Hair Algae, a Symptom Rather Than the Problem?

[FernBluffReef]

I purchased three sea hares to try and abolish my hair algae. Not all at the same time. I kept trying out of frustration. They all three died and never touched the hair algae IMO, so your mileage may vary.

Time (just under 9 months) and management of nutrients (phosphate) is the only thing that worked for me. I was surprised when I got overwhelmed by hair algae as tank was going on two years old before I experienced the ugly phase. I thought I had it made.

 

[Randy Holmes-Farley Verified Community Expert]

I purchased three sea hares to try and abolish my hair algae. Not all at the same time. I kept trying out of frustration. They all three died and never touched the hair algae IMO, so your mileage may vary.

Time (just under 9 months) and management of nutrients (phosphate) is the only thing that worked for me. I was surprised when I got overwhelmed by hair algae as tank was going on two years old before I experienced the ugly phase. I thought I had it made.

Thanks. I have 2 coming next week. We will see what happens., :)

 

[BeanAnimal]

A recent post by @Hans-Werner in Randy’s Tank and Learn thread inspired this thread.

Could hair algae or cyano be showing up because something else in the tank is dying or breaking down, rather than being the cause of the problem in the first place?

I believe that it can be both a symptom and a cause. We may see it localized when something dies or new rock or substrate added to the system. We also may see it become prolific and outcompete other organisms, taking their place. I think that Han's post has merit.

I am in the midst of a severe hair algae issue. It's depressing and gives me a new found empathy for those struggling with it.

I am not sure how I beat the last bout years ago. The only thing that I did was add a pile of turbo and astrea snails and an urchin with a lot of manual removal. It took a month or two to fully eradicate, but you could actually see the areas that the snails and urchins were working on, like mowed strips of lawn. I am not sure if they, the manual removal or time or a combination of all is what tipped the scale.

I am curious to see how your sea hares work out.

The lettuce sea slugs also sound promising if the sea hares don't do the trick.

 

[Randy Holmes-Farley Verified Community Expert]

The lettuce sea slugs also sound promising if the sea hares don't do the trick.

Yes, they could be a future try. :)

 

[sixty_reefer]

Algae, cyanos and dinos often grow only in specific spots in a tank. For example, I never get algae on rocks or substrate, even though my snails prefer the glass, while a 3D-printed stand for a Homophyllia grows Ulva(ria) all the time. The frag plug that is sitting on it, however, stays clean.
My powerheads grow Ulva(ria) too, and if I clean them with bleach or HCl, they get covered in diatoms until the sea lettuce comes back. I can only assume the harsh flow doesn't allow the right biofilm to establish, so I would have to get them covered in coralline before they stay free of other algae.

@Dan_P pointed me to this "periphyton theory", and so far it's the only explanation I've found for why algae skips certain spots that get exactly the same light and flow. The organisms living mostly unnoticed on our rocks, like coralline algae, diatoms, and biofilms, must have evolved ways to keep themselves free of algae. Otherwise they would eventually starve or get shielded from light and flow.

It also more or less explains the ugly phase and why sometimes "resetting" the periphyton with something like the UV sweeper or by bleaching rocks can help. The only thing I have not figured out yet is how to get the "good periphyton" to grow everywhere

Obviously, this is all just theory, but it can be backed to some extend by the scientific literature.

Do you have access to any scientific literature demonstrating that established periphyton can actively prevent nuisance algae from colonising surfaces? I’d be very interested in reading it, particularly how they distinguish that effect from competition, grazing or just normal ecological succession.

 

[EnterName]

Do you have access to any scientific literature demonstrating that established periphyton can actively prevent nuisance algae from colonising surfaces?

You obviously won't find a paper saying "periphyton in general" does this. Generalizing over that many organisms would be ridiculous. But chemical warfare (allelopathy) between algae species is well documented, and there are also bacteria that inhibit dinoflagellate growth. An interaction between these organisms is relatively obvious, but nobody (to my knowledge) has measured how it impacts our reef tanks yet, so I call it theory for now.

[...], particularly how they distinguish that effect from [...] normal ecological succession.

Ecological succession isn't an alternative explanation that has to be ruled out. It's just the description of what is happening, but not why it is happening.

That why has been studied for decades. The classic paper from 1977 is literally called "Mechanisms of succession in natural communities" written by Connell & Slatyer and they proposed three models: facilitation, tolerance and inhibition. In the inhibition model, early occupants keep later colonists out until something removes them.

That is literally what I described: established periphyton keeping algae off a surface, until something like bleach or a UV sweeper resets it. This is the inhibition model. So asking me to distinguish it from "normal ecological succession" is like asking whether a wound closed because of clotting or because of "normal healing".

[...], particularly how they distinguish that effect from competition, grazing [...]

The obvious way is grazer-free axenic cultures. Additionally, allelopathy can leave target cells present but impaired, while grazing removes them, so you have a lower cell count and will find cells in food vacuoles of protist grazers. There are also some general indicators for allelopathy found by Allen et al. & Leflaive et al. (2008) which helps to distinguish its effect from grazing.

 

[sixty_reefer]

You obviously won't find a paper saying "periphyton in general" does this. Generalizing over that many organisms would be ridiculous. But chemical warfare (allelopathy) between algae species is well documented, and there are also bacteria that inhibit dinoflagellate growth. An interaction between these organisms is relatively obvious, but nobody (to my knowledge) has measured how it impacts our reef tanks yet, so I call it theory for now.


Ecological succession isn't an alternative explanation that has to be ruled out. It's just the description of what is happening, but not why it is happening.

That why has been studied for decades. The classic paper from 1977 is literally called "Mechanisms of succession in natural communities" written by Connell & Slatyer and they proposed three models: facilitation, tolerance and inhibition. In the inhibition model, early occupants keep later colonists out until something removes them.

That is literally what I described: established periphyton keeping algae off a surface, until something like bleach or a UV sweeper resets it. This is the inhibition model. So asking me to distinguish it from "normal ecological succession" is like asking whether a wound closed because of clotting or because of "normal healing".


The obvious way is grazer-free axenic cultures. Additionally, allelopathy can leave target cells present but impaired, while grazing removes them, so you have a lower cell count and will find cells in food vacuoles of protist grazers. There are also some general indicators for allelopathy found by Allen et al. & Leflaive et al. (2008) which helps to distinguish its effect from grazing.

Sooo, no evidence for your claim. Got it.

 

[EnterName]

Sooo, no evidence for your claim. Got it.

Theory, not claim. I specifically pointed this out (see the last sentence you quoted in your initial question). I also gave you 3 articles for a start. If you look for "Allelopathy" you will find many more just for algae alone. That part isn't a theory, it's a well established fact. How far it applies to periphyton in our tanks is the theory.

One of the mentioned articles is part of the fundamental works behind the "ecological succession" you like to talk about, so I'm not sure you actually "got it". We have been here before... I can try to explain things to you, but I can't understand them for you. I don't want this to end up in another thread being locked up, so let's leave it at that.

 

[sixty_reefer]

I don't want this to end up in another thread being locked up, so let's leave it at that.

Is that a warning or just another hypothesis?