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Thread: Marine Allelopathy

  1. #31
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    That's what I usually find: about half the people have higher N, and half have higher P. In the end, if the scrubber is made stronger, both N and P go away. The question is, how to make them stronger without more size or wattage.
    Manipulating pH perhaps ?

    http://algaescrubber.net/forums/show...-Precipitation

  2. #32
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    Ok, let's put this one to bed;

    ABSTRACT: Allelopathy in aquatic environments may provide a competitive advantage to angiosperms, algae, or cyanobacteria in their interaction with other primary producers. Allelopathy can influence the competition between different photoautotrophs for resources and change the succession of species, for exarnple, in phytoplank- ton cornmunities. Field evidence and laboratory studies indicate that allelopathy occurs in all aquatic habitats (marine and freshwater), and that ail prirnary producing organisms (cyanobacteria, micro- and macroalgae as well as angiospenns) are capable of producing and releasing allelopathically active compounds. Although allelopathy also includes positive (stimulating) interactions, the majority of studies describe the inhibitory activity of ailelopathicaily active compounds. Different mechanisms operate depending on whether allelopathy takes place in the Open water (pelagic zone) or is Substrate associated (benthic habitats). Allelopathical interactions are especiaily common in fully aquatic species, such as submersed macrophytes or benthic algae and cyanobacteria. The prevention of shading by epiphytic and planktonic primary producers and the competition for space may be the ultimate cause for allelopathical interactions. Aquatic ailelochemicals often target multiple physiological processes. The inhibition of photosynthesis of competing primary producers seems tobe a frequent mode of action. Multiple biotic and abiotic factors determine the strength of allelopathic interactions. Bacteria associated with the donor or target organism can metabolize excreted aiielochemicals. Frequently, the impact of surplus or limiting nutrients has been shown to affect the overail production of allelochemicals and their effect on target species. Similarities and differences of ailelopathic interactions in marine and freshwater habitats as well as between the different types of producing organisms are discussed
    http://www.jlakes.org/web/Allelopath...s-CRPS2003.pdf

  3. #33
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    I haven't read all of this thread, just what I can from time to time, and certainly not all of the articles, maybe someday. This last one though is very intriguing. Aside from the rampant typos, from the quote above, a few big things I see:

    - bacteria are involved in processing of allelochemicals meaning adaptation to each other's form of warfare happens. This makes sense, and might explain why certain species of coral seem to "not like" scrubbers. Like my Zoas, that just do not last, and green birdsnest, along with hammers and frogspawn.

    - this warfare may not happen when limitation is not occurring. this mean that if the scrubber is balanced properly with the system, and NPK and whatever else the algae needs is present, you may not have problems with the above corals. So there may be a factor involved in preventing algae from "declaring war". This may mean that there is much more to the screen sizing decision that thought before. In the same breath, they say that "surplus or limiting nutrients" affects the production of chemicals. So much to learn.

    - the inhibition of growth due to allelopathy (from cyanobacteria) is likely the reason one scrubber I am running has produced only minimal amounts of algae in 4 months (1/4 cup total). Worth noting that it has improved in growth rate, and that under LEDs all of it is green, but still no where near effective filtration (high nutrient tank). This further grounds my decision to tear the tank down and start over.

    - bacteria are associated with the algae. I know several people who are testing the theory that the bacterial biofilms that grow on algae mats are symbiotic and have a parallel function/concept to Zeovit type systems. It is also worth noting that I am learning that certain types of carbon dosing do not necessarily compete with algal growth but rather seem to enhance it.

    Sooooo much uncharted territory here. Someone really needs to get me a big fat juicy grant so I can quit my job and study this stuff.

  4. #34
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    Sorry for the typos, it was transferred to Adobe reader on iPad before copying and pasting. To me it also explains why some people just cannot get a scrubber to grow, and also why I don't get algae growing on my display glass. There are multiple problems and benefits associated with this single theory such as nutrient uptake, growth of bacteria and algae etc, etc.

  5. #35
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    Seems like also a good argument for running carbon if you are having problems getting growth. Absorbing the alleopathic chemicals might allow different species to coexist until one overpowers the others due to environment/location (scrubber being favorable growth environment)

  6. #36
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    Quote Originally Posted by Floyd R Turbo View Post
    Seems like also a good argument for running carbon if you are having problems getting growth. Absorbing the alleopathic chemicals might allow different species to coexist until one overpowers the others due to environment/location (scrubber being favorable growth environment)

  7. #37
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    So, now we've gone from algae exudates and soft corals to hard corals also;

    http://www.advancedaquarist.com/2002/11/corals

    Seems as though most things in the ocean has a chemical defence, attack mode. Luckily it seems these can be skimmed out or adsorbed to activated carbon.

