John Stanley Gardiner, a British invertebrate zoologist, was educated at Marlborough College (a public school in Wiltshire, England, designed mainly for educating the sons of the clergy) and at Gonville and Gaius College, Cambridge, where he was awarded the degree Master of Arts (MA). He became a Fellow of Gonville and Gaius College in 1898 and was its Dean from 1903 to 1909. From 1902 to 1908 he was a demonstrator of animal morphology at Cambridge University and the next year was appointed professor of zoology.
As a young man Gardiner accompanied the Coral Reef Boring Expedition to Funafuti (in the south-east Pacific Ocean) in 1896 and afterwards published several papers on the corals he collected there, as well as on the geology and inhabitants of Rotuma Island, south of Funafuti. During 1899-1901 he was a member of an expedition to the Maldives (in the Indian Ocean, south-west of India) and the Laccadive Islands (now part of Lakshadweep, off the Malabar coast of India). Upon the expedition's return he edited The fauna and geography of the Maldive and Laccadive archipelagoes (Cambridge, 1903-1906), to which he contributed accounts of the corals and the distribution of land and marine animals. In 1905 he participated in the Indian Ocean Expedition of HMS Sealark. Later he described the Coelenterata of the British Antarctic (Terra Nova) Expedition (1910-1913) and the corrals collected by the Scottish National Antarctic Expedition (1914). His specialty was corals and coral reefs, on which he published numerous other papers and monographs.
The Government Biologist of the Cape Colony, J.D.F. Gilchrist*, sent Gardener the corals recovered during the marine biological survey of South African coastal waters around the turn of the twentieth century. Gardiner described these in "South African corals of the genus Flabellum, with an account of their anatomy and development" (Marine Investigations in South Africa, 1904, Vol. 2, pp. 115-154) and in "The turbinolid corals of South Africa" (Ibid, 1905, Vol. 3, pp. 93-130).
After serving as a member of government committees on fisheries in 1907-1908 and 1913 he was appointed Director of Scientific Investigations in the Ministry of Fisheries in 1920. His later publications included Geography of British Fisheries (1915), Coral reefs and atolls (1931), and (with P. Waugh) The flabellid and turbinolid corals (1938).
Gardiner's work was recognized by his election as a Fellow of the Royal Society in 1908. He was a Fellow also of the Linnean Society and the Royal Geographical Society. He received the Murchison award of the Royal Geographical Society in 1902 and in later years received the Agassiz Medal of the United States National Academy of Science, the Gold Medal of the Linnean Society, and the Darwin Medal of the Royal Society. He was a member of the British Association for the Advancement of Science from 1900.