The Western Pacific

archipelagic An archipelago ( ), sometimes called an island group or island chain, is a chain, cluster, or collection of islands. An archipelago may be in an ocean, a sea, or a smaller body of water. Example archipelagos include the Aegean Islands (the o ...

nation of

Tuvalu Tuvalu ( ) is an island country in the Polynesian subregion of Oceania in the Pacific Ocean, about midway between Hawaii and Australia. It lies east-northeast of the Santa Cruz Islands (which belong to the Solomon Islands), northeast of Van ...

, formerly known as the Ellice Islands, is situated northeast of

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

and is approximately halfway between Australia and

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

. It lies east-northeast of the

Santa Cruz Islands The Santa Cruz Islands form an archipelago in Temotu Province, Solomon Islands. They lie approximately to the southeast of the Solomon Islands (archipelago), Solomon Islands archipelago, just north of the archipelago of Vanuatu and are con ...

(belonging to the Solomons), southeast of

Nauru Nauru, officially the Republic of Nauru, formerly known as Pleasant Island, is an island country and microstate in the South Pacific Ocean. It lies within the Micronesia subregion of Oceania, with its nearest neighbour being Banaba (part of ...

, south of

Kiribati Kiribati, officially the Republic of Kiribati, is an island country in the Micronesia subregion of Oceania in the central Pacific Ocean. Its permanent population is over 119,000 as of the 2020 census, and more than half live on Tarawa. The st ...

, west of

Tokelau Tokelau (; ; known previously as the Union Islands, and, until 1976, known officially as the Tokelau Islands) is a dependent territory of New Zealand in the southern Pacific Ocean. It consists of three tropical coral atolls: Atafu, Nukunonu, an ...

, northwest of

Samoa Samoa, officially the Independent State of Samoa and known until 1997 as Western Samoa, is an island country in Polynesia, part of Oceania, in the South Pacific Ocean. It consists of two main islands (Savai'i and Upolu), two smaller, inhabited ...

and

Wallis and Futuna Wallis and Futuna, officially the Territory of the Wallis and Futuna Islands (), is a French island territorial collectivity, collectivity in the Oceania, South Pacific, situated between Tuvalu to the northwest, Fiji to the southwest, Tonga t ...

and north of

Fiji Fiji, officially the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean. It lies about north-northeast of New Zealand. Fiji consists of an archipelago of more than 330 islands—of which about ...

. It is a very small

island country An island country, island state, or island nation is a country whose primary territory consists of one or more islands or parts of islands. Approximately 25% of all independent countries are island countries. Island countries are historically ...

of . Due to the spread out islands it has the 38th largest

Exclusive Economic Zone An exclusive economic zone (EEZ), as prescribed by the 1982 United Nations Convention on the Law of the Sea, is an area of the sea in which a sovereign state has exclusive rights regarding the exploration and use of marine natural resource, reso ...

of . In terms of size, it is the second-smallest country in Oceania. The

islands of Tuvalu Tuvalu consists of nine separate islands: six atolls and three reef islands. An atoll typically consists of several motus: Tuvalu has a total of 124 islands and islets. Each island is surrounded by a coral reef. The soils of Tuvalu's islands are ...

consists of three

reef A reef is a ridge or shoal of rock, coral, or similar relatively stable material lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic component, abiotic (non-living) processes such as deposition (geol ...

islands and six

atolls An atoll () is a ring-shaped island, including a coral rim that encircles a lagoon. There may be coral islands or cays on the rim. Atolls are located in warm tropical or subtropical parts of the oceans and seas where corals can develop. Most of ...

, containing approximately of reef platforms. The reef islands have a different structure to the atolls, and are described as reef platforms as they are smaller tabular reef platforms that do not have a salt-water

lagoon A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') an ...

, although they have a completely closed rim of dry land, with the remnants of a lagoon that has no connection to the open sea or that may be drying up. For example,

Niutao Niutao is a reef island in the northern part of Tuvalu. It is one of the nine districts (islands) of Tuvalu. It is also one of the three districts that consist of only one island — not counting the three islets inside the closed lagoon. Niuta ...

has two lakes, which are brackish to saline; and are the degraded lagoon as the result of coral debris filling the lagoon. The soils of Tuvalu's islands are usually shallow, porous, alkaline, coarse-textured, with carbonate mineralogy and high pH values of up to 8.2 to 8.9. The soils are usually deficient in most of the important nutrients needed for plant growth (e.g., nitrogen, potassium and micronutrients such as iron, manganese, copper and zinc), so garden beds need to be enhanced with

mulch A mulch is a layer of material applied to the surface of soil. Reasons for applying mulch include conservation of soil moisture, improving soil fertility, fertility and health of the soil, reducing Weed control, weed growth, and enhancing the v ...

and fertiliser to increase their fertility. The Tuvalu islands have a total land area of only about 26 km², less than . The land is very low-lying, with narrow coral atolls. The highest elevation is above sea level on

Niulakita Niulakita is the southernmost island of Tuvalu, and also the name of the only village on this island. Niulakita has a population of 36 (2022 Census). The residents of Niulakita have moved to the island from Niutao. Niulakita is represented in ...

. Over 4 decades, there had been a net increase in land area of the islets of 73.5 ha (2.9%), although the changes are not uniform, with 74% increasing and 27% decreasing in size. The sea level at the Funafuti tide gauge has risen at 3.9 mm per year, which is approximately twice the global average. The rising sea levels are identified as creating an increased transfer of wave energy across reef surfaces, which shifts sand, resulting in accretion to island shorelines, although this process does not result in additional habitable land. As of March 2018

Enele Sopoaga Enele Sosene Sopoaga Privy Council of the United Kingdom, PC (born 10 February 1956) is a Tuvaluan diplomat and politician who was Prime Minister of Tuvalu from 2013 to 2019. Sopoaga was elected to Parliament of Tuvalu, Parliament in the 2010 T ...

, the prime minister of Tuvalu, stated that Tuvalu is not expanding and has gained no additional habitable land. Tuvalu experiences two distinct seasons, a wet season from November to April and a dry season from May to October. Westerly gales and heavy rain are the predominant weather conditions from November to April, the period that is known as ''Tau-o-lalo'', with tropical temperatures moderated by easterly winds from May to October.

Geography

Location:

Oceania Oceania ( , ) is a region, geographical region including Australasia, Melanesia, Micronesia, and Polynesia. Outside of the English-speaking world, Oceania is generally considered a continent, while Mainland Australia is regarded as its co ...

island An island or isle is a piece of land, distinct from a continent, completely surrounded by water. There are continental islands, which were formed by being split from a continent by plate tectonics, and oceanic islands, which have never been ...

group of nine islands comprising three

islands and six true

in the South

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

. The islands of Tuvalu are spread out between the

latitude In geography, latitude is a geographic coordinate system, geographic coordinate that specifies the north-south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from −90° at t ...

of 5° to 10° south and

longitude Longitude (, ) is a geographic coordinate that specifies the east- west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek lett ...

of 176° to 180°, west of the

International Date Line The International Date Line (IDL) is the line extending between the South and North Poles that is the boundary between one calendar day and the next. It passes through the Pacific Ocean, roughly following the 180.0° line of longitude and de ...

Geographic coordinates A geographic coordinate system (GCS) is a spherical or geodetic coordinate system for measuring and communicating positions directly on Earth as latitude and longitude. It is the simplest, oldest, and most widely used type of the various ...

