Question: what is the only trade union on the country where Fakanau is located?

full_context: Document 1: Tuvalu: An important creation myth of the islands of Tuvalu is the story of the te Pusi mo te Ali (the Eel and the Flounder) who created the islands of Tuvalu; te Ali (the flounder) is believed to be the origin of the flat atolls of Tuvalu and the te Pusin (the Eel) is the model for the coconut palms that are important in the lives of Tuvaluans. The stories as to the ancestors of the Tuvaluans vary from island to island. On Niutao, Funafuti and Vaitupu the founding ancestor is described as being from Samoa; whereas on Nanumea the founding ancestor is described as being from Tonga.
Document 2: Tuvalu: New Zealand has an annual quota of 75 Tuvaluans granted work permits under the Pacific Access Category, as announced in 2001. The applicants register for the Pacific Access Category (PAC) ballots; the primary criteria is that the principal applicant must have a job offer from a New Zealand employer. Tuvaluans also have access to seasonal employment in the horticulture and viticulture industries in New Zealand under the Recognised Seasonal Employer (RSE) Work Policy introduced in 2007 allowing for employment of up to 5,000 workers from Tuvalu and other Pacific islands. Tuvaluans can participate in the Australian Pacific Seasonal Worker Program, which allows Pacific Islanders to obtain seasonal employment in the Australian agriculture industry, in particular cotton and cane operations; fishing industry, in particular aquaculture; and with accommodation providers in the tourism industry.
Document 3: Tuvalu: Funafuti is the only port but there is a deep-water berth in the harbour at Nukufetau. The merchant marine fleet consists of two passenger/cargo ships Nivaga III and Manu Folau. These ships carry cargo and passengers between the main atolls and travel between Suva, Fiji and Funafuti 3 to 4 times a year. The Nivaga III and Manu Folau provide round trip visits to the outer islands every three or four weeks. The Manu Folau is a 50-metre vessel that was a gift from Japan to the people of Tuvalu. In 2015 the United Nations Development Program (UNDP) assisted the government of Tuvalu to acquire MV Talamoana, a 30-metre vessel that will be used to implement Tuvalu's National Adaptation Programme of Action (NAPA) to transport government officials and project personnel to the outer islands. In 2015 the Nivaga III was donated by the government of Japan; it replaced the Nivaga II, which had serviced Tuvalu from 1989.
Document 4: Fale, Tuvalu: Fale is an islet of Nukufetau, Tuvalu. The traditional history of Nukufetau recalls that in order to protect the atoll from raiders from Tonga, Lagitupu and Laupapa, two aliki (chiefs) protected Fale. Lagitupu and Laupapa created a trap at a place still called Tututekolo, which was beside a path which led to the beach, where they would surprise the raiders and spear them or split their skulls with an axe made from shells.
Document 5: Tuvalu: Required attendance at school is 10 years for males and 11 years for females (2001). The adult literacy rate is 99.0% (2002). In 2010, there were 1,918 students who were taught by 109 teachers (98 certified and 11 uncertified). The teacher-pupil ratio for primary schools in Tuvalu is around 1:18 for all schools with the exception of Nauti School, which has a teacher-student ratio of 1:27. Nauti School on Funafuti is the largest primary in Tuvalu with more than 900 students (45 percent of the total primary school enrolment). The pupil-teacher ratio for Tuvalu is low compared to the Pacific region (ratio of 1:29).
Document 6: Tuvalu: The popular sports in Tuvalu include kilikiti, Ano, football, futsal, volleyball, handball, basketball and rugby union. Tuvalu has sports organisations for athletics, badminton, tennis, table tennis, volleyball, football, basketball, rugby union, weightlifting and powerlifting. At the 2013 Pacific Mini Games, Tuau Lapua Lapua won Tuvalu's first gold medal in an international competition in the weightlifting 62 kilogram male snatch. (He also won bronze in the clean and jerk, and obtained the silver medal overall for the combined event.) In 2015 Telupe Iosefa received the first gold medal won by Tuvalu at the Pacific Games in the powerlifting 120 kg male division.
Document 7: Tuvalu: Fetuvalu offers the Cambridge syllabus. Motufoua offers the Fiji Junior Certificate (FJC) at year 10, Tuvaluan Certificate at Year 11 and the Pacific Senior Secondary Certificate (PSSC) at Year 12, set by the Fiji-based exam board SPBEA. Sixth form students who pass their PSSC go on to the Augmented Foundation Programme, funded by the government of Tuvalu. This program is required for tertiary education programmes outside of Tuvalu and is available at the University of the South Pacific (USP) Extension Centre in Funafuti.
