species identification through the BOLD database.

3.2. Phylogenetic Analysis

The phylogenetic relationships among eight Thunnus species were inferred using the Maximum Likelihood (ML) method, based on the Kimura 2-parameter model with a gamma distribution (G) to account for rate variation among sites. The analysis was performed using MEGA software, with 1000 bootstrap replicates to assess the robustness of the tree. The sequences obtained were aligned with reference sequences of Thunnus species from the Barcode of Life Data System (BOLD), and Katsuwonus pelamis were used as an outgroup to root the tree. The resulting phylogenetic tree (Figure 2) shows a well-supported division between the species within the Thunnus genus. The six samples identified as Thunnus maccoyii are grouped within a highly supported clade with a bootstrap value of 77%. This clade is distinct from other Thunnus species, confirming the strong genetic differentiation of Thunnus maccoyii from its relatives.
The Thunnus obesus samples also form a well-defined clade with high bootstrap support (66%), demonstrating clear genetic consistency among the individuals within this species. Interestingly, the Thunnus obesus clade is closely related to the Thunnus atlanticus, Thunnus albacares and Thunnus tonggol clade, which is supported by a bootstrap value of 21%. This suggests a closer evolutionary relationship between these two species compared to others in the tree. The single sample identified as Thunnus orientalis forms a distinct clade alongside reference sequences from BOLD, with a bootstrap value (57%). The proximity of the Thunnus orientalis clade to the Thunnus alalunga group suggests a potential evolutionary connection between these species, although further investigation would be needed to clarify the exact relationship.
The Thunnus albacares sample is placed within its expected clade, though the bootstrap support for this group is relatively low (23%), suggesting that the evolutionary relationships among members of this species may be less clearly resolved with the current dataset. However, the sample still clusters with high confidence within the Thunnus albacares species group, supporting its identification. The outgroup, Katsuwonus pelamis, is separated from the Thunnus genus, confirming its more distant evolutionary relationship. This separation provides a solid rooting point for the tree and further validates the observed phylogenetic structure within Thunnus. Overall, the tree supports the identification results obtained through BOLD and provides a clear visualization of the evolutionary relationships among the Thunnus species analyzed in this study. The bootstrap values generally indicate strong support for the major clades, particularly for Thunnus obesus, Thunnus maccoyii, and Thunnus orientalis.

3.3. Occurrence of Thunnus orientalis and T. maccoyii in Brazilian Waters

The geographical distribution of Thunnus orientalis outside the typical species habitat observed in other studies suggests that the specimen observed in the current study have migrated to Brazilian waters, passing through the Indic Ocean (Figure 3). Details of how this specimen might have appeared several kilometers from the previously known species range are discussed.