: to Map references:

Area:
''total:'' 26 km²
''land:'' 26 km²
''water:'' 0 km² Area – comparative: 0.1 times the size of

Washington, DC Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and Federal district of the United States, federal district of the United States. The city is on the Potomac River, across from ...

Land boundaries: 0 km Coastline: Maritime claims:
''contiguous zone:''
''exclusive economic zone:'' and
''territorial sea:'' Tuvalu's

(EEZ) covers an oceanic area of approximately . On 29 August 2012 an ''Agreement between Tuvalu and Kiribati concerning their Maritime Boundary'', was signed by their respective leaders that determined the boundary as being seaward of

Nanumea Nanumea is the northwesternmost atoll in the Polynesian nation of Tuvalu, a group of nine coral atolls and islands spread over about of the Pacific Ocean just south of the equator and west of the International Date Line. Nanumea is with a po ...

and

in Tuvalu on the one hand and

Tabiteuea Tabiteuea (formerly Drummond's Island) is an atoll in the Gilbert Islands, Kiribati, farther south of Tarawa. This atoll is the second largest and the most populated of the Gilbert Islands after Tarawa. The atoll consists of one main island, Aa ...

, Tamana and

Arorae Arorae (spelling variants: Arorai, Arurai; also known as Hope Island or Hurd Island“Captain Patterson, commanding the brig ''Elizabeth'', called it Hope Island: “Hope Island, in 2° 43′ S and 176° 56′ 25″ E, was the first discovery, t ...

on the other hand, along the

geodesics In geometry, a geodesic () is a curve representing in some sense the locally shortest path ( arc) between two points in a surface, or more generally in a Riemannian manifold. The term also has meaning in any differentiable manifold with a connec ...

connecting the points of latitude and longitude set out in the agreement. In October 2014 the prime ministers of Fiji and Tuvalu signed the ''Fiji-Tuvalu Maritime Boundary Treaty'', which establishes the extent of the national areas of jurisdiction between Fiji and Tuvalu as recognized in international law under the 1982 United Nations Convention on the Law of the Sea. Climate: tropical; moderated by easterly trade winds (March to November); westerly gales and heavy rain (November to March). Terrain: low-lying and narrow coral atolls. Elevation extremes:
''lowest point:''

0 m
''highest point:'' unnamed location, on

. Extreme points: Tuvalu - Funafuti - Approach

This is a list of the extreme points of

, the points that are farther north, south, east or west than any other location: * Northernmost point – Lakena

islet An islet ( ) is generally a small island. Definitions vary, and are not precise, but some suggest that an islet is a very small, often unnamed, island with little or no vegetation to support human habitation. It may be made of rock, sand and/ ...

* Easternmost point – Niuoko islet,

Nukulaelae Nukulaelae is an atoll that is part of the nation of Tuvalu, and it has a population of 300 (2017 census). The largest settlement is Pepesala on Fangaua islet with a population of 341 people (2022 Census). It has the form of an oval and consist ...

* Southernmost point –

* Westernmost point – Lakena islet,

Natural resources: fish. coconut Land use:
''arable land:'' 0%
''permanent crops:'' 60%
''forest:'' 33.3%
''other:'' 6.7% (2022 est.) Irrigated land: 0 km²

Trees and shrubs

Most common trees

Thaman (2016) described about 362 species or distinct varieties of vascular plants that have been recorded at some time on Tuvalu, of which only about 59 (16%) are possibly indigenous. The most common trees found on all islands are

coconut The coconut tree (''Cocos nucifera'') is a member of the palm tree family (biology), family (Arecaceae) and the only living species of the genus ''Cocos''. The term "coconut" (or the archaic "cocoanut") can refer to the whole coconut palm, ...

(''Cocos nucifera'') stands,

hibiscus ''Hibiscus'' is a genus of flowering plants in the Malva, mallow family, Malvaceae. The genus is quite large, comprising List of Hibiscus species, several hundred species that are Native plant, native to warm temperate, Subtropics, subtropical ...

(''Hibiscus tiliaceus''),

papaya The papaya (, ), papaw, () or pawpaw () is the plant species ''Carica papaya'', one of the 21 accepted species in the genus '' Carica'' of the family Caricaceae, and also the name of its fruit. It was first domesticated in Mesoamerica, within ...

(''Carica papaya''),

pandanus ''Pandanus'' is a genus of monocots with about 578 accepted species. They are palm-like, dioecious trees and shrubs native to the Old World tropics and subtropics. Common names include pandan, screw palm and screw pine. The genus is classified ...

(''Pandanus tectorius''), salt bush (''

Scaevola taccada ''Scaevola taccada'', also known as beach cabbage, sea lettuce, or beach naupaka, is a flowering plant in the family Goodeniaceae found in mangrove swamps and rocky or sandy coastal locations in the tropical areas of the Indo-Pacific. It is a co ...

''), ''

Premna serratifolia ''Premna serratifolia'' is a species of small tree or shrub in the family Lamiaceae. It blooms and fruits between May and November.Described by Dr. N Sasidharan (Dr. B P Pal Fellow), Kerala Forest Research Institute, Peechi in India biodiversity ...

'', ''

Tournefortia ''Tournefortia'', often called soldierbushes, is a genus of flowering plants in the borage family, Boraginaceae. It was first published under the name "Pittonia" by Charles Plumier in 1703, in honour of Joseph Pitton de Tournefort, Carl Linnaeu ...

samoensis'', zebra wood (''

Guettarda speciosa ''Guettarda speciosa'', with common names sea randa, or zebra wood, is a species of shrub in the family Rubiaceae found in coastal habitats in tropical areas around the Pacific Ocean, including the coastline of central and northern Queensland an ...

''), Kanava (''

Cordia subcordata ''Cordia subcordata'' is a species of flowering tree in the borage family. It can be found growing in eastern Africa, South Asia, Southeast Asia, northern Australia and the Pacific Islands including Hawaii. The plant is known by a variety of na ...

''), (beach cordia) and terminalia (''

Terminalia Terminalia may refer to: * Terminalia (festival) Terminalia () was an ancient Roman festival in honour of the god Terminus, who presided over boundaries. His statue was merely a stone or post stuck in the ground to distinguish between propert ...

samoensis''). Indigenous broadleaf species, including Fetau (''

Calophyllum inophyllum ''Calophyllum inophyllum'' is a large evergreen plant, commonly called tamanu, oil-nut, mastwood, beach calophyllum or beautyleaf. It is native to the Old World Tropics, from Africa through Asia to Australia and Polynesia. Due to its importance a ...

''), make up single trees or small stands around the coastal margin. While

Coconut The coconut tree (''Cocos nucifera'') is a member of the palm tree family (biology), family (Arecaceae) and the only living species of the genus ''Cocos''. The term "coconut" (or the archaic "cocoanut") can refer to the whole coconut palm, ...

palms are common in Tuvalu, they are usually cultivated rather than naturally seeding and growing. Tuvaluan traditional histories are that the first settlers of the islands planted

palms as they were not found on the islands. The two recorded mangrove species in Tuvalu are the common Togo (''

Rhizophora stylosa ''Rhizophora stylosa'', the spotted mangrove, red mangrove, small stilted mangrove or stilt-root mangrove, is a small to medium-sized evergreen tree in the family Rhizophoraceae. The specific epithet ' is from the Latin meaning 'stylus form', ref ...

