Amphidinium Dinoflagellate Treatment Methods

[Jaysin13]

Ok guys, I've had my phosphates up to .05 ish and nitrates at about 5 for a week and been using a python vacuum through a 10 micron sock for a week. Sand seems about the same every day. Looks great after vacuuming but back the next day..... Now I'm getting this on the power heads and some of the rocks..... Is this more dinoflagellate or another algae? Good or bad?

 

[dwest]

Yes, the other thread we'd kinda like to keep it to tried and true, whereas here - with this strain being unresponsive to UV there's a bit more justification for experimentation. Maybe the Si will turn out to be a key, maybe it'll be a slightly helpful tool among many, or maybe a complete dead end. We'll see!

This is a very astute point. I pegged nutrient competition and allelopathy as separate possible mechanisms, but they are very likely connected - competition triggering the allelopathy. Where I would dissent slightly is that I feel like we know what happens under P limitation - many systems have traveled that road, and the dinos do quite well at causing lots of problems. For that reason I'd lean toward keeping P, N, and Si all very available until the growth plateaus from having consumed some more minor element (like Fe or B12 etc.)


Anything for a fellow AP Phys teacher
Your oddball invert crew sounds weirdly like mine! holothuria, conch, limpets, chitons - I also got lucky with a large Cerith that laid eggs immediately, blessing me with a million tiny ceriths all over the sand. If you had an urchin and emeralds - we'd be almost totally in sync there.

Since you have filamentous algae (I'd call it green but you say brown - probably because of what covers the algae and not the filaments themselves) and diatoms, and your system has held stable elevated P and N for over a month now with very slow progress, and you have quality herbivores that'll actually eat diatoms, I'd say go for adding Silica. Check my comments linked at the first post, I think 1ppm Silica is a fine upper end target if you actually have a test kit that can read it. (Salifert failed me - I'll review Hannah as soon as mine arrives). Also the microscope will be crucial since you'll need it to tell what's going on - diatoms or dinos. You might even find the diatom competition suppresses new growth or reduces the filamentous algae too.

@Waterbourn it sounds like some of this discussion with dwest may apply to you too. If not, kinda give us a description and shots of your tank status outbreak, and microfauna report like dwest did.

Hey taricha, we are totally in synch with CUC. I also have an urchin and crabs (mine are red, not emeralds though...hitchhikers from my LR,...also my ceriths died) The AP teacher is connection is quite humorous in itself. Back to the thread...I saw that another poster in the main thread was using Hannah checker for silica. We have spring break in a week. When I get back, I'll re-assess. Then likely start silica dosing based on what I see. Let me know about your results with your Hannah. Will I be able to see what I need to see with my cheap $12 microscope? If not, you do have a recommendation? Thanks again.

 

[dwest]

Jaysin13, I'm not even close to an expert here. But if you buy the $12 microscope (see the main thread) you will likely get a positive ID. Then, a course of action, if required, can be laid out. It worked for me and many others. IMO, its very hard to ID based on your photo.

 

[Jose Mayo]

So ... turning over some older references in aquaculture articles, I found this specific work on Amphidinium that points to a target for the silica dosage in stimulating diatomaceous growth to combat dino flowering, relating its concentration to concentration of nitrate, as below:

"Some species of Amphidinium are known to have produced toxins. When a species of Amphidinium bloomed in a mariculture sediment pond fed by effluent water from semi-intensive fishponds, it was isolated and its physiological ecology was investigated to find its tolerances and optima for population growth (temperature, salinity, pH, nitrate/ammonia, phosphorus, and vitamin B12). In a preliminary test, an ether-soluble extract was toxic to mice. The Amphidinium sp. was eurytrophic, with a great facility for luxury consumption and the ability to store nitrate and phosphate for several generations. It needs vitamin B12 and formed cysts when exposed to high levels of ammonium. Its maximum growth rate was 1 division/day, and it grew well between 20 and 33 °C. It was tolerant of a wide range of pH (6.5–9.5; optima 6.5–8.6) and salinities (20–50‰; optima 22–32‰). The Amphidinium was outcompeted by diatoms if the Si/N ratio was kept at 1:1 or greater, suggesting that this factor could control its growth in sedimentation ponds used in integrated systems to grow mollusks. Eurytrophic organisms are difficult to control by environmental methods, thus, vigilance is required to ensure that bivalves fed from sediment ponds are not contaminated with toxins from this or any other dinoflagellate."

