PAM Fluorometer Study

[Steve Tyree]

Dana,

Looks like you are making some interesting contacts in Hawaii !
Nice article. However, as usual I have a few questions.

In reference to this part of the experiment

"A jig, holding the lamps, allowed quick and easy adjustments of
light intensity to predetermined levels. The submersible probe
of an Apogee Instruments quantum meter was placed immediately
next to the coral used in the experiments and measured light
energy, more specifically Photosynthetically Active Radiation
(PAR)."

You measured the 'energy' of the light to determine the
correct location for each predetermined jig position ? Dont
you mean you measured the Photon Flux Density ? Did you happen
to record the actual distance on the jig where the two different
bulbs were set for each predetermined intensity level ? Do you
know the total PAR PPFD emitted from the bulbs ?


Also, I am trying to determine the exact procedure you utilized to
calculate yield. Is it correct to assume that you exposed the coral
to the predetermined light intensities of each bulb for a
short pulse or was it over a few minutes ? Did you utilize the
saturation light pulse of the PAM meter ? If you only exposed the
corals to the bulb PPFD's given, the autofluorescence yield will include
both non-photochemical quenching and photochemical quenching. According
to the DIVING-PAM fluorometer manual the only way you can determine
autofluorescence yield due to photochemical quenching is by utilizing
a saturation pulse. You then determine the delta between saturaion
autofluorescence yield and non-photosaturation (lower light)
autofluorescence yield. The manual recommends utilizing the built
in pulse that the meter has. In fact they specifically state that the
only way to separate background ambient light levels from photosynthetic
autofluorescence is to utilize the short modulated pulses that the
PAM meter can emit. How can the light emitted from a bulb be modulated
in 3 micro second bursts and how can you sync that to the PAM meter?


Is it also possible that the fluorescent pigments within the Fungia
could have been interferring with the autofluorescence measurement ?
What specific steps did you take to negate any potential
fluorescent interference ? Would it not be best to measure isolated
zooxanthellae to avoid potential interference from the fluorescent
properties potentially inherent in the animal tissue ?


Another question concerns the physics of light capture. I am
assuming that you think the yellow and orange light emitted by
the 4,000 K was absorbed by pigments within the PCP
(peridinin-chlorophyl-protein) complex and utilized by the
photoreaction centers. Just which pigment in that complex has
the physical capabilities to absorb yellow or orange light ?


Can you site any captive reef that maintianed reef building
stony corals under this 175 watt 4,000 K halide successfully
for a year ? I am particularly concerned with Acropora, Montipora,
Pocilopora, etc .. Every aquarist I have meet that tried these
'inexpensive bulbs' did not have long term success. Can anyone
upload closeup images of a coral maintained for a year under a
4,000 K 175 watt bulb ? I know you may not be advocating this
particular bulb, but if your readings are applicable there should
be some success somewhere.


PS - No rush needed on this thread. I am very busy and it looks
like you also have your hands full. Diving with Mazel !
Whales leaping out your front window ! Tough life :>


Steve Tyree

 

[Dana Riddle]

Hi Steve,

Long time, so see. I do hope things are going well for you.

>>Nice article. However, as usual I have a few questions.<<

Thanks, and I thought so ;-).

>>You measured the 'energy' of the light to determine the
correct location for each predetermined jig position ? Dont
you mean you measured the Photon Flux Density ? Did you happen
to record the actual distance on the jig where the two different
bulbs were set for each predetermined intensity level ? Do you
know the total PAR PPFD emitted from the bulbs ? <<

Yes, PPFD. I did not record the height of the lamps. I have the Ocean Optics spec here now and the spectral data is in an Excel file. It appears as this article will go through post-peer review and I’m sure that information will be requested. The Ocean Optics instrument is a spectrometer and is up-gradable to a spectroradiometer with special software, so, for now, I’ll have to report the PPFDs from the PAR meter.

>>Also, I am trying to determine the exact procedure you utilized to
calculate yield. Is it correct to assume that you exposed the coral
to the predetermined light intensities of each bulb for a
short pulse or was it over a few minutes ? Did you utilize the
saturation light pulse of the PAM meter ? If you only exposed the
corals to the bulb PPFD's given, the autofluorescence yield will include
both non-photochemical quenching and photochemical quenching. According
to the DIVING-PAM fluorometer manual the only way you can determine
autofluorescence yield due to photochemical quenching is by utilizing
a saturation pulse. You then determine the delta between saturaion
autofluorescence yield and non-photosaturation (lower light)
autofluorescence yield. The manual recommends utilizing the built
in pulse that the meter has. In fact they specifically state that the
only way to separate background ambient light levels from photosynthetic
autofluorescence is to utilize the short modulated pulses that the
PAM meter can emit. How can the light emitted from a bulb be modulated
in 3 micro second bursts and how can you sync that to the PAM meter?<<

Using the non-saturating pulses of the PAM would have negated the experiment’s intent, so the lamps took the place of the PAM’s lamp at the low PPFDs. The length of exposure to the individual PPFD values was of short duration, followed by the 18,000 µM saturating pulse of the PAMs halogen lamp. We wanted to use ambient light and not the PAM’s sub-saturating pulses! So, yes, we looked at Fo, Fm and others. I’m not sure of the differences between the Mini-PAM and Diving-PAM.

