DIVE DRY WITH DR. BILL #608: A SEA FULL OF JELLY... "FISH"
Recently I once again had the pleasure of spending time with a group of Japanese divers and scientists from Shibuya Diving Industry near Tokyo. I had met Masanobu Shibuya back in July when he and members of his team visited Catalina to film our giant kelp (Macrocystis pyrifera) forests and other seaweed. My Japanese is very limited (I can say sushi, sashimi, arigato and hai) but Hazuki Yasuhara, his interpreter, made it easy to communicate our shared passion about marine life.
Masanobu, Hazuki and two new members of his team returned over the Columbus Day weekend to dive, study and film. Masanobu was interested in why I dive mostly at night here during the summer months. I explained that in part it was due to the crowds in the dive park during the day, especially the often poorly supervised snorkeling "tours." I told him I hated having to fight my way through a forest of thrashing legs and dive fins on my way out from and in to the dive park stairs.
Of course the other reason I dive at night is there is so much action... and I'm a "man of action!" Not only are the hungry kelp bass and moray eels out hunting for munchies like the poor blacksmith, but there are a host of critters that mate under the cover of darkness. Some of these include southern kelp crabs, brittle stars, abalone and worms. Munching and mating is the ticket to good diving for me (and good "Dive Dry with Dr. Bill" columns for you). Night diving becomes extra special this time of year thanks to the music floating down from JazzTrax up in the Casino ballroom.
Our first dive demonstrated my point to Masanobu. He was pleasantly surprised at the nocturnal activity we witnessed and filmed. Although like me he is no longer a "hunter" (at least not until food prices here go even higher), he was astounded at the population of lobster in the dive park. I told him that even in the now protected dive park the population may be numerous but not necessarily healthy. Legal hoop nets ringing the park boundary harvest the larger bugs leaving mostly "underage" kids. A truly healthy population would have more medium and large sized lobster in it. Population populations would refer to this as a skewed age distribution.
While on our first night dive, I spent some time filming my favorite warm water dive park visitor, the Guadalupe cardinalfish (Apogon guadalupensis). I had finally discovered the fish others had mentioned seeing in the park and found a number of "new" locations as well. I wrote earlier that I hadn't seen this species here since 2004. When I found several of them out of their daytime hiding places and feeding in open water, I tried filming them... until a nasty kelp bass decided it was time for a snack. Grrrr. Lights out!
While I was on the bottom filming the cardinalfish under the rock overhangs, I felt a tap on my shoulder. Masanobu wanted me to come up to the surface to see something. There was a diffuse "cloud" in the upper foot or so of the water column. Once my feeble eyes resolved it, I discovered it was a swarm of literally thousands of tiny (1/2") jellyfish. Yes, I know... the politically correct crowd wants us to call them sea jellies because they aren't really fish... but I'm smart enough to know the difference and I'm sure my readers are too.
It was difficult to film the jellies because there were so many of them. It was like trying to video a large school of fish and get each one in clear focus. I wish I had taken more footage of them because they were gone the next night. Fortunately Masanobu took a number of higher resolution still images so I could get a better look at them.
I researched pelagic (open water) "jellies" in my copy of Wrobel and Mills' Pacific Coast Pelagic Invertebrates and am pretty certain these tiny jellies are in the genus Solmaris. It would be impossible for me to identify them to species based on the video footage and still images alone. In fact, since I'm no expert on the taxonomy of jellyfish, I doubt I could tell even if I had living specimens under my microscope in Doc's "lab!"
Once I had the genus name, I could conduct further research via the Internet (what would I have done back in the days before my Harvard classmate Al Gore "invented" it?). I found that these cnidarians (animals with stinging cells like jellyfish, sea anemones, hydroids and coral) are usually subtropical or tropical in distribution (although some have been found as far north as Scotland). Yep, yet another visitor to our region from the south like the other species I've written about during this warm water episode.
I don't know if these jellies sting because there was no way their tiny stingers (nematocysts) could penetrate my thick Body Glove wetsuit (courtesy of the Meistrell family). I did feel a few jolts, but I think they came from the siphonophore (probably a young Praya) that was also present in the mix. The first time I ever saw and filmed that species, I was stung pretty seriously across my face but was at significant depth and couldn't return to the surface until my decompression obligation was fulfilled.
So once again I encounter a warm water visitor in our dive park. What an unusual year and the scientists aren't even certain whether this is a true El Niño or not. I'm beginning to think I shouldn't be too surprised if I descend one day soon and find a coral reef instead of a kelp forest in our waters! Well, until then I'll continue to book flights to places like Hawaii, the Caymans and the Egyptian Red Sea over the coming months to get my fill of tropical critters during our harsh southern California winters. Pray for rain... or do a rain dance.
Image caption: Masanobu, Hazuki and myself discussing our dive and the cloud of Solmaris jellyfish with a close-up courtesy of Masanobu.