DIVE DRY WITH DR. BILL #815: GARBAGE PIT DOWN UNDER
I recently returned from the 50th reunion of my Harvard Class of 1969 in Boston. It was wonderful too see the campus at my alma mater (probably for the last time), but even more so to see so many dorm mates from freshmen year, two of my roommates and their wives from senior year and many other classmates. There was one guy I barely knew while I was an undergraduate. I remember shaking his hand when he ran for class office and, much later, walking over to a blonde at a dorm party and being warned off by another classmate "That's Al's girl."
Yes, that classmate was none other than former Vice President Al Gore. He delivered a very passionate talk about climate change at one of our symposia. Many of my classmates said that if he had campaigned as energetically back in 2000, he would have beaten Bush (he did anyway, didn't he!). Al and I had a very early introduction to the topic of climate change (or global warming as it was called by many) thanks to Harvard professors like Roger Revelle.
Well, I'm not going to talk about what rapid climate change is going to do to us next decade or even 50 years from now. I'm not Nostradamus. If I were maybe I'd have become rich by foreseeing the future. However I do believe the data, both in terms of CO2 and temperature increases over the relatively short span of the industrial age. I've seen the evidence of ocean warming in the gradual northward migration into our waters of species usually found further to the south.
Rather than project forward, I'm going to look backward in this column. At least that way we can be reasonably certain we are right. More than a decade ago I was diving in the area of Hen Rock near White's Landing. At a depth of about 40 fsw (depending on tide), I saw a large number of shells scattered across the sandy bottom. Upon closer inspection, many of these were abalone (Haliotis spp.) or wavy top snails (Megastraea undosa).
Now as a well-edumacated marine biologist, I was pretty sure that these species did not congregate in a specific spot to die. Indeed, both species were considered delicacies by the Native Americans living on the island in the past, which led me to suspect this was one of their garbage heaps or middens. Many of us who live on or may have visited Catalina have probably seen such garbage heaps on land. I was first introduced to them in 1969 when the Toyon School did an emergency salvage archaeological dig at Two Harbors in preparation for the construction of a major hotel there. I have yet to see them break ground on it!
But why was this midden 40 ft down under (and I don't mean in Australia)? To the best of my knowledge no Pimugnan possessed SCUBA gear although some may have been into free diving. But why descend to deposit your trash in Davy Jones' Locker? A much more plausible explanation suggests that this spot was at the surface a few thousand years ago during the late Ice Age. As the glaciers melted and sea level rose, it dropped into the briny deep.
Yes, climate and sea level have changed many times over the 4.5 billion years of Planet Ocean's history. Although many, probably most, of those changes have occurred over reasonably long periods of time, a few have been fairly abrupt. One such example happened 252 million years ago (shortly before I was born) during the Permo-Triassic extinction which killed off the dinosaurs and many other species. The abruptness of this change is believed to have been due to the impact of an asteroid which created a global winter.
The mass extinctions we are seeing today, both due to human insensitivity toward wildlife and factors such as climate change, are happening on a very short time frame as well. The industrial age began in the United Kingdom about 1760 and in other areas as late as 1840. If we take 1800 as a baseline, that's just over 200 years. That's a pretty short time span in geologic time, thus causing difficulties in many species' abilities to adapt. Heck, if you believe literally in the Bible (or at least the human translations of the original documents), Methuselah and Noah would be just youngsters over that time frame!
© 2019 Dr. Bill Bushing. For the entire archived set of more than 800 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Images of the submerged Native American Midden near Hen Rock taken back in 2007.
I recently returned from the 50th reunion of my Harvard Class of 1969 in Boston. It was wonderful too see the campus at my alma mater (probably for the last time), but even more so to see so many dorm mates from freshmen year, two of my roommates and their wives from senior year and many other classmates. There was one guy I barely knew while I was an undergraduate. I remember shaking his hand when he ran for class office and, much later, walking over to a blonde at a dorm party and being warned off by another classmate "That's Al's girl."
Yes, that classmate was none other than former Vice President Al Gore. He delivered a very passionate talk about climate change at one of our symposia. Many of my classmates said that if he had campaigned as energetically back in 2000, he would have beaten Bush (he did anyway, didn't he!). Al and I had a very early introduction to the topic of climate change (or global warming as it was called by many) thanks to Harvard professors like Roger Revelle.
Well, I'm not going to talk about what rapid climate change is going to do to us next decade or even 50 years from now. I'm not Nostradamus. If I were maybe I'd have become rich by foreseeing the future. However I do believe the data, both in terms of CO2 and temperature increases over the relatively short span of the industrial age. I've seen the evidence of ocean warming in the gradual northward migration into our waters of species usually found further to the south.
Rather than project forward, I'm going to look backward in this column. At least that way we can be reasonably certain we are right. More than a decade ago I was diving in the area of Hen Rock near White's Landing. At a depth of about 40 fsw (depending on tide), I saw a large number of shells scattered across the sandy bottom. Upon closer inspection, many of these were abalone (Haliotis spp.) or wavy top snails (Megastraea undosa).
Now as a well-edumacated marine biologist, I was pretty sure that these species did not congregate in a specific spot to die. Indeed, both species were considered delicacies by the Native Americans living on the island in the past, which led me to suspect this was one of their garbage heaps or middens. Many of us who live on or may have visited Catalina have probably seen such garbage heaps on land. I was first introduced to them in 1969 when the Toyon School did an emergency salvage archaeological dig at Two Harbors in preparation for the construction of a major hotel there. I have yet to see them break ground on it!
But why was this midden 40 ft down under (and I don't mean in Australia)? To the best of my knowledge no Pimugnan possessed SCUBA gear although some may have been into free diving. But why descend to deposit your trash in Davy Jones' Locker? A much more plausible explanation suggests that this spot was at the surface a few thousand years ago during the late Ice Age. As the glaciers melted and sea level rose, it dropped into the briny deep.
Yes, climate and sea level have changed many times over the 4.5 billion years of Planet Ocean's history. Although many, probably most, of those changes have occurred over reasonably long periods of time, a few have been fairly abrupt. One such example happened 252 million years ago (shortly before I was born) during the Permo-Triassic extinction which killed off the dinosaurs and many other species. The abruptness of this change is believed to have been due to the impact of an asteroid which created a global winter.
The mass extinctions we are seeing today, both due to human insensitivity toward wildlife and factors such as climate change, are happening on a very short time frame as well. The industrial age began in the United Kingdom about 1760 and in other areas as late as 1840. If we take 1800 as a baseline, that's just over 200 years. That's a pretty short time span in geologic time, thus causing difficulties in many species' abilities to adapt. Heck, if you believe literally in the Bible (or at least the human translations of the original documents), Methuselah and Noah would be just youngsters over that time frame!
© 2019 Dr. Bill Bushing. For the entire archived set of more than 800 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page
Image caption: Images of the submerged Native American Midden near Hen Rock taken back in 2007.