>>Is it also possible that the fluorescent pigments within the Fungia
could have been interferring with the autofluorescence measurement ?
What specific steps did you take to negate any potential
fluorescent interference ?<<

I’ve done some reflectance/fluorescence experiments with that particular Fungia specimen. Although the animal has a pink and green fluorescence around the oral disc, the USB-2000-FL (specifically designed for fluorescence work) was unable to detect fluorescence from the brown tissues. Reflectance has the same signature of brown corals. Not to say there isn’t fluorescence there, just this instrument can’t detect it, and there is certainly no fluorescence apparent to the eye. I’ll take a photo of this coral next time I’m at NELHA – it is pretty darn brown.

>> Would it not be best to measure isolated
zooxanthellae to avoid potential interference from the fluorescent
properties potentially inherent in the animal tissue ? <<

That would certainly be an interesting experiment. As you know, the PAM was designed to measure fluorescent signals in situ, thus avoiding all the extra work.

>>Another question concerns the physics of light capture. I am
assuming that you think the yellow and orange light emitted by
the 4,000 K was absorbed by pigments within the PCP
(peridinin-chlorophyl-protein) complex and utilized by the
photoreaction centers. Just which pigment in that complex has
the physical capabilities to absorb yellow or orange light ? <<

Action spectra of isolated zooxanthellae show absorption at these wavelengths, and I’m assuming that these are minor absorption by chlorophylls A and C2. Same thing shows up in reflectance experiments of host/zooxanthellae.

>>Can you site any captive reef that maintianed reef building
stony corals under this 175 watt 4,000 K halide successfully
for a year ? I am particularly concerned with Acropora, Montipora,
Pocilopora, etc .. Every aquarist I have meet that tried these
'inexpensive bulbs' did not have long term success. Can anyone
upload closeup images of a coral maintained for a year under a
4,000 K 175 watt bulb ? I know you may not be advocating this
particular bulb, but if your readings are applicable there should
be some success somewhere.<<

Yes, me. We used a Philips 4,000K lamp over a 70-gallon aquarium for about 7 months, I think, before we gave the tank and all the corals to Bob Keane just before moving to Hawaii. We grew clams and SPS corals (with good coloration) under this lamp. Send me your email address and I’ll scan and send a photo. Hard to tell about your friends’ experiences. A number of factors are involved (including PPFD depreciation).

>>PS - No rush needed on this thread. I am very busy and it looks
like you also have your hands full. Diving with Mazel !
Whales leaping out your front window ! Tough life :> <<

And getting tougher ;-).

Aloha,
Dana

 

[Steve Tyree]

>Dana wrote

>Using the non-saturating pulses of the PAM would have negated the experiment’s
>intent, so the lamps took the place of the PAM’s lamp at the low PPFDs. The
>length of exposure to the individual PPFD values was of short duration,
>followed by the 18,000 µM saturating pulse of the PAMs halogen lamp. We
>wanted to use ambient light and not the PAM’s sub-saturating pulses! So, yes,
>we looked at Fo, Fm and others. I’m not sure of the differences between the
>Mini-PAM and Diving-PAM.

PAM is new to me and I am trying to understand exactly what was measured in this
particular experiemnt. Let me see if I understand what was done. The Fungia was
exposed to three different PAR PPFD emissions from two different metal halides
with differing spectral qualities. The lamps were calibrated by distance to
be emitting equivalent PAR PPFD values to an area near the coral for the three
separate exposures. The PAM meter was utilized to determine the quantum yield
generated from each lamp exposure. This reading was not pulse modulated and its
autofluorescence measurement would be affected by ambient light above 700 nm.
Nothing was done to differentiate ambient light > 700 nm and auto fluorescent
light due to photosynthesis. At each exposure the coral was then exposed to the
short saturating light pulse from the PAM meter and the autofluoresence from
photosynthesis was determined. This reading was pulse modulated and would be
able to differetiate ambient light > 700 nm from the resulting pulsed
autofluorescence due to photosynthesis. This pulse by the way only emits light
at about 660 nm and is meant to only be absorbed by chl a within its red
light absorption maxima. You then took the delta between the two. This type
of experiment has some other potential problems. The saturating pulse from the
PAM meter has vastly different spectral qualities then the light from the bulbs.
Also, peridinin is the dominant light collector within dinoflagellates
(ie Symbiodinium). The PCP complex is unique in that respect. So the pulse from
the PAM meter will not be collected by the dominant light collecting pigment
located within the zooxanthellae. Chl a will attempt to absorb it but the
primary function of chl a within the PCP complex is to process the light absorbed
by peridinin and pass it on if it is not overwhelmed. To really analyze
the light collection capabilities of dinoflagellates the PAM meter should be
emitting blue light for its pulse. At least in my humble opinion. I really am
having a hard time determining just what this type of experiment would be
analyzing.


>I’ve done some reflectance/fluorescence experiments with that particular Fungia
>specimen. Although the animal has a pink and green fluorescence around the oral
>disc, the USB-2000-FL (specifically designed for fluorescence work) was unable
>to detect fluorescence from the brown tissues. Reflectance has the same signature
>of brown corals. Not to say there isn’t fluorescence there, just this instrument
>can’t detect it, and there is certainly no fluorescence apparent to the eye. I’ll
>take a photo of this coral next time I’m at NELHA it is pretty darn brown.

Well you definitly cannot use the human eye to judge the amount of fluorescent
pigments that are present within a coral. The vast majority of shallow water
corals have medium to high concentrations of the pigments, even when the corals
appear brown to the human eye. The saturating pulse from the PAM meter would not
stimulate the red fluorescing pocilloporin, but the light from the bulbs
surely will.


>That would certainly be an interesting experiment. As you know, the PAM was
>designed to measure fluorescent signals in situ, thus avoiding all the extra work.