4. Discussion

The current study confirms the presence of the Pacific bluefin tuna, T. orientalis, in Brazilian waters. Analysis of the partial CO1 sequence from the Pacific bluefin tuna caught off Southern Brazil using BLAST (v2.14.0, NCBI, Bethesda, MD, USA) search showed 99.85% similarity, respectively, with published reference sequences for T. orientalis (BOLD accession no: FOA884-04). In addition, results for T. maccoyii, T. obesus and T. albacares were complete achieving 100% similarity, respectively, with published reference sequences for T. maccoyii captured off the West of Rottnest Island in Western Australia (BOLD accession no: FOA877-04); for T. obesus from South Africa (BOLD accession no: SAFCO26-11); and for T. albacares, without a record from the area of capture (GenBank accession no: ANGBF42001-19).
The phylogenetic tree inferred from the Maximum Likelihood method using the Kimura 2-parameter model showed that the obtained CO1 sequence analysis from the South Brazil large-size tuna specimens showed high accuracy in distinguishing among tuna species, namely T. albacares, T. obesus, T. maccoyii, and T. orientalis, as observed in similar studies [35,36,37]. On the other hand, the differentiation of T. alalunga into two clusters could be attributed to distinct populations of the species, as demonstrated by mt-DNA and microsatellite analyses [8,38,39]. According to the partial CO1 sequence, the upper cluster is referent to samples collected from the Atlantic (BOLD accession no: NEELS228-14; FOA868-04; GBMND68190-21; MOBIL8868-18; NEELS313-14) and the lower part from samples collected in the Mediterranean Ocean (BOLD accession no: DNATR1700-13; DNATR1703-13; DNATR1704-13). Despite some studies showing that the efficiency of CO1 as a marker for differentiating tuna species was previously considered problematic [8], the high accuracy provided by 1000 times bootstrap obtained in the sequences can be interpreted as valid for species identification. The COI gene is a reliable marker for species identification due to its high interspecific variation and intraspecific conservation [40]. Studies indicate that COI is highly effective in identifying Thunnus spp. [41]. Its standardized use in the BOLD database ensures the global comparability of sequences [42].
Biology 14 00340 g003
Figure 3. Spatial distribution of the biological samples (colored circles) collected by the pelagic longline fleet on the southeast–south Brazilian coast between 2018 and 2022. The colored areas represented the geographic range of Southern bluefin tuna Thunnus maccoyii and the Pacific bluefin tuna Thunnus orientalis, preferable areas, and spawning grounds. The arrows represent the movements of immature and mature individuals of T. orientalis and marine currents. Stars represent unvalidated and validated records of T. orientalis obtained in the FishBase Dataset [43] and scientific papers [9,10,37]. The dashed arrows represent a probable migratory route for T. orientalis until arriving in Brazilian waters.
Figure 3. Spatial distribution of the biological samples (colored circles) collected by the pelagic longline fleet on the southeast–south Brazilian coast between 2018 and 2022. The colored areas represented the geographic range of Southern bluefin tuna Thunnus maccoyii and the Pacific bluefin tuna Thunnus orientalis, preferable areas, and spawning grounds. The arrows represent the movements of immature and mature individuals of T. orientalis and marine currents. Stars represent unvalidated and validated records of T. orientalis obtained in the FishBase Dataset [43] and scientific papers [9,10,37]. The dashed arrows represent a probable migratory route for T. orientalis until arriving in Brazilian waters.
Biology 14 00340 g003
Besides the differentiation in the phylogenetic tree, T. orientalis was the only species without a predicted distribution for Brazilian waters [12,13]. The movements of T. orientalis are among the best documented of any highly migratory species, according to the ISC, even considering the large inter-annual variations of movement (numbers of migrants, the timing of migration, and migration routes) [44,45,46,47]. Adult fish of T. orientalis spawn in the Western North Pacific Ocean between the Philippine Sea and the Ryukyu (Nansei) Islands from late April to early July [24,48,49] and in the coastal area of the Sea of Japan from July to August [50,51]. After spawning, they generally migrate north to feeding grounds in the western Pacific and may reside there for their whole lives, being known as residents [49]. Young fish aged 0–1 hatched in the waters around the Ryukyu Islands and eastern Taiwan are transported north with the Kuroshio Current in the summer as they grow, whereas age-0 fish hatched in the Sea of Japan migrate along the Japanese and Korean coasts [21,52,53]. An unknown portion of immature T. orientalis ages 1–3 in the western Pacific underwent eastward migration across the Pacific Ocean, as demonstrated by analysis of electronic archival tags [21,45,54] and stable isotope in muscle tissues [30,55] and otoliths [56,57,58]. This migratory portion enters the California Current Large Marine Ecosystem at juvenile or subadult stages for feeding, spending up to four years before returning to the western Pacific for forage and reproduction, which depends on the ocean conditions [30,44,52,59]. A mechanism of eastward trans-Pacific migration is hypothesized due to the limitation of food sources in the western Pacific and favorable oceanographic conditions [60]. While T. orientalis are in the eastern Pacific, the juveniles make seasonal north–south migrations along the west coast of North America [45,61]. In the spring, T. orientalis reside in the waters off the southern coast of Baja California and, as the water warms up in summer, T. orientalis move northwest into the southern California bight. By fall, T. orientalis is found in the waters of central and northern California. After spending 3–4 years in the eastern Pacific, T. orientalis moves westward, presumably for purposes of spawning, as no spawning ground has been observed outside of the western Pacific. This westward migration was observed from December to March as T. orientalis began their migration along the coast of California [45].
In the West Pacific, the spawning areas are located between Taiwan and the Philippine Sea, the latter being considered as the main spawning area [49,53,62]. After spawning, T. orientalis should typically migrate north during the spring. In the springtime, high primary production and favorable environmental conditions are observed in the south portion of the Ryukyu Islands and the Philippines between April and June, along with similar conditions in the Indian Ocean, close to the coast of Timor-Leste, Java, and Sumatra [45,46,63]. Despite the southward migration of mature fish not being fully understood, the existence of favorable environmental conditions in both oceans suggests a possible connection between them, as well as the search for suitable habitats during the springtime, following the habitat suitability model’s predictions [64]. The most important oceanographic feature present in this area is the Indonesian Throughflow (ITF), which could serve as a possible passage for T. orientalis between the Pacific and the Indic oceans [65,66,67]. This flow could potentially allow vagrants of T. orientalis to enter other parts of the Indian Ocean [9,10,37]. The trajectory through the ITF can also be supported by some unvalidated records of species occurrence that could not be strictly validated for morphological or genetic analysis [20,67].
The first valid record was found in the doorsteps of the ITF pathway through the Philippines Sea provided by a “bluefin tuna” caught on 16 May North of Polilio Island by a hook and line fishing vessel. The individual was captured at 15°23.570 N, 121°59.868 E, and its identity was confirmed by molecular analysis as Thunnus orientalis, with 100% similarity for partial CO1 sequence (BOLD accession no: KU058179.1 [37]). In the Indian Ocean, the first valid record of T. orientalis was represented by a male bluefin tuna of 250 cm TL, weighting 217 kg, fished by a longline on 11 May 2017, between the Arabian Sea and the Sea of Oman, in the Sultanate of Oman. In this case, the morphometric characteristics, the meristic characters, and particularly the genetic analyses (mt-DNA) combined, confirmed the individual as Pacific bluefin tuna, the first found in this part of the Indian Ocean [9]. A second “probable” T. orientalis was captured by a longline near the Sri Lanka waters, in May of 2020. Despite the records never having been officially published, available pictures revealed a 2 m total length fish, close to 200 kg. Considering the location of the catch and images from caudal keels, this specimen was another vagrant Pacific bluefin tuna [10]. On 14 May 2021, two Yemenite fishermen caught a large bluefin tuna (227.5 cm total length and 375 kg) using handlines some miles offshore. Due to high prices on the local market, the fish was rapidly commercialized, making it impossible to obtain tissues for molecular analysis. However, the external characteristics, size, and weight were also compatible with Pacific bluefin tuna; in this case, the fish was caught around mid-May [10].
What all these three specimens of T. orientalis had in common is that they were all mature specimens and were captured in May, and the approximate reported location is in the outflow of the Equatorial Current, encircling most of the known distribution of T. orientalis. The approximate east–west trans-Pacific migration partially overlaps the route of the Pacific North Equatorial Current, which passes into the two known spawning areas of T. orientalis. Near the west Pacific coast, this current bifurcates to the north, giving rise to the Kuroshio Current. In the westward direction, it boosts the ITF, which imports water with a higher temperature and lower salinity from the western equatorial Pacific Ocean. The ITF also receives the contribution from the Pacific South Equatorial Current. When the ITF flows through Lombok Strait, Ombai, and the Timor Passages and enters the Indian Ocean, it transports a large amount of relatively warm and fresh water into the Indian Ocean towards Africa within the Indian Equatorial Current [64,65,66].
Following the validated (and non-validated) records of the occurrence of T. orientalis in the Indian Ocean [9,10,37,43], all follow the course of the ITF in a northerly direction originating from the North Equatorial Current towards Sri Lanka [64,65,66]. The most likely route, in line with validated records of the species’ occurrence, heads north with the Indian North Equatorial Current, aligning with the record of a T. orientalis caught in Sri Lanka, in May 2020 [37] and a second adult specimen caught in Sur, Sultanate of Oman, on 11 May 2017 in the Arabian Sea [9]. The other two positively identified fish were found in an area quite close by, in the Gulf of Aden [10]. Further west, there is the example of the adult specimen caught in Ash Shihr, Yemen, on 14 May 2021 and a juvenile specimen caught off Cape Guardafui, Somalia, between September and March in the years 1966–1972 [10]. This specimen had represented the end of the line of distance for migratory vagrant specimens of T. orientalis until the appearance of the individual captured off Brazilian waters.
The long journey to eastern Brazilian waters presents a huge extension when compared to the most distant ever fifth specimen recorded off Cape Guardafui, Somalia. From Cape Guardafui onwards, the Brazilian T. orientalis possibly took transportation along the Agulhas Current, which originates from the extension of the Indian North Equatorial Current flowing to South Africa [67]. After crossing the confluence of the Agulhas, the specimen could migrate as far as east Brazilian waters through the Atlantic South Equatorial Current. However, given the vastness of the Brazilian waters and the variability in tuna populations, this sample size may be too small to accurately represent the overall catch composition and the occurrence of different tuna species. It would be beneficial to increase the sample size in future studies to enhance the reliability of the results. For example, a larger sample could provide more accurate estimates of the proportion of each tuna species in the catches.
The current work suggests a possible migratory route for T. orientalis based on the evidence presented. Other authors have suggested an antipodal link between the North Pacific and the Atlantic Ocean through the Drake Passage, following the Upper Circumpolar Deep Water [68]. The proposed migratory route for T. orientalis to Brazilian waters is based on limited evidence and some assumptions. The evaluation of the present hypothesis would require more data, such as additional genetic analysis of specimens along the proposed route or direct tracking data (e.g., from satellite tags) and otolith chemical records. Another possible effect that could be correlated with this long migration involves climate change [10]. These marine environmental modifications logically affect tuna in the Atlantic, Indian, and Pacific Oceans [69,70,71]. The many and complex effects of climate change in the Indian Ocean in association with these increasing occasional catches may represent the beginning of a wider distribution range, as previously suggested [10,72]. Historic genetic analysis (mt-DNA) indicated that a differentiation event may have occurred in T. maccoyii; however, a recent connectivity between the two oceans may have connected T. maccoyii populations [73]. Moreover, the genetic structure analysis of T. maccoyii and T. orientalis provided evidence of their population expansion dating to the middle Pleistocene [72]. The validation of this hypothesis would, therefore, imply a readjustment of spatial management structures for these species [31].

