Cryptic Sponge & Sea Squirt Filtration Methodology

[Subsea]

Tim,
With respect to DOC procured by coral and DOC produced by macro, why are the bacteria feeding on these two different sources of DOC different.

If my understanding of DOC is currect, it an organic soup of many different components. If bacteria are oxygen producers or oxygen consumers then the DOC they consume must have different compounds.

Not able to measure DOC accurately, I blanket use GAC.

 

[karimwassef]

Why use anything? My focus has always been on reduced inorganic N and P. The organics are just food or life... that will generate more life. Sponges, corals, pods, worms, feather dusters, etc...

That natural abundance will naturally create opportunity for something to consume it. The downside for me has been the lack of predation to balance the explosive growth. Basically featherdusters, Xenia and GSP grew out of control - not algae. I need at least one angel and one butterfly to get things back in balance.

Just the way nature works it out.

 

[ca1ore]

FWIW, among the historical objections to the use of the ATS has been that they leech undesirables back into the aquarium. I saw Adey's system at the Smithsonian many years ago, and it was not doing well at all, though perhaps for reasons beyond just sole reliance on ATS. My own journey with these things (initiated with Adey's classic book) has 'convinced' me that the ATS can be a very useful component of a filtration system; just not the sole component. I run the output of my ATS through my large skimmer (to remove as much DOC as possible) and use GAC continuously (further DOC removal and any green coloration). Been doing it this way for a while, with good results. I do agree that a benthic/cryptic zone can be enormously beneficial - I run one as well.

 

[karimwassef]

I'm confused. I've had no issues with DOCs and I have a large healthy scrubber

 

[ca1ore]

I'm confused. I've had no issues with DOCs and I have a large healthy scrubber

Is that your sole form of nutrient removal?

 

[Scrubber_steve]

Why use anything? My focus has always been on reduced inorganic N and P. The organics are just food or life... that will generate more life. Sponges, corals, pods, worms, feather dusters, etc...

That natural abundance will naturally create opportunity for something to consume it. The downside for me has been the lack of predation to balance the explosive growth. Basically featherdusters, Xenia and GSP grew out of control - not algae. I need at least one angel and one butterfly to get things back in balance.

Just the way nature works it out.

I believe focus on removing DOC has been greatly influenced by the need to keep low NO3 & PO4 levels because DOC eventually breaks down into ammonia. Of course, if maintaining NO3 & PO4 at low levels isn't a problem for any particular person, removing DOC isn't an issue in that regard.

But toxic DOC, from corals is another issue, perhaps?

 

[karimwassef]

My algae are excellent N and P sequestration and recycling media... no issue with inorganic buildups .. and don't see much of a concern on DOCs either. It's just more food.

That even includes palythoa in the tank and a massive turf mass... not enough to make a difference. My only issue is a form of benthic bacteria that encrusts at high flow high light areas that would have been normally inhabited by algae, except that algae can't grow in my DT (reference the massive scrubber).

 

[Timfish]

Hi Timfish. Not wanting to sound rude, but what you've stated above could not be further from the truth in regards to why the Algae Turf Farm (ATF) was removed at the Great Barrier Reef Marine Park Authority (now Reef HQ & Coral Reef Exhibit) particularly in regards to dealing with water quality issues. Lets look at the facts concerning the algae scrubbers & the measures taken to improve water quality to improve coral mortality rates.

The algae scrubbers were in operation from 1987 to 2002 and were removed from the Coral Reef Exhibit (CRE) at the GBR Aquarium because -

1. Most importantly, the Algae Turf Farms effects on CRE filtration were negligible, especially when compared to the CRE's overall internal algal mass productivity. The ATF only accounted for 0.1% of systems overall algal mass)

2. they were too labour intensive (algae removal & servicing of troublesome dump buckets). The ATF consisted of 70 shallow PVC trays approximately 2 m in length and 1 m in width.

3. The pvc used to build the scrubbers was leaching toxins into the water. Possibly because they were affected by direct sun light. I know this because I was given a personal behind the scenes tour of the Aquarium in March this year by the Aquarium's Curator.

Now lets look at the actual measures taken to improve water quality to improve coral mortality rates.

A significant shift occurred during 2002 with how the CRE was maintained when the aquarium was closed to the public for almost five months to maintain and upgrade the facility.

The CRE history is divided into two periods "“
The "œOceanic Water period" (pre-2002) Average corals survival rate was only 20% to 30%

The "œEstuarine Water period" (2002 to present) corals survival rate increased to 70% to 80% (possibly higher now).