'') and the red-flowered mangrove Sagale ('' Lumnitzera littorea''), which is only reported on Nanumaga, Niutao, Nui and Vaitupu. Mangrove ecosystems are protected under Tuvaluan law. The land cover types found on Funafuti include inland

broadleaf forest A forest is an ecosystem characterized by a dense community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological functio ...

and woodland, coastal

littoral The littoral zone, also called litoral or nearshore, is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely i ...

forest and scrub,

mangroves A mangrove is a shrub or tree that grows mainly in coastal saline or brackish water. Mangroves grow in an equatorial climate, typically along coastlines and tidal rivers. They have particular adaptations to take in extra oxygen and remove sal ...

and wetlands, and coconut woodland and agroforest.

Native broadleaf forest

The native broadleaf forest is limited to 4.1% of the vegetation types on the islands of Tuvalu. The islets of the Funafuti Conservation Area have 40% of the remaining native broadleaf forest on

Funafuti Funafuti is an atoll, comprising numerous islets, that serves as the capital of Tuvalu. As of the 2017 census, it has a population of 6,320 people. More people live in Funafuti than the rest of Tuvalu combined, with it containing approximately 6 ...

atoll. The native broadleaf forest of Funafuti would include the following species, that were described by

Charles Hedley Charles Hedley (27 February 1862 – 14 September 1926) was a naturalist, specifically a malacologist. He was born in Britain, but he spent most of his life in Australia. He was the winner of the 1925 Clarke Medal. Early life Hedley was born ...

in 1896, which include the Tuvaluan name (some of which may follow

Samoan plant names Below are some Samoan plant names in alphabetical order in the Samoan language and their corresponding descriptions in English language, English. Many are used in traditional medicines in the Samoa Islands comprising Samoa and American Samoa. Se ...

): * ''Fala'' or Screw Pine, (''

Pandanus ''Pandanus'' is a genus of monocots with about 578 accepted species. They are palm-like, dioecious trees and shrubs native to the Old World tropics and subtropics. Common names include pandan, screw palm and screw pine. The genus is classified ...

'') * ''Puka'' or ''pouka'', (''

Hernandia ''Hernandia'' is a genus of flowering plants in the family Hernandiaceae. It was named after the Spanish botanist Francisco Hernández de Toledo. Species , ''Plants of the World Online'' accepted the following species: * '' Hernandia albiflora ...

peltata'') * ''Futu'', (''

Barringtonia asiatica ''Barringtonia asiatica'', known variously as fish poison tree, putat and beach Barrintonia among other names, is a species of plants in the brazil nut family Lecythidaceae. It is native to coastal habitats from Tanzania and Madagascar in the ...

'') * ''Fetau'', (''

'') * ''Ferra'', (''

Ficus ''Ficus'' ( or ) is a genus of about 850 species of woody trees, shrubs, vines, epiphytes and hemiepiphytes in the family (biology), family Moraceae. Collectively known as fig trees or figs, they are native throughout the tropics with a few spe ...

aspem''), native fig * ''Fau'' or ''Fo fafini'', or woman's fibre tree (''

Hibiscus tiliaceus ''Hibiscus tiliaceus'', commonly known as the sea hibiscus or coast cottonwood, is a species of flowering tree in the mallow family, Malvaceae, with a pantropical distribution along coastlines. It has also been introduced to Florida and New Zeal ...

'') * ''Lakoumonong'', (''

Wedelia ''Wedelia'' is a genus of flowering plants in the family Asteraceae. They are one of the genera commonly called "creeping-oxeyes". The genus is named in honor of German botanist and physician Georg Wolfgang Wedel, 1645–1721. Taxonomy There a ...

strigulosa'') * ''Lou'', (''

Cardamine ''Cardamine'' is a large genus of flowering plants in the mustard family, Brassicaceae, known as bittercresses and toothworts. It contains more than 200 species of annuals and perennials. Species in this genus can be found in diverse habitats w ...

sarmentosa'') * ''Meili'', (''

Polypodium ''Polypodium'' is a genus of ferns in the family Polypodiaceae, subfamily Polypodioideae, according to the Pteridophyte Phylogeny Group classification of 2016 (PPG I). The genus is widely distributed throughout the world, with the highest ...

''), fern * ''Laukatafa'', ''

Asplenium nidus ''Asplenium nidus'' is an epiphytic species of fern in the family Aspleniaceae, native to tropical southeastern Asia, eastern Australia, Hawaii (''ʻēkaha'' in Hawaiian), Polynesia,MacDonald, Elvin "The World Book of House Plants" pp.264 Popul ...

'', bird's-nest fern * ''Milo'' or ''miro'', (''

Thespesia populnea ''Thespesia populnea'', commonly known as the portia tree (), Pacific rosewood, Indian tulip tree, or milo, among other names, is a species of flowering plant belonging to the mallow family, Malvaceae. It is a tree found commonly on coasts ar ...

'') * ''Ngashu'' or ''Naupaka'', (''

'') * ''Ngia'' or ''Ingia'', (''

Pemphis ''Pemphis'' is a genus of maritime plants in family Lythraceae. It has only one species described in 1775, '' Pemphis acidula''. ''Pemphis'' are highly adaptive. Depending on environmental factors, they are densely branched, or low and spreadin ...

acidula''), bush * ''Nonou'' or ''nonu'', (''

Morinda citrifolia ''Morinda citrifolia'' is a fruit-bearing tree in the coffee family, Rubiaceae, native to Southeast Asia and Australasia, which was spread across the Pacific by Polynesian sailors. The species is now cultivated throughout the tropics and widel ...

'') * ''Pukavai'', (

Pisonia grandis ''Pisonia grandis'', the grand devil's-claws, is a species of flowering tree in the ''Bougainvillea'' family, Nyctaginaceae. Description The tree has broad, thin leaves, smooth bark and bears clusters of green sweet-smelling flowers that matur ...

) * ''Sageta'', ('' Dioclea violacea''), vine * ''Talla talla gemoa'', (''

Psilotum ''Psilotum'' is a genus of fern-like vascular plants. It is one of two genera in the family Psilotaceae commonly known as whisk ferns, the other being ''Tmesipteris''. Plants in these two genera were once thought to be descended from the earlies ...

triquetrum''), fern * ''Tausunu'' or ''tausoun'', (''

Heliotropium foertherianum ''Heliotropium arboreum'' is a species of flowering plant in the borage family, Boraginaceae. It is native to tropical Asia including southern China, Madagascar, northern Australia, and most of the atolls and high islands of Micronesia and Polyn ...

'') * ''Tonga'' or ''tongo'', (''

Rhizophora mucronata ''Rhizophora mucronata'' (loop-root mangrove, red mangrove or Asiatic mangrove) is a species of mangrove found on coasts and river banks in East Africa and the Indo-Pacific region. Description ''Rhizophora mucronata'' is a small to medium si ...

''), found around swamps * ''Tulla tulla'', (''

Triumfetta ''Triumfetta'' is a genus of plants in the family Malvaceae. Burbark is a common name for plants in this genus. The genus was originally described and published by Carl Linnaeus in his book Sp. Pl. on page 444 in 1753. There are about 176 s ...

procumbens''), whose prostrate stems trailed for several feet over the ground * ''Valla valla'', ('' Premna tahitensis'') The blossoms that are valued for their scent and for use in flower necklaces and headdresses include: ''Fetau'', (''

''); ''Jiali'', (''

Gardenia taitensis ''Gardenia taitensis'', also called Tahitian gardenia or tiaré flower, is a species of plant in the family Rubiaceae. It is an evergreen tropical shrub that grows to tall and has glossy dark green leaves that are long and are oppositely arran ...