5. Conclusions

The current study allowed us to identify for the first time in Brazil the southern bluefin tuna (Thunnus maccoyii) and the Pacific bluefin tuna (Thunnus orientalis), caught by the longline fleet operating in southeast and south Brazil, through DNA analysis. As mentioned above, records of catches of the species had already been reported in recent years, but unofficially and without much certainty about the process of identifying these catches due to the difficulties imposed by the dynamics of landing the catches in ports. Thus, there is no doubt that the species is caught with some frequency by the pelagic longline fishing fleet for tuna and tuna-like fish that operates in southeast and south Brazil. Although both tuna species are not under the responsibility of ICCAT for conservation and fisheries management, a task that falls to the CCSBT and ICS, respectively, these catches must be officially recorded and duly communicated to Brazil’s fisheries management body (SAP/MAPA), which will be responsible for transmitting this data to ICCAT, which will inform the CCSBT and the ICS.

Author Contributions

Conceptualization, R.S. (Rafael Schroeder) and R.S. (Rodrigo Sant’Ana); methodology, A.O.S.L.; validation, A.O.S.L.; formal analysis, A.O.S.L. and Y.d.O.L.; investigation, R.S. (Rafael Schroeder), R.S. (Rodrigo Sant’Ana), P.T., J.A.D., G.S.D., L.G., L.d.O., Y.d.O.L. and A.O.S.L.; resources, R.S. (Rodrigo Sant’Ana), P.T. and A.O.S.L.; data curation, R.S. (Rodrigo Sant’Ana); writing—original draft preparation, R.S. (Rafael Schroeder) and A.O.S.L.; writing—review and editing, R.S. (Rafael Schroeder), R.S. (Rodrigo Sant’Ana), P.T. and A.O.S.L.; project administration, R.S. (Rodrigo Sant’Ana), P.T. and A.O.S.L.; funding acquisition, R.S. (Rodrigo Sant’Ana), P.T. and A.O.S.L. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the Ministry of Fisheries and Aquaculture (MPA) and the National Council for Scientific and Technological Development (CNPq) for leading Call MCTI/MPA/CNPq No. 22/2015, aimed at the Management of Brazilian Marine Fisheries, which fully funded the project Technical-Scientific Support for the Development of Tuna and Related Fisheries in Brazil (Process: 445810/2015-7).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Data will be made available upon reasonable request.

