DIVE DRY WITH DR. BILL #344: THE RETURN OF GARY GARIBALDI
My very first column in this series was about our state marine fish, Gary Garibaldi, and his damsel family relatives. Currently I'm researching the second of two episodes on the garibaldi for my proposed "Munching & Mating in the Macrocystis" cable TV show. That means I've focused much of my recent diving and filming on them, as well as my Internet research during my surface intervals. This effort has given me enough for 40 minutes of video on their natural history, and that certainly merits another column on these colorful critters.
It seems that I first heard garibaldi were protected when I started diving Catalina waters 40 years ago. Much later I discovered they had not become our state salt water fish, and thereby received their protected status, until the 1990's. Of course the golden trout is our state fish, and was so designated in 1947. I never expect to see one since I shun fresh water (just like W. C. Fields did). The garibaldi's route to recognition was much bumpier. Way back in 1971 a report by the California Department of Fish & Game suggested garibaldi should be protected from recreational and commercial take. Like many such reports, that one remained on the shelf gathering dust until decades later.
In the late 1980's and early 1990's, collectors for the aquarium trade were vacuuming up young garibaldi off the reefs of Catalina and nearby San Clemente Islands. The Catalina Conservancy Divers (CCD) got involved in the effort to stop this. In 1993 Assembly Bill 1788 was signed into law restricting collecting of this species off Catalina's leeward coast, and allowing it elsewhere only between November and January, well outside of breeding season. A year later Assembly Bill 2812 would have protected this species as our state salt water fish, but it died in committee due to intense lobbying by the aquarium trade. Although only about 670 fish were reported as collected under permit that year, others estimated the take at several thousand. In 1995 my long-time friend Jean-Michel Cousteau and his Ocean Futures organization were instrumental in getting Assembly Bill 77 passed which protected the garibaldi and finally made it our State's marine fish.
We are now in the midst of mating season for these members of the damsel family. The pugnacious male garibaldi has established a nest site in his territory by weeding away all but three species of red algae (Ophidocladus californicus, Pterosiphonia dendroides and Spermothamnion snyderae if you really must know). The nests are very obvious as circular dark red patches on rocks, and may be as large as 10-15 sq. ft. I had noticed that nests in shallower waters tended to be on vertical surfaces, while those in deeper water were often on horizontal surfaces. At first I thought this might be to avoid direct sunlight on the eggs, but my research indicates it was due to the light requirements of the red algae in the nest.
The male attracts the lovely damsels to his lair by swimming in an oval-shaped pattern above the nest site. This is known as dipping, a behavior shared by many other damsel fish I've seen throughout the world. Females leave their own territories to survey the local guys, sometimes swimming as far as 650 feet from her territory to ensure she finds the right mate. Between her trips she must return to her territory to drive away competitors who might try munching her food supply in her absence. She may make many trips in her search for the guy with "the right stuff." Too bad she doesn't use the Plenty of Fish Internet dating site that I frequent... but then she may be aware of how unsuccessful that has been for me!
The ladies are very selective about their mates (just as the females of my species are... unfortunately). They inspect not only the male, but his behavior, the state of the nest and the condition of the eggs in it. Females prefer to lay eggs in nests containing fresh yellow eggs laid by other females. This is because eggs of different ages require different care by the tending male. If she selects a male with older greenish-gray eggs in his nest, she lays hers in a separate part of the nest. Her brood may number 15,-18,000 and the total number of eggs in a nest may be much greater. The male accepts many different females into his nest and tends the eggs for the 2-3 weeks it takes them to hatch into larvae. They will go through several brood cycles during mating season which may extend from March to as late as October.
I went to what I thought was a fresh (red) nest with no apparent eggs and sampled a very small patch (less than 1/2" square) of the red algae so I could videotape them under a microscope for my video. I was surprised to find that I had inadvertently sampled a few garibaldi eggs as well. They were not visible to my naked eye, so I didn't expect to see any under the microscope. The fresh yellow eggs are very obvious, but sometimes the older grayish eggs aren't as easy to see.
About two weeks ago I saw fresh yellow eggs in a number of nests. Temperatures at depth were in the toasty 60-66 degree Fahrenheit range. This is above the 59 F threshold believed to trigger reproduction in garibaldi. About two weeks ago, cold water coming up from deeper water dropped the temperatures to 53-57 degrees F. I spent several dives over two weekends during this period looking for garibaldi nests with older, developed eggs in them. I couldn't find any, only one or two nests in warmer shallow water with fresh eggs in them. I believe the cold water intrusion brought temperatures down below the minimum for reproduction and the garibaldi have temporarily suspended mating until the waters warm back up.
A few weeks back I reported on some interesting observations during my first night dive at the park in years. I noticed the normally highly aggressive males were not rushing out to prevent me from approaching their nests. In fact even when I got within inches, they seemed to just sit there and say "whatever." I was not aware that garibaldi males, like their blacksmith relatives, actually shelter at night and are not very active. Garibaldi specialist Dr. Paul Sikkel, who did much ground breaking work on garibaldi in Catalina waters a few decades ago, confirmed this. I guess we all need a little rest after an intense bout of mating. At least the garibaldi don't smoke!
Image caption: Female laying eggs in nest as male guards her, one of the red algae used to create nests; inadvertently collected garibaldi egg (1mm x 2mm) and male tending nest at night.