''); ''Boua'' (''

''); and ''

Crinum ''Crinum'' is a genus of about 180 species of perennial plants that have large showy flowers on leafless stems, and develop from bulbs. They are found in seasonally moist areas, including marshes, swamps, depressions and along the sides of strea ...

''.

Donald Gilbert Kennedy Donald Gilbert Kennedy (March 1898 – 1976) was a teacher, then an administrator in the British colonial service in the Gilbert and Ellice Islands Colony and the British Solomon Islands Protectorate. For his services as a Coastwatcher during th ...

, the resident District Officer in the administration of the

Gilbert and Ellice Islands The Gilbert and Ellice Islands (GEIC as a colony) in the Pacific Ocean was part of the British Empire from 1892 to 1976. It was a British protectorate, protectorate from 1892 to 12 January 1916, and then a crown colony, colony until 1 January 1 ...

Colony from 1932 to 1938, identified other trees found in the broadleaf forest: * ''Pua'', (

) * ''Kanava'', (

) Charles Hedley (1896) identified the uses of plants and trees from the native broadleaf forest as including: * Food plants:

; and ''Ferra'', native fig (''

aspem''). * Fibre:

; ''Ferra''; ''Fala'', Screw Pine, ''

''; ''Fau'' or ''Fo fafini'', or woman's fibre tree (''

''). * Timber: ''Fau'' or ''Fo fafini''; ''Pouka'', (''

peltata''); ''Ngia'' or ''Ingia'', (''

acidula''); ''Miro'', (''

''); and ''Tonga'', (''

''). * Dye: ''Valla valla'', ('' Premna tahitensis''); ''Tonga'', (''

''); and ''Nonou'', (''

''). * Scent: ''Fetau'', (''

''); ''Jiali'', (''

''); and ''Boua'' (''

''); ''Valla valla'', ('' Premna tahitensis''); and

. * Medicinal: ''Tulla tulla'', (''

procumbens''); ''Nonou'', (''

''); ''Tausoun'', (''

''); ''Valla valla'', ('' Premna tahitensis''); ''Talla talla gemoa'' (''

triquetrum''); ''Lou'', (''

sarmentosa''); and ''Lakoumonong'', (''

strigulosa''). Thaman (1992) provides a literature review of the ethnobiology of the Pacific Islands.

Climate and natural hazards

El Niño and La Niña

Tuvalu experiences the effects of

El Niño EL, El or el may refer to: Arts and entertainment Fictional entities * El, a character from the manga series ''Shugo Chara!'' by Peach-Pit * Eleven (''Stranger Things'') (El), a fictional character in the TV series ''Stranger Things'' * El, fami ...

and

La Niña LA most frequently refers to Los Angeles, the second most populous city in the United States of America. La, LA, or L.A. may also refer to: Arts and entertainment Music *La (musical note), or A, the sixth note *"L.A.", a song by Elliott Smit ...

that flow from changes in ocean temperatures in equatorial and central Pacific.

effects increase the chances of tropical storms and

cyclones In meteorology, a cyclone () is a large air mass that rotates around a strong center of low atmospheric pressure, counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere as viewed from above (opposite to an ant ...

; while

effects increase the chances of drought conditions in Tuvalu. On 3 October 2011, drought conditions resulted in a state of emergency being declared as water reserves ran low. Typically the islands of Tuvalu receive between 200mm to 400mm of rainfall per month, however a weak

effect causes a drought by cooling the surface of the sea around Tuvalu.

Tropical cyclones

Severe

tropical cyclone A tropical cyclone is a rapidly rotating storm system with a low-pressure area, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depending on its locat ...

s are usually rare, but the low level of islands makes them very sensitive to sea-level rise. Tuvalu experienced an average of three cyclones per decade between the 1940s and 1970s, however eight occurred in the 1980s. The impact of individual cyclones is subject to variables including the force of the winds and also whether a cyclone coincides with high tides. A warning system, which uses the

Iridium Iridium is a chemical element; it has the symbol Ir and atomic number 77. This very hard, brittle, silvery-white transition metal of the platinum group, is considered the second-densest naturally occurring metal (after osmium) with a density ...

satellite network, was introduced in 2016 in order to allow outlying islands to be better prepare for natural disasters. George Westbrook recorded a cyclone that struck

on 23–24 December 1883. A cyclone struck Nukulaelae on 17–18 March 1886. Captain Edward Davis of HMS ''Royalist'', who visited the Ellice Group in 1892, recorded in the ship's diary that in February 1891 the Ellice Group was devastated by a severe cyclone. A cyclone caused severe damage to the islands in 1894.

Cyclone Bebe Severe Tropical Cyclone Bebe, also known as Hurricane Bebe, was a pre-season storm during October 1972 in the South Pacific Ocean that severely affected Fiji, the Ellice Islands (now Tuvalu), and the Gilbert Islands (now Kiribati). Meteorologic ...

caused severe damage to

during the

1972–73 South Pacific cyclone season The 1972–73 South Pacific cyclone season ran year-round from July 1 to June 30. Tropical cyclone activity in the Southern Hemisphere reaches its peak from mid-February to early March. Seasonal summary ImageSize = width:825 height:230 PlotAr ...

. Funafuti's Tepuka Vili Vili

was devastated by Cyclone Meli in 1979, with all its vegetation and most of its sand swept away during the cyclone.

Cyclone Gavin Severe Tropical Cyclone Gavin was the most intense tropical cyclone to affect Fiji, since Cyclone Oscar of the 1982–83 cyclone season and was the first of three tropical cyclones to affect the island nations of Tuvalu and Wallis and Futuna dur ...

was first identified during 2 March 1997, and was the first of three tropical cyclones to affect Tuvalu during the 1996–97 cyclone season with Cyclones

Hina Hina may refer to: People and deities * Hina (given name), including a list of people and fictional characters with the name * Hina (goddess), the name assigned to a number of Polynesian deities. * Hina (singer), of 2021 group Lightsum Other u ...

and Keli following later in the season.

Cyclone Ofa Severe Tropical Cyclone Ofa was a powerful tropical cyclone that caused severe damage in Polynesia in February 1990. The system was first noted on January 27, 1990, near Tuvalu, as a shallow tropical depression that had developed within the So ...

had a major impact on Tuvalu in late January and early February 1990. On

Vaitupu Vaitupu is the largest atoll of the nation of Tuvalu. It is located at 7.48 degrees south and 178.83 degrees east. There are 1,077 people (2022 Census) living on with the main village being Asau. History Discovery and settlement The exa ...

Island around 85 percent of residential homes, trees and food crops were destroyed, while residential homes were also destroyed on the islands of

, Nui and

. The majority of the islands in Tuvalu reported damage to vegetation and crops especially bananas, coconuts and breadfruit, with the extent of damage ranging from 10 to 40 percent. In

sea waves flattened the Hurricane Bebe bank at the southern end of the airstrip, which caused sea flooding and prompted the evacuation of several families from their homes. In Nui and Niulakita there was a minor loss of the landscape because of sea flooding while there were no lives lost. Soon after the systems had impacted Tuvalu, a Disaster Rehabilitation Sub-Committee was appointed to evaluate the damage caused and make recommendations to the National Disaster Committee and to the Cabinet of Tuvalu, on what should be done to help rehabilitate the affected areas. In March 2015

Cyclone Pam Severe Tropical Cyclone Pam was the second List of the most intense tropical cyclones, most intense tropical cyclone of the South Pacific Ocean in terms of sustained winds and is regarded as one of the worst natural disasters in the history of ...

