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| Having delved into a bit of seagrass bed nutrient dynamics, a thought occured to me that I have not seen mentioned and if I don't get this down as a question now, I will forget. During the much windier (is that a word?) parts of the monsoon season here, I can go to the beach and tell which way the wind has been blowing and how hard by just the huge mounds of cast off (dead) sea grass blades that have been washed up onto shore. Being that seagrass derives its nutrients from its sediment (DSB), its leaves should contain a fair amount of nutrients, including carbon. With the amount of dead leaf litter on shore and it breaking down, it would only take a larger wave or rainfall to wash what must be nutrient rich water back into the ocean, where the near shore filatmentous algae would then be spurred to even greater growth, thus recycling or transporting the nutrients that were once found deep in the sediment of the grassbeds and into the filamentous algae community. Now if the wind were blowing offshore, then those blades of seagrass would most likely end up sinking into the deep ocean and adding their nutrients to the very deep benthic habitat that in turn would break down (release?) the sequestered nutrients which could then find their way back up into the light by upwellings and fuel the plankton, which in turn...feeds just about everything else. I think... Chuck
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Hi Chuck: Makes sense to me! This would be considered a part of the normal decomposition/recycling of all organic matter in the oceans. Makes no difference if it's a Whale that dies & decomposes or inshore Algae. The cycle of nature is truly amazing....... Steve
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| Had another thought last night and its driving me crazy this morning because I lost it...lol I must be getting at that age where I have to start writing things down, that or my hard drive is getting full and need to purge. I tell you what though, with all of this reading I'm doing, I will never look at seagrass beds the same and instead of just running across the lawn I am beginning to appreciate just how complex such things are. Chuck
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| Absolutely Chuck! And that's the reason why we can't reproduce something as diverse as a coral reef ecosystem in an enclosed glass cube no matter how large it is! Steve
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| In a single enclosed glass cube that is, Now that I know what I know by having seen it for myself, I want to say that I am surprised (but I'm not) that the majority of the hobby is so geared towards the single tank methods (a dark equipment filled sump don't count). Also think of the industry behind keeping single tanks going, its freaking huge. What I am really bugging out on is that if I can have what I think is a beautifull 80 gallon display maintained with a 20 gallon macro algae refugium and a 20 gallon sump with a mini turf scrubber and run it all on some CF bulbs, a single 250w MH, a couple of pumps and a fluidized chamber for carbon while supplementing only calcium, alkalinity and magnesium and hardly ever do a water change anymore, can you imagine what could be done with say a 100 gallon macro fuge, 100 gallon DSB seagrass bed and a suitably large ATS ? Great googly moogly! The diversity I have now would look like a guppy tank compared to that set up! I need a bigger apartment!!! Just seems like single tank systems spend their time fighting biology or doing really weird things to make up for their shortcomings. Hence the industry that gives us the eco aqualizor... Chuck
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I have wondered if within my seagrass tank i should leave the dead/decaying leaves when they fall away from the plant. I suspect that in leaving them I would potentially add yellowing compounds to the water and excess nutrients to the water column so I usually remove them as soon as I find them, but I wonder if leaving them in has some greater benefit for the seagrass and possible DSB infauna diversity as well.
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| That does sound like a bit of a quandry, while carbon would deal with any tannins, the biggie for me would be the decay, which in a seagrass habitat not only provides shelter for fauna but a great deal of food as well (bacteria all the way up to inverts), but since such fauna would be either seriously lacking or not diverse enough in an aquarium setting, I would remove it. Besides, nutrients (Phosphates/Nitrogen) is not something usualy lacking in anyones aquarium system and am sure there is more than enough for sediment enrichment just in the water. In other words, the leaf litter would rot without actualy being of benefit to the seagrass and would end up fueling something else as the leaf litter would not have its nutrients returned to the sediment by the infauna. Chuck
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Great observation chuck. And also there are the seagrass grazers e.g manatees that pull 'em out, eat 'em and through their digestive system export the nutrients to other communities like the abyss.
_________________________________________________________________Learn the way, forget the way, free the master within
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| Actually graveyardworm, from my experience, I don't think you will have nutrient problems just from leaving the dead stuff behind. I havn't removed anything from my tank in almost a year and I don't have any issues. I havn't measured anything in quite a while though. I suspect if you use an algae scrubber for export or remove some portion of live material regularly, you will be just fine. Any algae growing in the system will continue to soak up nutrients. I am rather surprised that I havn't seen much in the way of detritus accumulating at the bottom of my tank or refugium. Things are being recycled rather efficiently at the moment, and I don't have much diversity in the tank (never did). Chuck. I remember having a similar discussion with Ron a few years ago. From what I remember, critters go through regular population swings in small areas, but are repopulated by surrounding areas. Even a tank of a few thousand gallons is not big enough to survive local population swings. We also have the problem of providing a wide enough range of foods to support any sort of species diversity. You have a great opportunity being so close to a tropical sea. Fred P.S. feel free to post more seagrass pics here any time
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| Hey Fred, Are you saying that you have a mat of seagrass leaf litter? If so, after having spent an entire day reading, I was quite surprised at what actualy goes on down under that stuff. With you saying that you don't remove the litter and don't have any issues, that came as another surprise to me. As I study this coming week, might the answer reveal itself, unless you already know.. Am hoping to get face down in the grassbed again tomorrow, although its going to be a high tide which means a lot of breath holding (good work out for me as usual) and plan to get more photos as well as some of the sediment to sample the life found in the upper layers, I don't like to go too deep because its awfull stanky and the wife liked to have beat me the last time I brought some of that black goo into the house, had to do a quick about face... Chuck
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