Acknowledgments

The authors are completely indebted to all fishermen, owners and fish companies that allowed us to obtained biological samples, which was crucial to the development of the study.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Kaplan, D.M.; Chassot, E.; Amandé, J.M.; Dueri, S.; Demarcq, H.; Dagorn, L.; Fonteneau, A. Spatial management of Indian Ocean tropical tuna fisheries: Potential and perspectives. ICES J. Mar. Sci. 2014, 71, 1728–1749. [Google Scholar] [CrossRef]
  2. Pickens, B.A.; Carroll, R.; Schirripa, M.J.; Forrestal, F.; Friedland, K.D.; Taylor, J.C. A systematic review of spatial habitat associations and modeling of marine fish distribution: A guide to predictors, methods, and knowledge gaps. PLoS ONE 2021, 16, e0251818. [Google Scholar] [CrossRef]
  3. Thomson, A.I.; Archer, F.I.; Coleman, M.A.; Gajardo, G.; Goodall-Copestake, W.P.; Hoban, S.; Laikre, L.; Miller, A.D.; O’Brien, D.; Pérez-Espona, S.; et al. Charting a course for genetic diversity in the UN Decade of Ocean Science. Evol. Appl. 2021, 14, 1497–1518. [Google Scholar] [CrossRef]
  4. BRASIL. Instrução Normativa MPA/MMA No10, de 10 de Junho de 2011; MPA/MMA: Brasília, Brazil, 2011. [Google Scholar]
  5. Takeuchi, Y.; Suda, A.; Suzuki, Z. Review of information on large bluefin tuna caught by Japanese longline fishery off Brazil, from the late 1950s to the early 1960s. ICCAT CVSP 1999, 49, 416–427. [Google Scholar]
  6. Takeuchi, Y.; Oshima, K.; Suzuki, Z. Inference on nature of Atlantic bluefin tuna off Brazil caught by Japanese longline fishery around the early 1960s. In Proceedings of the Reports of the Standing Committee on Research and Statistics (SCRS), Madrid, Spain, 5–9 October 2009. [Google Scholar]
  7. Di Natale, A.; Idrissi, M.; Rubio, J. The mystery of bluefin tuna (Thunnus thynnus) presence and behavior in recent central-south Atlantic in recent years. Collect. Vol. Sci. Pap. ICCAT 2013, 69, 857–868. [Google Scholar]
  8. Viñas, J.; Tudela, S. A Validated Methodology for Genetic Identification of Tuna Species (Genus Thunnus). PLoS ONE 2009, 4, e7606. [Google Scholar] [CrossRef]
  9. Zaki, S.; Al-Mamary, J.; Al-Marzouqi, A.A.; Al-Kharusi, L. First record of the Pacific bluefin tuna Thunnus orientalis (Temminck & Schlegel, 1844) from the coast off Sur, Sultanate of Oman. Int. J. Environ. Agric. Biotechnol. 2017, 2, 1752–1757. [Google Scholar] [CrossRef]
  10. Di Natale, A.; Al Mabruk, S.A.A.; Zava, B. Unusual presence of bluefin tuna in the Gulf of Aden and in the Indian Ocean. In Proceedings of the 8th Working Party on Temperate Tunas (WPTMT), Mahe, Seychelles, France, 13–15 April 2022. [Google Scholar]
  11. UNIVALI/LEMA. Estatística Pesqueira de Santa Catarina, Consulta On-line. Projeto de Monitoramento da Atividade Pesqueira do Estado de Santa Catarina Disponível em: Laboratório de Estudos Marinhos Aplicados (LEMA). da Universidade do Vale do Itajaí (UNIVALI). 2023. Available online: http://pmap-sc.acad.univali.br (accessed on 29 September 2023).
  12. Collette, B.B.; Boustany, A.; Fox, W.; Graves, J.; Juan Jorda, M.; Restrepo, V. Thunnus albacares. The IUCN Red List of Threatened Species. 2021. Available online: https://www.iucnredlist.org/species/21857/46624561 (accessed on 18 September 2024).
  13. Collette, B.B.; Boustany, A.; Fox, W.; Graves, J.; Juan Jorda, M.; Restrepo, V. Thunnus alalunga. The IUCN Red List of Threatened Species. 2021. Available online: https://www.iucnredlist.org/species/21856/9325450 (accessed on 18 September 2024).
  14. Collette, B.B.; Boustany, A.; Fox, W.; Graves, J.; Juan Jorda, M.; Restrepo, V. Thunnus obesus. The IUCN Red List of Threatened Species. 2021. Available online: https://www.iucnredlist.org/species/21859/46912402 (accessed on 18 September 2024).
  15. Collette, B.B.; Diemens, P. Thunnus atlanticus. The IUCN Red List of Threatened Species. 2022. Available online: https://www.iucnredlist.org/species/155276/46931209 (accessed on 18 September 2024).
  16. Travassos, P.; Frédou, F.; Frédou, T.; Amorim, A.; Pimenta, E.; Hazin, F.; da Silva, G.B.; Andrade, H.A.; Leite, N.; Lessa, R.; et al. Projeto de Apoio Técnico-Científico ao Desenvolvimento da Pesca de Atuns e Afins no Brasil (Chamada MCTI/MPA/CNPq 22/2015—Linha Temática II—Atuns e afins); Universidade Federal Rural de Pernambuco: Recife, Brazil, 2022. [Google Scholar]
  17. Collette, B.; Graves, J. Tunas and Billfishes of the World; Johns Hopkins University Press: Baltimore, MD, USA, 2019; pp. 1–351. [Google Scholar]
  18. Patterson, T.A.; Evans, K.; Carter, T.I.; Gunn, J.S. Movement and behaviour of large southern bluefin tuna (Thunnus maccoyii) in the Australian region determined using pop-up satellite archival tags. Fish. Oceanogr. 2008, 17, 352–367. [Google Scholar] [CrossRef]
  19. Collette, B.B.; Boustany, A.; Fox, W.; Graves, J.; Juan Jorda, M.; Restrepo, V. Thunnus maccoyii. The IUCN Red List of Threatened Species. 2021. Available online: https://www.iucnredlist.org/species/21858/170082633 (accessed on 18 September 2024).
  20. Collette, B.B. Family Scombridae Rafinesque 1815—Mackerels, tunas, and bonitos. Calif. Acad. Sci. Annot. Checkl. Fishes 2003, 19, 1–28. [Google Scholar]
  21. Itoh, T.; Tsuji, S.; Nitta, A. Migration patterns of young PBF (Thunnus orientalis) determined with archival tags. Fish. Bull. 2003, 101, 514–534. [Google Scholar]