They are using it on some phytoplankton cultures. I bet though the original
patented designers had no clue someone would someday use the instrument to
measure the chlorophyll a autofluorescence from an animal :>


>Action spectra of isolated zooxanthellae show absorption at these wavelengths,
>and I’m assuming that these are minor absorption by chlorophylls A and C2. Same
>thing shows up in reflectance experiments of host/zooxanthellae.


Well the absorption curves for those two pigments, in isolation, show no
physical capability to absorb yellow or orange light. So another possibility
is that a change occurs to those two pigments as a reult of being bound in the
PCP complex. Unfortunately, no such drastic change is known. The only other
possibility is that a different unknown pigment is responsable. Concerning the
action spectrum cited - Do you know what the resolution of that particular
action spectrum was ? There is also an inherent problem with curves of this
nature. They overestimate the valleys and under estimate the peaks due to a
statistical artifact known as the 'package effect'. This is why curves of
this nature should really only be used to find the absorption peaks and
shoulders on the peaks. You can see the chl a and peridinin peaks very easy
in your referenced action spectrum.


>Yes, me. We used a Philips 4,000K lamp over a 70-gallon aquarium for about 7
>months, I think, before we gave the tank and all the corals to Bob Keane just
>before moving to Hawaii. We grew clams and SPS corals (with good coloration)
>under this lamp. Send me your email address and I’ll scan and send a photo.
>Hard to tell about your friends’ experiences. A number of factors are involved
>(including PPFD depreciation).


Send it to [email protected] . Please make sure its a small GIF file in
byte size but large in resolution. Can you list the sps corals that grew under
these bulbs ? Also note color morph and growth form, if you have the time. In
my travels I have now meet three people who tried these bulbs with sps and
failed. Dont know the specifics, but they tried the bulbs based on articles they
read online. Yours is the first case I have ever heard of where they apparently
worked for at least 7 months. Were they the 175 watt models ? What was the total
wattage in 4,000 K bulbs and what was the size of the reef. Were the corals fed ?
Were they the only source of light ?

Steve Tyree

 

[Dana Riddle]

Hi Steve,

To address your concerns...

>>Nothing was done to differentiate ambient light > 700 nm and auto fluorescent
light due to photosynthesis. At each exposure the coral was then exposed to the
short saturating light pulse from the PAM meter and the autofluoresence from
photosynthesis was determined. This reading was pulse modulated and would be
able to differetiate ambient light > 700 nm from the resulting pulsed
autofluorescence due to photosynthesis. This pulse by the way only emits light
at about 660 nm and is meant to only be absorbed by chl a within its red
light absorption maxima. You then took the delta between the two. This type
of experiment has some other potential problems. The saturating pulse from the
PAM meter has vastly different spectral qualities then the light from the bulbs.
Also, peridinin is the dominant light collector within dinoflagellates
(ie Symbiodinium). The PCP complex is unique in that respect. So the pulse from
the PAM meter will not be collected by the dominant light collecting pigment
located within the zooxanthellae. Chl a will attempt to absorb it but the
primary function of chl a within the PCP complex is to process the light absorbed
by peridinin and pass it on if it is not overwhelmed. To really analyze
the light collection capabilities of dinoflagellates the PAM meter should be
emitting blue light for its pulse. At least in my humble opinion. I really am
having a hard time determining just what this type of experiment would be
analyzing.
Re: Peridinin as the major pigment – what is your basis for that statement? Chl A is the major photopigment from the literature I’ve seen with peridinin as a major, though secondary, pigment. Peridinin collects and transfers light energy quite efficiently to PS II!
The 18,000 µmol flash from the halogen lamp (blue-enriched) saturates the photosystem; obviously this lamp cannot replicate sunlight at dawn, noon, twilight or any of the infinite spectral characteristics of sunlight filtered by oceanic or coastal waters, but it is used just the same by Mini-PAMs and Diving-PAMs. By its very nature, this lamp is “unnatural.” This halogen lamp is “white” and certainly contains those wavelengths harvested by peridinin. From what I understand, the same lamps are used in the Mini- and Diving-PAMs. I don’t think the photopigments care about the quality of light used for saturation, as long as they are saturated. The goal is to close the reaction centers. Obviously, Walz had to standardize the saturating light source and researchers are “stuck” with it, even if they’re doing coral/zooxanthellae P/I curves at 30 meters depth.
Halogen and other lamps produce near-IR and IR radiation and obviously the fiber optic cable transmits them. Though filtered, some near-IR makes it through. Corals also reflect these wavelengths quite efficiently.
The Ocean Optics spec I have has the ability to collect wavelengths in the near IR range, and both lamps generate very little within that range. At the low PPFD values we used, I don’t believe there would be false fluorescence. When I have time, I’ll check those lamps under identical PAR values and calculate the amount of energy above 710 nm from each lamp. The Ocean Optics used for analyses of spectral signatures within the article was best suited for UV/VIS, while my new one is best at UV(~350 and up)/ VIS and near IR, so this information is just recently available. BTW, since the spectral signatures were for illustrative purposes only in the article, I did not correct for the instrument’s electrical dark signal – it wasn’t necessary for the intended use. So don’t be mislead by the apparent near-IR in those graphs.
As a minor detail, the Mini-PAMs red LED peaks at 650 nm.