The changes made to the systems maintenance that were considered most critical to improving coral survival were "“

1. The switch from using priori ultra-clean oceanic water, collected offshore by barge, to using "˜less pure' estuarine water collected on the incoming tide from the Ross Creek to increase nutrients and provide an external source of plankton.

2. The removal of internal mechanical filtration (three large sand filters). This improve overall tank health by avoiding "˜over stripping' the water column of particulates and encouraging plankton production, greater food availability, and larval settlement, especially during spawning periods

3. Internal circulation was increased.

4. The use of calcium chloride to raise average calcium levels (~ 250 mg Ca2+.L-1, to 420 mg Ca2+.L-1)

https://www.burgerszoo.com/media/560570/chapter-26.pdf

https://www.burgerszoo.com/media/560502/chapter-9.pdf

I haven't had time yet to read the links you posted but a had some thoughts running around yesterday cleaning my tanks.

Nothing you posted contradicts Delbeek and Sprung. They didn't say the ATS was the only reason the Coral Reef Exhibit (CRE) at the GBR Aquarium had water quality issues but it was one of the steps taken to improve water quality. Your comments about the hassle their ATS was to maintain echos my own experience in my maintenance business and the main reason I stopped messing with them before I learned about the roles of DOC from algae in promoting pathogenic bacteria.

The steps you related the Coral Reef Exhibit (CRE) at the GBR Aquarium took deal with the problem fit's Veron's observations that reefs do better with nutrient inputs "Imported nutrients are usually transported to reefs from rivers; but if there are no rivers, as with reefs remote from land masses, nutrients can only come from surface ocean circulation. Often this supply is poor, and thus the vast ocean expanses have been refered to as "nutrient deserts". The Indo-Pacific has many huge atolls in these supposed deserts which testify to the resilience of reefs, but the corals themselves may lack the lush appearance of those of more fertile waters. Many reefs have another major supply of inorganic nutrients as, under certain conditions, surface currents moving against a reef face may cause deep ocean water to be drawn to the surface. This "upwelled" water is often rich in phosphorus* and other essential chemicals." J. E. N. Veron "Corals of Austrailia and the Indo-Pacific" pg 30. I found your post gratifying as the steps they took are basicly the same steps I take when I'm asked to remediate nuisance algae issues local aquarists have. Namely increasing nutrients, increase water changes and increasing manual removal with herbivores and removing any mechanical filtration (I'll also stop using GFO but I doupt they used it).

To be honest based on what I've read by Delbeek and Sprung and your own post about how the ATS was just a small fraction of the total algae in the Coral Reef Exhibit (CRE) at the GBR Aquarium it seems to me to fit Rohwer's DDAM model of reef degradation. (For those who haven't read his book "Coral Reefs in the Microbial Seas" I strongly recommend it to understand better the relationships between fish corals and algae and the conflicting roles the various types of DOC plays in promoting healthy and harmful microbes, kindle cersion is only $10.)


*[up to 2.0 mg/l, the average for most of the ocean]

 

[Scrubber_steve]

I haven't had time yet to read the links you posted but a had some thoughts running around yesterday cleaning my tanks.

Nothing you posted contradicts Delbeek and Sprung. They didn't say the ATS was the only reason the Coral Reef Exhibit (CRE) at the GBR Aquarium had water quality issues but it was one of the steps taken to improve water quality. Your comments about the hassle their ATS was to maintain echos my own experience in my maintenance business and the main reason I stopped messing with them before I learned about the roles of DOC from algae in promoting pathogenic bacteria.

The steps you related the Coral Reef Exhibit (CRE) at the GBR Aquarium took deal with the problem fit's Veron's observations that reefs do better with nutrient inputs "Imported nutrients are usually transported to reefs from rivers; but if there are no rivers, as with reefs remote from land masses, nutrients can only come from surface ocean circulation. Often this supply is poor, and thus the vast ocean expanses have been refered to as "nutrient deserts". The Indo-Pacific has many huge atolls in these supposed deserts which testify to the resilience of reefs, but the corals themselves may lack the lush appearance of those of more fertile waters. Many reefs have another major supply of inorganic nutrients as, under certain conditions, surface currents moving against a reef face may cause deep ocean water to be drawn to the surface. This "upwelled" water is often rich in phosphorus* and other essential chemicals." J. E. N. Veron "Corals of Austrailia and the Indo-Pacific" pg 30. I found your post gratifying as the steps they took are basicly the same steps I take when I'm asked to remediate nuisance algae issues local aquarists have. Namely increasing nutrients, increase water changes and increasing manual removal with herbivores and removing any mechanical filtration (I'll also stop using GFO but I doupt they used it).

