STEM Logo

Dive Dry with Dr. Bill

#619: Billions and Billions... Munched

It was just a few days before Christmas and, since I'd been a naughty boy and Santa wasn't going to come down my chimney (heck, I don't even have one), I decided to do another dive before getting ready to head overtown to spend Christmas with my granddaughters (and their Mom & Dad of course).

I'd done several deep dives recently so I planned to be a "shallow fellow" on this dive... but unlike more disciplined divers who plan their dive and dive their plan, I improvised. I did the same thing the year I ran for senior class V.P. in high school... took the finely crafted speech I'd spent weeks writing and when I got up to the podium, I tore it up and winged it... and won the election. I do it a lot now. I'm just not one to follow a script which is why I've never considered becoming a thespian. I do much better behind the camera.

There was a good current ripping through the dive park so I "flew" above the landscape of invasive Sargassum horneri, filming it as I passed overhead, then plummeted down to 80 feet where a huge school of blacksmith (Chromis punctipinnis) was hovering just above the bottom (probably trying to escape hungry cormorants). From there it was down to 100 ft to film the huge elk kelp (Pelagophycus porra) at depth before heading back up in the lee of the wreck of the Suejac at the harbor end of the dive park.

Now I'd gotten pretty much a free ride in that direction, but once I made my 180º turn, I headed back to the dive park stairs... against the current. I proceeded at a slower pace until I arrived about 30 ft from the exit. There an incredible sight awaited me. No, it wasn't that long sought after mermaid... remember, Santa said I'd been a bad boy last year. But it was a damsel... thousands of them in fact!

There in the shallows was another huge school of blacksmith, the blue and black damsel relative of the garibaldi. I'd seen such a gathering a few times on my past few dives and knew they must be feeding. I looked up toward the ocean surface and indeed there was a huge assemblage of tiny critters in the water. The blacksmith would rise up toward the surface, gulp down a few of these juicy tidbits, and then descend en masse toward the bottom. It was strange to watch these schools rise toward the surface then turn and descend toward the shallow bottom further from aerial predators... a cycle driven by munching, and avoiding being munched!

Now my eyes are not 20/20 by a long shot (although I can detect a teeny weeny yellow pok-a-dot bikini at 1,000 paces). In fact, I made an appointment with my optometrist before Christmas to get a new prescription. I could barely make out the tiny critters and the high definition video I shot on that dive didn't help. I guessed that they were one of two things: a hatch of tiny fish "fry" (although the blacksmith ate them like sushi and sashimi without even using a pan on a stove) or a member of the zooplankton (animal plankton), most likely shrimp-like euphausiids. You may know these by their more common name, krill. I'm leaning toward the latter, possibly a mating swarm of them blown in toward shore by the wind. Apparently this was another case where mating led to munching.

I went back the next day equipped with a small net to see if I could capture one of the tiny critters to positively identify it. Wouldn't you know... there were "billions and billions" of them the day before and not a single one the next day. I checked out all the blacksmith and they didn't look any fatter so the current must have carried the tiny critters off toward the East End. Next time I'll head up to the house right away and get something to collect one rather than wait a day!

Then it was off to the mainland for the holiday. While I was sitting on the couch in the living room at my son's house, my granddaughter Allison came up and said "Let's go SCUBA diving." Even at the tender age of four she knows how to get her Papa Bill's attention. I asked her how we could do that and she replied "get down on the floor and just dive." So my son and I joined her on the floor for three dives (she doesn't believe in 'surface intervals'). While we were "down under" she pointed out the sharks, turtles and "x-ray fish." Very cute... and I'm checking to see if I can legitimately record these dives in my log book!

HAPPY NEW YEAR TO ALL!

© 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!

To return to the list of ALL of Dr. Bill's "Dive Dry" newspaper columns, click here.


School of blacksmith descending away from predators and feeding on planktonic krill;
krill with enlarged image of a local species and krill, blacksmith and Casino.

This document maintained by Dr. Bill Bushing.
Material and images © 2014 Star Thrower Educational Multimedia