The Marine Environment of the Pitcairn Islands - Pew Environment ...

Executive summary
The extent of the Pitcairn Islands’ Exclusive Economic Zone
(EEZ), which defines the geographic extent of this report.
Introduction
The Pitcairn Islands are a group of four near-pristine small
islands which can claim to be some of the most remote
islands in the world. They are situated between latitudes
23° and 26° south and longitudes 124° and 131° west
and located in the crystal-clear waters of the central South
Pacific, about 2,200 km south-east of Tahiti and 2,100 km
west of Easter Island. The group comprises:
l Pitcairn Island, a high volcanic island of 450 ha with
lava cliffs and rugged hills rising to a peak at 347 m;
it is the only inhabited island, with a population of
around 60 as of 2012;
l Henderson (200 km east-north-east of Pitcairn) is the
largest island in the group with an area of 4,310 ha.
It is a raised fossilised coral atoll which rises to 33 m.
It is designated a UNESCO World Heritage Site on
account of its unique natural history and ecological
intactness, and it has been described as “a South
Pacific conservation jewel” 1 ;
l Ducie (472 km east of Pitcairn), the most southerly
coral atoll in the world, consists of a central lagoon
surrounded by four islets covering an area of 70 ha;
l Oeno (120 km north-west of Pitcairn) is a low coral
atoll of 65 ha comprising a central low-lying island
surrounded by a shallow lagoon and a fringing reef
(diameter approximately 4 km).
Together, all four islands and their surrounding waters out
to the 200 nautical mile limit – also known as the Exclusive
Economic Zone (EEZ) – span a vast area of ocean of about
836,000 km 2 , more than three times the size of the UK.
A brief history
It is believed that Pitcairn and Henderson were first
colonised by Polynesians in about AD 900 and their
The extent of the Indo-West Pacific biogeographic
province (shown in dark blue).
(Source: http://en.wikipedia.org/wiki/File:Indo-Pacific_
biogeographic_region_map-en.png)
occupation lasted until about 1450 2 . In 1606, Fernández
de Quirós was the first European to discover Henderson
Island (by now uninhabited) and Ducie Island. British
interest in the islands (and in Pitcairn in particular) began
more than a century-and-a-half later in 1767 when HMS
Swallow, under the command of Captain Philip Carteret,
encountered Pitcairn and mistakenly plotted its position
188 nautical miles west of its actual location. This mistake,
however, was to be of great benefit to the island’s next
inhabitants, the mutineers from HMS Bounty, who were
looking for a safe island hideaway in 1790, and remained
undiscovered there for 18 years. Pitcairn Island officially
became a British dependency on 29 November 1838. The
other three islands (Henderson, Oeno and Ducie) were
annexed by Great Britain in 1902 and were included in the
dependency in 1938. The Pitcairn Islands remain the only
UK Overseas Territory in the Pacific.
Biogeography
The Pitcairn Islands are located at the south-eastern
extremity of the Indo-West Pacific biogeographic province,
resulting in a number of barriers to the establishment of
species.
l Prevailing winds and currents are dominantly from the
east in the central South Pacific, with the Islands lying
upwind and upstream of all Indo-Pacific source areas.
l The Islands lie south of the Tropic of Capricorn
(23°26’S), with relatively cool waters and climates
imposing further barriers to the establishment of
tropical species.
Studies of groups as diverse as corals, reef fishes, vascular
plants and land birds support the arguments that
colonisation has been from the biologically rich source
areas to the west on the margins of South-East Asia,
The Marine Environment of the Pitcairn Islands The Marine Environment of the Pitcairn Islands
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