In 2012, these two species were split from Xantus's Murrelet (S. hypoleucus), which was listed as threatened by the state of California in 2004 and proposed for listing under the U.S. Endangered Species Act.

San Clemente is one of only two islands where both species are thought to be regularly sympatric (same area, not interbreeding).

A long-term monitoring plan is being developed and implemented by CIES, with the assistance of the Navy.

A 2009 summary indicated a breeding population of less than 100 murrelets on the island.

Monitoring (at-sea counting and capture, nest searches) is required to determine breeding status and timing and to measure population trends.

Population and habitat use data may assist the Navy in future conservation efforts.