>>Well you definitly cannot use the human eye to judge the amount of fluorescent
pigments that are present within a coral. The vast majority of shallow water
corals have medium to high concentrations of the pigments, even when the corals
appear brown to the human eye. The saturating pulse from the PAM meter would not
stimulate the red fluorescing pocilloporin, but the light from the bulbs
surely will.<<
Sometimes I should just keep my mouth shut. ;-). If I could truly judge fluorescence by eye, I would have kept the big bucks I shelled out for the Ocean Optics spectrometer. This instrument hasn’t found any fluorescent pigments in this particular Fungia specimen (aside from the oral disc). Fluorescent host pigments played no part in this experiment.

>>Well the absorption curves for those two pigments, in isolation, show no
physical capability to absorb yellow or orange light. So another possibility
is that a change occurs to those two pigments as a reult of being bound in the
PCP complex. Unfortunately, no such drastic change is known. The only other
possibility is that a different unknown pigment is responsable. Concerning the
action spectrum cited - Do you know what the resolution of that particular
action spectrum was ? There is also an inherent problem with curves of this
nature. They overestimate the valleys and under estimate the peaks due to a
statistical artifact known as the 'package effect'. This is why curves of
this nature should really only be used to find the absorption peaks and
shoulders on the peaks. You can see the chl a and peridinin peaks very easy
in your referenced action spectrum.<<
Steve, see Kirk’s “Light and Photosynthesis in Aquatic Ecosystems.” I’m basing my statements on the spectral absorption curves of chl A and C on pages 33 and 35. Not sure of the “package effect” of these charts. Based on research I’ve done, there is a fairly strongly absorption of yellow and orange wavelengths by brown corals (even in those demonstrating no fluorescence). When light intensity gets high (or a lamp is heavily weighted with these wavelengths), they are no longer absorbed and show as part of the reflectance. It’s a bit of a mystery to me too. Charlie Mazel found absorption spectra in coral tissues that were identical to phycoerythrin, though I’ve never seen this pigment mentioned in any other coral references.

>>Send it to [email protected] . Please make sure its a small GIF file in
byte size but large in resolution. Can you list the sps corals that grew under
these bulbs ? Also note color morph and growth form, if you have the time. In
my travels I have now meet three people who tried these bulbs with sps and
failed. Dont know the specifics, but they tried the bulbs based on articles they
read online. Yours is the first case I have ever heard of where they apparently
worked for at least 7 months. Were they the 175 watt models ? What was the total
wattage in 4,000 K bulbs and what was the size of the reef. Were the corals fed ?
Were they the only source of light ? <<
I’ll have to get the photo and details to you later.

Aloha,
Dana

 

[Steve Tyree]

Dana,

>Re: Peridinin as the major pigment – what is your basis for that statement?
>Chl A is the major photopigment from the literature I’ve seen with peridinin as a
>major, though secondary, pigment. Peridinin collects and transfers light energy
>quite efficiently to PS II! The 18,000 µmol flash from the halogen lamp (blue-enriched)
>saturates the photosystem; obviously this lamp cannot replicate sunlight at dawn,
>noon, twilight or any of the infinite spectral characteristics of sunlight filtered by
>oceanic or coastal waters, but it is used just the same by Mini-PAMs and Diving-PAMs.
>By its very nature, this lamp is “unnatural.” This halogen lamp is “white” and certainly
>contains those wavelengths harvested by peridinin. From what I understand, the same
>lamps are used in the Mini- and Diving-PAMs. I don’t think the photopigments care
>about the quality of light used for saturation, as long as they are saturated. The goal is
>to close the reaction centers. Obviously, Walz had to standardize the saturating light
>source and researchers are “stuck” with it, even if they’re doing coral/zooxanthellae
>P/I curves at 30 meters depth.


Studies of the PCP complex in dinoflagellates have detemined that peridinin is the
dominant light collecting pigment within the PCP complex. For example Amphidinium
carterae (that may be spelled incorrectly working off the top of my head here) has
4 peridinins to every 1 chl a within the light collecting antennae. This makes perfect
sense for dinoflagellate phytoplankton. At moderate depths they are occurring in
a violet/blue/green light field. Peridinin gives them the ability to absorb more blue
wavelengths and some green. Green light would be completely worthless to the zoox
if they lacked peridinin. Being stuck with a patented design and understanding its
limitations are two competely separate issues. Some researches analyzing ocean
plankton have not been getting correlation between yield and PI curves. Others have.
Clearly there are some limitations here that are not quite understood.


>Halogen and other lamps produce near-IR and IR radiation and obviously the fiber
>optic cable transmits them. Though filtered, some near-IR makes it through. Corals
>also reflect these wavelengths quite efficiently.
>The Ocean Optics spec I have has the ability to collect wavelengths in the near IR range,
>and both lamps generate very little within that range. At the low PPFD values we used, I
>don’t believe there would be false fluorescence. When I have time, I’ll check those lamps
>under identical PAR values and calculate the amount of energy above 710 nm from each
>lamp. The Ocean Optics used for analyses of spectral signatures within the article was
>best suited for UV/VIS, while my new one is best at UV(~350 and up)/ VIS and near IR,
>so this information is just recently available. BTW, since the spectral signatures were for
>illustrative purposes only in the article, I did not correct for the instrument’s electrical dark
>signal – it wasn’t necessary for the intended use. So don’t be mislead by the apparent
>near-IR in those graphs. As a minor detail, the Mini-PAMs red LED peaks at 650 nm.


The Diving-PAM filters light at 700 nm. Perhaps that would be better then utilizing 710 nm.
And also you do realize there are much more recent, more accurate PAS curves available
for coral. The one utilized in many recent related articles (last two years) shows that
yellow/orange is a factor of 4 or 5 to 1 less absorbed then blue/violet. Thats actually
getting closer to what the chl a isolated absorption curve shows (which is about 13
or 7 to 1).

