>>Using the value for the average weight of a Emiliana huxleyi coccolith given here which is considerably less than the Roth figure, I get a total weight for 10 billion cells (each with 10 liths) of 0.234 g per litre, but whichever figure you use it is indeed a small proportion within a unit volume of water (slightly more by volume as the liths are denser than water).>>
YOUR numbers are BETTER than mine...taking up LESS space in a liter than mine. Ok, can we assume then that you do not have a problem with the 10 billion cells number...at least as far as how much mass is within each liter of water? The light question is still unresolved. Do you agree that the 3x number for chalk rock is probably just a typo or error by Woodmorappe (not Snelling)?
>>The accompanying graph shows that at 300 mg CaCO3-C per m3 (this refers to weight by Carbon atom I think) light intensity drops by 50 % at about 3 metres depth and 90% at 10m depth. >>
The way I read the chart, it seems that is also true (close to it...80% or so) of water with NO calcite in it...the blue line below. ALSO, the MORE the calcite (red) the MORE the brightness in the 0 to 5m depths, where most of the growth happens.
If brightness is really so important (not sure it is...compared to other factors), then the bloom conditions could INCREASE growth. Is it your view that a bloom ends because of loss of light? Or does it usually end when the nutrients (including Ca ions) have been depleted?
From your site: Although each coccolith is invisibly small, when they are present in enormous numbers in the water they cause large changes in the way that light is transmitted or reflected by the water. Figures 1 and 2 below show the affect that different components in the water have on the inherent optical properties of the water, i.e. on the probabilities of absorption (termination) and of scattering (reflection) of photons. It can be seen that an intense bloom of Ehux (100 mg CaCO3-C m-3) causes a large increase in the scattering at all wavelengths of light (400-700nm) relevant to phytoplankton, but no change to the absorption [Balch et al, 1991;>>
This seems to say that even with an enormous bloom, the light is SCATTERED but it is not blocked (terminated) AT ALL. So the phytoplankton absorb just as much light.
>>Firstly, the increased scattering causes the ocean to become more reflective, i.e. the ocean's albedo increases. A greater proportion of the photons which pass through the water-surface from air to water subsequently leave again, from water to air, after having been scattered by coccolith particles in the water. For a typical ocean, the proportion of photons re-emitted by the water increases from 1% when there are no coccoliths in the water, to 3% with 100 mg CaCO3-C m-3 of coccoliths in the water, to 7% with 300 mg CaCO3-C m-3 of coccoliths.>>
All this says is that because the water appears white from space, the reflection of solar energy goes from a very very low albedo (1%, meaning 99% is absorbed) to a still very low 7% (93% is absorbed). It is doubtful that this would be so much reflection that it hurts the coccolith production. Indeed it could increase it, in the 10m top layers. Maybe lower too.
Also, the liths themselves absorb NONE of the light...but just change its direction, resulting in a whiter optical condition in the water, but not affecting absorption. However, it is true that your article does make the claim that
"The coccoliths shade the deeper water, reducing the amount of light available there. This reduces the depth of water which is habitable for the phytoplankton, because they require a minimum light intensity to survive."
Let me ask this, Wibble, if these creatures THRIVE and grow lots more liths due to the brightness in the upper layers...but then get heavy and fall to the lower levels and die there...but the bloom itself is not affected because it keeps on growing while the light and nutrients (and Ca ions) are present...couldn't that still mean massive deposition of liths? It appears they (some varieties, anyway) usually grow down to 200m, and the light that far down is VERY low (i.e. 1%) anyway. So if the top layer has a 1000x increase, but that means they only grow down to 100m (where perhaps the 1% level now is)...then it could still be a massive increase over normal conditions. Especially if they die off more rapidly or shed more liths...but the growth of the bloom still continues.
>>I will point out that the website I referenced above cites an observation of the most intense bloom ever measured. This was 115 million cells per litre off Norway in 1955 which is about 10x higher than the previous highest I could find.>>
I appreciate your pointing that out. Another 10x gets us to the 10 billion number. The Flood would greatly affect many growth factors, I believe.
>>a flood on this scale would also introduce vast amounts of light obscuring sediment, and powerful water currents which would stop blooms forming (they need calm conditions)>>
Could be. All YECs I know of would put these blooms near the end of the Flood. Some put them AFTER the Flood year. I am not sure when the "calm" might happen in the deeper parts of the ocean. I thought you said the produce chalk sediments far from land...and our oceans TODAY (at the surface) can be far from "calm" out there. If there were months when the turmoil was gone, maybe the Flood waters would be that calm by near the end of the flood. Upwelling water from below (after the rain all stopped in 40 days) for 110 days...then 250 days of no more upwelling...might get the conditions close to what would allow blooms.
>>I already addressed this in post#13. Blooms only occur in the Upper photic zone and don't produce coccoliths where its dark.>>
Some species thrive in the "lower photic"...which goes down to 200m...where it is PRETTY DARK.
>>I've already given you a source that says that only a few, weakly calcified species are capable of heterotrophy>>
Morphometric Variability in the Extant Coccolithophores: Implications for the Fossil Record By Alicia Catherine Muzika Kahn
I did a very brief search and found a book which suggests the opposite.
The most prolific (42% at 120m depth...for one sample) species (Florisphaera profunda) in "deep photic zone" (DPZ) does produce much calcite in the form of polygoliths (a different shape of coccolith, layered like petals of a flower...in fact sometimes the liths are referred to as coccoliths) and the expert who wrote the book indicated they are possibly heterotrophic. They live at a depth where the light is 1% of that in the upper photic zone AND there are more nutrients. And if they are NOT heterotrophic, then so what? The Flood would provide them more nutrients, in the form of non-biotic minerals, such as Ca ions. That could massively increase their growth anyway.
>>I've shown you that 90% of light is extinguished at 10m depth in intense blooms today. There is clearly problem then with an unprecedented 10 billion per litre over a whole 200m depth. (eutrophic zone to 200m is in clear waters)>>
I don't think light would be the limiting factor. With ZERO coccoliths, the light is 80% at 10m anyway. Plus the DPZ (down to 200m), where abundant species live, only has 1% light.
>>Irrelevant if you have no light in addition to massive sediment load and surging currents. The chalk layers are being laid down towards the end of the year or so of Flood according to your model remember, when the waters are draining off the land.>>
I'd say the blooms occur well before draining off the land. Besides, if these blooms are in the middle of the ocean, it would not matter that much that land surfaces are rising. AND it is NOT "no light". The sediments got laid down in the early-mid Flood year, so the upper ocean (top 200m?) would be clear or clearing.