Optimal Temperature

[Anonymous]

82 to what depth though, surface temp in other words?

I just looked at random buoyies on http://www.ndbc.noaa.gov/maps/Western_Pacific.shtml and it looks like any many places it riches 82 to depths greater then even 50 meters during the months I checked. I tried buoyies closest to shore FWIW>

 

[Anonymous]

Some sea surface temperatures.

 

[Anonymous]

NOTHING on a reef is stable and yet everything thrives, so why is stagnant stability such a desirable thing? and reasonable fluctuations something to fear? THAT IS THE ENTIRE POINT I AM TRYING TO MAKE!
Chuck

Chuck, what cracks me up, is you advocating both warm temps and saying fluctuations are great, but those "hotbeds of diversity", The Sulu Sea, Solomons, etc., the warmest on average ALSO have the smallest standard deviations of the temperature records I posted, on average less than a degree since 1945, eg., these most diverse reefs are also the most "stagnant" through time. Even hourly buoy data from guam have a standard deviation of less than a single degree C for a whole year.

 

[Charlesr1958]

NOTHING on a reef is stable and yet everything thrives, so why is stagnant stability such a desirable thing? and reasonable fluctuations something to fear? THAT IS THE ENTIRE POINT I AM TRYING TO MAKE!
Chuck

Chuck, what cracks me up, is you advocating both warm temps and saying fluctuations are great, but those "hotbeds of diversity", The Sulu Sea, Solomons, etc., the warmest on average ALSO have the smallest standard deviations of the temperature records I posted, on average less than a degree since 1945, eg., these most diverse reefs are also the most "stagnant" through time. Even hourly buoy data from guam have a standard deviation of less than a single degree C for a whole year.

And what cracks me up is that the majority of coral reefs are fringing reefs or are located extremely close to land masses which equates into shallow water, which can mean anywhere from a meter or two deep down to 25 meters on average, and being close to shore lines, lagoons, reef flats what ever the case may be, they are subject to frequent baths of very warm water as the tide changes only to be cooled down quickly at the next tidal change. Another good crack up is that the data you have shown are open ocean readings that have very little mixing of hot surface (20 feet and above) water and the cooler underlying depths of the open ocean. Not somewhere you are likely to find a tropical shallow water reef. Not to mention the fact that I take constant temp readings on numerous reefs here and have physcialy felt and recorded the flush of hot water washing over the corals as have others who have posted within this thread. That and "surface temp" in oceanographic terms extends to 100 feet below the surface. When you have spent four years studying and observing reef environments, one tends to have a bit of an understanding of what the environmental factors are. Spend even a week diving/snorkeling the reefs with a thermometer and then come talk to me about temperatures and fluctuations.

Chuck

 

[Anonymous]

And what cracks me up is that the majority of coral reefs are fringing reefs or are located extremely close to land masses which equates into shallow water, which can mean anywhere from a meter or two deep down to 25 meters on average, and being close to shore lines, lagoons, reef flats what ever the case may be, they are subject to frequent baths of very warm water as the tide changes only to be cooled down quickly at the next tidal change.

Yes Chuck, you're very observant :roll: . Now how about some REAL DATA. SHOW ME THE DATA CHUCK. The point flies right over your head. Bath of warm water on an already warm background thermal regime = small relative change. Bath of warm water in a cooler background thermal regime = larger relative change.

Basic math: Smaller relative change = more stable. "Warmer reefs" with "more diversity" = more stable.

Another good crack up is that the data you have shown are open ocean readings that have very little mixing of hot surface (20 feet and above) water and the cooler underlying depths of the open ocean. Not somewhere you are likely to find a tropical shallow water reef.

Chuck, do you really have the first clue regarding the provenance of the data I posted? Do you?

Not to mention the fact that I take constant temp readings on numerous reefs here

You do Chuck? You have thermographs? What kind? What depth? Where? How long have you been running them? What's your burst integration time? How did you select it the burst integration time? What frequency? Why are you hiding the data from us? Where's the data? WHERE's THE DATA?

