DOC and macro

Subsea

Premium Member
Dissoloved organic carbon entails a soup of compounds that do many things. Some of the more obvious are terpins which yellow the water. However, the less obvious things are a shift in the type of bacteria that inhabite our marine tanks.

Ken Felderman has published numerous peer reviewed papers on nutrient processing in our reef tanks. One in particular addresses carbon dosing with some interesting results. I found the data on DOC removal in a mature reef tank to be interesting. Removal of DOC by protein skimming is at best 30% - 40% depending on skimmer, removal by GAC is 50-60%, removal by reef inhabitants is 75% effective. The tank inhabitants recycle DOC and grow. The other two processes are nutrient export.


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Join Date: Dec 2006
Location: Austin, Tx
Posts: 1,116
Bugs Rule
Quote:
Originally Posted by Timfish View Post
Bugs Rule! Fascinating how research is proving some of the observations and conclusions of aquarists like Paul B and Steve Tyree. Rohwer's "Coral Reefs in the Microbial Seas" is an excellent place to start. The stuff done by Dr. Andreas Haas* showing the roles algae have in promoting heterotrophic (oxygen depleting) microbes and corals promote autotrophic (oxygen enriching) is a real eye opener on natural filtration in our systems.
De Deoij's** cryptic sponge research may be a bit off topic but proves Tyree's ideas on cryptic zones.

*Influence of coral and algal exudates on microbially mediated reef metabolism - PubMed
**http://www.rug.nl/research/portal/fi...letethesis.pdf
@Timfish
I thought your links were relevant enough to post again.


Considering that macro produces DOC, I have always used GAC to remove DOC. For me, dilution is not the solution to pollution. If it is in the tank, I would like it to feed DOC to something desirable. Yes, I would like my nutrient sink to be good stuff: pods, sponges, corals, macro and fish. I just did order both of Steve Tyree ebooks on cryptic sponges. My friend Timfish has many tanks set up for more than 20 years with numerous sponges. In some cases, he removes them from unlit refugiums and feeds his angel fish. In this case, he is sharing the wealth and helping a brother out. It is time for me to turn the lights off in my refugium and grow pods and sponges.
 
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I think what's striking reading about DOC is the contrast in the various types on microbiomes and promoting corals or algae and the role sponges have in processing it. Here's a list of links I've collected over the years.

"Coral Reefs in the Microbial Seas" This video compliments Rohwer's book of the same title (Paper back is ~$20, Kindle is ~$10), both deal with the conflicting roles of the different types of DOC in reef ecosystems. While there is overlap bewteen his book and the video both have information not covered by the other and together give a broader view of the complex relationships found in reef ecosystems

Changing Seas - Mysterious Microbes

Nitrogen cycling in hte coral holobiont

BActeria and Sponges

Maintenance of Coral Reef Health (refferences at the end)

Indirect effects of algae on coral: algae‐mediated, microbe‐induced coral mortality

Influence of coral and algal exudates on microbially mediated reef metabolism.
Coral DOC improves oxygen (autotrophy), algae DOC reduces oxygen (heterotrophy).

Role of elevated organic carbon levels and microbial activity in coral mortality

How microbial community composition regulates coral disease transmission
Critical to coral disease transmission – or resistance – is the coral's surface mucus layer,
which is produced in part by the coral's endosymbionts [12]. The mucus layer hosts a complex
microbial community, referred to hereafter as the surface microbial community (SMC). Because
the mucus environment is rich in nutrients, microbial population densities there are orders of
magnitude higher than in the surrounding water column [20]. Most established and emerging
pathogens are endemic to the ecosystem and typically present at low numbers in the SMC.
When stressed, the SMC can switch rapidly from a community associated with healthy corals to
diseased corals. In field studies during the 2005 summer bleaching event, Ritchie [28] observed
that "visitor" bacteria (bacterial groups otherwise not dominant) became the predominant
species in mucus collected from apparently healthy Acropora palmata.

Effects of Coral Reef Benthic Primary Producers on Dissolved Organic Carbon and Microbial Activity
Algae releases significantly more DOC into the water than coral.

Pathologies and mortality rates caused by organic carbon and nutrient stressors in three Caribbean coral species.
Starch and sugars (doc) caused coral death but not high nitrates, phosphates or ammonium.

Visualization of oxygen distribution patterns caused by coral and algae

Biological oxygen demand optode analysis of coral reef-associated microbial communities exposed to algal exudates
Exposure to exudates derived from turf algae stimulated higher oxygen drawdown by the coral-associated bacteria.

Microbial ecology: Algae feed a shift on coral reefs

Coral and macroalgal exudates vary in neutral sugar composition and differentially enrich reef bacterioplankton lineages.

Sugar enrichment provides evidence for a role of nitrogen fixation in coral bleaching

Elevated ammonium delays the impairment of the coral-dinoflagellate symbiosis during labile carbon pollution
(here's an argument for maintaining heavy fish loads if you're carbon dosing)

Excess labile carbon promotes the expression of virulence factors in coral reef bacterioplankton

Unseen players shape benthic competition on coral reefs.

Allelochemicals Produced by Brown Macroalgae of the Lobophora Genus Are Active against Coral Larvae and Associated Bacteria, Supporting Pathogenic Shifts to Vibrio Dominance.

Macroalgae decrease growth and alter microbial community structure of the reef-building coral, Porites astreoides.

