Rose Atoll, part 1

By Kerry Grimshaw

Photograph by Jean Kenyon

This afternoon we began our transit to Rose Atoll which is about 240 km (130 nautical miles) to the east of Tutuila. It is often referred to as Rose Island or Motu O Manu (meaning “island of seabirds”) and is the only atoll in the US Territory of American Samoa.

Rose Atoll was first documented in 1819 by Captain Louis de Freycinet who named the isle “Rose” after his wife. It was later visited in 1824 by Otto von Kotzebue and in 1839 by Dr. Charles Pickering, as part of the US exploring expedition, who was likely the first scientist to visit the atoll. Rose Atoll has always been uninhabited except for a brief time in the 1860s when there was an unsuccessful attempt to establish a fishing station and coconut plantation by a German firm. In 1920 a concrete monument was erected on Rose Island by the naval governor of American Samoa to commemorate his visit and allow public access to the atoll. Later in 1941, President Roosevelt made the atoll a naval defense area, but it was never used for that purpose. Rose Atoll became a National Wildlife Refuge on July 5, 1973 and a Marine National Monument on January 6, 2009.

Photograph from noaa.coris.gov

The formation of coral atolls was first described by Charles Darwin during his 5 year voyage through the South Pacific aboard the HMS Beagle from 1831 to 1836. An atoll starts with an oceanic volcano in tropical seas. A fringing coral reef forms on the flanks of the volcanic island and grows upward as the island subsides. The fringing reef separates from the island forming a lagoon as the inner part of the reef begins to subside along with the volcanic island forming a barrier reef. The outer edge of the barrier reef continues to grow and remains near sea level. Eventually the island completely subsides below the ocean surface leaving the barrier reef surrounding a lagoon thus forming a coral atoll.

We are looking forward to the diverse ecological community and habitats that an atoll provides. Rose Atoll will be only the 2nd atoll that we've visited on this mission (the other was Johnston Atoll) and it will be interesting to see how the coral reefs of Rose Atoll differ from those around Tutuila Island.