Am I supposed to be impressed that you know how to alias the hell out of a temperature signal?

When you have spent four years studying and observing reef environments, one tends to have a bit of an understanding of what the environmental factors are. Spend even a week diving/snorkeling the reefs with a thermometer and then come talk to me about temperatures and fluctuations.

LMAO. Chuck, you and your misplaced smugness are too much for me. Have fun with your snorkel and your thermometer. Whatever floats your boat there bud.

I leave you with this plot of more real in situ, useful data from a Kimbe Island reef datalogger (North side East/West New Britain). The data are recorded at half hour frequency from April 05 to April 07. I'm reporting daily means to you, with dotted lines representing plus/minus the daily standard deviation (in other words, each data point reflects the mean of n = 48 data points), and the standard deviation never exceeds plus or minus a half a degree C. A half a degree! That means 99% of variability (2 sigma) in a day at the site is within plus or minus SINGLE DEGREE.

These data, and those from other reefs, unlike Chuck's alleged constant measurements, are freely available to anyone who would like to play from here:

http://www.aims.gov.au/docs/data-centre ... tures.html

 

[Charlesr1958]

Thanks for proving my points, and the chart did so very well thank you. I never once said that a single day was going to deviate much from a reefs average, the arguement was at what temp was the average and if there were or were not temp swings over the course of a 24 hour period. I have no clue as to what you are trying to prove other than my own points? But thanks for the help anyways.

Oh, and by constant you know damn well I do not have data loggers and go by what I measure every time I enter the water, how proud you must be of your google skills. Although I do appreciate it. Since you have already provided the info and better info at that, I was going to post this photo to make a point and will still do so since I went through the trouble of taking it.

10:30am this morning at high tide, midway between shore and the reef wall, which is a sheer vertical drop to the bottom 744 meters below. So while very near to open ocean, it is also very near to shore, which even at high tides still runs in the 80's.

So for the last time, 82 is a perfectly good number to shoot for within a reef aquarium while having fluctuations from 80-84 over the course of a 24 hour period.

Thanks and ya all have fun!

Chuck

 

[Anonymous]

So for the last time, 82 is a perfectly good number to shoot for within a reef aquarium while having fluctuations from 80-84 over the course of a 24 hour period.

Thanks and ya all have fun!

Chuck

I am confused as to what you have been arguing about. The fourth post in this thread, before you posted, made 'your' point quoted above:

The issue isn't necessarily what temp you run the tank at. Some people keep their tanks at 82 with no problems. At this time of year, however, temp spiking can be a real issue. Either manual or electronically controlled turning off MH lights (yes they heat the water!) or fans for evap cooling can help keep the tank temp stable.

I like to keep my tank around 78 year round. One or two degree swing either way isn't all that bad.

 

[Charlesr1958]

To be honest, I'm confused myself at this point. Having had to go back to the original question which was a concern of what is the optimal temp for keeping a reef aquarium, which I have been argueing is in the low to mid 80's as well as having or allowing a few degree swing (80-84) during a 24 hour period as that is what happens on the reefs, I also stated that such swings "toughen" up the corals to where if there is an equipment failure and the tank heats up a bit beyond its norm the corals are better able to cope with it, just as they do on the reefs. Its the long term higher than normal temps that do the corals in, short durations as happens during tidal flushing is easily tolerated. And just to ensure others do not misunderstand that point, you can not run a tank at 76 or 78 and then just jack up the temp into the 80's, they will most likely bleach. Any changes made must be done gradualy over a long term to allow the corals to adapt, and they are adaptive little buggers at that, within reason.
So that now concludes my participation in this thread as I am and have been beating the proverbial dead horse far too long and often. Hopefully we all have gained some insights, I at least have gained a darn good link on the subject....lol Oh, and I do owe an apology or two as my frustration does and did get the best of me. Sorry about that.

