Chapter I Intro & Objectives - SPREP

PHOENIX ISLANDS PROTECTED AREA MANAGEMENT PLAN
Chapter III. Background, 1. Physical Setting of the Islands
Draft 1 March 2007
A.
Lagoon - According to Wilkes (1845), the lagoon was shallow and there were no navigable
passages, but on western side, the tide could flow into the lagoon. Maude (1937) reported
that there was no daily tidal rise and fall in the lagoon due to the nature of the two passages to
the sea.
The lagoon was between 5.5 to 7.3 m (3 to 4 fathoms) deep (Hydrographic Office 1940). It
was surveyed by the New Zealand Navy in 1938. The lagoon was filled with coral heads
(Hydrographer of the Navy 1969). There were two small ponds with milkfish fingerlings that
were closed to the lagoon (Government of Kiribati 1995).
Lagoon Openings - There were two breaks from the lagoon to the sea (Hydrographic Office
1940). Dahl (1980) reported that the lagoon on Nikumaroro (Nikumarora, Gardner) was
open. There was no navigable passage from the lagoon to the sea (Hydrographer of the Navy
1969). However, the passages into the lagoon could be navigated by canoe, but local
knowledge was required.
Stoddar and Fosberg (1994) described the channels from the lagoon to the sea, called by their
Poloynesian name, hoa. They reported that Abariringa (Canton) and Nikumaroro (Gardner)
had no hoa.
Reef Shelf - Nikumaroro (Gardner) was surrounded by an unbroken fringe reef that dries
during low tide (Hydrographic Office 1940; about 91 m (100 yards) dries according to Bryan
1941 and 1942). The fringe reef was 91 to 274 m (100 to 300 yards) wide (Bryan 1941 and
1942). Arrundel (1885) reported observing enormous masses of rock that had been uplifted
on the flat fringing reef.
Soil - Maude (1937) reported that the soil included a dark brown mould that extended down
to 1.2 m (4 ft). This was composed of guano and white coral fragments. In the 1978 survey
of Nikumaroro (Gilbert Islands 1978), soil profiles were taken. Details of these soil profiles
were provided in Gilbert Islands 1978).
In 1995, Government of Kiribati (1995) reported guano on Nikumaroro. Some of the soils
were rich in humus. In some areas, there was rich black topsoil. The soil profile was topsoil,
sand, gravel and sand, hard rock, small gravel, then water. Knudsen (1965) reported that the
soil on Nikumaroro (Gardner) was relatively rich (see also Garnett 1983).
B.
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