Stewing Corals

[MCsaxmaster]

Dana,

Very, very, very important observation. Well, one big thing to test (that leaps to mind) is this: corals are less likely to bleach at higher water flow rates--does temperature mediation by carrying away heat have an impact on this, and if so how much?

Like I said, very, very important. Surprises the heck out of me.

Best,

Chris

 

[RiddleLabs]

Aloha Chris,

These corals (Porites) were directly in the discharge of a Carlson Surge Device which 'dumped' every 45 seconds or so. The device holds about 4 gallons of water and discharges through two 3/4" pipes. Velocity (measured by a Marsh-McBirney electronic water velocity meter) peaks at ~1.75 ft/sec. Periodicity is about the same as a calm day in the ocean, but the velocity is 3X that of a calm day. One would expect that the discharge would keep the corals cool. I was surprised too - I stumbled upon this while just making sure as many parameters were standardized during an experiment.

Dana

 

[gman0526]

Aloha Dana!!!

Very interesting study. What about color related heat absorption? Could it be also a variable in these findings? I found this on Newton. Don't know if it's relevant or not.

http://www.newton.dep.anl.gov/askasci/gen99/gen99540.htm

Actually I can really see this happening, put a brick under the sun and it will be a lot warmer than the surrounding air even if air temp. is a lot lower. Maybe a bad example and i really don't know about heat absorption related to mass and density. Anyways Ty for your efforts Dana.

 

[RiddleLabs]

Aloha Gman0526,

Very good question about coloration and heat absorption. I have a very good answer - I don't have a clue if it makes a difference or not. Logically, it would but to what degree?

Thanks for the compliment - it's nice to know that someone actually reads the articles I write. Feedback - good or bad - is always appreciated! All that time in thelab can be boring, frustrating and tedious. For every article written, there are a couple (or 3) hypotheses tested and tossed out the window.

Dana

 

[RiddleLabs]

Aloha ReefCentral,

The article I mentioned that would back up the results I obtained with the thermistors has been published in the Jauary 2006 Limnology and Oceanography. Kathrina Fabricius is the author (a familiar name to those into soft corals). She documents that lighter colored corals don't suffer from 'overheating' as the darker corals can. She states that corals can be a much as 1.5 degrees C warmer than the ambient temperature. We know the same can happen in aquaria. I guess I need to get that article written...

Merry Christmas, Happy Holidays and a Really Neat New Years to all-

Dana

 

[greenbean36191]

For years it's been known that terrestrial plants alter the size of their leaves in different environments to maximize the temperature for increased photosynthesis. It would be interesting to see if rather than being controlled by just light availability and flow, the corals could also change their growth to optimize the temperature for photosynthesis.

 

[rcmike]

Interesting. One question though, how long after drilling the holes in the coral were the temperatures taken?