Chapter I Intro & Objectives - SPREP

PHOENIX ISLANDS PROTECTED AREA MANAGEMENT PLAN
Chapter III. Background, 1. Physical Setting of the Islands
Draft 1 March 2007
Gulbrandsen (1975) reported that whitlockite and apatite were the principal phosphate
minerals in surface deposits on Enderbury. Monetite and brushite were also present in small
amounts. All were derived from bird guano. Whitlockite appeared to have been formed
directly from guano, but it changed over time into apatite.
Burnett and Lee (1980) citing Tracey (1979) reported that there was about 9,072 metric tons
(10,000 tons) of phosphate left on Enderbury and that more than 90,072 metric tons (100,000
tons) had been mined. In 1995, Government of Kiribati (1995) reported that guano was
found on Enderbury. Black rich soil was also found under bushes and trees there.
MANRA (SYDNEY)
Dimensions - Manra (Sydney) is shaped like a triangle with rounded corners (Bryan 1941 and
1942). It is about 3.2 km (2 miles) (east to west) with 2.8 km (1 ¾ mile) long sides. The
beach is covered with sand, sandstone slabs, and coral rubble.
Manra (Sydney) had an elevation of 4.6 m (15 ft) (Hydrographic Office 1940).
A satellite image of Manra is provided in Figure III-1.6 below.
A
Figure III-1.6. Manra:
A - Satellite image (source: http://oceandots.com/pacific/rawaki/manra.htm);
B – Chart (source: U.S. Government Chart of 1943).
B
Lagoon - It has an enclosed, very salty lagoon with a depth of 5.5 m (3 fathoms)
(Hydrographic Office 1940; see also Bryan 1941 and 1942). The lagoon has numerous islets
and shoal patches.
The salty lagoon will no longer support marine life (Bryan 1941 and 1942). Fish and
mollusks were formerly abundant in the lagoon. Bryan (1941 and 1942) reported that the
depth of the lagoon had dropped 60 cm (2 ft) in the last 50 years.
Wester et al (1992) citing Bryan (1942) noted that the lagoon on Manra (Sydney) had limited
sub-surface exchange with ocean waters. Garnett (1983) noted that the water level of the
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