, the Category 5 cyclone that devastated

Vanuatu Vanuatu ( or ; ), officially the Republic of Vanuatu (; ), is an island country in Melanesia located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is east of northern Australia, northeast of New Caledonia, east o ...

, caused damage to houses, crops and infrastructure on the outer islands. A state of emergency was subsequently declared on 13 March. An estimated 45 percent of the nation's nearly 10,000 people were displaced, according to

Prime Minister A prime minister or chief of cabinet is the head of the cabinet and the leader of the ministers in the executive branch of government, often in a parliamentary or semi-presidential system. A prime minister is not the head of state, but r ...

. The three northern islands,

Nanumanga Nanumanga or Nanumaga is a reef island and a district of the Oceanian island nation of Tuvalu. It has a surface area of about 3 km2 with a population of 391 (2022 census). History On 9 May 1824 a French government expedition under Captain ...

and

were badly affected by flooding as the result of storm surges. More than 400 people from the northern island of Nanumanga were moved to emergency accommodation in the school buildings, as well as another 85 families from

in the south of Tuvalu. On Nui the storm surges contaminated the water supplies and damaged septic tanks and grave sites. The central islands of

and

Nukufetau Nukufetau is an atoll that is part of the nation of Tuvalu. The atoll was claimed by the US under the Guano Islands Act some time in the 19th century and was ceded in a treaty of friendship concluded in 1979 and coming into force in 1983. It h ...

were also affected by flooding caused by storm surges. The Situation Report published on 30 March reported that on Nukufetau all the displaced people have returned to their homes. Nui suffered the most damage of the three central islands (Nui, Nukufetau and Vaitupu); with both Nui and Nukufetau suffering the loss of 90% of the crops. Of the three northern islands (Nanumanga, Niutao, Nanumea), Nanumanga suffered the most damage, with 60–100 houses flooded and damage to the health facility. Vasafua islet, part of the Funafuti Conservation Area, was severely damaged by Cyclone Pam. The coconut palms were washed away, leaving the islet as a sand bar. Despite passing over to the south of the island nation,

Cyclone Tino Severe Tropical Cyclone Tino was a tropical cyclone which itself and an associated convergence zone caused significant damage across ten island nations in the South Pacific Ocean during January 2020. First noted as a tropical disturbance d ...

and its associated convergence zone impacted the whole of Tuvalu between January 16 - 19 of 2020.

Tsunami

Nui was struck by a giant wave on 16 February 1882; earthquakes and volcanic eruptions occurring in the basin of the

and along the Pacific

Ring of Fire The Ring of Fire (also known as the Pacific Ring of Fire, the Rim of Fire, the Girdle of Fire or the Circum-Pacific belt) is a tectonic belt of volcanoes and earthquakes. It is about long and up to about wide, and surrounds most of the Pa ...

are a possible cause of a

tsunami A tsunami ( ; from , ) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and underwater explosions (including detonations, ...

. There is earthquake activity in the Solomon Islands, where earthquakes occurred in relation to the New Hebrides Trench, and movement along the boundary of the Pacific Plate with, respectively, the Indo-Australia,

Woodlark The woodlark or wood lark (''Lullula arborea'') is the only extant species in the lark genus ''Lullula''. It is found across most of Europe, the Middle East, western Asia and the mountains of north Africa. It is mainly resident (non-bird migrati ...

, and Solomon Sea plates. Tuvalu has the third lowest tsunami risk of Pacific Island countries, with a maximum tsunami amplitude of 1.6m for a 2000-year return period (comparatively, the highest is 5.2m for PNG, and the lowest is 1m for Nauru). The assessment of the tsunami risk of Tuvalu was that major source of risk was activity associated with the New Hebrides trench. The orientation of the trench vis-à-vis the islands of Tuvalu results in the conclusion that most of the energy originating from New Hebrides trench is likely to be directed towards the southern islands of Tuvalu, so that the tsunami risk is lower for the northern islands when compared to the southern islands.

Climate data

Environment

Island, reef and lagoon habitats

Tuvalu consists of three

islands and six true

. Its small, scattered group of

have poor soil and a total land area of only about 26.26 square kilometres (less than 10 sq. mi.) making it the fourth smallest country in the world. The islets that form the atolls are very low-lying.

Nanumaga Nanumanga or Nanumaga is a reef island and a district of the Oceanian island nation of Tuvalu. It has a surface area of about 3 km2 with a population of 391 (2022 census). History On 9 May 1824 a French government expedition under Captain ...

are

islands and the six true atolls are

, Nui,

and

is the largest

atoll An atoll () is a ring-shaped island, including a coral rim that encircles a lagoon. There may be coral islands or cays on the rim. Atolls are located in warm tropical or subtropical parts of the oceans and seas where corals can develop. Most ...

of the nine low

islands and atolls that form the Tuvalu volcanic island chain. It comprises numerous islets around a central lagoon that is approximately (N–S) by (W-E), centred on 179°7’E and 8°30’S. On the atolls an annular reef rim surrounds the lagoon, with several natural reef channels. A standard definition of an ''atoll'' is "an annular reef enclosing a lagoon in which there are no promontories other than reefs and islets composed of reef detritus". The northern part of the Funafuti lagoon has a deep basin (maximum depth recorded of 54.7 m) basin, and the southern part of the lagoon has very narrow shallow basin. The eastern shoreline of

Fongafale Fongafale (also spelled Fogale or Fagafale) is the largest and most populated of Funafuti's islets in Tuvalu. It is a long narrow sliver of land, 12 kilometres long and between 10 and 400 metres wide, with the South Pacific Ocean and reef on the ...

in the Funafuti lagoon (''Te Namo'') was modified during World War II; several piers were constructed, beach areas filled, and deep water access channels were excavated. These alternations to the reef and shoreline have resulted in changes to wave patterns with less sand accumulating to form the beaches as compared to former times; and the shoreline is now exposed to wave action. Several attempts to stabilize the shoreline have not achieved the desired effect. The rising population results in increased demand on fish stocks, which are under stress; although the creation of the Funafuti Conservation Area has provided a fishing exclusion area that helps sustain fish populations across the Funafuti lagoon. Population pressure on the resources of Funafuti and in-adequation sanitation systems have resulted in pollution. The Waste Operations and Services Act 2009 provides the legal framework for the waste management and pollution control projects funded by the European Union that are directed to organic waste composting in eco-sanitation systems. Surveys were carried out in May 2010 of the reef habitats of Nanumea, Nukulaelae and Funafuti (including the Funafuti Conservation Area) and a total of 317 fish species were recorded during this ''Tuvalu Marine Life'' study. The surveys identified 66 species that had not previously been recorded in Tuvalu, which brings the total number of identified species to 607. The terrestrial invertebrates are land and shore crabs, including ''Paikea'' ('' Discoplax rotunda''), ''Tupa'' (''

Cardisoma carnifex ''Cardisoma carnifex'' is a species of terrestrial crab found in coastal regions from the east coast of Africa and the Red Sea across the Indo-Pacific to the Line Islands and the Tuamotu Archipelago. The range includes parts of northern Australia ...

