Coral Bleaching

[Shredded]

Has anyone had this happen to them?
I've had numerous coral bleaching events... but not the whole colony, just a small area near the bottom, maybe quarter sized and it only hit one colony twice, the rest just once and not all them as of yet. It tends to just take place every few weeks on one of my corals, then over the next few weeks, it repopulates the zooxanthellae and is back to normal. Its not growing over a dead area, you can watch it daily as the area colors back up and the polyps come back out. The rest of the colony is fuzzy and happy. The first few times I panicked, ran tests looking for the issue, but found nothing. It's gotten to the point now where I say a few choice words and ignore it as every time it has immediately come back. It starts to recover within a day. Still, what am I doing wrong? I do not think its a parasite. LFS suggested this. If it is, it just samples it and moves on. Ideas?

 

[saltyfilmfolks]

I’ve never really heard of that.
Following

And tagging.
#reefsquad
@Dana Riddle

 

[ndrwater]

I would check for flatworms. They can be difficult to see. They are about a 1/4" inch or less. Many times the color of the coral. Specifically, look for bite marks. Little round or oval white spots near the base if the coral. Unfortunately, what you are describing sounds alarmingly all to common with the dreaded flatworms infestation.

 

[MTBake]

I would look at lighting, flow and pests. As the coral matures, flow will change as there are now objects where there weren't before. The growth could also cause more shading from light but I feel this a rarer occurance. Pests are generally bad.

What are your parameters? Out of curiosity.

 

[MTBake]

Can you get pic?

 

[Flippers4pups]

Though STN and RTN happens frequently to hobbyist without them understanding the root cause.

Typically these events happen when SPS are weak. Weak? Conditions are less than what they need/changes are fast and not stable or were recently introduced into a system as a frag. Sometimes long kept colonies do this. So what causes this........ bacteria.
Each coral has on it's surface 1000's of bacteria, good and bad. Conditions of quick changes can cause the good bacteria to be reduced, allowing the bad to get a foot hold. This is why people say a system needs to be stable for them to stay healthy. They also say a system needs to be mature. Maturity allows the bacterial strains to establish and become healthy.

So, overall it's kinda unknown to most of us when this may or can happen. If we knew, then maybe we could keep it from happening.

Bleaching or "burnt tips" are something completely different, issues with different causes.

 

[Shredded]

Though STN and RTN happens frequently to hobbyist without them understanding the root cause.

Typically these events happen when SPS are weak. Weak? Conditions are less than what they need/changes are fast and not stable or were recently introduced into a system as a frag. Sometimes long kept colonies do this. So what causes this........ bacteria.
Each coral has on it's surface 1000's of bacteria, good and bad. Conditions of quick changes can cause the good bacteria to be reduced, allowing the bad to get a foot hold. This is why people say a system needs to be stable for them to stay healthy. They also say a system needs to be mature. Maturity allows the bacterial strains to establish and become healthy.

So, overall it's kinda unknown to most of us when this may or can happen. If we knew, then maybe we could keep it from happening.

Bleaching or "burnt tips" are something completely different, issues with different causes.

So question, I am new to SPS. The tank is about a year and a half old and my parameters are checked daily, sometimes multiple times as I was told stability is key, alkalinity 8.5, varies at most .1 to .2. Temp is 77 and varies no more then 1/2 degree daily, mag - 1380, calcium - 1450. Nitrates - 2ppm and phosphates - .17 ppm. The corals have all just started coloring up and to take off and grow. I want to clarify as you were referring to stn and rtn, slow tissue necrosis and rapid tissue necrosis, correct? To make sure I understand as a beginner I think I have seen this before as I lost several corals when I started. This differs from bleaching, right, where the coral expels the xoozenthellae? My corals are not losing tissue, (I have seen that happen and it's unmistakable at least if I'm not totally wrong.) The tissue is intact, polyps and all. They just simply lose total color for in about a quarter size area. Totally white. You can see the skeleton under but the tissue remains. The area from last weekend has already started to color up again. By next week it will be as it was. It's not like the coral is encrusting over the white area, it seems to just repopulate the xoozenthellae and goes on. Is what I have been thinking wrong? I'll try to get some pics of the area tomorrow.
Thanks!