>Sometimes I should just keep my mouth shut. ;-). If I could truly judge fluorescence
>by eye, I would have kept the big bucks I shelled out for the Ocean Optics spectrometer.
>This instrument hasn’t found any fluorescent pigments in this particular Fungia
>specimen (aside from the oral disc). Fluorescent host pigments played no part in this
>experiment.

Was the corals fluorescence measured under each bulb utilized in the PAM test ?
Blue light will stimulate more fluorescence then a green/yellow/orange light.

>Steve, see Kirk’s “Light and Photosynthesis in Aquatic Ecosystems.” I’m basing my
>statements on the spectral absorption curves of chl A and C on pages 33 and 35.
>Not sure of the “package effect” of these charts. Based on research I’ve done,
>there is a fairly strongly absorption of yellow and orange wavelengths by brown
>corals (even in those demonstrating no fluorescence). When light intensity gets
>high (or a lamp is heavily weighted with these wavelengths), they are no longer
>absorbed and show as part of the reflectance. It’s a bit of a mystery to me too.
>Charlie Mazel found absorption spectra in coral tissues that were identical to
>phycoerythrin, though I’ve never seen this pigment mentioned in any other coral
>references.

Light absorbed by a coral animal may contain non-photosynthetic absorption.
The curves I have for chl a (Kirk) show only a very very minor absorption in the yellow/orange
and orange range. Pretty much insignificant when compared to the blue/violet and red
peaks. The absorption of chl a in green and green/yellow is absolutely flat. Thats why
plants are green, trees are green and grass is green. Zooxanthellae are not green.
They are brown because of the presence of large amounts of peridinin.

Steve Tyree

 

[Dana Riddle]

Steve,

To answer your questions:

>>Send it to [email protected] . Please make sure its a small GIF file in
byte size but large in resolution. Can you list the sps corals that grew under
these bulbs ? Also note color morph and growth form, if you have the time. In
my travels I have now meet three people who tried these bulbs with sps and
failed. Dont know the specifics, but they tried the bulbs based on articles they
read online. Yours is the first case I have ever heard of where they apparently
worked for at least 7 months. Were they the 175 watt models ? What was the total
wattage in 4,000 K bulbs and what was the size of the reef. Were the corals fed ?
Were they the only source of light ?<<

This information was enetered in my notebook on 11/4/98. This tank (70-gallon), along with corals, was given to Bob Keane in late July, 1999, so these Philips "Home Depot" 175-watt lamps (350 watts total MH, plus 80 watts fluorescent) were used for at least nine months, if not a bit longer. These were supplemented with two 40-watt fluorescent lamps (Coralife 10Ks).

Initial PAR (about 3" below the inner arc tube and just below the water's surface - 445 - 485 µmol). Spectral composition, using glass cutoff filters: Blue = 129 µm; Green = 163 µm; Red = 234 µm.

Corals:
Acropora formosa, blue tip @ 95 µm.
Purple-tip Acropora, encrusting: 375 µm.
Branching purple-tip Acro: 286 µm.
Acropora nana, violet: 190 µm.
Stylophora pistillata, brown w/ green halo polyps:
122 µm.
Other inhabitiants: Montipora angulata, orange;
Stylophora pistillata, red; fluorescent green Rhodactis; various multicolored Discosoma spp.;
Tridacna crocea (good growth), Pachyclavarina (brown, rare); yellow Sarcophyton elegans; fluorescent green Sinularia sp., and many others.

This tank was used to grow corals for pigment-extraction experiments, and my notes center more on those than the actual aquarium conditions. I seem to recall that there were at least 100 corals in the aquarium.

Andy had a few fish in the tank, damsels and clownfish, plus a seahorse in the 20 gallon refugium, as I recall. She tended to feed the fish heavily.

I'll send the photo seperately. Not the best quality, but it'll give you an idea as to how the corals were shoehorned in.

Dana

 

[jamesw]

All right folks, Dana Riddle has sent me the picture of the corals from the system in question. The picture and text from Dana are posted below. Photos posted are copyright their originator:

Text:

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>
Attached is a photo of a fraction of the corals we maintained under the
4,000K "Home Depot" lamps (along with two 40 watt Coralife 10,000K
fluorescent lamps). We were conducting the respirometer trials at the
time, as well as some paper chromatography with coral pigments. This tank
served as a holding facility for corals used in these works; it was never
meant to be a "show" aquarium.
This is the only photo I have of that aquarium; it was likely done
hurriedly in a "there is one shot left on this roll and I need to get the
film developed" situation.

Note one of the corals has some tissue recession around the base. I
personally (and anecdotally) feel this had nothing to do with the lighting
and was more likely due to water motion (or lack thereof). In any case,
most of these corals are thriving and 'happy' in Atlanta with Bob Keane.
He still updates me periodically on my "babies." <hr></blockquote>

[ March 01, 2002: Message edited by: jamesw ]</p>

 

[jamesw]

Dana, If you don't mind sending us the photo, we can post it in this discussion thread. Send it to [email protected]

I think it would help the discussion and could benefit others.

