Vasafua
Vasafua is an islet of Funafuti, Tuvalu. Vasafua is part of the Funafuti Conservation Area, established in 1996 with the aim of preserving the natural fauna and flora of the area.
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.
Labour Party (UK)
The 1910 election saw 42 Labour MPs elected to the House of Commons, a significant victory since, a year before the election, the House of Lords had passed the Osborne judgment ruling that Trades Unions in the United Kingdom could no longer donate money to fund the election campaigns and wages of Labour MPs. The governing Liberals were unwilling to repeal this judicial decision with primary legislation. The height of Liberal compromise was to introduce a wage for Members of Parliament to remove the need to involve the Trade Unions. By 1913, faced with the opposition of the largest Trades Unions, the Liberal government passed the Trade Disputes Act to allow Trade Unions to fund Labour MPs once more.
Public-sector trade union
A public-sector trade union (or public-sector labor union) is a trade union which primarily represents the interests of employees within public sector or governmental organizations.
William Spence
William Guthrie Spence (7 August 1846 – 13 December 1926), Australian trade union leader and politician, played a leading role in the formation of both Australia's largest union, the Australian Workers' Union, and the Australian Labor Party.
Switzerland
Agricultural protectionism—a rare exception to Switzerland's free trade policies—has contributed to high food prices. Product market liberalisation is lagging behind many EU countries according to the OECD. Nevertheless, domestic purchasing power is one of the best in the world. Apart from agriculture, economic and trade barriers between the European Union and Switzerland are minimal and Switzerland has free trade agreements worldwide. Switzerland is a member of the European Free Trade Association (EFTA).
Edvard Johanson
Karl "Edvard" Johanson (1882 in Förlösa – 1936) was a Swedish trade union organizer. By profession he was a shoemaker, and belonged to the Shoe & Leather Industries Workers Union. He was the chairman of the Swedish Trade Union Confederation from 1930, when he succeeded Albert Forslund, to 1936, when he was succeeded by Arvid Thorberg.
Barry Desmond
He was born in Cork in 1935, and was educated at Coláiste Chríost Rí, the School of Commerce and University College Cork. He became a trade union official with the ITGWU (known later as SIPTU) and the Irish Congress of Trade Unions. His father Cornelius (Con) was Lord Mayor of Cork in 1965–66.
G20
Membership of the G20 consists of 19 individual countries plus the European Union (EU). The EU is represented by the European Commission and by the European Central Bank. Collectively, the G20 economies account for around 85% of the gross world product (GWP), 80% of world trade (or, if excluding EU intra-trade, 75%), two - thirds of the world population, and approximately half of the world land area.
USS Clover (1863)
USS "Clover" (1863) was a steam gunboat acquired by the Union Navy during the American Civil War. She was used by the Navy to patrol navigable waterways of the Confederacy to prevent the South from trading with other countries.
National Alliance of Postal and Federal Employees
The National Alliance Of Postal and Federal Employees (NAPFE) is a labor union in the United States. It was founded October 6, 1913 and is affiliated with the International Trade Union Confederation.
Trump tariffs
Beginning on June 1, 2018, the Trump administration imposed a 25% tariff on imports of steel, and a 10% tariff on aluminum, on the European Union, Canada, and Mexico. The tariffs angered U.S. allies, who planned retaliatory tariffs on U.S. goods, and heightened chances of a trade war. China said that it will retaliate for the tariffs imposed on $50 billion of Chinese goods that come into effect on July 6. India is also planning to hit back to recoup trade penalties of $241 million on $1.2 billion worth of Indian steel and aluminium. Other countries, such as Australia, are concerned of the consequences of a trade war.
Solidarity (Polish trade union)
Solidarity (Polish: Solidarność, pronounced (sɔliˈdarnɔɕt͡ɕ) (listen); full name: Independent Self - governing Labour Union ``Solidarity ''-- Niezależny Samorządny Związek Zawodowy`` Solidarność'' (ɲezaˈlɛʐnɨ samɔˈʐɔndnɨ ˈzvjɔ̃zɛk zavɔˈdɔvɨ sɔliˈdarnɔɕt͡ɕ)) is a Polish labour union that was founded on 17 September 1980 at the Lenin Shipyard under the leadership of Lech Wałęsa. It was the first trade union in a Warsaw Pact country that was not controlled by a communist party. Its membership reached 9.5 million members before its September 1981 Congress (when it reached 10 million), which constituted one third of the total working - age population of Poland.
Swedish Hotel and Restaurant Workers' Union
The Swedish Hotel and Restaurant Workers' Union (HRF) is a trade union in Sweden. It has a membership of 61,000 and is affiliated with the Swedish Trade Union Confederation
Canadian Postmasters and Assistants Association
The Canadian Postmasters and Assistants Association or CPAA represents rural postal workers for the Canada Post Corporation. The trade union belongs to the Canadian Labour Congress as the federation's smallest National Union.
Alice Henry
Alice Henry (21 March 1857 – 14 February 1943) was an Australian suffragist, journalist and trade unionist who also became prominent in the American trade union movement as a member of the Women's Trade Union League.
Eswatini
Swaziland is a developing country with a small economy. Its GDP per capita of $9,714 means it is classified as a country with a lower-middle income. As a member of the Southern African Customs Union (SACU) and Common Market for Eastern and Southern Africa (COMESA), its main local trading partner is South Africa. Swaziland's currency, the lilangeni, is pegged to the South African rand. Swaziland's major overseas trading partners are the United States and the European Union. The majority of the country's employment is provided by its agricultural and manufacturing sectors. Swaziland is a member of the Southern African Development Community (SADC), the African Union, the Commonwealth of Nations and the United Nations.
North American Union
Since at least the mid-19th century, numerous concepts for a union among Canada, Mexico and the United States of America, some including the Caribbean, the Central American and the South American countries, have been proposed, such as the North American Technate. Following the North American Free Trade Agreement (NAFTA) and the Maastricht Treaty going into effect there was speculation about the formation of a North American Union, similar to the European Union created by Maastricht, being a possible future step for the region. Several proposals for continental integration of North America advocated the creation of a union styled after the European Union, though many academic and business groups advocated less dramatic changes involving the formation of a customs union or common market.
American Federation of Labor
The American Federation of Labor (AFL) organized as an association of trade unions in 1886. The organization emerged from a dispute with the Knights of Labor (K of L) organization, in which the leadership of that organization solicited locals of various craft unions to withdraw from their International organizations and to affiliate with the K of L directly, an action which would have taken funds from the various unions and enriched the K of L's coffers. The Federation of Organized Trades and Labor Unions also merged into what would become the American Federation of Labor.

Question: What is the only trade union on the country in which Vasafua is located?
Answer: Tuvalu Overseas Seamen's Union