Dive Dry with Dr. Bill

#163: Other Intelligent Life on Planet Earth

One of my favorite dive sites in the world is Los Islotes, a tiny little islet about the size of Bird Rock and Ship Rock combined. It is located near Espiritu Santo and Isla Partida off La Paz, Mexico. There are several reasons I enjoy this small island. It has both a protected and an exposed side so the marine life is quite varied within a small distance. But the main reason is that it is home to a colony of California sea lions that are great fun to dive with. I dove this site a number of times when I worked as a marine biologist and videographer on the Lindblad Expeditions eco-cruise ships in that region.

On those dives I often had sea lions, especially the juveniles, playfully interacting with me. On one dive a sea lion jumped on top of me before I even had my fins on or my regulator in my mouth. It pushed me down to the bottom (only 20 ft) and I had a bit of trouble locating my regulator with the sea lion on top of me! Frequently the sea lions would come up and grab my snorkel, often tearing it loose from my mask. I stopped wearing snorkels when I dove there after the first few encounters. Once I was on the bottom filming snorkelers above me when I recognized one of our guests, a Hollywood movie producer, while filming. As I focused on our guest, a sea lion came up and started biting him. I could actually see a few pieces of his wetsuit torn off by the animal's sharp teeth. I was worried that our guest might be bloodied (and he was), but when I surfaced he was laughing about the incident.

Although Catalina has a fairly good population of these playful marine mammals, it is very rare for me to dive with one. Their history with humans in our waters has not always been a favorable one. Some fishermen would shoot them if they went after their catch. Fortunately the Marine Mammal Protection Act of 1972 afforded them protection, but offending parties still must be caught and effective disciplinary action taken before any lesson is learned.

The California sea lion population has been increasing in our region over the past few decades. It is my belief this is due to the warming of our local waters over the past century. Some of this warming may be due to global climate change, but I think it is also dominated by long- and short-term warming trends. We've all seen images of "Big Ben," the large sea lion that used to frequent Avalon near the start of the previous century. From the pictures, I am convinced that "Big Ben" was not a California sea lion, but a Stellar sea lion. This species is significantly larger, but prefers colder water.

I believe that as our waters warmed after the end of the "Little Ice Age" (about 1900), the California sea lion gradually replaced the Stellar sea lion as the dominant species in the Southern California Bight. The Stellar moved north into central and northern California where it exists today. As the competition from its larger relative decreased, the California sea lion was able to increase its population in our area. The ecological concept of "competitive exclusion" refers to the fact that two species which rely on similar resources often do not coexist in the same area. One outcompetes the other. This may have been the case between our two sea lions. However, when the water temperature warmed up, the California sea lions gained the edge as the Stellars retreated north.

On a recent dive at a site called Blue Car Wreck near the East End Quarry, I had one of those rare but wonderful encounters with a juvenile sea lion in our waters. We had noticed the youngster at the surface when the King Neptune approached the site, but it seemed to leave as the divers entered the water. I was down on the sloping boulder bottom filming when I sensed a presence near me. Hmmm... this area is known to have great whites patrolling, but I didn't hear any of that music that heralds the appearance of "Jaws." I turned to look and there was the sea lion swimming around watching me.

What surprised me was that it didn't flee when I pointed my camera at it. This was the start of a brief, but rewarding "friendship" of the type that makes diving so much fun (er, I mean work) for me. Here were two different species showing interest and curiosity in one another without fear. I get the same feeling when diving with black sea bass since they watch me as much as I watch them. It is a transcendent experience, one that involves going beyond the simply human and understanding that there are other cognizant species on planet Earth. One needn't focus on outer space to find other intelligent life in the Universe!

My young friend swam around, zooming in close to get a better look at me. My camera was rolling throughout the encounter. However, the best part was not our interaction, but occurred when my little friend started watching a school of blacksmith swimming near us. The sea lion actually "stood" with its rear flippers on the bottom and turned to watch the blacksmith (which are occasionally on his dinner menu). As it tried to balance upright, the surge slowly caused it to loose its "footing" (flippering) and the youngster started to fall over. Of course it quickly recovered and started swimming. Like any youngster, its attention span was limited and after a few minutes it swam away in search of other entertainment. That encounter certainly made my day.

© 2005 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. Buy my "Munching and Mating in the Macrocystis" DVD so you can take Dr. Bill home with you... we'll both be glad you did!

My little friend curious about the "other" intelligent life in the universe, showing off its swimming skills;
blowing bubbles and losing its balance amidst the blacksmith.

This document maintained by Dr. Bill Bushing.
Material and images © 2005 Star Thrower Educational Multimedia