Acropora at low tide

[ishmael]

I was browsing Veron's "Corals of the World" and noticed a few pictures of the Great Barrier Reef at low tide. I understand that probably only a very small percentage of corals throughout the world end up this exposed, however,
It got me to thinking,

A. Why am I so concerned when fragging/placement/removal from the tank in general of my acros, when in nature some of these corals spend hours exposed to the air/baking sun?

B. Does this exposure in nature actually contribute to the health of the coral?

C. Has anyone ever been innovative/courageous enough to incorporate this aspect of natural environment to the aquarium? Imagine viewing someone's tank at simulated low tide, 1/4 empty? ''

I have included rather crude pix of the pix. Unfortunately, my reprints don't do justice to the fact that these corals are absolutely gorgeous, sitting right out there in the air.

 

[spleify]

Thats pretty incredible stuff. There was a video of that floating around here a while ago. Thanks for sharing the pics.
And to think we all freak out if our corals are out of the water for a minute or two.....guess we can relax a little, huh?
Thanks again for sharing.

Spleify

 

[wetone]

I love those pix !! most of the time you can only get a view of a reef like that while scuba diving....

I frag my SPS quite a bit and I will take out the "mother" piece and place it in a seperate container in water...when ever possible, I will clip off the pieces to frag while under the water, if I cant I clip them and then put the pieces right back in the seperate container......my thought is to minimze the stress from the initial cut .
Once I'm ready to attach to the frag plugs, I take out the small pieces, dab them dry with paper towel and glue them...i let them sit for a few minutes, out of the water to let the glue setup and then place back in my seperate container before putting in my grow out tank.....
All my frags do well and this time in the air doesnt seem to hurt them

 

[jeffbrig]

Re: Acropora at low tide

<a href=showthread.php?s=&postid=11893879#post11893879 target=_blank>Originally posted</a> by ishmael

I love to refer people to this photo of waves crashing on the exposed reef. Think your tank has flow? Not compared to this.

 

[ReefTECK]

I'm glad you brought this topic up. I've mentioned building a tidal tank on several occasions and some people just write me off as crazy.

Although no studies, that I know of, have been made to offer evidence that this exposure, or even merely the flux of pressure from water above "x" coral species would be of significant benefit. Really, it's the single variable that we don't recreate or simulate in our reef aquariums.

Heres how I thought you could go about this, and still include all of your convenient gadgets. ie auto-top-off, skimmer, etc.

The tidal drain could be controlled with an electronic T-ball valve maybe?

Any flaws in this diagram, it's a pretty rough one!

 

[ReefTECK]

PS: how much was JEN Verons publication there? 120-150?

 

[JustinReef]

I would be careful recreating this. Do some research. This does not happen everday. I was in Australia for 6 months and visited the Great Barrier Reef for about 3 weeks and this did happen but only for a few days. The longest anything significant was exposed was about an hour. Most days, the reef was still mostly underwater. It depends on the time of year and goes in cycles. Its a cool idea but you should really know what your doing before you do it.

Im also a little curious as to why???

 

[JustinReef]

 

[seapug]

It's true that many acros are exposed at low tide, same thing goes for Zoanthids and many shallow water clam species. The pigmentation of the corals and the mucus they secrete protects them from the UV radiation. Whether or not the exposure is necessary to maintain their health is certainly questionable, so building a tank to simulate this may be interesting, but not worth the effort, IMO.

There is usually little problem letting your SPS corals get exposed during a water change or moving them from one tank to another, but that doesn't mean they like having dirty, greasy human fingers all over them while getting broken into pieces during a fragging project. It's most likely the HANDLING of them while they are out of the water that can be bad, not the exposure itself.

 

[JustinReef]

Personally I just do not see the reason behind trying it UNLESS its purely an experiment. There are many many extremely healthy coral colonies in the ocean that never get exposed to air, so I personally have my doubts about there being any real huge benefit to low tide. It just would be a very expensive mistake if it did not work out.

 

[tgunn]

I'm not sure I'd want to simulate this effect. I've always found when moving corals out of the tank even briefly that the smell is nasty...

Tyler

 

[ReefTECK]

Isn't the novelty of the idea reason enough to try? If I build a tank like this I would not go so much for the exposure of coral during the low tide, but rather take it down 8 to 10 inches (on a 30" tall tank) and set up some surge tanks for the reintroduction of all the water.

 

[Anemone]

Martin Moe showed an aquarium design that could create a tidal exposure area at MACNA XIV in 2002. Very cool to watch as the tidal area slowly drained, then slowly refilled in surges.

A description of the aquarium design is part-way down, in the "The Marine Multi Environment Aquarium System - Martin Moe" section:

http://reefkeeping.com/issues/2002-10/kk/feature/index.php

Kevin

 

[JustinReef]

<a href=showthread.php?s=&postid=11897662#post11897662 target=_blank>Originally posted</a> by ReefTECK
Isn't the novelty of the idea reason enough to try? If I build a tank like this I would not go so much for the exposure of coral during the low tide, but rather take it down 8 to 10 inches (on a 30" tall tank) and set up some surge tanks for the reintroduction of all the water.

A friend of mine has done this with his tank and its an awesome idea. He does not expose any of his corals though.

 

[respite]

I have never seen any problems with keeping acros out of the water for brief periods of time. Some acropora colonies are dry packed while imported from the indo pacific to america. As Seapug stated, cleanliness is important. Best practice is to wear latex gloves while you frag/glue.

Most exposed sps corals quickly slime over. I can only imagine a sps dominated tank at "low tide" will look like a mucus factory.

 

[seapug]

<a href=showthread.php?s=&postid=11897662#post11897662 target=_blank>Originally posted</a> by ReefTECK
Isn't the novelty of the idea reason enough to try? If I build a tank like this I would not go so much for the exposure of coral during the low tide, but rather take it down 8 to 10 inches (on a 30" tall tank) and set up some surge tanks for the reintroduction of all the water.

Absolutely! If you have the time, money and space, go for it. The issue is whether or not all the complicated plumbing and expense would provide any benefit over keeping them submerged where it has been proven they thrive. Surge tanks do provide benefits, but there are ways of designing them that do not expose the corals to air every few minutes.

As was said earlier, at the VERY most the corals on natural reefs are only exposed twice/day at low tide. In reality it probably occurs much less frequently. Setting up a tank that does this 10X/hour 24/7 won't exactly replicate a natural situation.

Plus, there is that issue of the stench that was mentioned before. Acros do have an unpleasant smell when exposed to air.

 

[ishmael]

Justinsmith, GREAT photographs. I always thought that tides occur daily. But then again, I live near the Hudson River.....
How about that huge leaf sitting on the coral?

GREAT Pix........

 

[ishmael]

Reeftek, Amazon $160...

 

[greenbean36191]

I always thought that tides occur daily.

They do, but the magnitude of change varies throughout the month, seasonally, and with the weather. The majority of reefs are never exposed to nearly this degree and on those where this does happen it's only a few times a year on the very lowest tides.

It's certainly not beneficial to the corals. Producing the huge amounts of mucus needed to protect themselves is very energetically expensive. Because this only happens occasionally, it's not a problem. If it happened more frequently it would be. Also, when this happens at midday under clear skies, a lot of these corals do partially bleach. Again, the frequency allows for recovery.

Yes, it's safe to expose your corals to the air occasionally and in fact shipping them without water is the safest way for many of them. However, it's not something I would recommend doing regularly.

 

[ishmael]

Well, your explanation really helps.

I inferred from the pictures (incorrectly, I see now) that this was a daily occurance.

So I based lot of my reasoning on this perception. I have learned a lot. Thanks!