DIVE DRY WITH DR. BILL #352: CARNAGE AT THE CASINO REDUX
When I was a student at Harvard in the 1960s there was a "space war" going on. No, it had nothing to do with landing on the lunar surface or developing anti-missile shields. It was the war for laboratory space between professors engaged in the new study of molecular biology and genetics, and those who focused on organismic biology and ecology. At the time, my professors like world renowned E. O. Wilson and H. Barraclough Fell, were in the latter camp. Out of a sense of honor to them, I never took any molecular genetics courses with the likes of the Double Helix's James D. Watson. I did make up for that by studying the subject very carefully when I had to teach molecular genetics and evolution at Toyon Bay.
I also learned an important new lesson in genetics the weekend before Labor Day when my son Kevin came out to spend time with "the old man in the sea." Kevin had not dived since moving to Denver last December. However, he quickly adjusted and within a few days was proving his father to be something of an air hog! He ended up diving me to exhaustion! What was my lesson? That the "diving gene" is indeed inheritable... because Kevin sure has it!
One of the things Kevin wanted to do while he was here was night diving. Great since I needed to film more footage in the dive park of the change in shifts that occurs at sunrise and sunset. He arrived in the late afternoon on Thursday, and we were soon suited up for a dusk dive. It was a bit early to see the "changing of the guard," but we had a great time. At the end of the Casino groyne (a fancy term for breakwater) a male giant sea bass appeared from inside the harbor and checked us out. It made several passes to assess whether we'd be competition for its fair lady friend. After I assured it that Kevin was already married, and neither of us were of the right species, it returned to her and we swam back to the dive stairs underwater.
The next night we descended after dark. This time the day shift was retiring and the night shift coming on duty. Blacksmith, which usually school in huge numbers to feed on plankton in our kelp beds, were seeking shelter in the rocks to avoid nocturnal predators. Even their normally pugnacious damsel fish relatives, the garibaldi, were hiding on the bottom. Some of the predatory sheephead were tucked into their nooks and crannies for the night. Taking their place were the lobsters, black sea urchins and lunker kelp or calico bass. Each ventured out from the protection of their daytime shelters to feed under the cover of darkness.
It is much easier to film lobsters when they are out in the open, rather than trying to cram my underwater video housing into their hiding places. My viewers want to see more than their heads and antennae sticking out of a hole. After all, when in season few are interested in eating those parts. The black or Coronado urchins, which normally hide from their sheephead predators during the day, are freed up to roam safely when the sheephead shelter and sleep at night. The beautiful bluish blacksmith look very funny with their heads buried in a crevice, frequently leaving their tales and fins sticking out. Gregarious during the day, they remain fairly sociable at night and you may see half a dozen sheltering together. However, if it gets too crowded, they will force newcomers out of the safety of their crevice. The sheephead will change color and pattern when they sleep, often exhibiting a more mottled coloration that probably helps them camouflage better. Kevin and I did see one color variant that I don't remember seeing before... a dark charcoal body with white blotches. Perhaps that's the "in" pattern for the coming fashion season.
On our third night dive we were treated to some real "ecology." Actually what we saw were ecological interactions since "ecology" refers to the study of biological communities and their interactions. I knew several other divers who have had harbor seals follow them at night and dart out to capture blacksmith caught in their dive lights. We didn't have any seals join us on our dives (nor any of the great whites that Kevin kept looking out to sea for). However, my video light would often capture blacksmith flitting around the rocks using strange evasive swimming tactics or sheltering in their holes. The lunker kelp bass adopted the strategy of the harbor seals and captured several blacksmith highlighted by my video lights. In the process of capturing the night life at Casino Point on film to share with my viewers, I was interfering with Mother Nature. I just hope the blacksmith that sacrificed their lives for my video will understand the "greater good."
