Dive Dry with Dr. Bill

#510: Fish Poopies

Occasionally an amorphous blob will descend towards me from the water column above as I dive the park. My scientific curiosity always gets the best of me and I immediately point my camera at it and follow its descent with my camera rolling. Why should these events trigger an immediate response from the good "doc?" Let me tell you a little story I heard from Jean-Michel Cousteau decades ago while working on one of his projects (or was it while drinking some fine French wine?).

Jean-Michel was on a lecture circuit and gave a talk about a subject near and dear to many of us... the oceans and the critters that live in them. As the initial applause quieted a bit, Jean-Michel opened the floor to questions from the audience. A little girl raised her hand and he called on her. She asked "Mr. Cousteau... how can you swim in the ocean with all those fish poopies?" I wasn't there to hear the laughter, but the young girl's question was certainly not out of line!

The amorphous objects I have filmed were just that... fish poopies. Heck, I'm even becoming an expert in identifying the species a given "poopie" comes from. As I often told students in my biology classes at Toyon in the 60s and 70s, "You are what you eat... minus what you excrete!" Fish which are mostly vegetarian (known as herbivores by scientists like myself) often release somewhat fibrous waste. Those which are flesh eaters (predators) give off a more chunky mix that may even include the undigested bones of their prey.

Now most people don't think about invertebrates when they think of "poopies." However, when underwater they should check out the sea cucumber, an echinoderm related to the starfish. Despite that connection, readers of my column are fully aware that neither star "fish" or their relatives are fish. Right? Sea cucumbers ingest sand and mud rich in organics (often the poop from other species), filter out the munchables (ugh) and release streams of "cleansed" sand.

One of the most frequent fish "excreters" in our waters must certainly be the opaleye (Girella nigricans). They rank as one of the "crappiest" of fish. I frequently see them with fibrous streams emanating from their butts. Photographers often complain about getting too many butt shots of fish as they turn to flee, but in this case it is a good perspective to record such (mis)behavior for "posteriority." I see at least one of these "trash fish" trailing poop on almost every dive I do in the park.

However, as far as prodigious poopers go, one fish seen during the summer and fall in our dive park probably takes the cake. I'm referring to the GIANT sea bass. Any fish that may reach 600 pounds is sure to contain a lot of "processed food" in its intestines. When that is released, it is like a virtual hail storm underwater! I've filmed it a number of times. Divers have also commented that they believe these gentle giants may swim over divers that bother them and intentionally release. I had one do that as I was following it with my camera rolling. I didn't even notice the stream of chunks until I was back at my computer editing the footage!

Here in Avalon we have faced issues of elevated bacterial levels in our waters. The impact on tourism has probably been significant, and the City is doing quite a bit to remedy this and bring our beaches back into compliance. The waters outside the Bay are generally considered among the cleanest in southern California. We don't have a major urban population scattered across our shores with a myriad of sewage and industrial wastes deposited such as occurs during overflows from major storm events. Keep in mind that all bacteria are not harmful. The human body may harbor 100 trillion bacteria (weighing a total of up to five pounds) many of which actually aid in our body functions.

I did once get a serious bacterial infection while diving as Jean-Michel's guest at his resort in Fiji. Fortunately I travel with Cipro and that cleared it up quickly. Should YOU be worried about swimming or diving with the fish poopies? I'm not a medical doctor or a microbiologist who specializes in bacteria (what fun would that be?). Some bacteria are species specific and will only infect certain organisms. Most likely many of the bacteria in invertebrates or fish are not a threat to humans. I might worry more about critters that are closer to us evolutionarily... especially mammals like California sea lions! And I would NEVER swim in waters where whales have been taking a dump!!!

© 2012 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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"Fish" poopies from a warty sea cucumber, an opaleye, a giant sea bass and a California sea lion.

This document maintained by Dr. Bill Bushing.
Material and images © 2012 Star Thrower Educational Multimedia