Dive Dry with Dr. Bill

#572: Munching... and Being Munched

I hope you aren't tired of reading about the fascinating squid that dwell in the waters off our coast. I could write column after column about my dives with them, but I promise this will be the last for a while. Why? Well, because it is about their demise following the previous article about mating. Time this week for munching... both what they eat, and how they reach their final resting place as a menu item for many critters from both land and sea.

On our final day of filming with the Cousteau team last month, "Murph" (Dr. Richard C. Murphy, old friend and former Vice-President of The Cousteau Society) and I dove Descanso Bay while Jean-Michel and Holly were filmed by the crew at the base of the giant kelp forest in the dive park. The day before "Murph" had visited the site of the incredible mating orgy (spawning event if you prefer to be more politically correct) and came back to say he now wanted to call it "the graveyard." Both of us wanted to film it before the rest of the crew moved there to film another segment.

There were very few live squid (Doryteuthis opalescens) in evidence as we swam along at depths between 35 and 75 feet. Instead, thousands of squid bodies littered the bottom along with the fresh bright white clusters of eggs. After 10-14 days of frenetic mating, the lives of many of these "calamari" were over. The primary function of any species, to reproduce itself, had taken place at least at this site and any squid still living had moved on.

During their somewhat brief lives, market squid feed on fish, shrimp, crabs, molluscs and are even cannibalistic on younger squid. The young paralarvae feed on crustaceans and other small critters in the plankton. In turn it is an important munchie for a wide range of predators. These include sharks, large fish including white sea bass, dolphins, sea lions, seals and a number of marine bird species. On our earlier dives I had watched as predators gathered to take advantage of the smorgasbord provided by the living and dying squid. This is what The Mutual Eating Society is all about. When some individuals were threatened, they releases a dark cloud of ink just like their relatives the octopus do.

All around me on the earlier dives, I could see hundreds of fish of many different species feeding on the dying and dead quid. I was not surprised to see carnivores like the garibaldi and sheephead taking bites of the defenseless cephalopods. After all, they are not vegans. Others including the black perch and halfmoon were somewhat surprising to see joining the feast. However, even the normally herbivorous opaleye didn't miss a chance to chow down. I have read that although their diet further south is almost exclusively vegetarian, in colder waters opaleye will add animal matter for more energy. I even saw a flatfish, a C-O sole (Pleuronichthys coenosus), chomping down on the tentacles of one squid.

"Murph" was a bit surprised to see large groups of blacksmith tearing away at the freshly laid eggs. Most scientists assume fish do not eat the eggs, but these blacksmith seemed to be ripping the capsules apart to get at the eggs. Some also fought over the dead bodies. I had first filmed this behavior about 10 years ago off Hen Rock so I was not surprised. I also noticed schools of senorita doing the same. Now unless you believe the fertilized egg is already a living creature, these poor eggs disappeared before they could even begin life as a larval squid. I even saw cormorants diving nearby, but wasn't certain if they were going after the squid or the blacksmith feeding on them.

Other squid predators include the extremely deadly Homo sapiens. This year the commercial quota for squid, set at 118,000 short tons, had essentially been met as early as October 18th and the fishery closed early. That catch will be marketed as fresh food, frozen for export and sold as bait. The California fishery was started up in the Monterey area by Chinese immigrants around 1860. By about 1900 the fishery was dominated by Italian immigrants. Today about 90% of squid landings come from southern California, especially the Channel Islands.

I mentioned in a previous column how my dinner guests years ago in Chicago turned up their noses at my gourmet calamari dinner. However, these cephalopods are prized in other regions of the globe such as Asia and Italy. Their appeal in the States did increase when the marketing people decided to make a few changes and refer to squid as calamari. Soon they became a food delicacy that some compared with abalone. Obviously those diners had never tasted real abalone, but for my palate squid will do in a pinch!

Now it may have been a great year for squid fishers, but I had talked to local lobsterman Andy Wadley who said they are not pulling up many bugs in their traps. At first I didn't see the connection, but then I realized why. With tasty calamari scattered all over the bottom to feed on, why would any self respecting "bug" have to climb into a trap to get a can of cat food or whatever bait was being employed?

On Christmas day I made another visit to "the graveyard." I was somewhat astonished to find not a single carcass on the ocean floor where a few days before there were thousands. The predators and scavengers (including the "bugs") must have had a field day cleaning up all that protein. Instead of bodies, I found nothing but squid "pens" (called a gladius) littering the bottom. They are made of chitin which is largely indigestible... somewhat like my cooking (unless one has a cast iron stomach)

So in addition to the wondrous exhibition of animal behavior demonstrated by a squid run, there are interesting ecological consequences for our beloved kelp forests. Squid spend much of their lives away from shore feeding on critters in the plankton and midwater regions. Then they migrate into nearshore regions to spawn and die. By doing so, they transfer a lot of carbon and other nutrients into the kelp forests that can pass through the residents of these magnificent habitats. And that's what ecology is all about... the recycling of matter and the transfer of energy within ecological systems. Pardon me while I grab a bite of matter and energy from the fridge.

© 2014 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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The squid graveyard as seen from above and dead squid bodies;
blacksmith fighting over a piece of squid and the squid pens (gladii) littering the bottom.

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