 

[Flippers4pups]

So question, I am new to SPS. The tank is about a year and a half old and my parameters are checked daily, sometimes multiple times as I was told stability is key, alkalinity 8.5, varies at most .1 to .2. Temp is 77 and varies no more then 1/2 degree daily, mag - 1380, calcium - 1450. Nitrates - 2ppm and phosphates - .17 ppm. The corals have all just started coloring up and to take off and grow. I want to clarify as you were referring to stn and rtn, slow tissue necrosis and rapid tissue necrosis, correct? To make sure I understand as a beginner I think I have seen this before as I lost several corals when I started. This differs from bleaching, right, where the coral expels the xoozenthellae? My corals are not losing tissue, (I have seen that happen and it's unmistakable at least if I'm not totally wrong.) The tissue is intact, polyps and all. They just simply lose total color for in about a quarter size area. Totally white. You can see the skeleton under but the tissue remains. The area from last weekend has already started to color up again. By next week it will be as it was. It's not like the coral is encrusting over the white area, it seems to just repopulate the xoozenthellae and goes on. Is what I have been thinking wrong? I'll try to get some pics of the area tomorrow.
Thanks!

Sounds like a precursor to RTN. Just doesn't go all the way or "bugs"

Not totally ruling out "bugs". Could be in your case.

 

[Dana Riddle]

Years ago, I believed white spots around the base of corals were due to low flow and/or low lighting - but these white spots only got worse with no recovery seen. Years later, I began to attribute these spots to nocturnal parasites, such as Phestilla nudibranchs on Porites corals, but coral tissues did not recover quickly, if at all. An observation of the areas surrounding a Phestilla nudibranch saw polyp retraction, bleaching, and a general malaise. I'll throw this out for consideration - some sort of nocturnal/light-hating 'bug' is exuding an irritant that causes loss of zoox, polyp retraction, etc. As usual, long-distance analyses are difficult at best. I'll follow this and see how it shakes out.

 

[Shredded]

Hi Mr Riddle,
You probably don't remember, as you speak to so many people, but you and i stood by the pool at MACNA at the meet and greet and talked about my tank and coral growth while we ate. I really appreciated your help! I did wind up switching over to and LED/T5 combo this week. Now, to clarify, none of these occurrences have taken place after switching to the new lighting. They all occurred before with metal halide/t5 lighting. But, the new combination has only been running since Sunday. If anything I think I have seen increased/rapid growth after the lighting change even with the lights in the acclimation mode. I hesitantly say that perhaps those areas that lost color are actually coloring up quicker then normal but could be wishful thinking. Its a 300 gallon tank with 4 Maxspect XF250 Gyres, 2 on each side, pulsing for flow, plus two wave maker power heads on the back that I move daily to mix it up. While the lighting change scares me as I have not dealt with LED before, have always been old school metal halide, my LFS, where all my corals come from run the same lights and they shared their lighting file with me so I know these corals do well under these light as they grow light freaking weeds in his store. Still, no guarantee, but I think its as safe as I can be to switch over. I am taking off early today and will run a full battery of tests and post everything and will try to get a good camera to get some close up pics of those areas as a cell phone camera just doesn't cut it. I appreciate everyone's input!

Thanks,
Jeff

 

[Scott Campbell]

Hi Mr Riddle,
You probably don't remember, as you speak to so many people, but you and i stood by the pool at MACNA at the meet and greet and talked about my tank and coral growth while we ate. I really appreciated your help! I did wind up switching over to and LED/T5 combo this week. Now, to clarify, none of these occurrences have taken place after switching to the new lighting. They all occurred before with metal halide/t5 lighting. But, the new combination has only been running since Sunday. If anything I think I have seen increased/rapid growth after the lighting change even with the lights in the acclimation mode. I hesitantly say that perhaps those areas that lost color are actually coloring up quicker then normal but could be wishful thinking. Its a 300 gallon tank with 4 Maxspect XF250 Gyres, 2 on each side, pulsing for flow, plus two wave maker power heads on the back that I move daily to mix it up. While the lighting change scares me as I have not dealt with LED before, have always been old school metal halide, my LFS, where all my corals come from run the same lights and they shared their lighting file with me so I know these corals do well under these light as they grow light freaking weeds in his store. Still, no guarantee, but I think its as safe as I can be to switch over. I am taking off early today and will run a full battery of tests and post everything and will try to get a good camera to get some close up pics of those areas as a cell phone camera just doesn't cut it. I appreciate everyone's input!