  22. Tanaka, Y.; Satoh, K.; Iwahashi, M.; Yamada, H. Growth-dependent recruitment of Pacific bluefin tuna Thunnus orientalis in the northwestern Pacific Ocean. Mar. Ecol. Press Ser. 2006, 319, 225–235. [Google Scholar] [CrossRef]
  23. Lewis, A.D. Conservation Management and Measures (CMM). In Proceedings of the Conservation Management and Measures from the Western and Central Pacific Fisheries Commission, Nagasaki, Japan, 3–6 September 2012. [Google Scholar]
  24. Ashida, H.; Suzuki, N.; Tanabe, T.; Suzuki, N.; Aonuma, E. Reproductive condition, batch fecundity, and spawning fraction of large Pacific bluefin tuna Thunnus orientalis landed at Ishigaki Island, Okinawa, Japan. Environ. Biol. Fish. 2015, 98, 1173–1183. [Google Scholar] [CrossRef]
  25. Collette, B.B.; Boustany, A.; Fox, W.; Graves, J.; Juan Jorda, M.; Restrepo, V. Thunnus orientalis. The IUCN Red List of Threatened Species. 2021. Available online: https://www.iucnredlist.org/species/170341/170087840 (accessed on 18 September 2024).
  26. Proctor, C.H.; Thresher, R.E.; Gunn, J.S.; Mills, D.J.; Harrowfield, I.R.; Sie, S.H. Stock structure of the Southern Bluefin Tuna Thunnus maccoyii: An investigation based on probe microanalysis of otolith composition. Mar. Biol. 1995, 122, 511–526. [Google Scholar] [CrossRef]
  27. Grewe, P.M.; Elliott, N.G.; Innes, B.H.; Ward, R.D. Genetic population structure of Southern Bluefin Tuna (Thunnus maccoyii). Mar. Biol. 1997, 127, 555–561. [Google Scholar] [CrossRef]
  28. Tseng, M.C.; Smith, P.J. Lack of genetic differentiation observed in Pacific Bluefin Tuna (Thunnus orientalis) from Taiwanese and New Zealand waters using mitochondrial and nuclear DNA markers. Mar. Freshw. Res. 2012, 63, 198–209. [Google Scholar] [CrossRef]
  29. Nomura, S.; Kobayashi, T.; Agawa, Y.; Margulies, D.; Scholey, V.; Sawada, Y.; Yagishita, N. Genetic population structure of the Pacific Bluefin Tuna Thunnus orientalis and the Yellowfin Tuna Thunnus albacares in the North Pacific Ocean. Fish. Sci. 2014, 80, 1193–1204. [Google Scholar]
  30. Madigan, D.J.; Boustany, A.; Collette, B.B. East not least for Pacific bluefin tuna. Science 2017, 357, 356–357. [Google Scholar] [CrossRef]
  31. Kerr, L.A.; Whitener, Z.T.; Cadrin, S.X.; Morse, M.R.; Secor, D.H.; Golet, W. Mixed stock origin of Atlantic bluefin tuna in the U.S. rod and reel fishery (Gulf of Maine) and implications for fisheries management. Fish. Res. 2020, 224, 105461. [Google Scholar] [CrossRef]
  32. Ivanova, N.V.; Zemlak, T.S.; Hanner, R.H.; Hebert, P.D.N. Universal primer cocktails for fish DNA barcoding. Mol. Ecol. Notes 2007, 7, 544–548. [Google Scholar] [CrossRef]
  33. Ratnasingham, S.; Hebert, P.D.N. BOLD: The Barcode of Life Data System (http://www.barcodinglife.org). Mol. Ecol. Notes 2007, 7, 355–364. [Google Scholar] [CrossRef]
  34. Kimura, M. A simple method for estimating evolutionary rate of base substitutions through comparative studies of nucleotide sequences. J. Mol. Evol. 1980, 16, 111–120. [Google Scholar] [CrossRef] [PubMed]
  35. Alvarado Bremer, J.R.; Stequert, B.; Robertson, N.W.; Ely, B. Genetic evidence for inter-oceanic subdivision of bigeye tuna (Thunnus obesus) populations. Mar. Biol. 1998, 132, 547–557. [Google Scholar] [CrossRef]
  36. Paine, M.A.; McDowell, J.R.; Graves, J.E. Specific identification of Western Atlantic Ocean scombrids using mitochondrial DNA cytochrome c oxidase subunit I (COI) gene region sequences. Bull. Mar. Sci. 2007, 80, 353–367. [Google Scholar]
  37. Sarmiento, K.P.; Ventolero, M.F.H.; Ramiscal, R.V.; Cruz, W.S.D.; Santos, M.D. First DNA evidence on the occurrence of Pacific bluefin tuna, Thunnus orientalis in northern Philippine waters. Mar. Biodivers. Rec. 2016, 9, 25. [Google Scholar] [CrossRef]
  38. Davies, C.A.; Gosling, E.M.; Was, A.; Brohpy, D.; Tysklind, N. Microsatellite analysis of albacore tuna (Thunnus alalunga): Genetic structure in the North-East Atlantic Ocean and Mediterranean Sea. Mar. Biol. 2011, 158, 2727–2740. [Google Scholar] [CrossRef]
  39. Montes, I.; Iriondo, M.; Manzano, C.; Arrizabalaga, H.; Jiménez, E.; Pardo, M.Á.; Goñi, N.; Davies, C.A.; Estonba, A. Worldwide genetic structure of albacore Thunnus alalunga revealed by microsatellite DNA markers. Mar. Ecol. Prog. Ser. 2012, 471, 183–191. [Google Scholar] [CrossRef]
  40. Kunal, S.P.; Kumar, G. Cytochome Oxidase I (COI) sequence conservation and variation patterns in the yellowfin and longtail tunas. Int. J. Bioinform. Res. Appl. 2013, 9, 301–309. [Google Scholar] [CrossRef]
  41. Cawthorn, D.M.; Steinman, H.A.; Witthuhn, R.C. Establishment of a mitochondrial DNA sequence database for the identification of fish species commercially available in South Africa. Mol. Ecol. Resour. 2011, 11, 979–991. [Google Scholar] [CrossRef]
  42. Mahapatra, S.; Rathipriya, A.; Dwivedy, P.; Suresh, E.; Shanmugam, S.A.; Kathivelpandian, A. Character-based identification system of scombrids from Indian waters for authentication and conservation purposes. mtDNA, Part B. Resour. 2020, 5, 3221–3224. [Google Scholar] [CrossRef]
  43. Froese, R.; Pauly, D. Fish Base. World Wide Web Electronic Publication. 2024. Available online: www.fishbase.org (accessed on 1 April 2024).
  44. Bayliff, W.H. A review of the biology and fisheries for northern bluefin tuna, Thunnus thynnus, in the Pacific Ocean. FAO Fish. Tech. Pap. 1994, 2, 244–295. [Google Scholar]
