DIVE DRY WITH DR. BILL #454: WOW... THAT IS SOME OWIE!
I thought I might get skunked this year and not see a single giant sea bass in the dive park. Of course I had seen the ones feeding at the Pleasure Pier. While doing the Sea Trek monitoring last May, a bat ray dust storm reduced visibility to 0-3 feet, and I saw a very hazy "critter" swimming toward me that looked to be about 12 feet long. Of course that evoked images of Jaws (parts of which were filmed in our waters near Torqua Springs back when I was teaching marine biology at Toyon). As it approached MUCH more closely, it materialized into two giant sea bass swimming head-to-tail just wanting to check out the bubble blowing intruder. Whew!
Now speaking of Jaws (something the powers that be are not always happy about my doing), some have seen the images from a month or so ago of a large great white shark (GWS) munching away on a giant sea bass (GSB). A few years back I even saw a GSB with a very large crescent shaped bite mark on both dorsal flanks. It could only have come from a GWS or very large mako attacking the fish from above. Gulp, I always thought GWS attacked from below, and therefore I was safe if I dove close to the bottom. They still haven't learned how to bury into the sand and jump out to surprise their prey... or me! However, if one did attack me from above (not something I worry much about), it would get a mouthful of metal from my SCUBA tank! Certainly crunchy... but not very satisfying. Besides, the only GWS that has passed close to me while I was uncaged had no real interest in munching me. We are just not on their menu... especially the ladies, since these are "man eating" sharks.
A few weeks ago divers began seeing a badly injured GSB right in the dive park. Some thought the injuries might have come from a GWS attack. For two days I went out to film this beleaguered beast. Rest assured, the damage was not caused by any known species of shark I'm familiar with. A more likely explanation would be an encounter with the mechanical shark used in the filming of Jaws... or the one Jean-Michel Cousteau's son Fabien climbed inside of to film from when I was down off Guadalupe Island in 2005 to shoot the GWS with Dr. Guy Harvey. Although I am an ecologist rather than a medical doctor (my bank balance proves this), my assessment of the injuries are that they came from the propeller of a boat. The GSB may have rolled on impact since the injuries occurred on both sides of its body, or possibly the vessel had twin screws. Whichever, the poor bass certainly got "screwed."
Many divers were very concerned about the extent of these injuries and the possibility they might prove fatal. My semi-educated guess is that they will not. As far as I could see, none of the gashes penetrated the thick muscle layer into the body cavity. The GSB was able to swim fairly well... generally keeping me at bay while I filmed. However, it has not been seen recently to the best of my knowledge. Other divers reported seeing a second GSB tending the injured fish. On the second day I filmed it, another large head entered my video frame from stage left and I confirmed it had company. Based on the behavior I observed, the injured GSB appears to be a female while the smaller one is a male.
Encounters between Homo sapiens and Stereolepis gigas (GSB) are usually quite benign to both parties and often quite thrilling. Divers frequently hover and watch them for the entire duration of their dive. Despite their incredible size (historically up to 800 according to Holder, although the injured one was about 350 lbs), the GSB are very docile. Even when the males are hopped up on hormones and chasing one another away from "their" ladies, they have never bumped me once despite heading directly toward me. Of course I had already reassured them their females were of no interest to me. I'm certainly not that desperate for a date!
As the GSB recover from a long history of overfishing dating back to the late 1800s, and more recent exploitation through capture in gillnets (which are now banned in California waters), more and more humans will get the opportunity to see these fantastic fish. And it won't just be those of us who submerge into the briny deep. Anglers are accidentally hooking up with them more frequently too (in the sense of the fishing term, not the common lingo for "couple formation" among today's youth). The vast majority treat such an incident with great concern and do their best to return the fish to depth where it will survive. Many now know that puncturing their swim bladders can lead to infection and death, and that the best action is to carefully swim the fish down until the pressure recompresses the swim bladder.
This time of year the GSBs usually are hovering near the bottom, making them largely immune from "attack" by a boat's propeller (well, except for some of our "weekend warriors" like the boat operator that motored over the boundary line into the dive park and headed towards the stairs!). I've thought in the past that bobbing just above the bottom was a defense mechanism to prevent shark attacks as well. Occasionally one will see them higher up in the water column, but generally at a depth where they are safe from passing vessels. How this one got nicked is an interesting question. Possibly it was caught by an angler and swam into the spinning prop(s). I can only hypothesize (but that's what scientists are supposed to do!).
There is one type of fisher that does really get my goat. Oh, wait, we got rid of those nasty pests... maybe I should say goatfish. And they are devotees of my favorite form of recreation (well, okay... second favorite form), SCUBA diving. I'm referring to the few bad apples among the spearfishing community. Most spearos I know are knowledgeable about species identification, legal size and take limits. They hunt for food, and I have no problem with that (as long as their vision is acute and they don't mistake me for a plump piscine! However, recently yet another GSB has been seen with a very serious spear wound that apparently penetrated the entire girth of the fish. At times I wish our GSBs weren't so docile and had sharp teeth like a GWS so they could return the "favor" when this happens.
Image caption: The injured GSB seen recently in the dive park, and a male sheephead inspecting one of the wounds (for comparative size).