Cheers
James

 

[Steve Tyree]

Dana,

Thanks for the photo and the data from your experiments. Unfortunately about
all I can tell from the photo is that corals were present. Not enough detail
to judge zooxanthellae density or pigment intensity. Taking quality photos of
corals was not easy back in those days, so I can understand why this is the best
we have to go on. However from what I have seen here, there really is no reason to change
my recomendation that 6,500 K color temperatures are the minimum acceptable temperature
for colorful sps. IMHO - Your experiment (although you did utilize the 175 watt
4,000 K halides) did not meet the requirements I would need to change my
assessment.

- It was not at least one year long.

- Their were supplemental 10,000 K fluorescents utilized that were providing 18.6
percent of the total light wattage.

- The photographic evidence is not of a quality good enough to make an accurate
assessment of the health and vitality of the coral and algal symbiosis.

- No photographic or quantified growth data was provided.

- No theoritically plauseble explanation can be given for why your original PAM
data did not even support the 1980 PAS curve you illustrated within the
article. According to that old curve, blue/violet light is absorbed by a factor
as great as 2 to 1 over yellow/orange light. More recent PAS curves happen to
show a factor as high as 5 to 1. I have also provided a few reasons in earlier posts
as to why your PAM readings may not have been quantifying what your experimental
design was intending to be quantifying. You apparently were utilizing the PAM
meter in a manner it was not intended to be utilzied (non pulse modulated
operation).


There are other concerns I have with the latest data presented. In your experimental
fragment tank 24 % of the light was classified as blue by your filtration analysis.
How does the 4,000 K emit any significant blue light at all ? The spectum curve within
your original article only shows about 12 % of the output of the 4,000 K (approximated
by curve area anlaysis) to be emitted below 500 nm wavelengths. My speculation is that
the 129 micromolar of blue light you measured in the fragment tank was being primarily
generated by the fluorescent 10,000 K bulbs.


BTW - You do realize that recent analysis of the stony corals fluorescent pigment
excitation and emission maxima illustrate that the sps corals themselves
may be aware that wavelengths of light are extremely important aspects of
the functioning of their symbiotic dinoflagellate algae ? Although I will
continue to keep an open mind on the subject, IMHO the questioning of the
significance of light wavelength is a dead horse issue that no longer needs
beating. Unless of course you think us young apes have learned more then the
ancient corals apparently have learned about the physics of dinoflagellate
light reception :>

Steve Tyree

 

[jamesw]

Hi Steve,

Interesting post. I had a look at Dana's photo and "had a think" about the article again after reading your post.

In your last message, you said:

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>However from what I have seen here, there really is no reason to change my recomendation that 6,500 K color temperatures are the minimum acceptable temperature for colorful sps. IMHO - Your experiment (although you did utilize the 175 watt 4,000 K halides) did not meet the requirements I would need to change my
assessment.<hr></blockquote>

I REALLY don't think the point of this experiment was to try to "convert" hobbyists to using 4,000K lamps. I think it was more to show that photosynthesis rates of corals are nearly the same whether using 10kK lamps or 4kK lamps.

Everybody has had a chance to look at the photo now, and I think MOST (Can never say "all" in this hobby) of us would agree that the appearance of the aquarium is not as pleasing to the eye as when using 10kK lamps.

But then that was never the point of the article, IMO.

Cheers
James Wiseman

 

[Dana Riddle]

Hi Steve,
>>Thanks for the photo and the data from your experiments.<<
You bet.
>> Unfortunately about all I can tell from the photo is that corals were present. Not enough detail to judge zooxanthellae density or pigment intensity. Taking quality photos of corals was not easy back in those days, so I can understand why this is the best we have to go on. However from what I have seen here, there really is no reason to change my recomendation that 6,500 K color temperatures are the minimum acceptable temperature for colorful sps. IMHO - Your experiment (although you did utilize the 175 watt 4,000 K halides) did not meet the requirements I would need to change my assessment.<<
As they say in Hawaii – “No worries.” I’ll present the evidence I have and let each and every person decide for themselves. Use of the 4,000K lamps was not an experiment per se. A local Home Depot was liquidating their stock for $18/lamp, and I bought all they had. I used them because I wanted to save the $100 lamps for other things. Colorful SPS? I don’t recall the article addressing the coloration issue. This article examined photosynthesis, not coloration – too different issues, IMO. But I must say that we used 5,500K Venture lamps for two years at Wildlife with good coloration noted in SPS corals. And the 4,000K lamp for 9+ months with “good” growth and coloration (albeit with help with 40watt fluorescent lamps).
As for the 4,000K lamps being useful – remember, there was a time (the mid ‘80’s) when we had none of the exotic lamps of today. Let’s look at the “cutting edge” references of the time:
The Marine Aquarium Reference, Martin Moe, 1989, page 70: “Given proper intensity, light with a color temperature of 5000 to 7000K and a wavelength pattern with peaks in the 475 and 650 nm wavelength ranges will provide the right quality of lighting.”
The Reef Aquarium, Volume 1, Delbeek and Sprung, 1994, page 189: “With 4300K light, the colours of the animals and appearance of the tank is not as good as with daylight spectrum, but most corals will grow as long as they receive bright light.”
These two works guided thousands to success with reef aquaria.
And a third reference:
Aquarium Frontiers, Spring, 1994. “Sexual reproduction and recruitment of the stony coral Pocillopora verrucosa” by Steve Tyree. Look at the rather famous (and fabulous) photos of your colorful SPS tank, taken on 2/24/94 (as stated in the article). The article states “The upgrade to 6500K (from 5500K) metal halide lamps was done on 2/20/94.” Are we to believe the coloration changes occurred in 4 days?
I suppose you can tell I like to debate the coloration issue ;-).
>>It was not at least one year long.<<
By this standard, few 10,000K lamps would cut the mustard.
>>The photographic evidence is not of a quality good enough to make an accurate
assessment of the health and vitality of the coral and algal symbiosis.<<
I really doubt any photographic evidence would be good enough – pigment extraction, analyses, even the “rotten cabbage” odor of healthy corals, etc., would (might) do the trick. Not photos.
>> No photographic or quantified growth data was provided.<<
I’m amused that the bar gets lowered with each exchange. We’re clearly on a tangent not covered in the article or by a controlled, experimental process…. Just good, ol’ anecdotal (but first-hand) evidence.
- >>No theoritically plauseble explanation can be given for why your original PAM data did not even support the 1980 PAS curve you illustrated within the
article. According to that old curve, blue/violet light is absorbed by a factor
as great as 2 to 1 over yellow/orange light. More recent PAS curves happen to
show a factor as high as 5 to 1. I have also provided a few reasons in earlier posts as to why your PAM readings may not have been quantifying what your experimental design was intending to be quantifying.<<
- I’m going to give Dr. Olaizola some credit – I went to him and asked, “Can we do this?,” and so it went. He was not surprised that we saw a non-significant difference in ETRs – this is consistent with his findings in marine algae.
-
- >>You apparently were utilizing the PAM
meter in a manner it was not intended to be utilzied (non pulse modulated
operation)<<
- Hmmmm. The PAM meter is designed to estimate ETRs and we did use pulsed amplitude for the saturation flashes. We simply substituted the metal halide lamps’ light in a manual “extended pulse” mode.