I remember in my early days of diving at Toyon that I rarely did a night dive. Back then I was still quite nervous about encountering "the landlord" underwater under cover of darkness. Of course watching "Jaws" didn't help... and kept me OUT of the water entirely, at least until I saw "Jaws II" a few years later. People often associate night with feeding time for sharks. I did have every expectation of seeing harmless horn sharks out in the open looking for munchies. Kevin and I only saw them in their caves, which made me wonder if they'd overslept. Another possible explanation is that frequent interaction with divers, sometimes bordering on harassment, has forced them out of the dive park and into the safer waters of the outer harbor.
The highlight of our night dives came when I was filming about half a dozen blacksmith hiding in a small cave. I was sitting on the sandy bottom watching them in my viewfinder, when I sensed something approaching from above. I assumed it was a kelp bass and kept filming. Was I surprised when a moray eel swam into my field of view and started attacking the blacksmith. Now like me, morays do not have excellent eyesight yet hunt largely at night. Even with my video lights blazing, this one wasn't scoring a lot of direct hits on the poor blacksmith (who appeared a bit shell shocked afterwards). Of the six, I think the moray only took one. However, the action was quick and lively and I had trouble following it as it darted here and there after the darting damsels.
There are people who say they "love" Nature yet are abhorred when they see a lion attack a wildebeest, a hyena gnawing on the carcass of a gazelle, a killer whale taking a sea lion pup, or a spearfisher shooting a sheephead. To love "Nature" one must understand that it functions based on the flow of matter and energy through the various food chains and food webs. We are all involved in the "Mutual Eating Society" as I've called it since my early days teaching biology at Toyon. Animals kill one another, but almost entirely for food and only a few for what we might interpret as "pleasure." In fact these apparent acts of "play" may actually be training sessions for hunting in many cases. This is one reason why I focus on the "munching" that goes on in our Macrocystis kelp forests. Speaking of which, I'm getting a little hungry... time to head to Vons for some pan dulce to fuel today's diving and add a little more "natural insulation" for the approaching cold waters of winter.
Image caption: Blacksmith sheltering at night from predators, lunker calico approaching blacksmith; moray appears on the scene, half-blind moray misses... this time!
When I was a student at Harvard in the 1960s there was a "space war" going on. No, it had nothing to do with landing on the lunar surface or developing anti-missile shields. It was the war for laboratory space between professors engaged in the new study of molecular biology and genetics, and those who focused on organismic biology and ecology. At the time, my professors like world renowned E. O. Wilson and H. Barraclough Fell, were in the latter camp. Out of a sense of honor to them, I never took any molecular genetics courses with the likes of the Double Helix's James D. Watson. I did make up for that by studying the subject very carefully when I had to teach molecular genetics and evolution at Toyon Bay.
I also learned an important new lesson in genetics the weekend before Labor Day when my son Kevin came out to spend time with "the old man in the sea." Kevin had not dived since moving to Denver last December. However, he quickly adjusted and within a few days was proving his father to be something of an air hog! He ended up diving me to exhaustion! What was my lesson? That the "diving gene" is indeed inheritable... because Kevin sure has it!
One of the things Kevin wanted to do while he was here was night diving. Great since I needed to film more footage in the dive park of the change in shifts that occurs at sunrise and sunset. He arrived in the late afternoon on Thursday, and we were soon suited up for a dusk dive. It was a bit early to see the "changing of the guard," but we had a great time. At the end of the Casino groyne (a fancy term for breakwater) a male giant sea bass appeared from inside the harbor and checked us out. It made several passes to assess whether we'd be competition for its fair lady friend. After I assured it that Kevin was already married, and neither of us were of the right species, it returned to her and we swam back to the dive stairs underwater.
The next night we descended after dark. This time the day shift was retiring and the night shift coming on duty. Blacksmith, which usually school in huge numbers to feed on plankton in our kelp beds, were seeking shelter in the rocks to avoid nocturnal predators. Even their normally pugnacious damsel fish relatives, the garibaldi, were hiding on the bottom. Some of the predatory sheephead were tucked into their nooks and crannies for the night. Taking their place were the lobsters, black sea urchins and lunker kelp or calico bass. Each ventured out from the protection of their daytime shelters to feed under the cover of darkness.
