Every winter, thousands of visitors flock to the Piedras Blancas elephant seal rookery to watch the antics of pupping and mating season, and hopefully learn about where the seals go once they leave the viewing area.
Adult seals spend 70 to 80 percent of their lives at sea, migrate thousands of miles to depths as great as 1 mile, and forage on fish such as shark, crab, ratfish and squid, all information gathered by researchers at the Dan Costa Lab at UC Santa Cruz and the Tagging of Pacific Predators program (TOPP).
For the past few weeks, an elephant seal with an antennae-like tag attached to its head and the number B821 on his back was seen at San Simeon Cove. B821, or “Mike,” is a part of the Ph.D. research project of Sarah Kienle that studies the diving behavior and foraging ecology of male elephant seals.
The antenna on Mike’s head was part of a sea mammal research unit (SMRU) tag used to transmit the seal’s location at sea and foraging sites via satellite. The 9-year-old male elephant seal was tagged at Año Nuevo in August, and the tag transmitted his migration to Alaska before it stopped transmitting. In order to obtain the complete data set, the research team needed to retrieve the tag.
When Mike showed up at San Simeon Cove in January near the pier, there was a prime opportunity to do just that. Brian Hatfield from USGS and Sea For Yourself kayak outfitters owner, Cubby Cashen, joined me in providing daily updates on Mike’s location over the next few weeks. If the $8,000 tag and the missing data could be collected, the research team had to move fast before Mike left the cove for good, usually in March after the females who have weaned their pups depart.
Earlier this month, with time running out, a team of six well-trained researchers drove from UCSC to San Simeon Cove, only to find that Mike was nowhere to be seen. After the team spent several hours of searching the beach and nearby surf, with the sun setting over San Simeon Point, Mike slowly swam from the southerly direction and hauled out at his favorite spot by the pier.
Prepared to assist, State Parks rangers, Monterey Bay National Marine Sanctuary staff, Coastal Discovery Center docents and Cubby set up a wide perimeter around the seal to allow the research team to work. The researchers calmly and expertly tranquilized the seal, removed the SMRU tag, took samples used to assess physiology and the condition of the animal, as well as to perform isotopic analysis that gives information on where Mike fed and what he ate. Within an hour, Mike was awake and back to his old self, without his satellite hat.
Since the 1970s, dozens of elephant seals have been tracked, allowing increased understanding of their adaptations to life at sea, especially their movement, foraging ecology and energetics. For more information, go to: http://bit.ly/21oLd0B.
As Education and Outreach Specialist, Carolyn Skinder staffs the Monterey Bay National Marine Sanctuary’s southern office and oversees operation of the Coastal Discovery Center at San Simeon Bay.