  45. Boustany, A.; Matteson, R.; Castleton, M.; Farwell, C.; Block, B. Movements of Pacific bluefin tuna (Thunnus orientalis) in the Eastern North Pacific revealed with archival tags. Prog. Oceanog. 2010, 86, 94–104. [Google Scholar] [CrossRef]
  46. Block, B.A.; Jonsen, I.D.; Jorgensen, S.J.; Winship, A.J.; Shaffer, S.A.; Bograd, S.J.; Hazen, E.L.; Foley, D.G.; Breed, G.A.; Harrison, A.L.; et al. Tracking apex marine predator movements in a dynamic ocean. Nature 2011, 475, 86–90. [Google Scholar] [CrossRef]
  47. Whitlock, R.E.; Hazen, E.L.; Walli, A.; Farwell, C.; Bograd, S.J.; Foley, D.G.; Castleton, M.; Block, B.A. Direct quantification of energy intake in an apex marine predator suggests physiology is a key driver of migrations. Sci. Adv. 2015, 1, e1400270. [Google Scholar] [CrossRef]
  48. Chen, K.S.; Crone, P.; Hsu, C.C. Reproductive biology of female Pacific bluefin tuna Thunnus orientalis from southwestern North Pacific Ocean. Fish. Sci. 2006, 72, 985–994. [Google Scholar] [CrossRef]
  49. Shiao, J.-C.; Tanaka, Y.; Hsu, J.; Cheng, C.-C.; Wang, P.-L. Contribution rates of different spawning and feeding grounds to adult Pacific bluefin tuna (Thunnus orientalis) in the northwestern Pacific Ocean. Deep-Sea Res. I: Oceanogr. Res. Pap. 2021, 169, 103453. [Google Scholar] [CrossRef]
  50. Tanaka, Y.; Mohri, M.; Yamada, H. Distribution, growth and hatch date of juvenile Pacific bluefin tuna Thunnus orientalis in the coastal area of the Sea of Japan. Fish. Sci. 2007, 73, 534–542. [Google Scholar] [CrossRef]
  51. Okochi, Y.; Abe, O.; Tanaka, S.; Ishihara, Y.; Shimizu, A. Reproductive biology of female Pacific bluefin tuna, Thunnus orientalis, in the Sea of Japan. Fish. Res. 2016, 174, 30–39. [Google Scholar] [CrossRef]
  52. Inagake, D.; Yamada, H.; Segawa, K.; Okazaki, M.; Nitta, A.; Itoh, T. Migration of young bluefin tuna, Thunnus orientalis Temminck et Schlegel, through archival tagging experiments and its relation with oceanographic condition in the western North Pacific. Bull. Natl. Res. Inst. Far Seas Fish. 2001, 38, 53–81. [Google Scholar]
  53. Fujioka, K.; Masujima, M.; Boustany, A.M.; Kitagawa, T. Horizontal movements of Pacific bluefin tuna. In Biology and Ecology of Bluefin Tuna; Kitagawa, T., Kimura, S., Eds.; CRC Press: Boca Raton, FL, USA; London, UK; New York, NY, USA, 2015; pp. 101–122. [Google Scholar]
  54. Kitagawa, T.; Kimura, S.; Nakata, H.; Yamada, H.; Nitta, A.; Sasai, Y.; Sasaki, H. Immature Pacific bluefin tuna, Thunnus orientalis, utilizes cold waters in the Subarctic Frontal Zone for trans-Pacific migration. Environ. Biol. Fishes 2009, 84, 193–196. [Google Scholar] [CrossRef]
  55. Tawa, A.; Ishihara, T.; Uematsu, Y.; Ono, T.; Ohshimo, S. Evidence of westward transoceanic migration of Pacific bluefin tuna in the Sea of Japan based on stable isotope analysis. Mar. Biol. 2017, 164, 94. [Google Scholar] [CrossRef]
  56. Kawazu, M.; Tawa, A.; Ishihara, T.; Uematsu, Y.; Sakai, S. Discrimination of eastward trans-Pacific migrationof the Pacific bluefin tuna Thunnus orientalis through otolith δ13C and δ18O analyses. Mar. Biol. 2020, 167, 110. [Google Scholar] [CrossRef]
  57. Hane, Y.; Ushikubo, T.; Yokoyama, Y.; Miyairi, Y.; Kimura, S. Natal origin of Pacific bluefin tuna Thunnus orientalis determined by SIMS oxygen isotope analysis of otoliths. PLoS ONE 2022, 17, e0272850. [Google Scholar] [CrossRef] [PubMed]
  58. Mohan, J.A.; Dewar, H.; Snodgrass, O.E.; Miller, N.R.; Tanaka, Y.; Ohshimo, S.; Rooker, J.R.; Francis, M.; Wells, R.J.D. Otolith geochemistry reflects life histories of Pacific bluefin tuna. PLoS ONE 2022, 17, e0275899. [Google Scholar] [CrossRef] [PubMed]
  59. Perle, C.R. Movements and Migrations of Manta Rays, Pacific Bluefin Tuna, and White sharks: Observations and Insights at the Intersection of Life History Strategy and Marine Ecosystem Structure. Ph.D. Thesis, Stanford University, Stanford, CA, USA, 2011. [Google Scholar]
  60. Polovina, J.J. Decadal variation in the Trans-Pacific migration of northern bluefin tuna (Thunnus thynnus) coherent with climate-induced change in prey abundance. Fish. Oceanogr. 1996, 5, 114–119. [Google Scholar] [CrossRef]
  61. Kitagawa, T.; Boustany, A.; Farwell, C.; Williams, T.; Castleton, M.; Block, B. Horizontal and vertical movements of juvenile bluefin tuna (Thunnus orientalis) in relation to seasons and oceanographic conditions in the eastern Pacific Ocean. Fish. Oceanogr. 2007, 16, 409–421. [Google Scholar] [CrossRef]
  62. Kitagawa, T.; Kato, Y.; Miller, M.J.; Sasai, Y.; Sasaki, H.; Kimura, S. The restricted spawning area and season of Pacific bluefin tuna facilitate use of nursery areas: A modeling approach to larval and juvenile dispersal processes. J. Exp. Mar. Biol. Ecol. 2010, 393, 23–31. [Google Scholar] [CrossRef]
  63. Yati, E.; Sadiyah, L.; Satria, F.; Alabia, I.D.; Sulma, S.; Prayogo, T.; Marpaung, S.; Harsa, H.; Kushardono, D.; Lumban-Gaol, J.; et al. Spatial distribution models for the four-commercial tuna in the sea of maritime continent using multi-sensor remote sensing and maximum entropy. Mar. Environ. Res. 2024, 198, 106540. [Google Scholar] [CrossRef]
  64. Gordon, A.L.; Fine, R.A. Pathways of water between the Pacific and Indian oceans in the Indonesian seas. Nature 1996, 379, 146–149. [Google Scholar] [CrossRef]
  65. Gordon, A.L. Oceanography of the Indonesian Seas and Their Throughflow. Oceanography 2005, 18, 14–27. [Google Scholar] [CrossRef]