It is much easier to film lobsters when they are out in the open, rather than trying to cram my underwater video housing into their hiding places. My viewers want to see more than their heads and antennae sticking out of a hole. After all, when in season few are interested in eating those parts. The black or Coronado urchins, which normally hide from their sheephead predators during the day, are freed up to roam safely when the sheephead shelter and sleep at night. The beautiful bluish blacksmith look very funny with their heads buried in a crevice, frequently leaving their tales and fins sticking out. Gregarious during the day, they remain fairly sociable at night and you may see half a dozen sheltering together. However, if it gets too crowded, they will force newcomers out of the safety of their crevice. The sheephead will change color and pattern when they sleep, often exhibiting a more mottled coloration that probably helps them camouflage better. Kevin and I did see one color variant that I don't remember seeing before... a dark charcoal body with white blotches. Perhaps that's the "in" pattern for the coming fashion season.
On our third night dive we were treated to some real "ecology." Actually what we saw were ecological interactions since "ecology" refers to the study of biological communities and their interactions. I knew several other divers who have had harbor seals follow them at night and dart out to capture blacksmith caught in their dive lights. We didn't have any seals join us on our dives (nor any of the great whites that Kevin kept looking out to sea for). However, my video light would often capture blacksmith flitting around the rocks using strange evasive swimming tactics or sheltering in their holes. The lunker kelp bass adopted the strategy of the harbor seals and captured several blacksmith highlighted by my video lights. In the process of capturing the night life at Casino Point on film to share with my viewers, I was interfering with Mother Nature. I just hope the blacksmith that sacrificed their lives for my video will understand the "greater good."
I remember in my early days of diving at Toyon that I rarely did a night dive. Back then I was still quite nervous about encountering "the landlord" underwater under cover of darkness. Of course watching "Jaws" didn't help... and kept me OUT of the water entirely, at least until I saw "Jaws II" a few years later. People often associate night with feeding time for sharks. I did have every expectation of seeing harmless horn sharks out in the open looking for munchies. Kevin and I only saw them in their caves, which made me wonder if they'd overslept. Another possible explanation is that frequent interaction with divers, sometimes bordering on harassment, has forced them out of the dive park and into the safer waters of the outer harbor.
The highlight of our night dives came when I was filming about half a dozen blacksmith hiding in a small cave. I was sitting on the sandy bottom watching them in my viewfinder, when I sensed something approaching from above. I assumed it was a kelp bass and kept filming. Was I surprised when a moray eel swam into my field of view and started attacking the blacksmith. Now like me, morays do not have excellent eyesight yet hunt largely at night. Even with my video lights blazing, this one wasn't scoring a lot of direct hits on the poor blacksmith (who appeared a bit shell shocked afterwards). Of the six, I think the moray only took one. However, the action was quick and lively and I had trouble following it as it darted here and there after the darting damsels.
There are people who say they "love" Nature yet are abhorred when they see a lion attack a wildebeest, a hyena gnawing on the carcass of a gazelle, a killer whale taking a sea lion pup, or a spearfisher shooting a sheephead. To love "Nature" one must understand that it functions based on the flow of matter and energy through the various food chains and food webs. We are all involved in the "Mutual Eating Society" as I've called it since my early days teaching biology at Toyon. Animals kill one another, but almost entirely for food and only a few for what we might interpret as "pleasure." In fact these apparent acts of "play" may actually be training sessions for hunting in many cases. This is one reason why I focus on the "munching" that goes on in our Macrocystis kelp forests. Speaking of which, I'm getting a little hungry... time to head to Vons for some pan dulce to fuel today's diving and add a little more "natural insulation" for the approaching cold waters of winter.
Image caption: Blacksmith sheltering at night from predators, lunker calico approaching blacksmith; moray appears on the scene, half-blind moray misses... this time!
