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Diver Dave & the Denver Aquarium – Episode 5 (Reservoir)
dontdiveenuf - 11/02/2013 6:03 AM
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Category: Educational
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Diver Dave & the Denver Aquarium – Episode 5 (Reservoir)Fresh Water, White Hunger. Part 5 of Several Installments.

Reservoir is a relatively narrow exhibit – about 17’ deep by 20’ wide, and full of catfish, gar, pike, sturgeon, and bass. Setting up the siphon was much the same as for the other exhibits, although we control the pump, rather than having to call Life Support to turn it on and off. As I was getting in with my instructor, Sara W, we noticed one small gar lying on the bottom step, right next to the riser. It was so still we were concerned about its health, so I gently nudged its tail with one of my fins. It took off like a rocket.

While I was siphoning I kept feeling taps on my limbs. After a couple of times I looked over and realized that it was various catfish and sturgeon, anxious to be fed. The largest sturgeon of all was quite persistent, and gave me a smack on the facemask. Over the course of about 20 minutes of siphoning I got used to the sight (and feel) of these prehistoric-looking fish gliding between my legs, checking out my fins, and rubbing up against my head.

Like the rays and shovelnoses, sturgeons’ mouths are on the bottom. What I didn’t realize was that they also extend their jaws down and out a considerable distance, kind of like the jaws of the creature in ‘Alien.’ It was quite a shock, especially when one did it directly in front of me, expecting a hand-out.

Feeding the sturgeons and catfish wasn’t nearly as difficult as it can be with the rays. Perhaps it was because Sara had told me to keep moving around while I fed them. Instead of having to hold the food until the animals take it, I just waited until a target was in front of me, then dropped it in their path. But the timing had to be just right, otherwise the bass (who are fed by scatter-feeding at the surface) dart in and snag the food. There were a couple of smaller sturgeons that hung out at the bottom that I had to make an effort to feed, but everyone else was quite happy to swarm around.
I’d never really looked at a whole catfish before, even at fish markets, so seeing them coming directly at me with their mouths agape was a bit startling. You don’t expect their mouths to expand as much as they do, and surrounded by whiskers (which on the larger ones are more like ropes) it was a bizarre sight.

There are a couple of huge catfish that hang out in the darkest corner of the tank; I think one of them is around 5 feet long from nose to tail, with a mouth that looked almost as large. When it opened its mouth to inhale its food, it gave me an inkling perhaps of what it’ll be like to be in the shark tank.

Feeding the gar and pike was a different experience altogether. We feed them small fish at the surface, from the edges of the tank. They both need to be fed by holding the fish (gripped by tongs, which we hold in our chain mail gloves) near the side of their mouth. The gar, with their needle-like snouts, as often as not will snap at the fish, then glide away. But if they’re not quick to move away, a bass will dart in and grab a piece, as the food will be hanging out of one or both sides of the mouth. The pike are fairly non-descript feeders, acting much like the gar, but seemed to learn faster that they had to get out of the feeding zone or else be mugged.

There was one small white gar that was shy – it stayed in an upper corner of the tank under a couple of small logs, and only approached us after we were well into the feeding. Unfortunately the bass would often knock it out of the way as we tried to feed it, but we did eventually get a couple of pieces into it.

My third Reservoir dive was a morning dive with Stephen S and Jerry E. Stephen has been with the Aquarium since the very first days, when it was ‘Ocean Journey.’ Jerry and I started with feeding the pikes and gars, and this time I had much more luck with getting the white gar to eat. In fact, everyone seemed to know they were going to get fed this morning, as they completely swarmed the dive platform before we’d even set foot on the first step.

My job was to set up the siphon and filter the middle section, before the 10:30am feeding time for the sturgeons and catfish, which is advertised for the public to see. Several times I’d look up to see a sturgeon coming straight at me, apparently expecting to get fed. I tried not to touch them, of course, and resorted to putting the siphon hose between the fish and myself – they’d run into it and turn away, or back off. But at one point I felt two sharp smacks on my head – hard enough that I thought Jerry or Stephen had kicked me. Instead it was one of the larger sturgeons, who wanted to remind me that he was waiting to be fed. I’m sure I cut a comical figure glancing around every few seconds, dodging the sturgeons and catfish, while trying to do a good job siphoning the gravel.