Physiological ecology and possible control strategy of a toxic marine dinoflagellate, Amphidinium sp., from the benthos of a mariculture pond

In another hand, and still on the factors that can give rise to dinoflagellate blooms, it seems that the control of nitrogen, especially urea, can be an excellent limitation to be considered, as below:

"All dinoflagellate blooms were observed to co-occur with elevated levels of urea (>1.5 μM nitrogen). In total, we found 14 instances of elevated urea levels, of which 10 co-occurred with dinoflagellate blooms. In all cases where urea was <1.5 μM nitrogen (seven occasions), no dinoflagellate blooms were found (Fig.1). The occurrence and/or abundance of dinoflagellate blooms was not found to be correlated significantly with any other nutrient parameter."

Cooccurrence of Elevated Urea Levels and Dinoflagellate Blooms in Temperate Estuarine Aquaculture Ponds

From the above, and only as an idea, it might be interesting to consider the aggressive reduction of nitrates and the adjustment of the silica dosage, aiming at the ratio 1/1 (nitrate / silica), to reach the control goal more quickly, by competition between diatoms / dinoflagellates.

Regards

 

[taricha]

Now I'm getting this on the power heads and some of the rocks..... Is this more dinoflagellate or another algae? Good or bad?

I second dwest on "no way to tell from that pic"

Hey taricha, we are totally in synch with CUC. I also have an urchin and crabs (mine are red, not emeralds though...hitchhikers from my LR,...also my ceriths died) The AP teacher is connection is quite humorous in itself. Back to the thread...I saw that another poster in the main thread was using Hannah checker for silica. We have spring break in a week. When I get back, I'll re-assess. Then likely start silica dosing based on what I see. Let me know about your results with your Hannah. Will I be able to see what I need to see with my cheap $12 microscope? If not, you do have a recommendation? Thanks again.

Just got my Hannah stuff. It's Party* time!
*by "Party" I mean measuring infrequently monitored water parameters.


You can almost certainly see what you need to with the kids scope. You'll just have to work hard to overcome the shakiness (plastic body) and image distortion (poor quality optics). The AMscope $60-70 range gets you the equivalent of what I use (actually mine is a discarded HS biology lab scope *hint hint*), and under the right conditions - the 430x setting can image dino flagella and bacterial wiggles.

 

[taricha]

this specific work on Amphidinium that points to a target for the silica dosage in stimulating diatomaceous growth to combat dino flowering, relating its concentration to concentration of nitrate,

yep! That paper is what we are using as a playbook for the Si approach.
Here's the post that I linked to in the First Post as fairly to-the-point instructions based on the paper.

For Large Cell Amphidinium only, anyone wanting to try dosing Silica to have diatoms outcompete the dinos as outlined in this paper previously discussed.

Brightwell SpongeXcel silicate source
Salifert Si test kit [Edit: Can't recommend Salifert Si at the moment. 0 for 3 on user reports so far.]

I'm going to presume a 10 gal tank with 10ppm No3 = 2.25 ppm N

"1 drop per gallon of water increases ionic silica concentration by ~0.20 ppm."
Test (guessing zero Si)
day 1&2 - 5 drops (.20ppm cumulative Si)
Test (guessing zero Si)
days 3,4,5,6 - 10 drops (1.0 ppm cumulative Si)
Test (guessing some small amount Si)
days 7,8,9 - 16 drops (0.32 ppm per day, 2.0 ppm cumulative Si)
Test (no idea what it'll show at this point)

When It says "Test" I'd check for diatom growth, overall tank health, Si and N and P to see consumption by the tank to see if it's shifting.
If the Si keeps getting eaten up immediately, with no signs in tank changes, I'd continue upping drops by +5 drops per 10 gal every 3 days.
If something is happening like a shift toward noticeable diatom bloom, then I'd hold dose steady for a few days and monitor the relative amounts of diatoms/dinos.
If Si accumulates (I doubt, but possible) wait and see what happens around 0.5ppm Si for a few days. This is approximately the paper's Si levels.
If after a few days of monitoring at 0.5ppm Si, the dino growth is still much more significant than diatoms, then I'd continue upping the dose by +5 drops per 10 gal every 3 days, up to 1.5-2ppm Si then I'd hold/back off the dose. I wouldn't attempt to exceed around 2.25 ppm Si which is 1:1 Si:N at 10ppm NO3.
I suspect the system will start producing lots of diatoms well before you ramp up to a sustained 1:1 Si:N at 10ppm NO3.

