By the third day of cage diving with these incredible sharks, patterns in their behavior had become apparent. We discovered there was no need to get up early because the sharks seemed to take the morning off (must be night "people"). We could watch them on the fathometer swimming beneath our boats at depths of 60 to 90 feet. This meant I could sleep in until mid-morning... if I were willing to forego breakfast. However, I couldn't resist the eggs Benedict served that morning!
Shortly before we left, I watched a Discovery Kids special about great white sharks feeding on sea lions. Fellow UCSB grad student and Cousteau associate, Dr. Rocky Strong, was one of the scientists involved in this special. He was inside a motorized sled-like cage with a camera, diving with the sharks. The footage was spectacular. The great whites would come up at great speed from deeper water and hit the sea lions from below, thrusting them out of the water (usually in the shark's maw).
Our group had a "sea lion" made of shaggy carpet that was set floating near the boat. I only saw one shark "attack" it and the wool must not have tasted good because it never returned. On the first day, I observed a great white attack one of the baits vertically from deeper water, rushing up so fast I barely got the camera going. Unfortunately the water was too murky that day to get any good footage of it. Most of the "attacks" on our baits were done much differently than the method used in the TV special.
A shark would slowly approach one of the baits, often swimming around it to "assess" (an anthropomorphism?) the situation. It might make several such passes before deciding to take the bait. Once they decided they liked the menu item, a shark would usually approach the bait slowly, open its mouth, ingest the bait and swim away. On a few occasions the shark didn't snap the rope that held the bait, and it had to shake its head to tear the bait free. These "attacks" were actually very precise, measured and not at all "ferocious."
Of course the baits were used primarily to draw the sharks closer to the boats and cages so the scientists could study them, and they could be "harpooned" with a satellite radio tag for the GIS/GPS tracking studies. These tags penetrated the shark's skin and surface tissue and were anchored by a small "mushroom" at the tip. Through these tags, PIER and other scientists were able to track the movements of these sharks over time. It was through such studies that biologists learned great whites travel long distances. Sharks from Guadalupe have been tracked as far as the Hawaiian Islands.
The practice of recreational shark dives involving baiting is controversial. Many biologists and divers feel that using bait to attract the sharks makes them associate food with humans. And, of course, it's just a small step for them to associate humans as food! Guadalupe is a dive destination where shark trips often alternate with uncaged free and SCUBA diving trips. This trip was a scientific one, so baiting was necessary to ensure the greatest number of animals could be drawn close to be tagged for study.
Conditions on this third day had declined a bit. We were anchored on the protected leeward coast of Guadalupe. However incoming swells from a big storm far off in the Pacific diffracted around the island's north end, affecting our anchorage. The height of the Kelsey Lee's flying bridge made the boat rock a bit more than the others. By this time, I was in the cage filming under fairly good conditions. I heard the crew tapping on the top of the cage, and assumed they were ready to change SCUBA tanks. I poked my head up through the cage's bars and was told to get out quickly. The rocking motion now bordered on possible damage to the boats so the cage was removed as soon as I was back on board.
The Kelsey Lee motored away from the Polaris Supreme and sat about 100 yards away. The Polaris' crew started towing the cage to our boat so we could continue diving. By the time they got to us, Packy had decided that we only had about two more hours before we would be leaving Guadalupe and it wasn't worth attaching the cage for that short a time. There was a storm forecast so we were leaving a day early to avoid it. The crew towed it back, and both cages were hoisted back on the deck of the Polaris.
Within an hour all three boats were on a northward return course. We quickly rounded the north end of Guadalupe and the water got choppier as the swell hit us directly (and as Packy cranked it up to its 25 knot cruising speed). We ran for a few hours at that speed until dark, then dropped down to about 12 knots. I had the midnight to 2:00 am watch, so I went to get some shut-eye about 8:30. Chase and Phil woke me up at midnight and I managed to negotiate the spiral staircase to the wheel house without falling back down into the salon. The next two hours were spent watching the radar, GPS and infrared (IR) camera screens. I was familiar with the first two, but had never seen a bow-mounted IR camera. It was sensitive enough to image the waves and horizon in front of us based on very slight temperature differences. It would also image any floating debris, or another vessel, passing in front of us.
My shift passed with only an insignificant alarm sounding. I crawled into bed about 2:30 am and slept until we were about two hours out of Newport Beach. I wondered why we were going so slow, and soon discovered we were in a thick fog along the coast. Packy, Chase and John threaded the needle back into the harbor and we were soon back in the Kelsey Lee's slip. Since we arrived a day early, I rushed to catch the last boat from San Pedro. With an extra day, I was able to get the underwater shark footage edited quickly.
Hey, Packy... any interest in taking the Kelsey Lee to Australia or South Africa to film the great whites there? I'm game!
As an aside, it was very sad to watch news reports of the recent tsunami disaster in southern Asia and Africa. I e-mailed several of the people I met while diving southern Thailand a few years ago. The island of Koh Phi Phi, where I spent two wonderful weeks, was devastated. Fortunately my friends there were safe, but the dive shop was washed out to sea, compressors and all. Others I had met died in the deluge. I plan to donate directly to the relief effort there and hope some of my readers, in the spirit of the season, will consider contributing to support relief efforts in the affected region... or the one involving the fire here at home.
© 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.
Great white carefully taking two yellowtail baits as
an hors d'oeuvre
before the main course (me... or the elephant seals on the beach?)
Great white shark tearing yellowtail bait from float and passing by cage.
This document maintained by
Dr. Bill Bushing.
Material © 2005 Star Thrower Educational Multimedia