''), ''Kamakama'' ('' Grapsus albolineatus''), a range of hermit crabs, ''Uga'' (''

Coenobita :''The junior homonym ''Coenobita'' Gistl, 1848 is now the moth genus '' Ectropis. The genus ''Coenobita'' contains 17 species of terrestrial hermit crabs. Several species in this genus are kept as pets. Ecology ''Coenobita'' species carry w ...

spp'') and the coconut crab, ''Uu'' (''

Birgus latro The coconut crab (''Birgus latro'') is a terrestrial species of giant hermit crab, and is also known as the robber crab or palm thief. It is the largest terrestrial arthropod known, with a weight up to . The distance from the tip of one leg to t ...

''). Also important are a range of land snails, misa (''

Melampus In Greek mythology, Melampus (; , ''Melampous'') was a legendary soothsayer and healer, originally of Pylos, who ruled at Argos. He was the introducer of the worship of Dionysus, according to Herodotus, who asserted that his powers as a seer ...

spp'') used to make shell leis (ula) and traditional handicrafts, which includes the decoration of mats, fans and wall hangings.

Environment – climate change issues

Since there are no streams or rivers and groundwater is not potable, most water needs must be met by catchment systems with storage facilities; beachhead erosion because of the use of sand for building materials; excessive clearance of forest undergrowth for use as fuel; damage to coral reefs from the bleaching of the coral as a consequence of the increase of the ocean temperatures and acidification from increased levels of carbon dioxide; Tuvalu is very concerned about global increases in greenhouse gas emissions and their effect on rising sea levels, which threaten the country's underground water table. Tuvalu has adopted a national plan of action as the observable transformations over the last ten to fifteen years show Tuvaluans that there have been changes to the sea levels. Because of the low elevation, the islands that make up this nation are threatened by current and future

sea level rise The sea level has been rising from the end of the last ice age, which was around 20,000 years ago. Between 1901 and 2018, the average sea level rose by , with an increase of per year since the 1970s. This was faster than the sea level had e ...

. The highest elevation is above sea level on

, which gives Tuvalu the second-lowest maximum elevation of any country (after the

Maldives The Maldives, officially the Republic of Maldives, and historically known as the Maldive Islands, is an Archipelagic state, archipelagic country in South Asia located in the Indian Ocean. The Maldives is southwest of Sri Lanka and India, abou ...

). However, the highest elevations are typically in narrow storm dunes on the ocean side of the islands which are prone to over topping in tropical cyclones, such as occurred on

with

Tuvalu is mainly composed of coral debris eroded from encircling reefs and pushed up onto the islands by winds and waves. Paul Kench at the

University of Auckland The University of Auckland (; Māori: ''Waipapa Taumata Rau'') is a public research university based in Auckland, New Zealand. The institution was established in 1883 as a constituent college of the University of New Zealand. Initially loc ...

in New Zealand and Arthur Webb at the

South Pacific Applied Geoscience Commission The Pacific Islands Applied Geoscience Commission (SOPAC) was an inter-governmental regional organisation dedicated to providing services to promote sustainable development in the countries it serves. In 2010, its functions had been transferred to ...

released a study in 2010 on the dynamic response of reef islands to sea level rise in the central Pacific. Tuvalu was mentioned in the study, and Webb and Kench found that seven islands in one of its nine atolls have spread by more than 3 per cent on average since the 1950s. One island, Funamanu, gained 0.44 hectares, or nearly 30 per cent of its previous area. In contrast, Tepuka Vili Vili has suffered a net loss in area of 22 percent since 1896. The shape and orientation of the reef has also changed over time. Further research by Kench et al., published in 2018 identifies rising sea levels as creating an increased transfer of wave energy across the reef surfaces of the atolls of Tuvalu, which shifts sand, resulting in accretion to island shorelines. Over 4 decades, there had been a net increase in land area of the islets of 73.5 ha (2.9%), although the changes are not uniform, with 74% increasing and 27% decreasing in size. However, this process does not result in additional habitable land. The storm surge resulting from a

can dramatically shift coral debris. In 1972 Funafuti was in the path of

. Tropical Cyclone Bebe was a pre-season

that impacted the Gilbert,

Ellice Islands Tuvalu ( ) is an island country in the Polynesian subregion of Oceania in the Pacific Ocean, about midway between Hawaii and Australia. It lies east-northeast of the Santa Cruz Islands (which belong to the Solomon Islands), northeast of Van ...

, and

island groups.Bureau of Meteorology (1975) ''Tropical Cyclones in the Northern Australian Regions 1971–1972'' Australian Government Publishing Service The storm surge created a wall of coral rubble along the ocean side of

and

Funafala Funafala is an islet of Funafuti, Tuvalu that is inhabited by five families, with a church also located on the islet. Funafala means 'the pandanus of Funa', the name of a chief, after whom also the group has been named Funafuti. Cyclones of 1883 & ...

that was about long, and about thick at the bottom. The cyclone knocked down about 90% of the houses and trees on Funafuti and contaminated sources of drinking water as a result of the system's storm surge and fresh water flooding. Tuvalu is affected by

perigean spring tide A perigean spring tide is a tide that occurs three or four times per year when a perigee (the point nearest Earth reached by the Moon during its 27.3-day elliptic orbit) coincides with a spring tide (when the Sun, the Moon, and Earth are nearly ...

events which raise the sea level higher than a normal

high tide Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tables ...

. The highest peak tide recorded by the

Tuvalu Meteorological Service The Tuvalu Meteorological Service (TMS) is the principal meteorological observatory of Tuvalu and is responsible for providing weather services to the islands of Tuvalu. A meteorological office was established on Funafuti at the time the islands of ...

was on 24 February 2006 and again on 19 February 2015. As a result of historical sea level rise, the

king tide A king tide is an especially high spring tide, especially the perigean spring tides which occur three or four times a year. King tide is not a scientific term, nor is it used in a scientific context. The expression originated in Australia, Ne ...

events lead to flooding of low-lying areas, which is compounded when sea levels are further raised by

effects or local storms and waves. In the future, sea level rise may threaten to submerge the nation entirely as it is estimated that a sea level rise of in the next 100 years could make Tuvalu uninhabitable.Hunter, J. A. 2002
Note on Relative Sea Level Change at Funafuti, Tuvalu
. Retrieved 13 May 2006. Tuvalu experiences westerly gales and heavy rain from October to March – the period that is known as ''Tau-o-lalo''; with tropical temperatures moderated by easterly winds from April to November. Drinking water is mostly obtained from rainwater collected on roofs and stored in tanks; these systems are often poorly maintained, resulting in lack of water. Aid programs of Australia and the European Union have been directed to improving the storage capacity on Funafuti and in the outer islands.

Borrow Pits Remediation (BPR) project

When the airfield, which is now

Funafuti International Airport Funafuti International Airport is an airport in Vaiaku on Funafuti, an atoll that serves as the capital of the island nation of Tuvalu. It is the sole international airport in Tuvalu. Fiji Airways operates between Suva, Nadi and Funafuti. It i ...

, was constructed during World War II. The coral base of the atoll was used as fill to create the runway. The resulting

borrow pit Digging, also referred to as excavation, is the process of using some implement such as claws, hands, manual tools or heavy equipment, to remove material from a solid surface, usually soil, sand or rock on the surface of Earth. Digging is actual ...

s impacted the fresh-water

aquifer An aquifer is an underground layer of water-bearing material, consisting of permeability (Earth sciences), permeable or fractured rock, or of unconsolidated materials (gravel, sand, or silt). Aquifers vary greatly in their characteristics. The s ...