"All dinoflagellate blooms were observed to co-occur with elevated levels of urea (>1.5 μM nitrogen). In total, we found 14 instances of elevated urea levels, of which 10 co-occurred with dinoflagellate blooms. In all cases where urea was <1.5 μM nitrogen (seven occasions), no dinoflagellate blooms were found (Fig.1). The occurrence and/or abundance of dinoflagellate blooms was not found to be correlated significantly with any other nutrient parameter."

That's an interesting paper. A couple of takes from it. It seems to specifically suggest that high levels of Organic N favor Dino bloom more strongly than the levels of N (or P - they didn't really look a P much) overall. It's another piece pointing to the notion that dinos are well equipped to thrive on organic nutrients while simple inorganic nutrients favor growth of other classes. That idea form several published papers is the basis (along with hobbyist experience) for advocating P & N dosing as helpful vs heavy feeding as unproductive.
I also like that it's an aquaculture facility so is discussing dinoflagellates in a high nutrient system. That's coming at the problem from a different angle than most papers - and it may address why a few people have little success with simply elevating nutrients. It is possible to have a dino bloom in a tank that has plenty of nutrients - if the tank is getting high levels of some organics.
Furthermore, this may be specifically relevant to our sandbed Amphidinium dinos. regardless of what our water tests, our sandbeds are often quite a storehouse of organic forms of nutrients. I've heard reports of people testing the porewater (water from between the sand grains) and getting large ammonia and other readings. Also many tanks that have amphidinium also have cyano mats often mixed together - and cyano mats are often driven by buildup of decaying organic matter
"Nutrient concentrations in the water-column were consistently low, but markedly increased just above substrata (both sandy and hard) covered with BCMs [Benthic Cyanobacterial Mats]. This was true for sites with both high and low BCM coverage, suggesting that BCM growth is stimulated by a localised, substrate-linked release of nutrients from the microbial degradation of organic matter....This organic matter is transported by currents and settles on the seabed at sites with low hydrodynamics...."
Honestly, it sounds like they were writing this about my tank at the onset of my amphidinium dinos.
Ooh and they also tie the decaying organic matter to passing along Iron to the cyano which is pretty interesting, as many of us suspect dinos have a strong and sometimes limiting need for iron "Increased dissolved organics in the water column may facilitate the transport of bio-available Fe and P to L. majuscula [a cyano] via the formation of Fe-organic complexes [30,31]...
...Due to the degradation, an anoxic zone develops at the sediment surface. The ensuing Fe3+ reduction leads to release of Fe3+-bound phosphate to the water column, and possibly also of Fe2+ [46]. This local nutrient release from the benthos subsequently stimulates the growth of BCMs. "

 

[Jose Mayo]

Yes, it seems that you are on the track of something useful, to control this pest so unpleasant for the hobby. I'm happy to keep up with the work.

Best regards

 

[dwest]

I was hoping someone could take a look at my photos below. Taricha thought I should get a sample of my sand to check for amphidinium. I took these microscope photos of my sand. Note I still use my $12 microscope. None of the "suspected dinos" are moving (although I did see a couple moving in my hair algae samples from my tank glass. But again, just a couple). All of the other movies I see of others have lots of motion. So, no movement = no dinos??? Or is this wishful thinking?

 

[dwest]

Taricha, checked out the amscope and patiently hoping for your success with both the Hannah checker and silica trials. I will be on standby until after spring break in a couple of week. Also, I did receive your biology scope hint!

 

[Jose Mayo]

So ... just thinking here ... it is known that some species of benthic dinoflagellates, such as O. ovata, migrate to the water column obeying the absence of light, others, like Amphidinium, seem to remain mostly landed on the substrate, which makes them less vulnerable to methods, such as UV, for their control ...