Chuck

 

[Anonymous]

To be honest, I'm confused myself at this point. Having had to go back to the original question which was a concern of what is the optimal temp for keeping a reef aquarium, which I have been argueing is in the low to mid 80's as well as having or allowing a few degree swing (80-84) during a 24 hour period as that is what happens on the reefs,

Great. All that was well within the ranges expressed prior to you joining the thread.

I also stated that such swings "toughen" up the corals to where if there is an equipment failure and the tank heats up a bit beyond its norm the corals are better able to cope with it, just as they do on the reefs.

For which there is not yet any evidence. It may be true, it may not. There are lots of things that seem to make sense in this hobby, but don't pan out in reality. I mean this not as 'you're wrong', rather as a caution.
Furthermore, when I mentioned heat spikes on page 1, I was referring to events of more than 'a bit beyond its norm'. Its not uncommon for people to experience temp jump of 10 degrees or more in the spring and summer.

Its the long term higher than normal temps that do the corals in, short durations as happens during tidal flushing is easily tolerated.

Long term heat spikes do kill corals. At the same time there are lots of people who have experience short term temp hikes that have killed corals.

And just to ensure others do not misunderstand that point, you can not run a tank at 76 or 78 and then just jack up the temp into the 80's, they will most likely bleach. Any changes made must be done gradualy over a long term to allow the corals to adapt, and they are adaptive little buggers at that, within reason.

Yep.

So that now concludes my participation in this thread as I am and have been beating the proverbial dead horse far too long and often.

Thats the third or fourth time you said that! :wink: IME as an admin, most people who make 'I am done with this thread' statements often post again anyway, so I usually advise to just leave those kinds of statements out.

Hopefully we all have gained some insights, I at least have gained a darn good link on the subject....lol Oh, and I do owe an apology or two as my frustration does and did get the best of me. Sorry about that.

Chuck

Its all good! Discussion forums are for discussion!

 

[pcardone]

Thanks Thales

 

[pcardone]

On a side note. I have dove the Philippines and the devastation is horrible. I thought it was from fishing with dynamite.

 

[Anonymous]

When diving Guam, we noticed IMMEDIATELY the effects of a zero fishing policy on the base. Including some very, very friendly fish.

 

[Charlesr1958]

When diving Guam, we noticed IMMEDIATELY the effects of a zero fishing policy on the base. Including some very, very friendly fish.

The same is true here in the Philippines, thankfully all the small outlying islands have been designated as santuarys with resorts having taken over the role of marine enforcement which allows them to "rope" off entire reefs and then charge a small entrance fee to divers ($1.50) as well as many communities also adopting their reefs, saving them for divers/tourists and keeping out fishermen and their destructive habits.

This is an example of such areas and while relatively small, it makes a huge difference, outlying islands rope off the whole surrounding reef in such a manner.

As with all dive destinations now, it has become a matter of knowing where to go.

A Virtual Philippine Reef Tour

Chuck

 

[eric.m.s]

A recent study worth reading regarding temperature and thermal stress on Acroporas.

Reference
Middlebrook, R., Hoegh-Guldberg, O. and Leggat, W. 2008. The effect of thermal history on the susceptibility of reef-building corals to thermal stress. The Journal of Experimental Biology 211: 1050-1056.

The authors collected branches of the reef-building coral Acropora aspera -- which contains the dinoflagellate symbiont Symbiodinium (clade C3) -- from three large colonies on the reef flat adjacent to the Heron Island Research Station at the southern end of Australia's Great Barrier Reef. Multiple upward-growing branch tips were placed on racks immersed in running seawater within four 750-liter tanks that were maintained at the mean local ambient temperature (27°C) and exposed to natural reef-flat summer daily light levels. Then, two weeks prior to a simulated bleaching event -- where water temperature was raised to a value of 34°C for a period of six days -- they boosted the water temperature in one of the tanks to 31°C for 48 hours, while in another tank they boosted it to 31°C for 48 hours one week before the simulated bleaching event. In the third tank they had no pre-heating treatment, while in the fourth tank they had no pre-heating nor any simulated bleaching event. At different points throughout the study, they measured photosystem II efficiency, xanthophyll and chlorophyll a concentrations, and Symbiodinium densities.