Thanks,
Jeff

For what it is worth - I have a bright green plating montipora that does this exact same thing on a sporadic basis. Large patches will lose all color for no apparent reason becoming stark white. But then regain color extremely quickly (within a week) with no loss of coral. Most of the colony is completely unaffected. Bright green patches will be side by side with completely white patches in the same lighting and flow area. It freaked me out at first but now I don't worry about it. Nothing else in the tank shows any sign of distress and I gave up trying to solve the mystery. The coral often looks better than ever after the bleaching event (or whatever it is). Makes no sense to me.

 

[Gregg @ ADP]

In the studies I’ve read on bleaching in nature, there does not appear to be a consensus on who does what. Do the corals expell the zooxanthellae? Do the zooxanthellae die off? Do they make a break for it? Does it even matter in this case?

In my experience with corals, the super-simplified take is: when something is wrong, things get worse.

Like us or any other organism, healthy corals can ride out rough times. Injury, disease, temporary bad conditions (within reason). They aren’t that delicate. We’re talking about arguably the oldest phylum of Animalia on Earth.

The world is an imperfect place, and corals are equipped to handle that. Coach Saban once said, ‘Ignore the stat line and watch the trend line’. If an overall healthy coral has some blemishes, but it’s not losing tissue and it’s not getting worse, and the coral otherwise has good color and growth, I don’t know that I would worry too much. If your environment is good and nutrition for the coral is adequate, just keep an eye on it.

 

[Shredded]

Good example. The rest of the coral remains totally unaffected. Fuzzy polyp extension, great color, just the spot. Correct me if I am wrong but I have also read that too much xoozenthellae in a coral can produce excess motabolites that actually irritate the coral causing the coral to flush out the xooanthellae thus causing bleaching... could this be the coral "adjusting" the population so as to correct the situation? I think it has just been recent that my tank has reached a mature stage. Corals that I have had for six months, and not died , not changed either, have started to color up and grow. While sitting here thinking about this it occcurs to me that the corals that this has happened to, have suddenly gone thru a rapid growth stage. Just a thought.

 

[Oshengems]

For the past few moths I kept gettin random acros get RTN I thought it was too much light at first since I had swapped lights, then had some alk swings and that’s when it really started I thought it was my numbers but discovered it was acro eating flatworms, pay attention to your other corals specifically montiporas, every other single one of my corals are doing great only my acros were suffering

 

[Oshengems]

Btw even with RTN and flatworms on them my green slimmer Oregon Tort and Cali Tort had excellent Polyp Extensión

 

[Dana Riddle]

Hi Mr Riddle,
You probably don't remember, as you speak to so many people, but you and i stood by the pool at MACNA at the meet and greet and talked about my tank and coral growth while we ate. I really appreciated your help! I did wind up switching over to and LED/T5 combo this week. Now, to clarify, none of these occurrences have taken place after switching to the new lighting. They all occurred before with metal halide/t5 lighting. But, the new combination has only been running since Sunday. If anything I think I have seen increased/rapid growth after the lighting change even with the lights in the acclimation mode. I hesitantly say that perhaps those areas that lost color are actually coloring up quicker then normal but could be wishful thinking. Its a 300 gallon tank with 4 Maxspect XF250 Gyres, 2 on each side, pulsing for flow, plus two wave maker power heads on the back that I move daily to mix it up. While the lighting change scares me as I have not dealt with LED before, have always been old school metal halide, my LFS, where all my corals come from run the same lights and they shared their lighting file with me so I know these corals do well under these light as they grow light freaking weeds in his store. Still, no guarantee, but I think its as safe as I can be to switch over. I am taking off early today and will run a full battery of tests and post everything and will try to get a good camera to get some close up pics of those areas as a cell phone camera just doesn't cut it. I appreciate everyone's input!

Thanks,
Jeff

Yes I do recall, and good to hear from you Jeff! Looking forward to the photos...

