[Coral-List] PAR logger

[Jeremy J. Sofonia]

Dear Ian,

I agree with Mark in his recommendation in the use of the Li-Cor  
brand.  I've used these in the past and they have served us well.

One thing that I would also suggest in regard to your study on the  
effect of sunlight intensity is to include a sensor not only at the  
depth of your subject corals, but also at the surface (i.e. two  
meters).  This way, you can assess the initial intensity of light in  
comparison to what is received by your corals and, as such, estimate  
light attenuation through the water column.  Obviously, I don't have  
detail on your proposed study, but you may find that this provides  
for more interesting discussion without much additional cost or effort.

Kind Regards,

Jeremy


JEREMY J. SOFONIA
Senior Marine & Environmental Consultant
SKM Australia Pty. Ltd.

7th Floor, Durack Centre
263 Adelaide Terrace
Perth, WA 6000

http://www.skm.com.au


On 27/01/2007, at 2:54 AM, Mark Warner wrote:

> Ian,
> The HOBO pendant is only good for getting an idea of relative light
> intensity. Download the manual and you see that the spectral  
> response of the
> sensor is very heavy in the red and peaks around 900 nm. Thus, this  
> will not
> give you synonymous values to PAR. For your question, PAR is  
> better, as it
> is grounded in the wavelength range (400-700 nm) that has biological
> significance for photosynthetic organisms.
>
> Most submersible PAR sensors & loggers are simple, easy to use and  
> reliable,
> but they are not cheap. For a slightly cheaper alternative to the  
> commonly
> used Li-Cor brand, have a look here: http://www.apogee-inst.com/.
>
> Cheers,
>
> Mark
>
>
> coral-list-request at coral.aoml.noaa.gov wrote:
>
>> Does anyone know of a simple, easy to use, reliable, submersable  
>> PAR logger?
>> Or has anyone used the HOBO(r) Pendant 64K Temp/Light Data Logger  
>> to measure
>> light intensity related to coral bleaching. In general, would light
>> "intensity" (meaured in lumens) be an appropriate measure of the  
>> effect of
>> sunlight intensity on corals or is PAR a better method to get at this
>> question?
>>
>> All the best,
>> ian lundgren
>> Buck Island Reef National Monument
>
> -----------------------------------
> Mark E. Warner
> Assistant Professor
> University of Delaware
> College of Marine and Earth Studies
> 700 Pilottown Rd.
> Lewes, DE 19958
> USA
>
> Phone: 302-645-4365
> Fax:  302-645-4028
>
>
>
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