Sanctuary Integrated Monitoring Network
Monitoring Project

Point Piedras Blancas Northern Elephant Seal Monitoring

Principal Investigator(s)

  • Brian Hatfield
    United States Geological Survey (USGS)


  • USGS
Start Date: September 01, 1990

We have monitored, by systematic counts, the growth in population numbers and distribution of breeding Northern Elephant Seals at Piedras Blancas since the colony's inception in the fall of 1990. A number of weaned seals are flipper tagged with white tags each year. Members of Friends of the Elephant Seal and college students have participated in the tag re-sighting effort.

Summary to Date

Annual summary data and figures for each year since 2011 are under the 'Documents' tab.

Study Parameters

  • Reproduction
  • Tagging
  • Abundance
  • Movements within and among colonies
  • Distribution

Figures and Images

Figure 2: Map of the Piedras Blancas area with generalized coastal geomorphic features. At the northern and southern ends of the study area, about 90 and 130 pups were born in the 2004/2005 season, respectively.