  66. Talley, L.D.; Pickard, G.L.; Emery, W.J.; Swift, J.H. Pacific Ocean. In Descriptive Physical Oceanography: An Introduction, 6th ed.; Academic Press: London, UK, 2011; pp. 303–362. [Google Scholar]
  67. Talley, L.D.; Pickard, G.L.; Emery, W.J.; Swift, J.H. India Ocean. In Descriptive Physical Oceanography: An Introduction, 6th ed.; Academic Press: London, UK, 2011; pp. 363–399. [Google Scholar]
  68. Arkhipkin, A.I.; Laptikhovsky, V.V.; Brickle, P. An antipodal link between the North Pacific and South Atlantic Oceans? Deep Sea Res. Part I Oceanogr. Res. Pap. 2010, 57, 1009–1011. [Google Scholar] [CrossRef]
  69. O’Shea, E.J.A. Changes in habitat preference of tuna species and implication for regional fisheries management: Southern bluefin tuna fishing in the Indian Ocean. Aust. J. Marit. Ocean Aff. 2016, 8, 117–131. [Google Scholar] [CrossRef]
  70. Townhill, B.L.; Couce, E.; Bell, J.; Reeves, S.; Yates, O. Climate Change Impacts on Atlantic Oceanic Island Tuna Fisheries. Front. Mar. Sci. 2021, 8, 634280. [Google Scholar] [CrossRef]
  71. Vaihola, S.; Kininmonth, S. Climate Change Potential Impacts on the Tuna Fisheries in the Exclusive Economic Zones of Tonga. Diversity 2023, 15, 844. [Google Scholar] [CrossRef]
  72. Tseng, M.-C.; Shiao, J.-C.; Hung, Y.-H. Genetic identification of Thunnus orientalis, T. thynnus, and T. maccoyii by a cytochrome b gene analysis. Environ. Biol. Fish. 2011, 91, 103–115. [Google Scholar] [CrossRef]
  73. Ku, J.E.; Kim, J.-K.; Kim, D.N.; Lee, S.I. Shallow population structure of southern bluefin tuna, Thunnus maccoyii (Castelnau, 1872) Between Indian and Atlantic Oceans inferred from mitochondrial DNA sequences. mtDNA Part B. 2021, 6, 2548–2552. [Google Scholar] [CrossRef]
Biology 14 00340 g001
Figure 1. Spatial distribution of the operations of the pelagic longline fleet along the Brazilian coast in 2018–2022 and volumes of total catch in the major fishing grounds: Espírito Santo (ES), Rio de Janeiro (RJ), São Paulo (SP), Paraná (PR), Santa Catarina (SC), and Rio Grande do Sul (RS). The white spots represent the geographical position of the samples individualized by a unique Sample ID.
Figure 1. Spatial distribution of the operations of the pelagic longline fleet along the Brazilian coast in 2018–2022 and volumes of total catch in the major fishing grounds: Espírito Santo (ES), Rio de Janeiro (RJ), São Paulo (SP), Paraná (PR), Santa Catarina (SC), and Rio Grande do Sul (RS). The white spots represent the geographical position of the samples individualized by a unique Sample ID.
Biology 14 00340 g001
Biology 14 00340 g002
Figure 2. Phylogenetic tree inferred using the Maximum Likelihood (ML) method based on the Kimura 2-parameter model with gamma distribution. The sequences obtained in this study are indicated by filled stars (✦). Bootstrap values (1000 replicates) are shown next to the branches. Katsuwonus pelamis was used as an outgroup. Illustrations of the tuna species were adapted from FAO Species Catalogue: Vol. 2 Scombrids of the World and represented by different colors.
Figure 2. Phylogenetic tree inferred using the Maximum Likelihood (ML) method based on the Kimura 2-parameter model with gamma distribution. The sequences obtained in this study are indicated by filled stars (✦). Bootstrap values (1000 replicates) are shown next to the branches. Katsuwonus pelamis was used as an outgroup. Illustrations of the tuna species were adapted from FAO Species Catalogue: Vol. 2 Scombrids of the World and represented by different colors.
Biology 14 00340 g002
Table 1. DNA concentration, quality (260 nm/280 nm), and species identification results for nine Thunnus samples based on the Barcode of Life Data System (BOLD). Species identity (%) reflects the match between the COI sequences obtained and the reference sequences in the BOLD database, along with their corresponding reference codes. Accession numbers of sequences deposited in the GenBank database were also included.
Table 1. DNA concentration, quality (260 nm/280 nm), and species identification results for nine Thunnus samples based on the Barcode of Life Data System (BOLD). Species identity (%) reflects the match between the COI sequences obtained and the reference sequences in the BOLD database, along with their corresponding reference codes. Accession numbers of sequences deposited in the GenBank database were also included.
Sample IDDNA AnalysisBOLD Best IDAccession Numbers
Concentration (ng/uL)Quality (260/280 nm)SpeciesID (%)Ref
LGM079125.62.05Thunnus maccoyii100FOA877-04PV265537
LGM08053.41.96Thunnus maccoyii100FOA877-04PV265538
LGM08171.32.00Thunnus maccoyii100FOA877-04PV265539
LGM08255.12.11Thunnus maccoyii100FOA877-04PV265540
LGM084179.52.02Thunnus orientalis99.85FOA884-04PV265541
LGM08527.72.09Thunnus obesus100SAFC026-11PV265542
LGM08621.92.19Thunnus maccoyii100FOA877-04PV265533
LGM08749.12.00Thunnus maccoyii100FOA877-04PV265534
LGM08880.72.06Thunnus obesus100SAFC026-11PV265535
LGM08942.72.19Thunnus albacares100ANGBF42001-19PV265536
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Schroeder, R.; Sant’Ana, R.; Lima, A.O.S.; Dallabona, J.A.; Delabary, G.S.; Gavazzoni, L.; Oliveira, L.d.; Laaf, Y.d.O.; Travassos, P. A Crusade Throughout the World’s Oceans: Genetic Evidence of the Southern Bluefin Tuna Thunnus maccoyii and the Pacific Bluefin Tuna Thunnus orientalis in Brazilian Waters. Biology 2025, 14, 340. https://doi.org/10.3390/biology14040340