Feeding was a rodeo – this time made even more interesting by the fact that there was only one chum bucket for the two of us. Jerry held on to it in the middle of Section 2, while I would dip my hand in, grab a handful of squid and mackerel pieces, and try to cover them from the bass as I swam to another part of the tank. I made an effort to get the larger catfish to come out from behind their rocks so the guests could see just how big they were, as well as see how they feed. And a couple of times I managed to lure a sturgeon to grab its food in full display. It looked like one or two kids squealed with delight (or maybe screamed in horror – it’s hard to tell thru several inches of acrylic).

On the way out the white gar seemed to take a particular interest in me. As I was swimming across the surface, I came nose to nose with it; we just hung in the water, not moving, staring at each other. I was tempted to just wait and see how long it would last, but Jerry and Stephen were waiting for me so I swung around it and headed for the dive platform, which was mobbed by the other pikes and gars.

For my last Reservoir training dive I was with Bill M. Bill is a long-time volunteer at the Aquarium, having been a diver and docent since its ‘Ocean Journey’ days. Bill is full of information and showed me behind a couple of doors on the dive level that I’d not noticed, one overlooking the Tiger enclosure. He let me call all of the shots on the dive, as a sort of final exam. During the post-dive debriefing he said that I demonstrated a knowledge and comfort in the water and activities that many of the more experienced divers didn’t show. Compliments on my diving ability are always appreciated!
I elected to do the scrubbing while Bill siphoned, and once the doors opened found quite a few distractions with kids showing up at the windows. Besides the usual hand-waving, I’ve started doing a ‘meet & greet’ with the guests – I press my hand against the window and they do the same, then I give them the ‘Ok’ and ‘Thumbs Up’ signals. Most of them get a real kick out of it – the problem being that if there are several kids in the room they ALL have to do it, so I sometimes spend more time than I ought. But interacting with the visitors really adds something to their experience, and I find that I really enjoy and look forward to it as well. I managed to get across to one parent that she should use her camera, signaled to her kid to turn around, and I think she was able to get a decent picture of her child with a diver in the background. I managed to do that a couple more times, and still finished the scrubbing part of the dive within a few minutes of target.

Feeding time was a real hoot. Bill fed the gars and pikes at the surface while I took on the sturgeon and catfish. The aquarists had left instructions to try to focus on the smaller sturgeon, and not feed much to the catfish, and that was a real challenge. At one point I felt Theodore (the largest of the sturgeons) sucking on my head; thank goodness I was wearing a hood or I may have gotten an impromptu haircut; as it was it felt like a brief scalp massage. A couple of the other larger sturgeon tried to give me hickeys on my legs and arms, and the bass were amazingly fast and aggressive. What surprised me was that at one point I found myself staring into the snout of the white gar. It was unusual enough to see gars near the bottom at all, but the white one, who is on the small side and rather timid, appeared to be interested in me (or more likely the food) enough to brave the bass, sturgeons and catfish. Unfortunately it darted away before I had a chance to offer it anything.

I was able to lure a couple of the larger catfish out of hiding to feed in front of the window, as well as some of the gars to turn and show their mouths to the visitors as they took the food I was offering. I also managed to get whacked in the mask a few times by the bass, and a couple of the sturgeon thought they’d try chainmail as an aperitif. Rather than trying to extricate my hand, it was just a matter of waiting a bit until they decided they weren’t making any progress in swallowing the fingerlings; being in full view of the public also lent incentive to not panicking!

Dave Madorsky lives with his wonderfully supportive family in the Denver Metropolitan Area; his personal philosophy is, “Anytime I’m underwater and still breathing is a GOOD time!”

Disclaimer: Most pictures were taken by Dave Madorsky, but some are from public domain sources to better illustrate the sea life described.

Episode 6>>