. In the low areas of Funafuti the sea water can be seen bubbling up through the porous coral rock to form pools with each high tide. Since 1994 a project has been in development to assess the environmental impact of transporting sand from the lagoon to fill all the borrow pits and low-lying areas on

. In 2013 a feasibility study was carried out and in 2014 the Tuvalu Borrow Pits Remediation (BPR) project was approved, so that all ten borrow pits would be filled, leaving Tafua Pond, which is a natural pond. The New Zealand Government funded the BPR project. The project was carried out in 2015 with 365,000 sqm of sand being dredged from the lagoon to fill the holes and improve living conditions on the island. This project increased the usable land space on Fongafale by eight per cent.

Tuvalu Coastal Adaptation Project (TCAP)

The

Tuvalu Coastal Adaptation Project The Tuvalu Coastal Adaptation Project (TCAP) was launched in 2017 to meet the challenges to Tuvalu resulting from Climate change in Tuvalu, climate change and sea-level rise affecting the islands of Tuvalu. Tuvalu was the first country in the Pac ...

(TCAP) was launched in 2017 for the purpose on enhancing the resilience of the islands of Tuvalu to meet the challenges resulting from higher sea levels. Tuvalu was the first country in the Pacific to access climate finance from

Green Climate Fund The Green Climate Fund (GCF) is a Funding, fund for climate finance that was established within the framework of the United Nations Framework Convention on Climate Change (UNFCCC). Considered the world's largest fund of its kind, GCF's objective ...

, with the support of the

UNDP The United Nations Development Programme (UNDP) is a United Nations agency tasked with helping countries eliminate poverty and achieve sustainable economic growth and human development. The UNDP emphasizes on developing local capacity towar ...

. In December 2022, work on the Funafuti reclamation project commenced. The project is to dredge sand from the lagoon to construct a platform on

that is meters long and meters wide, giving a total area of approximately 7.8 ha. (19.27 acres), which is designed to remain above sea level rise and the reach of storm waves beyond the year 2100. The Australian

Department of Foreign Affairs and Trade The Department of Foreign Affairs and Trade (DFAT) is the department of the Australian government responsible for foreign policy and international relations, development aid (under the name Australian Aid), consular services, overseas trad ...

(DFAT) also provided funding for the TCAP. Further projects that are part of TCAP are capital works on the outer islands of

and

aimed at reducing exposure to coastal damage resulting from storms.

Topographic and Bathymetric Survey

In May 2019, TCAP signed an agreement with Fugro, for it to carry out an airborne LIDAR (Light Detection and Ranging) survey across the nine

. LIDAR is a

remote sensing Remote sensing is the acquisition of information about an physical object, object or phenomenon without making physical contact with the object, in contrast to in situ or on-site observation. The term is applied especially to acquiring inform ...

method that uses light in the form of a pulsed laser that will produce high quality mapping of the reef and lagoon

bathymetry Bathymetry (; ) is the study of underwater depth of ocean floors ('' seabed topography''), river floors, or lake floors. In other words, bathymetry is the underwater equivalent to hypsometry or topography. The first recorded evidence of wate ...

(sea floor mapping to 50-meter depths) and accurate

topography Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the landforms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary sci ...

(land elevation data). This aerial survey will provide high quality baseline data to assess the relationship between water levels and wave dynamics and their impact on the islands of Tuvalu. The survey will also provide baseline data for shoreline monitoring, coastal vulnerability assessment and planning.

Controls on plastic waste and recycling of domestic waste

From 1 August 2019, specific single-use plastic items are subject to a ban on importation into Tuvalu, an importation levy was also imposed on specific items, such as refrigerators and vehicles, to raise money to pay for their recycling or shipment out of the country when they cease to be usable. The new rules are contained in two regulations: the Waste Management (Prohibition on the Importation of Single-Use Plastic) Regulation 2019 and the Waste Management (Levy Deposit) Regulation 2019, which regulations are made under the Waste Operations and Services Act 2009.

Environment – international agreements

Tuvalu is a party to:

Biodiversity Biodiversity is the variability of life, life on Earth. It can be measured on various levels. There is for example genetic variability, species diversity, ecosystem diversity and Phylogenetics, phylogenetic diversity. Diversity is not distribut ...

Climate Change Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...

Climate Change-Kyoto Protocol The was an international treaty which extended the 1992 United Nations Framework Convention on Climate Change (UNFCCC) that commits state parties to reduce greenhouse gas emissions, based on the scientific consensus that global warming is occ ...

Desertification Desertification is a type of gradual land degradation of Soil fertility, fertile land into arid desert due to a combination of natural processes and human activities. The immediate cause of desertification is the loss of most vegetation. This i ...

Hazardous Waste Hazardous waste is waste that must be handled properly to avoid damaging human health or the environment. Waste can be hazardous because it is Toxicity, toxic, Chemical reaction, reacts violently with other chemicals, or is Corrosion, corrosive, ...

Law of the Sea Law of the sea (or ocean law) is a body of international law governing the rights and duties of State (polity), states in Ocean, maritime environments. It concerns matters such as navigational rights, sea mineral claims, and coastal waters juris ...

, Ozone Layer Protection,

Ship Pollution A ship is a large watercraft, vessel that travels the world's oceans and other Waterway, navigable waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research and fishing. Ships are generally disti ...

Whaling Whaling is the hunting of whales for their products such as meat and blubber, which can be turned into a type of oil that was important in the Industrial Revolution. Whaling was practiced as an organized industry as early as 875 AD. By the 16t ...

''signed, but not ratified:'' none Tuvalu signed the

Convention on Biological Diversity The Convention on Biological Diversity (CBD), known informally as the Biodiversity Convention, is a multilateral treaty. The Convention has three main goals: the conservation of biological diversity (or biodiversity); the sustainable use of its ...

(CBD) in 1992, and ratified it in December 2002. Tuvalu signed the

Pacific Islands Cetaceans Memorandum of Understanding The Memorandum of Understanding (MoU) for the Conservation of Cetaceans and their Habitats in the Pacific Island Region is a Multilateral Environmental Memorandum of Understanding concluded under the auspices of the Convention on Migratory Sp ...

on 9 September 2010. Tuvalu is a party to the Waigani Convention that bans the importation into forum island countries of hazardous and radioactive wastes and to control the transboundary movement and management of hazardous wastes within the south pacific region and is also a party to the

Minamata Convention on Mercury The Minamata Convention on Mercury is an international treaty designed to protect human health and the environment from anthropogenic emissions and releases of mercury and mercury compounds. The convention was a result of three years of meetin ...

Stockholm Convention on Persistent Organic Pollutants Stockholm Convention on Persistent Organic Pollutants is an international environmental treaty, signed on 22 May 2001 in Stockholm and effective from 17 May 2004, that aims to eliminate or restrict the production and use of persistent organi ...

Vienna Convention for the Protection of the Ozone Layer The Vienna Convention for the Protection of the Ozone Layer is a multilateral environmental agreement signed in 1985 that provided frameworks for international reductions in the production of chlorofluorocarbons due to their contribution to the ...

and the

Montreal Protocol The Montreal Protocol on Substances That Deplete the Ozone Layer is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion. It was agreed on 16 ...

on Substances that Deplete the Ozone Layer. Tuvalu is in the process of completing its accession to the

Basel Convention The Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal, usually known as the Basel Convention, is an international treaty that was designed to reduce the movements of hazardous waste between nations ...

to protect human health and the environment against the adverse effects that may result from the generation, transboundary movements and management of hazardous and other wastes.