To be honest based on what I've read by Delbeek and Sprung and your own post about how the ATS was just a small fraction of the total algae in the Coral Reef Exhibit (CRE) at the GBR Aquarium it seems to me to fit Rohwer's DDAM model of reef degradation. (For those who haven't read his book "Coral Reefs in the Microbial Seas" I strongly recommend it to understand better the relationships between fish corals and algae and the conflicting roles the various types of DOC plays in promoting healthy and harmful microbes, kindle cersion is only $10.)


*[up to 2.0 mg/l, the average for most of the ocean]

Hi Tim; Sorry, but I believe that everything I wrote contradicts Delbeek and Sprung, if they suggested that the Algae Turf Farm had anything at all to do with water quality issues in the Coral Reef Exhibit. Its a complete falacy.

It was only 0.1% of the systems total algae mass, & to suggest that it played a part in water quality issues would be plain silly of them. In fact there was no effort or focus at all in regards to reducing the internal system algae mass as part of the revision of how the system was run when switching to the Estuarine Water period. The decrease in coral mortality came about by the several measures taken to provide food for the corals. They were basically starving to death. That & the increase in calciums levels were the basis of the improved coral health.

They have a budget & attending to seventy notoriously troublesome dump buckets, as well as seventy 2 metre by 1 metre screens just wasn't practicle, relatively speaking. Otherwise, it was reported that the ATF was actually doing the job as intended. How much of an affect the toxins leaching from the pvc had I don't know. But in any case that's an issue quite seperate from the scrubbers general operational effect.

It seems to me that you are focusing on natural reefs, that due primarily to external forces, have been negatively affected by algae's ability to adapt to the circumstances & dominate. To then extrapolate this to an aquarium might just be stretching things a bit, particularly in regards to the use of algae as a filtration system. Whether a macro in a fuge, or the filamentous algae growing on the screen of a modern downflow scrubber, the total system algae is controlled as it is exported as it grows. In the meantime, the algae does an incredible job of controlling nitrogen & phosphate in the aquarium, reduces co2 while adding oxygen & stabilizes pH when illuminated when the tank lights are out.

What ever pathogens that may be produced by various algae, those & toxins produced by corals seem to be dealt with by skimming & activated carbon. Triton certainly don't see the use of a large fuge of macro algae as detrimental, as it is the core of their systems filtartion method, a method that doesn't include water changes.

Algae is in fact a vital component of a normally functioning healthy reef. Its a primary producer, the begining of the food chain.

Anyway, that's just my 2 cents worth. :wavehand:

 

[karimwassef]

I certainly hope so. My plan is to build a 20' x 13' 2000gal solar turf scrubber greenhouse next to my sunroom to scrub my 2000gal display tank. That's in addition to in-tank elevated scrubbers and raised solar fuge for shrimp.

<a href="http://s1062.photobucket.com/user/karimwassef/media/Designs/0_zpsgujxusn8.jpg.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/Designs/0_zpsgujxusn8.jpg" border="0" alt=" photo 0_zpsgujxusn8.jpg"></a>

I've never considered algae, particularly turf, as detrimental to my systems. In fact, I consider their success to be critical.

 

[Steve Tyree]

Karim,

Is the pink stuff hard to the touch ?

 

[Steve Tyree]

Subsea,

Dont want to spend time on the issue, but the dissolved organics released by macroalgae tend to promote higher virulent bacteria populations. This was determined in a DNA testing of bacteria. What we need to do is fine species of macroalgae that release less of these specific DOCs. But I don't use macroalgae, so not my dog fight. Lol. I use coralline algae and snails.

 

[karimwassef]

No. It's spongy, but the dendrites (the streaming things that radiate from one node to the other) are brittle.

 

[Steve Tyree]

Excellent info from Timfish and TwinFallz.

Tim, I did suspect the chaeto would release less DOC. Basic test being how slimy does it feel. Lol.

TwinFallz, thanks for the behind the scenes info. Yeah, an Oceanic Reef system already has plenty of turf algae eating organisms cropping the turf back. Same in our Oceanic Reef DTs. The only piece of the puzzle left for me is the processing of herbivore waste. Other then letting it getting refined and settling in the abyss.

