DIVE DRY WITH DR. BILL #381: BLACK ABALONE... GOING, GOING, GONE?
I arrived on the island August 24, 1969, on board the Golden Doubloon dive boat. My stay here was to be a one year adventure, and a chance to save up enough $$$ to return to the Greek Islands and write the Great American (Dive?) Novel. Having grown up in Chicago, I knew of Catalina since my Great Uncle "Papa George" Halas owned the Chicago Bears and at that time they played in beautiful Wrigley Field. On occasion Dad and I got to sit in the family box next to the Wrigley's seats. Of course we were from the poor side of the family... "Papa George" had married my Great Aunt Minnie Bushing, and although my grandfather had helped bankroll the formation of the team, in those days it didn't take a fortune! After all, why should a sports team get paid "big bucks" for just playing a game.
I had taken the teaching job at the old Toyon school sight unseen... after I fell asleep during my interview in the Hayes Bickford Cafe near Harvard. I had little idea what to expect when I arrived on the island. During the month I spent with my parents in Chicago before departing, I read a novel by John Fowles called The Magus suggested to me by my friend Susie Hoover. The book was about a young British schoolteacher who took a job teaching at a small private school on the Greek Island of Spetses where I had spent a few days during the summer of 1968 (referring to it as Spetsai in my trip diary). It turned out to be nearly prophetic about what would eventually happen to me on Catalina. I've read the book dozens of times since then and still can't figure out the ending.
However, there were several things I was not aware of when I finally arrived on Catalina. I woke up to the smell of bacon and came up on the dive boat's deck to see a magnificent island that could easily have been the equal of the Greek islands of Rhodes or Crete where I did a fair bit of free diving the previous summer. The only major differences were that the islanders spoke English... and there was no ouzo to be found. I convinced Wayne Stout at Tom Cat's Liquor to buy a case, promising him I'd buy anything left over at the end of the school year. Now I was set to explore the new wonders that awaited me on Catalina. One of the first was some gooey green mess called guacamole. Not bad. Then my students introduced me to a snail known as an abalone. I was hooked!
But this column isn't about me, it's about the black abalone (Haliotis cracherodii)... the poor relative of the greens, pinks, reds and whites. When I arrived on the island, this subtidal and often intertidal snail was so abundant they were stacked on top of one another. One reason they were so numerous was the regional extinction of the sea otter in our waters which was a major predator on them before the early 19th century. However, I was told not to bother with the blacks because they were very tough. Living up high where the waves and swell impacted them, they needed stronger muscles known as a "foot" to hold onto the rocks for dear life. So instead, I dove deeper for the more tender species of this group, enjoying many dinners of abalone and lobster in my first six years on Catalina. About 1975 I stopped taking both myself, but still enjoy a lobster or two today if someone else does the hunting.
As the other species of abalone declined in our waters, more people were willing to pound a bit harder and took the easy-to-capture black abalone from the rocks. A significant commercial fishery for blacks took large numbers from the 1930s through the 1960s. Then, in the mid 1980s a disease known as withering syndrome or withering foot syndrome struck the abalone populations in the warmer waters of southern California. This disease is triggered by a bacterial pathogen that causes the muscular foot to atrophy and wither away. The bacterium, Xenohaliotis californiensis, attacks the lining of the digestive tract which reduces the production of the enzymes necessary to digest its food. To compensate for this, the abalone consumes its own muscle tissue in the foot to survive.
Without the foot, the abalone can not protect itself from predators by adhering tightly to the rocks, nor can it easily feed since the foot is used to capture drift algae like kelp. Once this disease infects a population, the decline is precipitous, with mortality as high as over 90% within a year. Some individuals may remain healthy, but it has been many years since I've seen a black abalone in our waters. If they carry the bacterium in their system, an outbreak among the survivors may be triggered by changing environmental conditions such as the warmer water temperatures experienced during El Niño years.
