Dive Dry with Dr. Bill

027: "The" Other Santa Catalina Island

More than thirty years ago I learned we weren't the only Santa Catalina Island on Earth. Although not as intriguing as discovering we aren't the only planet in the Universe with life, this information did peak my interest in the "other" Catalina. A natural history guide I was reading talked about the unique rattleless rattlesnake on Catalina. It turned out the island they were referring to was in the Gulf of California, commonly called the Sea of Cortez in the US (where that name does not conjur up images of the murderous conquest of the native people by the Spanish in what later became Mexico). I decided back then that some day I would visit the "other" Catalina.

My opportunity came decades later when Lindblad Expeditions hired me as Underseas Specialist on their cruises in the Gulf of California Special Biosphere Preserve. This protected area includes the offshore islands along the Baja California coast from La Paz to Loreto, of which Isla Santa Catalina is the most remote. Scientists have referred to this set of islands as another Galapagos due to the unique species found there, a distinction often given to our own Channel Islands region as well.

Our planned itinerary included stops at Isla Catalina on each of the four cruises I served on. However, weather and sea conditions pernitted only a single visit on December 21st. Due to excellent weather, our first two trips reached Isla Carmen further north near Loreto. From there we could easily see Isla Santa Catalina off in the distance. On the third cruise a windy first night at sea reduced our cruising time and we finally ended up the next morning circling Catalina looking for whales.

Isla Catalina is about 13 miles from Punta San Marcial on the Baja coast. It is close in size to our West End, about 7 1/2 miles long and two miles wide. Like our own island, it is rugged and steep. If you "ignore" the native people, it was first "discovered" in 1633 by Francisco de Ortego while on a pearling expedition for Spain. The La Paz area later became famous for its pearling industry. The island did not receive its present name until 1850 when the U. S. Navy charted the region, and thereby created confusion with our own island. The highest point on its main ridge is 1,543 feet. Due to a lack of water, the island was never inhabited permanently.

The desert conditions limit vegetation to cacti and other drought-tolerant species. Plants endemic to Catalina, that is found only there, include a member of the mint family and a giant barrel cactus reaching heights of 10 feet. Mice are among the dominant mammals, and all are members of a single species found only there. The endemic rattleless rattlesnake undoubtedly survives on this food source. With no large grazers (like bison or horses), or humans, the warning of a rattle is unnecessary although there is a remnant nub where the rattle once was before disappearing through evolutionary change.

The unusual reptiles of this island and region reinforce the theory of island biogeography, proposed by my professor E. O. Wilson and his colleague Robert MacArthur while I was a student of his at Harvard in the late 1960's. It was this theory that led me to our own Catalina after graduation to study marine island biogeography, the distribution of nearshore undersea life. I had written papers on the subject while an undergraduate and it is a major research interest of mine to this day.

After cruising the backside, Captain George of the MV Sea Bird brought us into an anchorage at Elephant Rock near the southern end of the island facing the Baja coast. He and the expedition leader, Betty Lu, smiled and said "time to get wet!" After three decades I was achieving my goal. I dove alone for over an hour with a Zodiac watching from the surface. The dive site was incredible... large boulders and rocky reefs but, of course, no giant kelp! The waters were full of giant damselfish (a relative of our garibaldi) in mating coloration, king angelfish, barberfish, coronet fish and even the finescale triggerfish. This last species can also be seen in Lover's Cove, having arrived from Mexico during the warm waters of the 1982-83 El Nino. It was here that I also saw the only octopus I encountered during my stay. I'm looking forward to diving Isla Santa Catalina again when I return to La Paz the middle of this month.

Over the years I have learned there are more than these two Santa Catalina Islands. Alaska, Brazil, Columbia, Costa Rica, Scotland, the Dominican Republic, and the Solomon Islands all have one as well. Perhaps I'll add diving each of them to my list of 999,999 lifetime goals, but for now I'll settle for the two I have dived.

© 2003 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 49, 10:00 AM and 5:00 PM weekdays.

Image caption: Cacti dominate on dry Isla Santa Catalina; Elephant Rock dive site;
octopus and male giant damsel fish in the waters of Isla Santa Catalina

This document maintained by Dr. Bill Bushing.
Material © 2003 Star Thrower Educational Multimedia