 

[tripdad]

"Almost all the nutrients on an oceanic reef are bound up within the existing biomass. What is available in the water column is very minor compared to existing biomass. That is true of organic and inorganic. That is Darwin's Paradox. All that live living in a nutrient desert basically." by Steve Tyree.

Thanks for stating this, I have argued this point on many occasions with all the focus on low nutrient numbers these days. I probably over simplify it. I suggest that a reef is NOT a low nutrient space but rather a space where every possible nutrient is being exploited by something which in turn creates a nutrient source for something else to exploit so it is a low "residual nutrient" space. That our problem in our tanks is our lack of biodiversity relative to the ocean. So that when we strip our water we fail to understand that the oceans "nutrients" are being used by the biodiversity not that they were never there in the first place.

 

[Steve Tyree]

Tripdad,

Good way to state that situation. Thanks. The reef ecosystem builds up over time slowly collecting nutrients. Terristrial nutrients are concentrated in the nutrient rich soil. The oceanic reef exists in very poor nutrient soil, seawater. But after decades the reef system biomass looks extremely dense and full of life. In fact in a few cases the reef produces an excess of organic nutrients into the ocean water. It is basically a slowly building up ecosystem. Time is the key factor. I think we have also spent too much time analyzing the inorganic nutrients and not enough time on the organics. Mainly due to testing difficulties.

 

[Scrubber_steve]

In regards to algae releasing distinct exudates (compared to coral exudates) that possibly enhance virulent bacteria, I browsed through his paper -

Coral and macroalgal exudates vary in neutral sugar composition and differentially enrich reef bacterioplankton lineages
Craig E Nelson, Stuart J Goldberg, Linda Wegley Kelly, Andreas F Haas, Jennifer E Smith, Forest Rohwer and Craig A Carlson
https://www.nature.com/ismej/journal/v7/n5/full/ismej2012161a.html

From the Abstract
Increasing algal cover on tropical reefs worldwide may be maintained through feedbacks whereby algae outcompete coral by altering microbial activity.
We hypothesized that algae and coral release compositionally distinct exudates that differentially alter bacterioplankton growth and community structure.

We collected exudates from the dominant hermatypic coral holobiont Porites spp. and three dominant macroalgae, one each Ochrophyta (brown),
Rhodophyta (red) and Chlorophyta (green). We characterized exudates by measuring dissolved organic carbon (DOC) and fractional dissolved combined
neutral sugars (DCNSs) and subsequently tracked bacterioplankton responses to each exudate over 48 hours.

Coral exudates engendered the smallest shift in overall bacterioplankton community structure, maintained high diversity and enriched taxa from
Alphaproteobacteria lineages containing cultured representatives with relatively few virulence factors.

In contrast, macroalgal exudates selected for less diverse communities heavily enriched in copiotrophic Gammaproteobacteria lineages containing
cultured pathogens with increased virulence factors.

Our results demonstrate that algal exudates are enriched in DCNS components, foster rapid growth of bacterioplankton and select for bacterial
populations with more potential virulence factors than coral exudates.


Results
Our results generally indicate that exudates from fleshy macroalgae are more labile than exudates from corals, with bacterioplankton growing to higher
densities and consuming more DOC on exudates from the brown alga Turbinaria and the red alga Amansia.

Relative to the macroalgae, the exudates from the hermatypic coral Porites and the calcareous macroalga Halimeda (green) were dominated by galactose,
glucose and mannose+xylose, much like the composition of ambient seawater.

= = = = = = = = = = = = = = = = =

It was found in this study, at least, that brown & red algae are the culprits, with green algae exudate compositionally indistinct from Porites coral exudate

 

[tripdad]

Ok Twinfallz, can you distill that down a little for me. I am not a scientist nor claim to be scientific in my reef keeping. If I'm understanding you correctly then when using algae in the aquarium, say in a macro fuge, we should stay away from red and brown algae as they increase the risk of virulence?

 

[karimwassef]

But turf still rocks!

 

[NS Mike D]

Ok Twinfallz, can you distill that down a little for me. I am not a scientist nor claim to be scientific in my reef keeping. If I'm understanding you correctly then when using algae in the aquarium, say in a macro fuge, we should stay away from red and brown algae as they increase the risk of virulence?

That was my general take, but, as usual, the proverbial devil is in the details. The alga tested were "Ochrophyta (brown), Rhodophyta (red) and Chlorophyta (green)."

Cheato and culpera are in the division of Chlorophyta and I suspect the stuff growing on algae turf scrubbers are as well.


Anecdotally, this kind of supports those using macro in refugiums and ATS reporting successful tanks.