Macroalgal extracts induce bacterial assemblage shifts and sublethal tissue stress in Caribbean corals.

Biophysical and physiological processes causing oxygen loss from coral reefs.

Global microbialization of coral reefs
DDAM Proven

Coral Reef Microorganisms in a Changing Climate, Fig 3

Ecosystem Microbiology of Coral Reefs: Linking Genomic, Metabolomic, and Biogeochemical Dynamics from Animal Symbioses to Reefscape Processes


Because sponges are essential players in the carbon, nitrogen and phosphorus cycle(s) on reefs here's some links to research done with them.

Element cycling on tropical coral reefs.
This is Jasper de Geoij's ground breaking research on reef sponge finding some species process labile DOC 1000X faster than bacterioplankton. (The introduction is in Dutch but the content is in English.)

Sponge symbionts and the marine P cycle

Phosphorus sequestration in the form of polyphosphate by microbial symbionts in marine sponges

Differential recycling of coral and algal dissolved organic matter via the sponge loop.
Sponges treat DOC from algae differently than DOC from corals

A Vicious Circle? Altered Carbon and Nutrient Cycling May Explain the Low Resilience of Caribbean Coral Reefs

Surviving in a Marine Desert The Sponge Loop Retains Resources Within Coral Reefs
Dissolved organic carbon and nitrogen are quickly processed by sponges and released back into the reef food web in hours as carbon and nitrogen rich detritus.

Natural Diet of Coral-Excavating Sponges Consists Mainly of Dissolved Organic Carbon (DOC)

The Role of Marine Sponges in Carbon and Nitrogen Cycles of COral Reefs and Nearshore Environments.

Aura-biomes are present in the water layer above coral reef benthic macro-organisms
 
As I watched Coral Reefs in the Microbial Seas, Rhower detailed two groups of DOC by the bacteria they feed: hetotroph and autotroph. Coral DOC is composed mostly of lipids & proteins and algae DOC is glucose, which is carbon. When fish/herbivores are removed from the reef due to human overfishing, algae proliferates and coral is smothered by bacteria that are proliferating from a sugar diet.

While not completely covered in this presentation, Rohwer demonstrated that pH fluctuation on a healthy reef was 8.3 - 7.8. His research showed that reduced oxygen during nightly pH swings was the critical parameter on declining reefs. So instead on focusing on controlling nighttime pH fluctuations, hobbiest should focus on maintaining high oxygen levels to promote a healthy environment.
 
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@Timfish

During the last minute of first UCTV video, clams were shown to suck up bacteria & viruses. Would oysters perform as well?

Initial reaction is to think any clam, mussle or oyster would do the same function, they've been shown to clear water pretty fast. But But time after time research is showing not only species specific responses but also gentoype and context specific responses. So it might seem a safe guess but it's still a guess.
 
I was once cautioned not to feed live mussels to my reef tank if I had ornamental clams. The idea being that wild mussels from Chesapeake Bay could carry a virus that was detrimental to clam.

At present, DOC & POC are being consumed by cryptic sponges. If bacteria & viruses are POC and thus consumed by filter feeders, then I am interested in finding ornamental filter feeders to complete the circle. I like the idea of an ornamental clam. and I am still looking for a healthy Sea Apple.


I think that diver collected sand & rock at tank startup brings in a wealth of diversity that can easily support the most finicky filter feeder. In the case of apples in my tank. when I stirred top inch of dsb, the feeding frenzy was own. Everybody’s feathers came out to feed.

@Timfish
What do you feed your ornamental clams?
 
Nothing. At the moment I don't ahve any Tridacna clams Pat. I lost several in the freeze last year and haven't replaced them. I also lost several juvinile "Turkey Wing" clams as well as an adult I moved from another system from this post 10 years ago. Fortunately the parents survived.

 
I was fortunate in the Big Freeze and never lost electricity. I have some Turkey clams still and plan on adding live oysters soon. I am exporting for profit GSP rocks from 75G to make room for a future order of gulf live rock.
 

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Nothing. At the moment I don't ahve any Tridacna clams Pat. I lost several in the freeze last year and haven't replaced them. I also lost several juvinile "Turkey Wing" clams as well as an adult I moved from another system from this post 10 years ago. Fortunately the parents survived.

Sorry for your loss. 🤗

what did you feed your clams.
 
Other than phytoplankton, are there good foods to add to keep Tridacnid clams happy?
Bright White light provides the lion share of its nutrient intake.
However, a small cloud of phyto over the clam in still water will be quickly filtered.
They are constantly pulling stuff from the water, so is it necessary, I say no with the exception of clams under 2”.
These guys likely can use some phyto.
Maintain Strontium.
FE9E213D-966D-4C0B-92EF-3BDBECDBE58B.jpeg
 
Bright White light provides the lion share of its nutrient intake.
However, a small cloud of phyto over the clam in still water will be quickly filtered.
They are constantly pulling stuff from the water, so is it necessary, I say no with the exception of clams under 2”.
These guys likely can use some phyto.
Maintain Strontium.
View attachment 32371322
WOW. Lovely!
Also, clams like nitrogen. Gerald Hesslinger at ipsf forgo a doctorate at Harvard to grow clams on IndoPacific islands to help native populations with a sustainable harvest to grow an economy..

PS: For a short time, Gerald and Walt Smith partnered to grow clams. I think Walt Smith has partnered with Tampa Bay Saltwater to produce sustainable diver collected live rock.
 
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