My very first column in this series was about our state marine fish, Gary Garibaldi, and his damsel family relatives. Currently I'm researching the second of two episodes on the garibaldi for my proposed "Munching & Mating in the Macrocystis" cable TV show. That means I've focused much of my recent diving and filming on them, as well as my Internet research during my surface intervals. This effort has given me enough for 40 minutes of video on their natural history, and that certainly merits another column on these colorful critters.
It seems that I first heard garibaldi were protected when I started diving Catalina waters 40 years ago. Much later I discovered they had not become our state salt water fish, and thereby received their protected status, until the 1990's. Of course the golden trout is our state fish, and was so designated in 1947. I never expect to see one since I shun fresh water (just like W. C. Fields did). The garibaldi's route to recognition was much bumpier. Way back in 1971 a report by the California Department of Fish & Game suggested garibaldi should be protected from recreational and commercial take. Like many such reports, that one remained on the shelf gathering dust until decades later.
In the late 1980's and early 1990's, collectors for the aquarium trade were vacuuming up young garibaldi off the reefs of Catalina and nearby San Clemente Islands. The Catalina Conservancy Divers (CCD) got involved in the effort to stop this. In 1993 Assembly Bill 1788 was signed into law restricting collecting of this species off Catalina's leeward coast, and allowing it elsewhere only between November and January, well outside of breeding season. A year later Assembly Bill 2812 would have protected this species as our state salt water fish, but it died in committee due to intense lobbying by the aquarium trade. Although only about 670 fish were reported as collected under permit that year, others estimated the take at several thousand. In 1995 my long-time friend Jean-Michel Cousteau and his Ocean Futures organization were instrumental in getting Assembly Bill 77 passed which protected the garibaldi and finally made it our State's marine fish.
We are now in the midst of mating season for these members of the damsel family. The pugnacious male garibaldi has established a nest site in his territory by weeding away all but three species of red algae (Ophidocladus californicus, Pterosiphonia dendroides and Spermothamnion snyderae if you really must know). The nests are very obvious as circular dark red patches on rocks, and may be as large as 10-15 sq. ft. I had noticed that nests in shallower waters tended to be on vertical surfaces, while those in deeper water were often on horizontal surfaces. At first I thought this might be to avoid direct sunlight on the eggs, but my research indicates it was due to the light requirements of the red algae in the nest.
The male attracts the lovely damsels to his lair by swimming in an oval-shaped pattern above the nest site. This is known as dipping, a behavior shared by many other damsel fish I've seen throughout the world. Females leave their own territories to survey the local guys, sometimes swimming as far as 650 feet from her territory to ensure she finds the right mate. Between her trips she must return to her territory to drive away competitors who might try munching her food supply in her absence. She may make many trips in her search for the guy with "the right stuff." Too bad she doesn't use the Plenty of Fish Internet dating site that I frequent... but then she may be aware of how unsuccessful that has been for me!
The ladies are very selective about their mates (just as the females of my species are... unfortunately). They inspect not only the male, but his behavior, the state of the nest and the condition of the eggs in it. Females prefer to lay eggs in nests containing fresh yellow eggs laid by other females. This is because eggs of different ages require different care by the tending male. If she selects a male with older greenish-gray eggs in his nest, she lays hers in a separate part of the nest. Her brood may number 15,-18,000 and the total number of eggs in a nest may be much greater. The male accepts many different females into his nest and tends the eggs for the 2-3 weeks it takes them to hatch into larvae. They will go through several brood cycles during mating season which may extend from March to as late as October.
I went to what I thought was a fresh (red) nest with no apparent eggs and sampled a very small patch (less than 1/2" square) of the red algae so I could videotape them under a microscope for my video. I was surprised to find that I had inadvertently sampled a few garibaldi eggs as well. They were not visible to my naked eye, so I didn't expect to see any under the microscope. The fresh yellow eggs are very obvious, but sometimes the older grayish eggs aren't as easy to see.
About two weeks ago I saw fresh yellow eggs in a number of nests. Temperatures at depth were in the toasty 60-66 degree Fahrenheit range. This is above the 59 F threshold believed to trigger reproduction in garibaldi. About two weeks ago, cold water coming up from deeper water dropped the temperatures to 53-57 degrees F. I spent several dives over two weekends during this period looking for garibaldi nests with older, developed eggs in them. I couldn't find any, only one or two nests in warmer shallow water with fresh eggs in them. I believe the cold water intrusion brought temperatures down below the minimum for reproduction and the garibaldi have temporarily suspended mating until the waters warm back up.
A few weeks back I reported on some interesting observations during my first night dive at the park in years. I noticed the normally highly aggressive males were not rushing out to prevent me from approaching their nests. In fact even when I got within inches, they seemed to just sit there and say "whatever." I was not aware that garibaldi males, like their blacksmith relatives, actually shelter at night and are not very active. Garibaldi specialist Dr. Paul Sikkel, who did much ground breaking work on garibaldi in Catalina waters a few decades ago, confirmed this. I guess we all need a little rest after an intense bout of mating. At least the garibaldi don't smoke!
Image caption: Female laying eggs in nest as male guards her, one of the red algae used to create nests; inadvertently collected garibaldi egg (1mm x 2mm) and male tending nest at night.