    Grozinger (1983) found a biologically active compound in Madracis mirabilis that is also found in nudibranchs and sponges. Stony corals can also inhibit growth of marine algae (De Ruyter van Steveninck 1988). Finally, Sheppard (1979) concluded that non-contact necrosis between nearby stony coral colonies resulted from allelopathic chemicals produced by the stony corals.
    Various effects may result, from reactions by other organisms that range from acute toxicity, to a general "failure to thrive," to no visible effects (even though there may be very significant effects that are simply not visible to the aquarist, such as changes in respiration or photosynthesis rates). There may also be cumulative effects, with low levels produced increasing over time so that levels that initially had no effects begin being expressed over time on various organisms, perhaps in various ways. Such a progressive increase of metabolite concentrations could help explain the "old tank syndrome"
    Many of the more toxic compounds studied across terrestrial and marine systems occur in the polar aqueous fractions of extracted tissues. This is not to say that nonpolar compounds with deleterious effects do not exist, but that the majority seems to be polar. As such, they may be more likely to be removed by foam fractionation.
    I would also suggest that the use of activated carbon maybe among the more effective ways of dealing with such secondary compounds, as it has been found to be effective in the absorption of similar compounds from terrestrial plants.

  8. #38
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    A bit more general Allelopathy related stuff. Seems everything is at it!http://www.international-allelopathy...1275822225.pdf
    166. Significance of Algal Allelochemicals in Naturaland Agroecosystem A.S. AhluwaliaDepartment of Botany, Panjab University, Chandigarh,160014, India Algae and cyanobacteria are known to employallelochemicals in the offensive and defensive interactionsamong themselves and with higher plants, which play animportant role in structuring the aquatic community. We,however, witness little progress in better understandingthe role of algal chemicals in aquatic and wetland ecology.Demonstrating allelopathic activities in aquatic system, forexample, is considered difficult because of dispersion ofallelochemicals due to continuous movement of water andless chances of lack of contact between competingorganisms and chemicals. This talk will discuss thesignificance of well-replicated field studies from differentgeographical locations in appreciating algal allelopathy.To understand wetland and aquatic ecology, bloomformation, lake succession, algal invasion and dominanceof certain algae in a given ecosystem, more research isneeded on chemical warfare between and among algae andcyanobacteria.
    5th World Congress on Allelopathy

  9. #39
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    Now I've got a bit of time to look into this, there's lots of interweb stuff on allelopathy. Eric Borneman writes;

    http://www.reefkeeping.com/issues/2003-12/eb/index.php

    Myth 8: The statement, "but my water quality checks out fine."

    In his articles here (and elsewhere), as well as in his forum on Reef Central called The Reef Chemistry Forum, Randy Holmes-Farley provides extensive information on the nature of common (and sometimes uncommon) chemicals in reef aquaria. Ron Shimek, and others, have also covered various topics in chemistry and biochemistry over time frames spanning ten years and more. Until relatively recently, only a few chemicals were generally considered in reef aquaria, and the ability to accurately measure those parameters has frequently been called into question.


    My point above is that aquarists routinely check a variably complete set of a handful of chemical parameters in variably accurate ways to make the oft-repeated statement, "my water quality checks out fine." As has been discussed elsewhere, there are many difficulties of being assured that such statements are true, and the more recent information concerning more exotic and toxic chemical species including various metals and organometallics virtually ensure that there might be many reasons to suspect that one's water quality might not be "fine," despite routine testing for common parameters.


    To take this issue a step further, one must necessarily include the bounty of organic chemicals produced by organisms in aquariums called secondary metabolites. I am both pleased and troubled that the word "allelopathy" has become a regular word in many aquarists' vocabulary. It is almost impossible to describe how varied the products of metabolism can be in the marine environment. In short, virtually every organism in the tank has them, produces them, and releases them. The effects of secondary metabolite chemistry are significant enough to cause real and sometimes dramatic effects in the wild where dilution effects are vast. So common and numerous are these compounds that conferences, books, and journals are devoted entirely to the subject. I would urge readers to look through a copy of the Journal of Natural Products to see the scope of this topic (it is only one of many sources of such information). Each issue consists of several hundred pages (often filled with 1-2 paragraph descriptions) of metabolites derived and isolated from natural sources (organisms) and, sometimes, a brief description of potential effects (usually based on chemical structures similar to those of known function). In any given issue, about 20-50 percent of the chemicals are from marine organisms, and many are from tropical marine organisms. For example, here are the relative feature articles from the past two issues alone:


    Novel Oxylipin Metabolites from the Brown Alga Eisenia bicyclis


    Isolation and Structure Determination of Lyngbyastatin 3, a Lyngbyastatin 1 Homologue from the Marine Cyanobacterium Lyngbya majuscula. Determination of the Configuration of the 4-Amino-2,2-dimethyl-3-oxopentanoic Acid Unit in Majusculamide C, Dolastatin 12, Lyngbyastatin 1, and Lyngbyastatin 3 from Cyanobacteria


    Semiplenamides A-G, Fatty Acid Amides from a Papua New Guinea Collection of the Marine Cyanobacterium Lyngbya semiplena


    Komodoquinone A, a Novel Neuritogenic Anthracycline, from Marine Streptomyces sp. KS3


    Placidenes C-F, Novel -Pyrone Propionates from the Mediterranean Sacoglossan Placida dendritica


    Plakortides M and N, Bioactive Polyketide Endoperoxides from the Caribbean Marine Sponge Plakortis halichondrioides.