There are other concerns I have with the latest data presented. In your experimental
fragment tank 24 % of the light was classified as blue by your filtration analysis.
How does the 4,000 K emit any significant blue light at all ? The spectum curve within
your original article only shows about 12 % of the output of the 4,000 K (approximated
by curve area anlaysis) to be emitted below 500 nm wavelengths. My speculation is that
the 129 micromolar of blue light you measured in the fragment tank was being primarily
generated by the fluorescent 10,000 K bulbs.

>>BTW - You do realize that recent analysis of the stony corals fluorescent pigment
excitation and emission maxima illustrate that the sps corals themselves
may be aware that wavelengths of light are extremely important aspects of
the functioning of their symbiotic dinoflagellate algae ? Although I will
continue to keep an open mind on the subject, IMHO the questioning of the
significance of light wavelength is a dead horse issue that no longer needs
beating. Unless of course you think us young apes have learned more then the
ancient corals apparently have learned about the physics of dinoflagellate
light reception :><<
If the corals know, they’re not talking – it’s up to us to figure it all out. ;-).

I’m sending the spectrometer’s analyses of the Philips 4,000K and the Venture 5,500K lamps to James for possible upload. As you’ll see, there isn’t a great deal of difference between the 4KK and 5500K lamps.

Dana

 

[Steve Tyree]

Hi Steve,

> This article examined photosynthesis, not coloration – too different issues, IMO. But I must say that we
>used 5,500K Venture lamps for two years at Wildlife with good coloration noted in SPS corals. And the
>4,000K lamp for 9+ months with “good” growth and coloration (albeit with help with 40watt fluorescent lamps).

Why do you think corals develop fluorescing pigments ? Recent evidence points to the probabiliy that
they are modifying the light field that the internal algae is recieving. Therefore, the two issues are apparently
connected. Its hard to quantify 'good coloration'. Would make a better case if species were listed, color
morphs given and images were provided documenting the color.

>As for the 4,000K lamps being useful – remember, there was a time (the mid ‘80’s) when we had none of the
>exotic lamps of today. Let’s look at the “cutting edge” references of the time: The Marine Aquarium Reference,
>Martin Moe, 1989, page 70: “Given proper intensity, light with a color temperature of 5000 to 7000K and a
>wavelength pattern with peaks in the 475 and 650 nm wavelength ranges will provide the right quality of lighting.”
>The Reef Aquarium, Volume 1, Delbeek and Sprung, 1994, page 189: “With 4300K light, the colours of the
>animals and appearance of the tank is not as good as with daylight spectrum, but most corals will grow as
>long as they receive bright light.” These two works guided thousands to success with reef aquaria.

They were not dealing with the more difficult to keep colored SPS corals back when Martin wrote his book.
However, in 1995 when Martin and his wife looked at the colorful sps within my reef, they did make an
enlightening discovery. My reef was illuminated with 2-400 watt 20,000 K radiums and three 10,000 K
Aqualine Buschke 175 watt plus VHO actinics. They brought a pair of blue blocker sunglasses with them and
when examining the corals with the blue blockers on, the pigmentation was much more intense. In fact
it was screaming :> Martins assertion that "peaks at 475 and 650 wavelength ranges provide the right quality
of lighting" is still accurate for the peridinin pigment and the red peak within chlorophyll a. Note however that
your 4,000 K bulb does not even meet these peak requirements. Concerning the Sprung reference, yes you
can make up for poor quality with greater intensity. Even the 5,500 K has one small blue spike in it. Your
4,000 K however not only lacks blue, it lacks the proper red.

>Aquarium Frontiers, Spring, 1994. “Sexual reproduction and recruitment of the stony coral Pocillopora verrucosa”
>by Steve Tyree. Look at the rather famous (and fabulous) photos of your colorful SPS tank, taken on 2/24/94
>(as stated in the article). The article states “The upgrade to 6500K (from 5500K) metal halide lamps was done on
>2/20/94.” Are we to believe the coloration changes occurred in 4 days? I suppose you can tell I like to debate the
>coloration issue ;-).

