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Dive Dry with Dr. Bill

#645: The Gentle Giants Return

If you are a regular reader of my weekly column, you know that one of my favorite finned friends is the giant sea bass. If you are not a regular reader, try a good laxative or eat Raisin Bran each morning like I do. Although many refer to the species Stereolepis gigas by the common names black sea bass or giant black sea bass, the preferred common name is giant sea bass (GSB).

They were called black sea bass in days of old (well before my time of course) because when anglers caught these behemoths and weighed them in, they were often dark in color. However, when one encounters them alive underwater, they may be dark, silvery, spotted or counter shaded (light belly and darker dorsal). Besides, there has been a fish in the Atlantic referred to as the black sea bass for many years and the two aren't even closely related.

Many have asked me about their true size and weight. I generally don't take a commercial scale underwater with me, and the fish are usually neutrally buoyant so I couldn't weigh them if I did. Historically it has been said they reached lengths of about 7 1/2 feet and up to 800 pounds. I've never seen one I thought in that weight class, but have seen a few that reached that length but seemed closer to 600 pounds. Perhaps they were on Jenny Craig or the Atkins diet. However, last summer researchers from Dr. Larry Allen's lab at Cal State Northridge, used a laser measuring device and recorded one fish at nine feet... and that's no fish story!

Many of the fish that Catalina anglers brought in back in the late 1800s and early 1900s were weighed in at 250-400 pounds. Some have thought that looking back at these weigh in photos and comparing the height of the angler with the length and recorded weight of the fish, we are over-estimating the size of the ones we see today. I have pointed out to several of them that humans were generally of significantly shorter stature during that time period than today, and one would really need to know how tall the angler was to validate any comparisons.

Due to the sad ecological state of the dive park, I have not done near as many dives there this year as I would normally do. It just brings tears to my eyes to see the impacts of the warm water, low nutrient levels, hurricane and storm surge, the invasive Asian seaweed and the lack of true kelp forests. Besides, highly diverse tropical coral reefs have beckoned. However, recently I did pick up the pace and had four dives in a row where I had GSB encounters.

The first three were typical of many "early season" encounters. The bass were in high gear, swimming vigorously past me allowing for just a few seconds of video. On my fourth dive I had a rendezvous more typical of mid- or late-season. I slowly approached a pair of GSBs hovering above the bottom in about 75 ft of water. By moving slowly and staying low, I presented a less threatening approach than those who wildly flail their arms and flash strobes into the eyes of these fish. I also maintained my bite on my regulator mouthpiece so they would not see my fangs!

This paid off with a rewarding 20+ minute encounter giving me an opportunity to film the giant sea bass and their behavior. I could have remained with them longer, but felt they deserved some privacy for their tryst. The male was noticeably larger than his dainty companion, if you can call 250 pounds dainty. Not sure that qualifies as a "little lady." While filming them, another male tried to swoop in and capture her heart... but just like at the Chi Chi or Marlin Club, her potential mate chased him off.

During mid- and late-season, pairs form with a single male dominating the attention of a female. He has probably fought off the advances of other males prior to that, and proven his strength and endurance to her. The male "tends" the female, often hovering close by, circling her or nudging her if he wants to move on. To the best of my knowledge no one has yet observed GSBs mating in the wild, only captive ones in aquaria. Based on my observations they seem to seek the privacy of thick kelp during the latter stages of courtship. Unfortunately, there isn't much privacy for them this summer given the general lack of kelp in our waters. At least they are more likely to get lucky than the good doctor!

© 2015 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. You can also watch these episodes in iPod format on YouTube through my channel there (drbillbushing). 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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Male GSB giving me the eye and his little lady; male enticing female to move and leading her off (just 10 feet)

This document maintained by Dr. Bill Bushing.
Material and images © 2015 Star Thrower Educational Multimedia