Middlebrook et al. report that the symbionts of the corals that were exposed to the 48-hour pre-bleaching thermal stress "were found to have more effective photoprotective mechanisms," including "changes in non-photochemical quenching and xanthophyll cycling," and they further determined that "these differences in photoprotection were correlated with decreased loss of symbionts, with those corals that were not pre-stressed performing significantly worse, losing over 40% of their symbionts and having a greater reduction in photosynthetic efficiency," whereas "pre-stressed coral symbiont densities were unchanged at the end of the bleaching.

In the words of the three researchers, "this study conclusively demonstrates that thermal stress events two weeks and one week prior to a bleaching event provide significantly increased thermal tolerance to the coral holobiont, suggesting that short time-scale thermal adaptation can have profound effects on coral bleaching." In addition, they say that "both corals and Symbiodinium have been shown to possess a wide variety of genes that encode for stress response proteins, which can impart protection, indicating that a more comprehensive study is required to elucidate all of the underlying mechanisms of thermal bleaching." All things considered, therefore, it may well be that earth's reef-building corals are not nearly as helpless before the specter of possible future global warming as the world's climate alarmists have made them out to be.

 

[Anonymous]

Heh. Very interesting stuff, Eric.

 

[Charlesr1958]

Thank you for that!

As it is killing me to not say " I told you so! Neener, Neener NeeeeeNerrrrr " I'll instead let this line do so for me -

"those corals that were not pre-stressed performing significantly worse, losing over 40% of their symbionts and having a greater reduction in photosynthetic efficiency"

Chuck

 

[Anonymous]

Thank you for that!

As it is killing me to not say " I told you so! Neener, Neener NeeeeeNerrrrr " I'll instead let this line do so for me -

"those corals that were not pre-stressed performing significantly worse, losing over 40% of their symbionts and having a greater reduction in photosynthetic efficiency"

Chuck

I don't think that article suggests anything we don't already acknowledge. If you knew your tank was going to hit 93 degrees in a couple weeks, you'd want to raise the temperature.

 

[Anonymous]

:lol: I'm sorry Matt, but you guys were arguing against the idea or concept that Chuck put out that stressing corals may lead to healthier or more resilient corals, rather in the same way that subjecting other organisms to stressors might improve their ability to recover (i.e. vigor).

 

[Anonymous]

:lol: I'm sorry Matt, but you guys were arguing against the idea or concept that Chuck put out that stressing corals may lead to healthier or more resilient corals, rather in the same way that subjecting other organisms to stressors might improve their ability to recover (i.e. vigor).

The study shows that stressing corals does lead to more thermally resilient corals. Thermally resilient does not necessarily mean "healthier" if there are no thermal stresses. This study shows that corals subjected to a short term stress of 88 degrees will deal with a stress of 93 degrees better. So what if the bleaching event (rise in temperature to 93 degrees) never happens? Should we all be running our tanks in the mid to high 80's to prepare for a temp spike that may never happen if it is to the long term detriment of the corals?

I'd be curious to see growth rates/photosynthetic activity of the non-prestressed corals vs. prestressed corals that were NOT exposed to the bleaching event. If the latter performed better than the former, you can "neener, neener" all you like.

 

[Anonymous]

I always maintained my SPS tank at 83 degrees, that way when it spiked to 86 on the hottest days, nothing noticed.

I have to laugh when I see threads where someone is panicking about their tank spiking to 82 - raise your tank temp numbnutts.