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
A – Satellite image (source: http://oceandots.com/pacific/rawaki/birnie.htm);
B – Chart (source: U.S. Government Chart of 1943).
B
Lagoon - Birnie has a small shallow brackish pond (274 x 46 m (300 yards x 50 yards)) in its
center (Hydrographic Office 1940; brackish lagoon according to Pompey 1972a). Dahl
(1980) reported that the lagoon was brackish (see also Hydrographic Office 1916; supersaline
according to Garnett 1983). The depth of the lagoon was 1.8 m (Hydrographer of the Navy
1969). Bryan (1941 and 1942) noted that in some accounts the lagoon was nearly dry, but in
other accounts the lagoon had a depth of 1.8 m (6 ft).
Wester et al (1992) citing Bryan (1942) noted that the lagoon on Birnie had limited subsurface
exchange with ocean waters. The size and salinity of the lagoon depended on
rainfall. Maude (1937) reported that the lagoon on Birnie was fed by a small stream that first
went through a curious artificial pond formed by coral slabs cemented together.
Reef Shelf - The shelf dried at low tide and extends about 46 m (50 yards) offshore
(Hydrographic Office 1940). On the southern point of the island, a shoal extends out 1.2 km
(1,300 yards) southward. The depth of this bank is less than 5.5 m (Hydrographer of the
Navy 1969).
Soil - There may be some phosphate deposits on Birnie, but only in small amounts since it
was never worthwhile to exploit them (Garnett 1983).
ENDERBURY
Enderbury emerged about 2,400 years before present (BP) with an average emergence
magnitude of about 1.0 m (Tracy 1972; see also Nunn 1994).
Dimensions - Enderbury is a nearly solid island with a small shallow pond a few hundred
meters (yards) across which was the remains of the lagoon (Bryan 1941, 1942, and 1974).
The island is almost 4.8 km (3 miles long) (north and south) and about 1.6 km (1 mile) wide
(Bryan 1941, 1942, and 1974).
7