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Laysan (; ) is one of the Northwestern Hawaiian Islands, located northwest of Honolulu. It has one land mass of , about in size. It is an atoll of sorts, although the land completely surrounds Laysan Lake, some above sea level, that has a salinity approximately three times greater than the ocean. Laysan's Hawaiian name, Kauō, means "egg".
It was mined for guano in the late 19th century and early 1900s, which resulted in the release of rabbits who had been brought in for food. After mining ceased, the rabbits ate up the natural vegetation causing a couple dozen plant and one bird species to go extinct. The rabbits were removed by 1923, and from then on until modern times it has been a nature reserve.
The island is the home of the rarest duck in the world, the Laysan Duck.
Lake Laysan, a , brown, hypersaline lake in the island's interior, has varied in depth over the decades. In the 1860s, the lake was at most deep, but by the 1920s it averaged only in depth, because of the build-up of sand that had been blown into it by dust storm. The best way to find fresh water on Laysan is to observe where the Laysan finch are drinking, because fresh water floats on the saltier water and accumulates around the shore.
A U.S. Geological Survey study found that Laysan, Midway Atoll, and Pacific islands like them, could become inundated and unfit to live on during the 21st century." Storm Surges, Rising Seas Could Doom Pacific Islands This Century : Atolls and other low-lying islands in the Pacific Ocean may not slip under the waves but they will likely become uninhabitable due to overwashing waves" ClimateWire and Scientific American April 12, 2013
A United States government survey of Pacific Ocean geography in 1828 included the earlier whalers' reports, as well as a sighting of an island fitting Laysan's description by a Captain "Brigs".Jeremiah N. Reynolds, Address on the subject of a surveying and exploring expedition to the Pacific Ocean and South Seas: Delivered in the Hall of Representatives on the evening of April 3, 1836 (New York:1836), pp. 201 & 223. That might refer to Captain John Briggs of New Bedford, who could have come across the island as early as 1822.In The New Bedford Mercury, February 21, 1823, p. 3, the ship Persia reports sighting Briggs' ship Wilmington & Liverpool Packet northwest of Midway Island. Various publications name Captain Stanyukovich, of the ship Moller, as the discoverer of Laysan. Although he mapped the island in 1828, and attempted to name it for his ship, he was clearly there after the , at least.
In 1857, Captain John Paty, of the Manuokawai, annexed Laysan to the Kingdom of Hawaii.
The island had an economic value due to the presence of guano. In 1859, Captain Brooks, of the ship Gambia, traveled to the island and wrote that there was guano there, but "not of sufficient quantity to warrant any attempts to get it".Rauzon 2001, pg.101. Despite that, in 1890, George D. Freeth and Charles N. Spencer successfully petitioned the Kingdom of Hawaii for permission to mine guano on Laysan and agreed to make royalty payments to the Kingdom. Around were extracted per day. Given that, towards the end of the guano mining era, iron-hulled sailing ships had a capacity of , Laysan produced a shipload every two months.
Working conditions at the guano mine were grueling. In August 1900, workers mutinied against the American management. The strike action turned to violence because of a language barrier. As a result, there were two deaths and two injuries.
The publicity about Laysan attracted scientists and, in the next decade, many of the island's unique species were scientifically examined for the first time.Rauzon 2001, p.104. However, the guano mining affected the island's ecosystem dramatically. Professor William Alanson Bryan of the Bernice P. Bishop Museum estimated that there were 10 million seabirds on Laysan in 1903 but, eight years later, the estimate was that there were little more than a million. In those eight years, the Pritchardia palms that were unique to Laysan, and the island's sandalwood trees ( Santalum ellipticum), both became extinct.
1894 marked the arrival of Laysan's most notorious inhabitant, German Empire immigrant Max Schlemmer, who was the superintendent of the guano mining operation. He released , , English hares and guinea pigs on the island, expecting them to multiply and provide supplies for a future meat-canning business. That had a disastrous effect on Laysan's indigenous flora and fauna.
In 1923, the Tanager Expedition arrived and achieved its aim of exterminating the last rabbits. The bird population had been reduced to about a tenth of its former size. Three endemic taxa had become extinct, as had numerous other plant species. Two other endemic species, the Laysan duck and the Laysan finch, still survive, but are endangered.
Garbage from passing ships often washes ashore on Laysan. That poses a danger to birds because they can swallow plastic waste, which remains undigested and crowds their stomachs, leaving no room for their normal food. According to observations in her 2006 mission log, Patricia Greene, a NOAA Teacher-at-Sea, found that most of the plastic was of Japanese origin.Greene 2006. Additionally, in the 1990s, biologists found that a container of poisonous carbofuran had floated ashore and burst open above the high tide line, creating a "dead zone" in which any living thing was killed.Rauzon 2001, p.126-127.