AMA Style

Schroeder R, Sant’Ana R, Lima AOS, Dallabona JA, Delabary GS, Gavazzoni L, Oliveira Ld, Laaf YdO, Travassos P. A Crusade Throughout the World’s Oceans: Genetic Evidence of the Southern Bluefin Tuna Thunnus maccoyii and the Pacific Bluefin Tuna Thunnus orientalis in Brazilian Waters. Biology. 2025; 14(4):340. https://doi.org/10.3390/biology14040340

Chicago/Turabian Style

Schroeder, Rafael, Rodrigo Sant’Ana, André O. S. Lima, Juliana A. Dallabona, Gabriela S. Delabary, Lucas Gavazzoni, Luciana de Oliveira, Yan de O. Laaf, and Paulo Travassos. 2025. "A Crusade Throughout the World’s Oceans: Genetic Evidence of the Southern Bluefin Tuna Thunnus maccoyii and the Pacific Bluefin Tuna Thunnus orientalis in Brazilian Waters" Biology 14, no. 4: 340. https://doi.org/10.3390/biology14040340

APA Style

Schroeder, R., Sant’Ana, R., Lima, A. O. S., Dallabona, J. A., Delabary, G. S., Gavazzoni, L., Oliveira, L. d., Laaf, Y. d. O., & Travassos, P. (2025). A Crusade Throughout the World’s Oceans: Genetic Evidence of the Southern Bluefin Tuna Thunnus maccoyii and the Pacific Bluefin Tuna Thunnus orientalis in Brazilian Waters. Biology, 14(4), 340. https://doi.org/10.3390/biology14040340

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