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
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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.
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.
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
Benthic primary producers in tropical reef ecosystems can alter biogeochemical cycling and microbial processes in the surrounding seawater. In order to quantify these influences, we measured rates of photosynthesis, respiration, and dissolved organic carbon (DOC) exudate release by the dominant...
peerj.com
Role of elevated organic carbon levels and microbial activity in coral mortality
Reef coral cover is in rapid decline worldwide, in part due to bleaching (expulsion of photosynthetic symbionts) and outbreaks of infectious disease. One important factor associated with bleaching and in disease transmission is a shift in the composition of the microbial community in the mucus...
pubmed.ncbi.nlm.nih.gov
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.
Benthic primary producers in marine ecosystems may significantly alter biogeochemical cycling and microbial processes in their surrounding environment. To examine these interactions, we studied dissolved organic matter release by dominant benthic taxa and subsequent microbial remineralization in...
journals.plos.org
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.
Planar optodes were used to visualize oxygen distribution patterns associated with a coral reef associated green algae (Chaetomorpha sp.) and a hermatypic coral (Favia sp.) separately, as standalone organisms, and placed in close proximity mimicking coral-algal interactions. Oxygen patterns were...
peerj.com
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.
Algae-derived dissolved organic matter has been hypothesized to induce mortality of reef building corals. One proposed killing mechanism is a zone of hypoxia created by rapidly growing microbes. To investigate this hypothesis, biological oxygen ...
www.ncbi.nlm.nih.gov
Microbial ecology: Algae feed a shift on coral reefs
Human pressures on coral reefs are giving macroalgae a competitive advantage over reef-building corals. These algae support larger, and potentially pathogenic, microbial populations that are metabolically primed for less-efficient, yet faster, carbohydrate remineralization, perpetuating a...
www.nature.com
Coral and macroalgal exudates vary in neutral sugar composition and differentially enrich reef bacterioplankton lineages.
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...
www.ncbi.nlm.nih.gov
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)
Labile dissolved organic carbon (DOC) is a major pollutant in coastal marine environments affected by anthropogenic impacts, and may significantly con…
www.sciencedirect.com
Excess labile carbon promotes the expression of virulence factors in coral reef bacterioplankton
Coastal pollution and algal cover are increasing on many coral reefs, resulting in higher dissolved organic carbon (DOC) concentrations. High DOC concentrations strongly affect microbial activity in reef waters and select for copiotrophic, often potentially virulent microbial populations. High...
www.nature.com
Unseen players shape benthic competition on coral reefs.
Recent work has shown that hydrophilic and hydrophobic organic matter (OM) from algae disrupts the function of the coral holobiont and promotes the invasion of opportunistic pathogens, leading to coral morbidity and mortality. Here we refer to these dynamics as the (3)DAM [dissolved organic...
www.ncbi.nlm.nih.gov
Allelochemicals Produced by Brown Macroalgae of the Lobophora Genus Are Active against Coral Larvae and Associated Bacteria, Supporting Pathogenic Shifts to Vibrio Dominance.
Diverse microbial communities associate with coral tissues and mucus, providing important protective and nutritional services, but once disturbed, the microbial equilibrium may shift from a beneficial state to one that is detrimental or pathogenic. Macroalgae (e.g., seaweeds) can physically and...
www.ncbi.nlm.nih.gov
Macroalgae decrease growth and alter microbial community structure of the reef-building coral, Porites astreoides.
With the continued and unprecedented decline of coral reefs worldwide, evaluating the factors that contribute to coral demise is of critical importance. As coral cover declines, macroalgae are becoming more common on tropical reefs. Interactions between these macroalgae and corals may alter the...
www.ncbi.nlm.nih.gov
Macroalgal extracts induce bacterial assemblage shifts and sublethal tissue stress in Caribbean corals.
Benthic macroalgae can be abundant on present-day coral reefs, especially where rates of herbivory are low and/or dissolved nutrients are high. This study investigated the impact of macroalgal extracts on both coral-associated bacterial assemblages and sublethal stress response of corals. Crude...
www.ncbi.nlm.nih.gov
Biophysical and physiological processes causing oxygen loss from coral reefs.
Analysis of 60 sites in three ocean basins suggests that overgrowth of fleshy algae on coral reefs supports higher microbial abundances dominated by copiotrophic, potentially pathogenic bacteria via the provision of dissolved inorganic carbon.
www.nature.com
Coral Reef Microorganisms in a Changing Climate, Fig 3
Coral reefs are one of the most diverse and productive ecosystems on the planet, yet they have suffered tremendous losses due to anthropogenic disturbances and are predicted to be one of the most adversely affected habitats under future climate ...
www.ncbi.nlm.nih.gov
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.)
Coral reefs are economically important ecosystems that have suffered unprecedented losses of corals in the recent past. Why have Caribbean reefs in particu
academic.oup.com
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.
Coral-excavating sponges are the most important bioeroders on Caribbean reefs and increase in abundance throughout the region. This increase is commonly attributed to a concomitant increase in food availability due to eutrophication and pollution. ...
www.ncbi.nlm.nih.gov
The Role of Marine Sponges in Carbon and Nitrogen Cycles of COral Reefs and Nearshore Environments.
As coral reef habitats decline worldwide, some reefs are transitioning from coral- to algal-dominated benthos with the exact cause for this shift remaining elusive. Increases in the abundance of microbes in the water column has been correlated with an increase in coral disease and reduction in...
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.
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.
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.
Does anybody know the species of these clams? The parents showed up on some live rock either 10 or 15 yers ago. The baby showed up in the sump last fall. Last additions of anything with a substrate was 5 or 6 years ago.
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.
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.
Does anybody know the species of these clams? The parents showed up on some live rock either 10 or 15 yers ago. The baby showed up in the sump last fall. Last additions of anything with a substrate was 5 or 6 years ago.
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.
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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