Dive Dry with Dr. Bill

#474: Filming the "Great White"

If you are a regular reader of this column, you are already aware that I have had the pleasure of filming great whites from a cage in the waters of Guadalupe Island off Baja California back in 2005. That scientific expedition to tag these magnificent fish was sponsored by the Pfleger Institute of Environmental Research. The footage I shot there was used by scientist and marine artist Dr. Guy Harvey in his television show "Portraits from the Deep." A few years later while buddied up with internationally known marine muralist Wyland, we had a 14 foot great white swim past us (although since it was behind my back I didn't get to grab any footage).

So last weekend when I told my 3,300 Facebook friends I was heading out to film another great white, very few of them even blinked an eye. Besides, Dr. Bill would never tell you a lie, now would he? After four months out of the water back in Michigan and Florida, I gathered my video and SCUBA gear up at the house to transport it to our destination. For the first time in years I had to actually put my brain into "think" mode instead of autopilot because I was well out of my routine after being high and dry for so long. I even asked a few local instructors what it would cost to take a refresher course... despite the fact that this winter represents the 50th anniversary of the very first time I went down under on SCUBA!

I checked and double checked all my gear to ensure I was prepping properly for the dive. Despite being mostly a solo diver, I would have three buddies this time. Catalina Divers Supply instructor Ruth Harris was critical to the success of this mission. I'm sure you've all heard the tale that all a diver has to do when confronted with a great white is stab your buddy with your dive knife and swim like Hades! But that's not why I needed buddies on this dive. Ruth was the only one who knew the exact location of the great white we were seeking.

Now if you thought Dr. Bill was crazy enough to go after a great white shark with nothing but his wetsuit to protect his delicate flesh, you really don't know me very well! Besides, the fact that I was carrying my video gear reduces the likelihood I will actually see one by a factor of one zillion. The great white we sought was a completely different beast. In fact, it was not particularly fond of human... or any other flesh. It survives entirely on vegetarian fare. I'm talking about the great white abalone, Haliotis sorenseni (not to be confused with halitosis).

Earlier Ruth had discovered a single specimen of this endangered species. Its numbers are so low that it is considered reproductively extinct. Abalone have to be within a foot or two of one another so the gametes they release can fertilize and the egg disperse with the currents. Of course a single abalone is hardly capable of creating little ones... it takes two to tango (or is it tangle?). Federal (NOAA) and state (CDF&G) agencies are very concerned about the possible demise of this species (not to mention the devastation of others like the black, pink, green and red in SoCal). Now I'm "mature" enough to remember the days when abalone were stacked on top of one another and I could watch one grow for several years, giving it an opportunity to sow its wild oats before taking it for dinner. The black abalone, also now an endangered species, was very common but taken only as a last resort. However, I had never filmed a white abalone in all my years of diving.

The white ab has a deep, oval sheel that is thinner than those of most other local abalone. The shell has three to five open, elevated pores for the respiratory current. They are commonly five to eight inches across, reaching a maximum of ten. Although known from Point Conception to Bahia Tortugas in Baja, they were most common in the Channel Islands region prior to intense harvesting by sport and commercial divers. The depth range has been stated as subtidal to 200 feet, with them being most common in 80-100 feet. Today I consider those "shallow" dives (since I'm such a "deep" person), but in the 60s and 70s I rarely descended below 60 feet. At such depths they are less subject to wave action than their shallow water cousins and do not need the lower profile, thick shells and tough muscular foot found on the greens, pinks and blacks. Of course my abs are tough and muscular like those species!

Whites feed on deeper water algae such as Laminaria farlowii (oarweed), Agarum fimbriatum (fringed sieve kelp) and several species of red algae. Ruth demonstrated that they will also take our giant bladder kelp (Macrocystis pyrifera) if it is offered. Based on my experience munching algae, the giant kelp is much more delicate and tasty. Of course I tend to eat hamburger, but will accept filet mignon (although cost dictates MY choice rather than availability).

NOAA estimates there were millions of these snails years ago, but that the current population is 1,600 to 2,500. That represents a 99% reduction in white abalone density between the 1970s and now. While there used to be as many as one individual per square meter (about one square yard), today they average about one per 10,000 square meters. Like this one, they are frequently found alone (just like Dr. Bill). Because these survivors are scattered at various geographic locations and depths, they are unable to reproduce so the population consists of older individuals (just like Dr. Bill). Whites may live 35 to 40 years.

The species was not even discovered until 1940. The main reason it was driven to reproductive extinction is because its flesh was considered to be among the most tender and flavorful. The commercial fishery for them began in the early 1970s, peaked in mid-decade and collapsed in the 1980s. The State closed the fishery in 1996 and the white abalone became the first marine invertebrate on the federal Endangered Species List in 2001. It is believed the only way this species will survive much longer is through human intervention... strict conservation measures, captive breeding and outplanting. The small current population, with its diminished genetic diversity, means that even if they successfully recover they may be very sensitive to limited genetic variability issues.

My "rustiness" showed on my dive with Ruth, Larry and Robin. No, the dive gear all worked fine. However, while back in Florida, I had disabled the external display on my camcorder so we could view my niece's wedding video without having to look at all the numbers. I forgot to reactivate it so my underwater rig's display showed none of the details I needed to know. In addition, I accidentally put the system into manual focus, so all the video I shot of the ab on that dive was OOF (out of focus). Curses. I truied relocating it the following day with absolutely no luck. Thankfully Ruth has allowed me to use several of her pictures for this column. Thanks!

© 2011 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 29, 10:00 AM weekdays and on Charter Communications Cable channel 33 at 7:30 PM on Tuesdays in the Riverside/Norco area. Please help me climb out of self-imposed poverty... buy my DVD's (see this link). Yes, take Dr. Bill home with you... we'll both be glad you did!

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Views of the white abalone, its epipodium (tissue along outer edge of foot with sensory tentacles)
and Laminaria, one of the algal species it feeds on.

This document maintained by Dr. Bill Bushing.
Material and images © 2011 Star Thrower Educational Multimedia