Document 8: Tuvalu: Tuvaluans are well known for their seafaring skills, with the Tuvalu Maritime Training Institute on Amatuku motu (island), Funafuti, providing training to approximately 120 marine cadets each year so that they have the skills necessary for employment as seafarers on merchant shipping. The Tuvalu Overseas Seamen's Union (TOSU) is the only registered trade union in Tuvalu. It represents workers on foreign ships. The Asian Development Bank (ADB) estimates that 800 Tuvaluan men are trained, certified and active as seafarers. The ADB estimates that, at any one time, about 15% of the adult male population works abroad as seafarers. Job opportunities also exist as observers on tuna boats where the role is to monitor compliance with the boat's tuna fishing licence.
Document 9: Music of Tuvalu: The traditional music of Tuvalu consists of dances, including "fatele", "fakanau" and "fakaseasea". The influence of the Samoan missionaries sent to Tuvalu by the London Missionary Society from the 1860s resulted in the suppression of songs about the traditional religions or magic and many songs were lost. As the influence of the missionaries diminished in the 20th century the traditional dances were revived and the siva dance tradition from Samoa also became popular. The "fatele", in its modern form, is performed at community events and to celebrate leaders and other prominent individuals.
Document 10: Mali: Malian musical traditions are derived from the griots, who are known as "Keepers of Memories". Malian music is diverse and has several different genres. Some famous Malian influences in music are kora virtuoso musician Toumani Diabaté, the late roots and blues guitarist Ali Farka Touré, the Tuareg band Tinariwen, and several Afro-pop artists such as Salif Keita, the duo Amadou et Mariam, Oumou Sangare, and Habib Koité. Dance also plays a large role in Malian culture. Dance parties are common events among friends, and traditional mask dances are performed at ceremonial events.
Document 11: Tuvalu: Community Training Centres (CTCs) have been established within the primary schools on each atoll. The CTCs provide vocational training to students who do not progress beyond Class 8 because they failed the entry qualifications for secondary education. The CTCs offer training in basic carpentry, gardening and farming, sewing and cooking. At the end of their studies the graduates can apply to continue studies either at Motufoua Secondary School or the Tuvalu Maritime Training Institute (TMTI). Adults can also attend courses at the CTCs.
Document 12: Tuvalu: A traditional sport played in Tuvalu is kilikiti, which is similar to cricket. A popular sport specific to Tuvalu is Ano, which is played with two round balls of 12 cm (5 in) diameter. Ano is a localised version of volleyball, in which the two hard balls made from pandanus leaves are volleyed at great speed with the team members trying to stop the Ano hitting the ground. Traditional sports in the late 19th century were foot racing, lance throwing, quarterstaff fencing and wrestling, although the Christian missionaries disapproved of these activities.
Document 13: Samoa: Lemi Ponifasio is a director and choreographer who is prominent internationally with his dance Company MAU. Neil Ieremia's company Black Grace has also received international acclaim with tours to Europe and New York. Hip hop has had a significant impact on Samoan culture. According to Katerina Martina Teaiwa, PhD from the University of Hawaii at Manoa, "Hip hop culture in particular is popular amongst Samoan youth." Like very many other countries, hip hop music is popular. In addition, the integration of hip hop elements into Samoan tradition also "testifies to the transferability of the dance forms themselves," and to the "circuits through which people and all their embodied knowledge travel." Dance both in its traditional form and its more modern forms has remained a central cultural currency to Samoans, especially youths.
Document 14: Amatuku: Amatuku is an islet of Funafuti, Tuvalu on which the Tuvalu Maritime Training Institute is located. Access to Amatuku is from Tengako, which is the peninsula at the north end of Fongafale islet.
Document 15: Tuvalu: Christianity came to Tuvalu in 1861 when Elekana, a deacon of a Congregational church in Manihiki, Cook Islands became caught in a storm and drifted for 8 weeks before landing at Nukulaelae on 10 May 1861. Elekana began proselytising Christianity. He was trained at Malua Theological College, a London Missionary Society (LMS) school in Samoa, before beginning his work in establishing the Church of Tuvalu. In 1865 the Rev. A. W. Murray of the LMS – a Protestant congregationalist missionary society – arrived as the first European missionary where he too proselytised among the inhabitants of Tuvalu. By 1878 Protestantism was well established with preachers on each island. In the later 19th and early 20th centuries the ministers of what became the Church of Tuvalu (Te Ekalesia Kelisiano Tuvalu) were predominantly Samoans, who influenced the development of the Tuvaluan language and the music of Tuvalu.
ground_truth: Tuvalu Overseas Seamen's Union
sub_queries: Fakanau >> country Answer: Tuvalu
What is the only trade union on Tuvalu ? Answer: Tuvalu Overseas Seamen's Union