    New Polyhydroxy Sterols: Proteasome Inhibitors from a Marine Sponge Acanthodendrilla sp.
    New Brominated Labdane Diterpenes from the Red Alga Laurencia obtusa


    Briaexcavatolides S-V, Four New Briaranes from a Formosan Gorgonian Briareum excavatum


    The Synthesis of SO-3, a Conopeptide with High Analgesic Activity Derived from Conus striatus


    New Cembrane Diterpenes of the Marine Octocoral Eunicea tourniforti from the Eastern Caribbean


    Isolation and Structure Determination of an Antimicrobial Ester from a Marine Sediment-Derived Bacterium


    Identification of New Okadaic Acid Derivatives from Laboratory Cultures of Prorocentrum lima


    One can imagine what twenty years worth of this type of research has produced. In the feature articles of the past two issues of a single journal, we see novel chemicals derived from sponges, soft corals, dinoflagellates, bacteria, algae, cyanobacteria and mollusks. These are, of course, in addition to those already known from these organisms. Some sponges, algae, and soft corals have been identified that produce in excess of 40 separate chemical compounds.


    They are termed "secondary metabolites" because in many cases these compounds do not seem to have a function in basic metabolism. However, many are extremely bioactive, and have diverse effects on other organisms, including being lethal. Of course, the effects are largely unknown and many of these chemicals are not produced to have an effect on organisms that would not ordinarily be encountered by the producer of the compound. Other compounds may have an unintentional effect. Furthermore, various compounds may be very specific in the species they affect, and in how they affect those species. In almost all cases, pairwise tests of one species on another have not been done for any effects. There is little to no information as to what the ultimate fate or reactivity of these organics products might be in any environment, much less in aquaria. Finally, these bioactive compounds are highly concentrated in the closed small water volumes of our aquaria. For some examples of the scope of secondary metabolite chemistry from coral reef organisms, see the boxes below which I have derived from various primary and secondary literature over the years. The listings in the boxes are by no means exhaustive.


    I hesitate to make such seemingly alarming statements, for I am concerned that such "unknowns" may become the fuel for more myths. It would be comparatively easy for such information to be used as an excuse on which to blame the death or failure to thrive of various tank inhabitants. However, the fact that virtually every inhabitant in our aquaria is producing variable amounts of novel, uncharacterized, and well-known bioactive secondary metabolites of mostly unknown effects, and may be reactive with a host of other largely unknown organic and inorganic compounds present in our tanks, makes our water a complex soup with no two tanks being alike - or predictable.


    The take-home message of this myth is that it is practically not possible to say "my water tests fine." All we can do is recognize certain facts, and act accordingly. In my opinion and experience, the most pragmatic solution is dilution and absorption by the use of water changes, protein skimming, and activated carbon. I fully realize the many issues that might stem from this simple advice, especially in light of the materials provided by authors as mentioned above. However, if nothing else, it seems to potentially simplify the many potential chemical interactions that might be occurring.


    Potential: Innocuous to lethal. I believe many inexplicable problems in the survival of aquarium species may be due to secondary metabolites. Some are well known to occur, others are purely speculative. However, there remains the incontrovertible fact that there are effects, and that every reef aquarium has organisms producing a pharmacopoeia of bioactive compounds.


    Distribution: Ubiquitous. Every day, aquarists around the world use hobby test kits to measure the levels of perhaps 1-6 variables for which tests are available. There are no tests available for the 4-Amino-2,2-dimethyl-3-oxopentanoic acid unit in Majusculamide C, Dolastatin 12, Lyngbyastatin 1, and Lyngbyastatin 3 from Cyanobacteria that were discovered last month. For all we know, this unit causes 100% mortality in Trachyphyllia geoffroyi. Then again, it might not.

  10. #40

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    Quote Originally Posted by Floyd R Turbo View Post
    Seems like also a good argument for running carbon if you are having problems getting growth. Absorbing the alleopathic chemicals might allow different species to coexist until one overpowers the others due to environment/location (scrubber being favorable growth environment)
    This may have some validity. I just installed a carbon reactor and the growth of algae on the screen has developed exponentially from what it was prior. I will clean the screen tomorrow, which will be 11 days from the last cleaning and take pics. It's thick and green, which is very cool

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