Funafuti atoll

Structure of Funafuti atoll

consists of a narrow sweep of land between wide, encircling a large lagoon (''Te Namo'') of about long and wide. The average depth in the Funafuti lagoon is about . With a surface of , it is by far the largest lagoon in Tuvalu. The northern part of the lagoon has a deep basin (maximum depth recorded of 54.7 m) basin, and the southern part of the lagoon has very narrow shallow basin. The land area of the 33 islets aggregates to , less than one percent of the total area of the atoll. The boreholes on

islet at the site now called ''Darwin's Drill'', are the result of drilling conducted by the

Royal Society of London The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, r ...

for the purpose of investigating the

formation of coral reefs A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. C ...

to determine whether traces of shallow water organisms could be found at depth in the

coral Corals are colonial marine invertebrates within the subphylum Anthozoa of the phylum Cnidaria. They typically form compact Colony (biology), colonies of many identical individual polyp (zoology), polyps. Coral species include the important Coral ...

of Pacific atolls. This investigation followed the work on

The Structure and Distribution of Coral Reefs ''The Structure and Distribution of Coral Reefs, Being the first part of the geology of the voyage of the Beagle, under the command of Capt. Fitzroy, R.N. during the years 1832 to 1836'', was published in 1842 as Charles Darwin's first monogra ...

conducted by

Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English Natural history#Before 1900, naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all speci ...

in the Pacific. Drilling occurred in 1896, 1897 and 1898. Professor

Edgeworth David Sir Tannatt William Edgeworth David (28 January 1858 – 28 August 1934) was a Welsh Australian geologist, Heroic Age of Antarctic Exploration, Antarctic explorer, and military veteran. He was knighted for his role in World War 1. A hou ...

of the

University of Sydney The University of Sydney (USYD) is a public university, public research university in Sydney, Australia. Founded in 1850, it is the oldest university in both Australia and Oceania. One of Australia's six sandstone universities, it was one of the ...

was a member of the 1896 "Funafuti Coral Reef Boring Expedition of the Royal Society", under Professor William Sollas and lead the expedition in 1897.David, Mrs Edgeworth, ''Funafuti or Three Months on a Coral Atoll: an unscientific account of a scientific expedition'', London: John Murray, 1899 However, the geologic history of atolls is more complex than Darwin (1842) and Davis (1928) envisioned. The survey of the atoll published in 1970 described its structure as being:

Aquifer salinization of Fongafale Islet, Funafuti

The investigation of groundwater dynamics of

Islet,

, show that tidal forcing results in salt water contamination of the surficial aquifer during

spring tides Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tables c ...

. The degree of aquifer salinization depends on the specific

topographic Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the landforms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary scienc ...

characteristics and the

hydrologic Hydrology () is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and drainage basin sustainability. A practitioner of hydrology is called a hydro ...

controls in the sub-surface of the atoll. About half of Fongafale islet is reclaimed swamp that contains porous, highly permeable coral blocks that allow the tidal forcing of salt water. There was extensive swamp reclamation during World War II to create the air field that is now the

. As a consequence of the specific topographic characteristics of Fongafale, unlike other atoll islands of a similar size, Fongafale does not have a thick

freshwater lens In hydrology, a lens, also called freshwater lens or Ghyben-Herzberg lens, is a convex layer of fresh groundwater that floats above the denser saltwater and is usually found on small coral or limestone islands and atolls. This aquifer of fresh w ...

. The narrow fresh water and brackish water sheets in the sub-surface of Fongafale islet results in the

taro Taro (; ''Colocasia esculenta'') is a root vegetable. It is the most widely cultivated species of several plants in the family Araceae that are used as vegetables for their corms, leaves, stems and Petiole (botany), petioles. Taro corms are a ...

swamps and the fresh groundwater resources of the islet being highly vulnerable to salinization resulting from the rising sea-level. In addition to the increased risk of salinized by the sea-level rise, the freshwater lens is at risk from over extraction due to the large population that now occupies Fongafale islet; the increased extraction can be exacerbated by a decrease of the rainfall recharge rate associated with the climate change. Water pollution is also a chronic problem, with domestic wastewater identified as the primary pollution source. Approximately 92% of households on Fongafale islet have access to septic tanks and pit toilets. However, these sanitary facilities are not built as per the design specifications or they are not suitable for the geophysical characteristics, which results in seepage into the fresh water lens and run off into coastal waters. On

and on the other islands, rainwater collected off the corrugated iron roofs of buildings is now the primary source of fresh water. On Funafuti a desalination unit that was donated by Japan in 2006 also provides fresh water. In response to the 2011 drought, Japan funded the purchase of a 100 m³/d desalination plant and two portable 10 m³/d plants as part of its Pacific Environment Community (PEC) program. Aid programs from the European Union and Australia also provided water tanks as part of the longer-term solution for the storage of available fresh water.

Aquifer salinization and the impact on Pulaka production

Swamp taro (''

Cyrtosperma merkusii ''Cyrtosperma merkusii'' or giant swamp taro, is a crop grown throughout Oceania and into South and Southeast Asia. It is a riverine and "swamp crop" similar to taro, but "with bigger leaves and larger, coarser roots." There are no demonstrably ...

''), known in Tuvalu as ''

Pulaka Pulaka, '' Cyrtosperma merkusii'', or swamp taro, is a crop grown mainly in Tuvalu and an important source of carbohydrates for the area's inhabitants. It is a "swamp crop" similar to taro, but "with bigger leaves and larger, coarser roots." The ...

'', is grown in large pits of composted soil below the water table, Pulaka has been the main source for

carbohydrate A carbohydrate () is a biomolecule composed of carbon (C), hydrogen (H), and oxygen (O) atoms. The typical hydrogen-to-oxygen atomic ratio is 2:1, analogous to that of water, and is represented by the empirical formula (where ''m'' and ''n'' ...

s, it is similar to

, but "with bigger leaves and larger, coarser roots". In recent years the Tuvaluan community have raised concerns over increased salinity of the groundwater in pits that are used to cultivate pulaka. Pits on all islands of Tuvalu (except

) were surveyed in 2006.

and

each had one pit area in which salinity concentrations thought to be too high for successful swamp taro growth. However, on Fongafale in

all pits surveyed were either too saline or very marginal for swamp taro production, although a more salt tolerant species of

(''Colocasia esculenta'') was being grown in Fongafale. The extent of the salinization of the aquifer on Fongafale Islet is the result of both man-made changes to the

that occurred when the air field was built in World War II by reclaiming swamp land and excavating coral rock from other parts of the islet. These topographic changes are exacerbated by the groundwater dynamics of the islet, as tidal forcing pushes salt water into the surficial aquifer during spring tides. The

of each atoll is a fragile system.

Tropical cyclone A tropical cyclone is a rapidly rotating storm system with a low-pressure area, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depending on its locat ...

s and other storm events also result in wave wash over and extreme high water also occurs during spring tides. These events can result in salt water contamination of the fresh groundwater lens. Periods of low rainfall can also result in contraction of the freshwater lens as the coconut trees and other vegetation draw up the water at a greater than recharge than it can be recharged. The over extraction of ground water to supply human needs has a similar result as drought conditions.