 

[Shredded]

Hope everyone had a good weekend. Friday, I took half a day off and spent a solid 8 hours just working on the tank, and tank room. People are always looking to do less work on their tanks (so they can sit and enjoy them more), me, I get enjoyment and relaxation from working on mine. Kind of like my tank build never ends. If I didn't have to work, i could do this every day. One of the things that I did was to re calibrate all my dosers. (If you don't do that regularly you will be surprised how much they get off after running for just a couple of months) I ran a full battery of tests and my alkalinity was down about .3, which is what prompted me to re calibrate all the heads and has it turned out the alkalinity doser was no longer dosing 8.6 but 8.2. When I was done for the day, I had the doser manually dose 30 ml of sodium carbonate to bump my dKH up .2, 15 ml to adjust .1 on 300 gallons (the most I ever adjust at a time manually). I have a GHL, KH Director but it is down at this time so I monitor twice KH daily as the director normally measures 8 times per day and adjusts. As I was lying in bed that night thinking, I BELIEVE I FIGURED IT OUT! I think that when I have had to dose manually to adjust the dKH is when the "spot bleaching" incidents have occurred. And while .2 is a small adjustment, my dosing tubes are in the last compartment of my sump with my twin return pumps and will not have disseminated much. And guess which corals have been having issues? The ones in line of the outputs from the return pumps. I figured if I was correct, that I had just caused another one. The next morning, there it was, a nice big spot on my red planet. My guess is that while normal dosing, even with an adjustment from the Director is not an issue (doses 75 times per day) that the "blast" at the concentration from a manual dose is the cause. At this point, they do recover and I have not lost one yet, probably because I don't adjust much at at time. So, as usual, stupidity on my part. Eventually I will figure it out. The reason I put my tubes there as it was the last access port I had left, I will either have to cut another or never manually dose using the doser but that does eliminate the possibility of remote adjusting. Thanks for everyone's input and help. I will keep this updated to see if it ever happens again to verify my hypothesis.

 

[Dana Riddle]

Hope everyone had a good weekend. Friday, I took half a day off and spent a solid 8 hours just working on the tank, and tank room. People are always looking to do less work on their tanks (so they can sit and enjoy them more), me, I get enjoyment and relaxation from working on mine. Kind of like my tank build never ends. If I didn't have to work, i could do this every day. One of the things that I did was to re calibrate all my dosers. (If you don't do that regularly you will be surprised how much they get off after running for just a couple of months) I ran a full battery of tests and my alkalinity was down about .3, which is what prompted me to re calibrate all the heads and has it turned out the alkalinity doser was no longer dosing 8.6 but 8.2. When I was done for the day, I had the doser manually dose 30 ml of sodium carbonate to bump my dKH up .2, 15 ml to adjust .1 on 300 gallons (the most I ever adjust at a time manually). I have a GHL, KH Director but it is down at this time so I monitor twice KH daily as the director normally measures 8 times per day and adjusts. As I was lying in bed that night thinking, I BELIEVE I FIGURED IT OUT! I think that when I have had to dose manually to adjust the dKH is when the "spot bleaching" incidents have occurred. And while .2 is a small adjustment, my dosing tubes are in the last compartment of my sump with my twin return pumps and will not have disseminated much. And guess which corals have been having issues? The ones in line of the outputs from the return pumps. I figured if I was correct, that I had just caused another one. The next morning, there it was, a nice big spot on my red planet. My guess is that while normal dosing, even with an adjustment from the Director is not an issue (doses 75 times per day) that the "blast" at the concentration from a manual dose is the cause. At this point, they do recover and I have not lost one yet, probably because I don't adjust much at at time. So, as usual, stupidity on my part. Eventually I will figure it out. The reason I put my tubes there as it was the last access port I had left, I will either have to cut another or never manually dose using the doser but that does eliminate the possibility of remote adjusting. Thanks for everyone's input and help. I will keep this updated to see if it ever happens again to verify my hypothesis.

Interesting! Alkalinity can act as a carbon source for photosynthesis. And chlorophyll concentrations can vary greatly over a coral's surface. Is it possible that the alkalinity increases, combined with a higher flow, could have boosted photosynthesis beyond the point where protective mechanisms were overwhelmed?

 

[timtim4]

I have a colony of star polyps that my shrimp attacked without me knowing, and when the shrimp died the colony was flourishing again and there haven't been any problems with the colony ever since. so check if an fish / invertebrate is attacking it.