It is hard to imagine that a once extremely common species like the black abalone could almost totally disappear from the waters off southern California within a decade or two. Even scarier is the apparent fact, based on scientific studies, that the disease is working its way north up the central California coast where it is even threatening populations in the Monterey Bay area. The initial impacts were largely restricted to our southern waters since the pathogen flourished in the warmer waters here. Abalone in colder waters were thought to be somewhat "immune" to the devastating effects since the pathogen did not fare as well there. However, the waters off central California are warming, presumably due to global climate change. The future for the black abalone there may not look good. This could also spell trouble for the sea otter that still feeds on these abalone along that stretch of California's coast.
Both commercial and recreational take of this species was stopped in 1993. The black abalone was finally listed as an endangered species by NOAA last year (2009). Any recovery is complicated by the continued presence of withering foot syndrome, and also the abalone's reproductive strategy. Abalone take 5 to 7 years to reach sexual maturity. When mature, they need other abalone in close proximity to mate with since they are broadcast spawners, releasing sperm and eggs into the water column. Abalone must get up close and personal for success... with estimates of the required "level of intimacy" being within 18" to three feet. Just last week the Center for Biological Diversity sued the federal government for failing to designate and protect what is known as "critical habitat" for them (as is required by law within one year of achieving endangered status).
How many more species of marine life will reach endangered status, or extinction, in my lifetime? Certainly far too many. The failure of a ban on blue fin tuna, prized in Japan for sushi, at this month's United Nations Convention on International Trade in Endangered Species (CITES) meeting was very sad news. A similar fate occurred for proposals to ban the trade of red and pink coral used in jewelry, and four species of sharks (scalloped hammerhead, oceanic white tip, porbeagle and spiny dogfish). We have seen that marine species and ocean ecosystems can be resilient if action is taken in time. Look at the apparent recovery of our giant sea bass. However, action needs to be taken... and time is probably running out for dozens (and possibly hundreds to thousands) of species due largely to human actions... including lobbying by commercial interests from a number of other countries.
Image caption: A black abalone in the intertidal at Toyon Bay ca. 1972.
I arrived on the island August 24, 1969, on board the Golden Doubloon dive boat. My stay here was to be a one year adventure, and a chance to save up enough $$$ to return to the Greek Islands and write the Great American (Dive?) Novel. Having grown up in Chicago, I knew of Catalina since my Great Uncle "Papa George" Halas owned the Chicago Bears and at that time they played in beautiful Wrigley Field. On occasion Dad and I got to sit in the family box next to the Wrigley's seats. Of course we were from the poor side of the family... "Papa George" had married my Great Aunt Minnie Bushing, and although my grandfather had helped bankroll the formation of the team, in those days it didn't take a fortune! After all, why should a sports team get paid "big bucks" for just playing a game.
I had taken the teaching job at the old Toyon school sight unseen... after I fell asleep during my interview in the Hayes Bickford Cafe near Harvard. I had little idea what to expect when I arrived on the island. During the month I spent with my parents in Chicago before departing, I read a novel by John Fowles called The Magus suggested to me by my friend Susie Hoover. The book was about a young British schoolteacher who took a job teaching at a small private school on the Greek Island of Spetses where I had spent a few days during the summer of 1968 (referring to it as Spetsai in my trip diary). It turned out to be nearly prophetic about what would eventually happen to me on Catalina. I've read the book dozens of times since then and still can't figure out the ending.
However, there were several things I was not aware of when I finally arrived on Catalina. I woke up to the smell of bacon and came up on the dive boat's deck to see a magnificent island that could easily have been the equal of the Greek islands of Rhodes or Crete where I did a fair bit of free diving the previous summer. The only major differences were that the islanders spoke English... and there was no ouzo to be found. I convinced Wayne Stout at Tom Cat's Liquor to buy a case, promising him I'd buy anything left over at the end of the school year. Now I was set to explore the new wonders that awaited me on Catalina. One of the first was some gooey green mess called guacamole. Not bad. Then my students introduced me to a snail known as an abalone. I was hooked!