To replace the native Pritchardia palms that had become extinct, the FWS wanted to bring in Pritchardia remota from Nīhoa, a similar species to Laysan's lost fan palm. The next step was to be introducing Nīhoa millerbirds, to replace the extinct Laysan millerbirds that are closely related. Those transfers were to accomplish a two-fold goal: to restore Laysan to an ecology similar to its pre-industrial one, and to protect those two species from extinction by maintaining a second population on Laysan. That way, if diseases, fires, or hurricanes obliterate the Nīhoa population, the population can be revived by translocation from Laysan.Rauzon 2001, p.122.
Period of extinction
The reproduced rapidly, and their appetite soon far exceeded the available vegetation on the island. Complaints about that, and about poaching of the bird population, led President Theodore Roosevelt to declare the Northwestern Hawaiian chain a bird sanctuary in 1909. Schlemmer continued to allow the Japanese to export bird wings illegally and so was removed from the island. However, without plant cover, much of the soil and sand became loose and blew about in dust storms. By 1918, the rabbits had eaten so much that the remaining vegetation was only enough to sustain 100 of them. Twenty-six plant species had been eradicated, and the Laysan millerbird had become extinct.Rauzon 2001, p.110
Recent history
Like most of the Northwestern Hawaiian islands, Laysan is currently uninhabited. It is protected by the Hawaiian Natural Life Act of 1961 and is under the stewardship of the U.S. Fish and Wildlife Service, who have had success in eliminating pests, restoring the island's vegetation, and boosting the populations of species considered endangered.
Sandbur eradication
In 1991, the United States Fish and Wildlife Service began an effort to eradicate sandbur, an alien grass, which was first introduced in the 1960s by US Armed Forces personnel. Sandbur crowds out the native bunchgrass, which is habitat for birds.Rauzon 2001, p.120. At a cost of almost one million dollars, the sandbur had been almost was completely removed by 2000. With that threat gone, the USFWS hoped to restore Laysan to its condition prior to discovery.
"Laysan fever"
In 1991, several workers on Laysan contracted a feverish illness previously unknown there or anywhere else. It affected workers on Laysan in varying levels of severity: one woman was evacuated for persistent fever, but others exhibited very mild symptoms. Cedric Yoshimoto, of the University of Hawaii at Mānoa School of Public Health, wrote that "surveillance has identified a newly-described illness of humans termed 'Laysan fever (LF)' It is associated with bites of the seabird tick Ornithodoros... [and] joins a short list of human illnesses associated with seabird colonies..."Rauzon 2001, p.123. The symptoms of Q fever overlap significantly with those of Laysan fever, and scientists have speculated as to their possible common causes.Rauzon 2001, p.125.
Possible ancient Hawaiian presence
In 2003, an archaeology examining sediment cores found pollen from coconut palms deep below the bottom of the central lagoon. That unexpected find raised several questions. Before that, no evidence existed that the coconut ever reached any of the Hawaiian Islands before the arrival of the voyagers. Further, there has never been any physical evidence that the ancient Hawaiians extended their exploration of the Hawaiian chain beyond Nīhoa and Mokumanamana (Necker). Dating the sediment containing the Cocos pollen is imprecise, but appears to have been deposited some time between 5,500 years ago and the arrival of Europeans in Hawaiian waters in the late 18th century. The full length of the core was and is thought to represent a record spanning 7,000 years. Coconut pollen was not found in the deeper (older) part of the core. However, cores from Guam in the western Pacific Ocean show the presence of coconut trees there as early as 9,000 years ago, well before human habitation. Hawaiian traditions suggest that the Hawaiians were aware that islands existed to the north-west, and the pollen evidence could be interpreted as proof of early Hawaiian visits to Laysan. More precise dating of the sediment layers will be needed to better interpret the find.TenBruggencate 2005
Distinctive species of Laysan
Laysan is generally regarded as the "gem" of the NWHI, with the most biodiversity. It is home to the Laysan duck, the rarest duck in the world.Liittschwager 2005, p.131. The other native land bird of Laysan is the Laysan finch, an opportunistic hunter. Eighteen other bird species nest there and use Lake Laysan, the only lake in the NWHI, as a rest stop or breeding ground. Laysan also has its share of native plants, many of which, such as Eragrostis variabilis, were extirpated from Laysan during its "extinction period" and then reintroduced from other leeward islands by scientists.Liittschwager 2005, p.128. Like most other of the NWHI, Laysan is home to Hawaiian monk seals and green sea turtles.
Birds
Invertebrates
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