That reef also had two VHO actinic lights. That was the norm for coralife retrofit kits back in those days. Halides
plus the violet actinics. So when you combine 5,500 K halides with actinic 03 VHO fluorescents the resulting color
temperature is far above 5,500 K. You can examine the improvement in the coloration of the tank from the 6,500
K bulbs by looking at the Sprung/Delbeek photo of that reef. I was able to keep much better pigmentation (photo
documented) under the 6,500 K and actinic 03 combo. Then of course there are other more recent images in
a few other books showing what the 20,000 K Osrams can do.

>I really doubt any photographic evidence would be good enough – pigment extraction, analyses, even the
>“rotten cabbage” odor of healthy corals, etc., would (might) do the trick. Not photos.

You would be surprised what one can do with a nice digital camera. For example a reef aquarist I visited
with just last night took an outstanding closeup of an Acropora. He has had the camera less then a month.
The bleached mottled appearence due to the flatworms eating his Acropora were very visible. Anyway, the
rich base brown coloration of healthy corals can easily be spotted with a decent photo. How in the world are
divers assessing possible coral bleaching ?

> I’m going to give Dr. Olaizola some credit – I went to him and asked, “Can we do this?,” and so it went. He
>was not surprised that we saw a non-significant difference in ETRs – this is consistent with his findings in
>marine algae.

Was that not cyanobacteria ?

> Hmmmm. The PAM meter is designed to estimate ETRs and we did use pulsed amplitude for the
>saturation flashes. We simply substituted the metal halide lamps’ light in a manual “extended pulse” mode.

The extended pulse mode cannot distinguish chlorophyll photosynthetic autofluorescene and non-photosynthetic
autofluoresence. At least according to the Diving-PAM manual.

>If the corals know, they’re not talking – it’s up to us to figure it all out. ;-).

Yes. Us apes. With eyes designed to find yellow bananas in green trees. Perhaps we can learn just a thing or
two from the ancient corals.

>I’m sending the spectrometer’s analyses of the Philips 4,000K and the Venture 5,500K lamps to James for
>possible upload. As you’ll see, there isn’t a great deal of difference between the 4KK and 5500K lamps.

There sure is a difference if you look at the spectral curve within the original article.

Anyway, I am travelling for the next few days. Have a great time in Hawaii Dana. Still hope to see you again
someday.

Steve Tyree

 

[Dana Riddle]

Hi Steve,
Hope your trip went well. Our comments are clearly straying outside the article’s scope. I have a coral fluorescence article in the works, so I’m sure we can discuss that later. Just a couple of quick comments:
>>There sure is a difference if you look at the spectral curve within the original article.<<
Actually, the 4,000K lamp’s spectral pie chart is remarkably similar to the one in the article (when one groups blue wavelengths together, green/yellow together and so on). Bear in mind that the 5,500K info was not presented in the article (a 12,000K was examined). I can only guess that this is the source of confusion.
>>Anyway, I am travelling for the next few days. Have a great time in Hawaii Dana. Still hope to see you again someday.<<
You’re 4 hours away from Hawaii… I’m glad we can disagree and not be disagreeable. Here’s a quote from Bob Buddemeier in the latest “Coral Reefs”:

“Integrating human expertise is an even more challenging goal than assembling shared data sets - "turf," egos, and the institutional pressures that reward competition over cooperation all have to be modified or overcome. In particular, interdisciplinary problems almost by definition mean that nobody will have expertise or leadership in all aspects. The role, even if part-time, of beginner or journeyman is not a comfortable one for many researchers. To ease the transition into more broadly shared, cooperative efforts, we suggest that multiple pathways are needed: formal and informal; print, electronic, and face-to-face; multidisciplinary and interdisciplinary; and even cooperative and adversarial - but the "adversarial" mode needs to be disciplined, principled disagreement… and not simply posturing or argument for the sake of scoring debating points.”

How true. I haven’t received one single comment after asking for opinions on the experimental protocol I posted a few weeks back. Looks like I’ll go this experiment alone. Too bad.
Dana
<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote

 

[Steve Tyree]

>Dana wrote

>How true. I haven’t received one single comment after asking for opinions on the
>experimental protocol I posted a few weeks back. Looks like I’ll go this experiment
>alone. Too bad.

Sorry for my late response. Very busy and will have to bail on this thread. Just so
you know, the only reason I commented on your article is because I just completed about
42,000 words, compiled and assembled 55 figures and constructed 31 tables concerning
stony coral/algal lighting and pigmentation for the Microcosms Stony Coral Book.
Needless to say, the information I have complied comes to the opposite conclusion that
your article comes to (175 watt 4,200 K bulbs can support healthy shallow water stony
corals). In fact, I would state that the bulb is a good example of a very poor quality
bulb for stony corals and their algae. Confronting our differences I think is required
here since it could possibly affect the health of corals held within captive systems
and would obviously have an affect on my conclusions within the Microcosm Stony Coral
Book. Perhaps we can continue the discussion later again after that book has been
published.

Steve Tyree

 

[Dana Riddle]

Hi Steve,

Microcosm is still publishing? Under the TFH banner?

Yes, would like to see more of your argument. All I can say is that the 4,000K lamp worked for us (although there were two 40-watt fluorescent lamps along side). After this first-hand evidence, the fact that the respirometer and PAM experiments presented the same results becomes academic.

Same for the post showing the practically non-existant differences between 4,000 and 5,500K lamps. I can't speak as to why the lamps didn't work for you.

Looking forward to your book.

Dana