But this column isn't about me, it's about the black abalone (Haliotis cracherodii)... the poor relative of the greens, pinks, reds and whites. When I arrived on the island, this subtidal and often intertidal snail was so abundant they were stacked on top of one another. One reason they were so numerous was the regional extinction of the sea otter in our waters which was a major predator on them before the early 19th century. However, I was told not to bother with the blacks because they were very tough. Living up high where the waves and swell impacted them, they needed stronger muscles known as a "foot" to hold onto the rocks for dear life. So instead, I dove deeper for the more tender species of this group, enjoying many dinners of abalone and lobster in my first six years on Catalina. About 1975 I stopped taking both myself, but still enjoy a lobster or two today if someone else does the hunting.
As the other species of abalone declined in our waters, more people were willing to pound a bit harder and took the easy-to-capture black abalone from the rocks. A significant commercial fishery for blacks took large numbers from the 1930s through the 1960s. Then, in the mid 1980s a disease known as withering syndrome or withering foot syndrome struck the abalone populations in the warmer waters of southern California. This disease is triggered by a bacterial pathogen that causes the muscular foot to atrophy and wither away. The bacterium, Xenohaliotis californiensis, attacks the lining of the digestive tract which reduces the production of the enzymes necessary to digest its food. To compensate for this, the abalone consumes its own muscle tissue in the foot to survive.
Without the foot, the abalone can not protect itself from predators by adhering tightly to the rocks, nor can it easily feed since the foot is used to capture drift algae like kelp. Once this disease infects a population, the decline is precipitous, with mortality as high as over 90% within a year. Some individuals may remain healthy, but it has been many years since I've seen a black abalone in our waters. If they carry the bacterium in their system, an outbreak among the survivors may be triggered by changing environmental conditions such as the warmer water temperatures experienced during El Niño years.
It is hard to imagine that a once extremely common species like the black abalone could almost totally disappear from the waters off southern California within a decade or two. Even scarier is the apparent fact, based on scientific studies, that the disease is working its way north up the central California coast where it is even threatening populations in the Monterey Bay area. The initial impacts were largely restricted to our southern waters since the pathogen flourished in the warmer waters here. Abalone in colder waters were thought to be somewhat "immune" to the devastating effects since the pathogen did not fare as well there. However, the waters off central California are warming, presumably due to global climate change. The future for the black abalone there may not look good. This could also spell trouble for the sea otter that still feeds on these abalone along that stretch of California's coast.
Both commercial and recreational take of this species was stopped in 1993. The black abalone was finally listed as an endangered species by NOAA last year (2009). Any recovery is complicated by the continued presence of withering foot syndrome, and also the abalone's reproductive strategy. Abalone take 5 to 7 years to reach sexual maturity. When mature, they need other abalone in close proximity to mate with since they are broadcast spawners, releasing sperm and eggs into the water column. Abalone must get up close and personal for success... with estimates of the required "level of intimacy" being within 18" to three feet. Just last week the Center for Biological Diversity sued the federal government for failing to designate and protect what is known as "critical habitat" for them (as is required by law within one year of achieving endangered status).
How many more species of marine life will reach endangered status, or extinction, in my lifetime? Certainly far too many. The failure of a ban on blue fin tuna, prized in Japan for sushi, at this month's United Nations Convention on International Trade in Endangered Species (CITES) meeting was very sad news. A similar fate occurred for proposals to ban the trade of red and pink coral used in jewelry, and four species of sharks (scalloped hammerhead, oceanic white tip, porbeagle and spiny dogfish). We have seen that marine species and ocean ecosystems can be resilient if action is taken in time. Look at the apparent recovery of our giant sea bass. However, action needs to be taken... and time is probably running out for dozens (and possibly hundreds to thousands) of species due largely to human actions... including lobbying by commercial interests from a number of other countries.
Image caption: A black abalone in the intertidal at Toyon Bay ca. 1972.