The "new" is that NITROGEN (N) metabolism seems to play a role in this, because of the concentration differences in the various levels of the water column, in the natural environment. At least this is what I think I read in the conclusions of the paper below, in which the vertical migration of the dinoflagellates, but not the diatoms, is related to the stress produced by the limitation of N. I think that the information could be useful to increase the efficacy of the UV filter on your disposal. See below:

"Dinoflagellates use various strategies to acquire and assimilate N, depending on their trophic preferences and life styles. Some make an extensive use of transporters, others preferentially ingest prey and still others exploit both strategies equally. Enzymes for uptake and assimilation of N seem to share homology and kinetic properties with those reported in other photosynthetic eukaryotes. A remarkable feature both found in diatoms and dinoflagellates is their adaptability to changes in environmental N concentrations, particularly under stress conditions. Some mechanisms are common, such as symbiosis and transcriptional control; others are particular to dinoflagellates, like mixotrophy and vertical migration. With the advent of next-generation sequencing technologies, transcriptomic and even genomic tools will soon help in identifying and characterizing the molecular components involved in dinoflagellate N metabolism. Understanding how N is put in dinoflagellates will certainly help to better predict their behavior into our future anthropogenically altered aquatic ecosystems."

Putting the N in dinoflagellates

Best regards

 

[dwest]

Thank you Jose Mayo. From your understanding, is this "vertical migration" a physical migration? I guess I'm asking do the amphidinium physically rise from the sand bed when N is limited?

 

[Jose Mayo]

Thank you Jose Mayo. From your understanding, is this "vertical migration" a physical migration? I guess I'm asking do the amphidinium physically rise from the sand bed when N is limited?

Yes, it seems to be what happens in the natural oligotrophic environment.

Regards

 

[Jose Mayo]

Another factor, which may be important in the control of Amphidinium in relation to vertical mobility, to optimize the UV filter result, is that, unlike O. ovata, which occupies the substrate during the day and prefers to swim at night, Amphidinium carterae prefers to swim under the light, to perform photosynthesis, so ... perhaps a good action is to leave a spot of photosynthetically active light on (dichroic lamp?), near the exit of the overflow, to aid the transport of Amphidium to the sump and to submit it to UV filtration.

Mobility of Amphidinium carterae Hulburt measured by high-frequency ultrasound

Highlight: "The results of this study showed the DVM (Diel vertical migration) of A. carterae in response to light. Upward mobility during the day was for photosynthesis, and downward mobility during the night was due to the gravity."

Regards

 

[saltwaterpicaso]

has silica dosing been working and what exactly are you bdosing

 

[taricha]

has silica dosing been working and what exactly are you bdosing

Hard to say yet. A couple of possible successes, some no effects, most not enough info to say yet.
Brightwell Spongexcel - is a silica source
And Hanna Low range silica hi705 is the only test that's been consistently good for people. I played around with my tester for first time today, and am pleased with results.

See first post for more details on method.

 

[taricha]

A comment on hanna Silica tester hi705, Brightwell SpongExcel Silica, and measurements & targets
We want to compare the amount of Silica to the amount of Nitrogen and get something approaching 1:1 ratio of Si to N, to follow example of the paper.
N we measure as NO3 so multiply NO3 by 0.226 to get Nitrogen.
I'm going to target 5ppm NO3 = 1.13ppm N, and an equal amount ~ 1.2ppm Si
SpongExcel gives its concentration in terms of Si - great: 1 drop = 0.20ppm Si per gallon (1ml = 4ppm Si per gal)
so target concentration * gallons / 0.20 = # of drops ... (target conc * gallons/4 = # of mL)
1.2 ppm Si * 70 gal / 4mL = 21 mL (420 drops)
This is just to see the total scale of the Si addition - not that you'd add it all at once. I've been dosing a couple of weeks up to now adding 20+ drops a day and increasing 10% a day.
The hanna silica meter measures SiO2 so multiply the reading by 0.467 to get Silicon for direct comparison.

My tank tested at 0.34 SiO2 = 0.159ppm Si
After addition of 22 drops *0.20 / 70 gal = +0.063ppm Si the new level should = 0.222ppm Si
2 hours later the tester gave 0.52 SiO2 = 0.243ppm Si. Considering the uncertainties in measuring drops, my volume, and the meter - this is a pretty confidence-building result.

