August 27, 1999

Hi Everyone,

During a conversation at work today, a woman mentioned that she had taken a vacation up to Hearst Castle this summer and while up there she saw elephant seals resting on the beach near there.

She noticed that a few had faded orange tags on their flippers and that one of the seals had a tag that may have had 709 as the last three numbers. She couldn't make out the first number. It sounded familiar so when I got home today I looked in my records. Guess what, The seal that the woman saw on the beach may have been "Mac", the elephant seal that we tracked via a satellite tag a couple of years ago. Mac has become one of the more famous seals from L.A. because videos of his story and his release off Catalina has appeared in reruns on the Animal Planet Network on a regular basis. It would be nice to think that "Mac" is still alive and well.

The following is a synopsis of Mac's Story.


To find out more about the movements of rehabilitated elephant seals, on July 28, 1997 Mac, a yearling seal treated at the Marine Mammal Care Center, was released off Catalina Island bearing a satellite tracking and TDR (Time and Depth Recorder) device on his back. The device would transmit a signal to a satellite whenever the seal surfaced that had the seal's position, time underwater, and depth that he reached during each dive.

The tracking program came about because of my curiosity about where our rehabilitated elephant seals swam to after being release. I spent many months researching satellite tracking devices, searching for the means to mount a tag and then coordinating the project.

The seal chosen for the project had stranded in Malibu on June 3 because of complications from a difficult molt, along with a heavy parasite infestation and was taken to the Marine Mammal Care Center at Fort MacArthur, in San Pedro, for treatment.

His skin looked pretty awful when he came in. His first nickname at the center was "Big Icky". Feminine products had to be used to help his post molt skin problem. Pretty embarrasing for a male seal!

After nearly two months of treatment, he was healthy and ready to be released. The satellite tag from WhaleNet was placed on his back using epoxy. Greg Early of the New England Aquarium did the mounting and handled the data from the satellite transmissions. Mac additionally had a National Marine Roto Tag (# 3709) placed on his left rear flipper by Jackie Ott. My wife Pam came up with the satellite tracked seal's official name; Mac (as in Fort MAC Arthur). After Mac was released, it took awhile to calibrate the readings from the satellite. In fact, for the first couple of days, my readings had Mac headed toward Las Vegas!

When we finally started getting accurate readings, we were amazed to find out that this young seal was making some amazing dives. Although most of his dives were in the 10 to 15 minute range, every so often he would do a really long dive of over an hour. And as time went on, his dive became deeper and deeper. Several dives took him down past 1000 feet. Thats deeper than most Navy submarines can go. One of the interesting observations was that his longer duration dives were relatively shallow, in the 100 to 600 feet range.

After release, Mac made a beeline westward for over two hundred miles! He then headed back toward the coast, hitting land near Vandenberg Air Force Base. After hugging the coast northward, Mac spent a few days off San Simeon and the elephant seal rookery at Pietros Blancos. He then swam up the coast to Monterey Bay where he really decided to take in the sights there. He spent weeks crisscrossing Monterey Bay, going from the Southern end of the bay near Monterey, to the Northern end near the elephant seal rookery of Ano Nuevo and back.

It was in the deep Monterey Bay submarine canyon that he made his deepest dive. One that took him past 1500 feet. By the time that Mac decided to head back southward, his satellite tag had been tranmitting for over 2 months and had survived thousands of pounds of water pressure. Good signal fixes and data were becoming harder to come by.

His last "fix" put him off San Nickolas Island on October 10. At the time there was fear that perhaps a shark had gotten him. But three days later a faint signal was received by the satellite from Mac. It wasn't enough to get a position, but it was enought to let us know that the transmitter had resurfaced. It was as if Mac wanted to send one last transmission to let us know he was still OK.

That was what we thought was the last we'd hear from Mac.
But as it may have turned out, years later, "Mac the Tracked" may be back!

Information on "Mac" can still be accessed on WhaleNet at

Thats all for now.

Hugh Ryono