Overall takeaways:
Si meter and source are reliable.
Even at my very small doses, I'm accumulating some measurable Si.
My tank is consuming Si, but slower than would be expected.
Tank is growing diatoms, and seems to be growing more diversity of them.
It's not really possible to say if the increasing diversity of observed diatoms is due to increasing concentration of Si or simply length of time with available Si.
The "explosion" of diatom growth was very short lived (like 1-2 days) they are now very stable or gradually increasing.
Other things besides Si, P, and N are likely limiting diatom growth to some extent. This maybe should be expected in stable older tanks - tanks don't undergo exponential phase growth of anything for very long before a plateau.
My inverts seem to be fine with new diatoms on the diet. They seem to graze the areas with most diatom growth.
Copepod population on the glass may have increased slightly.
I'll continue slowly ramping up to 1.2 ppm Si to match 1 to 1 the Si to N at 5 ppm No3, and see how the system behaves.

Edit: I don't have a dinos so my observations will be about generally how a system behaves at sustained ~1ppm Si balanced with N.

 

[taricha]

has silica dosing been working?

Very little data and it's inconclusive.
Successes sound like this....

Update: sand samples show only a few Amphidinium Dino’s, good population of diatoms. I had some concerns about a few areas but the color is more of a golden brown. Silicate still around 2ppm. I’m thinking we always have some dinoflagellates in our tanks, the only time we see them is when a bloom occurs. There are a lot of people on here that are more expert than I that maybe able to expand on that subject.
Pictures show what my tank looked like on 1/18/18 when I showed up here and what it looks like today, that’s less than 30 days. I have not vacuumed the sand since Saturday, lights are up to almost my normal intensity and color.
The methods for controling Dino’s in this thread goes against what a lot of us have been told for the last couple of years but they work!

The limiting micro nutrient isn't Si I can say that much. I have it in my tank at about 12 - 13 ppm currently and it had no perceivable impact on dino growth. In NSW it is at 1 - 2 ppm. The dinos have actually decreased significantly in growth rate.

From everything I have read, I'm led to believe it is Fe. I think other algae becomes Fe limited too as my GHA finally stopped growing. Before it was out of control. Other macros seemed to have slowed too. There is still plenty of PO4 and NO3 in the water also. In excess of the minimum levels recommended in this thread. They don't seem to be going down any more, at all. I still see minor growth from other algae but nothing from dinos.

I believe I have hit the limitation point and the other algae is out competing the dinos for the limited resource. This is the principal behind competition mentioned in this thread. But to get there you need other algae, like GHA and diatoms.

These are generally what successes sound like. Very little sign of allelopathy (maybe we don't have the "right" diatoms, but some signs point to diatoms being effective at helping limit the trace elements that are used up when a dino bloom loses steam.

 

[taricha]

On the other hand, the reports of success should be tempered a bit. Trace element limitation may hold down the dinos to some level, but perhaps not low enough to be what we need...

Back in February I thought I had beat Dino’s in my 180..... well, not quit. I had raised my N and P also dosed silicate. My testing showed good population of diatoms and very few Dino cells.
Currently N is way up at 25ppm, P is around .5ppm. Kept up silicate dosing to At least 1ppm. Lately noticed light golden brown (diatoms) areas where looking a little different, pulled out the microscope and sure enough Dino’s are back living happily with the diatoms! I thought the two couldn’t coexist!
I did remove some of my sand bed but Hesitant to remove more as I now have 2 diamond gobies and 2 sand tiger conchs.
My question is should my N. be closer to 5ppm and P.1ppm?
My corrective action today has been; 1: change auto feeder to feed less. 2:Start up GFO. 3: Increase light period in refugium by 2 hours. 4: DOsed silicate to 2ppm.
Suggestion welcomed!

There aren't many amphidinium cells, maybe a half dozen - many of the moving things are actually diatoms. I'd peg the ratio at 10:1 diatoms to dinos (round cells), but the dinos are still there in some numbers.
Bebow, could you give details on tank circumstances and maintenance between the "disappearance" and "reappearance" of dinos?

 

[taricha]

It’s not the thick snotty mess that I had but I can see the difference in color, golden brown for diatoms then darker brown in the Dino concentrated areas. If I keep the Si up around 3ppm I have diatoms, when it drops below 1 ppm I get a mix. Still no algae or cyano.

When you say 3ppm and 1ppm, do you mean on the hanna Si meter which reports SiO2, or did you convert to Si?
(You can multiply SiO2 number by 0.47 to get Si.)

 

[JAMSOURY]

Following! I’m going to start dosing si. Is there some sort of calculator so I know how much to put in?