mangroves

[schanz]

I don't see many posts on this forum about mangroves anymore. I was thinking of creating a fuge with these plus some macros. I was wondering if a DSB could still function as a DSB and have mangroves in it. Would the DSB loose it's anaerobic layer with roots running through it? Could the mangroves keep the sand from becoming a phosphate pit?

 

[prop-frags]

tagging along - I planted mangroves in my refug in hopes that your assumptions are correct.

 

[PRC]

I just asked one of these questions on another monster DSB thread. Here's the result:

Originally posted by PRC
Here's an idea sure to be shot foll o holes, but what the heck. How about a remote DSB with a bunch of Mangroves planted in it. Could they possibly absorb enough phosphorous directly out of the sand bed to temper spikes of PO4 release?
Thanks to all for all this great info!
Paul

Hi Paul,

Unfortunately mangroves are very slow growers. Some of the more successful hobbyist with this tree have reported 3 or 4 leaves/ year growth.

Another thing I think of with mangroves is the substrate that they lived in around South Florida. If all those mature mangrove trees down there can't stop the substrate from going rotten, then I don't think they would do much good with my high organic reef tank.
Steve

I'm still not sold that mangroves are not efficient nutrient exporters compared to macroalgae. I have several mangroves that are growing leaves at a rate closer to 1-2 per month than 3-4 per year. The mass of wet growth on my Caulerpa is significantly higher than that on my Mangroves but I wouldn't be too surprised if the dry weights were close to equal. Caulerpa appears to be mostly water to me, whereas mangrove leaves, roots and stem seem to be pretty solid stuff. I've found some studies that have actual data on nutrient export for a variety of macros but I haven't been able to find anything on mangroves other than opinions.
I guess if the roots release oxygen they would definitely impede anoxic activity in the DSB. But if they're absorbing nitrates who needs the DSB anyway.
Paul

 

[ButterfyBoy]

I think true sea grasses are likely to be a better choice for nutrient export than mangrove seedlings. Sea grass meadows are one of the most productive ecosystems on earth, with peak production having been recorded at up to 5000g/m^2/year of carbohydrate. That's a *lot* of material -- the highest producing ecosystems on earth yield in the range of 6000g/m^2/year. I'm a little surprised we don't hear more about people using seagrasses.

 

[schanz]

What does seagrass require? Does it grow submerged, half submerged? I think I remember reading that it required high light. I've been watching my energy consumption lately. Hopefully T5's or PC would grow it.

Reading on other, older threads on mangroves, I saw it mentioned that they didn't do well in normal salinity. What salinity are your's growing in PRC?

 

[billsreef]

Sea Grasses such as turtle grass grow completely submerged. They need deep sand beds and generally bright lighting. As for if the t5's or PC's will work, depends on the depth of the tank.

 

[phdezra]

I figured I'd chime in here since I am using mangroves (Rhizopora mangle). These are MY observations in my tank; doesn't mean it'll work the same in yours. Now that the qualifier is out of the way... :rolleye1:

I have a 135gal tank, with a few easy corals (Xenia colony, large Star Polyps colony, small Capnella, a few Mushrooms, small Anthelia), and a DSB (approx 100 lbs of LS and 100 lbs of LR). I also have a ~20 gal sump/refugium. I do NOT run a skimmer 24/7. I have 7 medium sized fish. IMHO, this is NOT a heavy biolad for a 135 gal tank. :strange:

Tank has been running for ~9 months. About 8 months ago, I bought some Mangroves off of eBay, and figured I'd give it a try. Since I have about 30 lbs. of Miracle Mud in the fuge, along with wads of Caulerpa, and 16 hours reverse cycle lighting, I figured it was worth a shot. I stuck 8 Mangrove stalks/shoots in, and all but forgot about them. Some of them I stuck IN the fuge's sand bed, others I simply floated in it. The tops were exposed in all situations.

Periodically, I would look in on them, and noticed they were doing *nothing*. :fun4: They were not rotting though, so I let them be. Every so often I checked them, and it looked like leaves were growing at the rate of approx 1-2 per month. Two weeks ago, I looked at them again. The root growth on the ones that have 'taken hold' is incredible. The roots are 6+ inches, and thick as a pencil on some. :bigeyes: Some are buried in the sand, some are floating in a mix of macroalgae.

Do the mangroves help export lots of nutrients in my system? Tough to say, but no one in my tank is complaining. I would definitely say that it does not hurt the system and likely has at least a small positive effect. BUT if you have a heavy bioload in your system, it may only make a dent.

I plan on adding another 8-10 stalks. One thing that seems clear to me is that there is a ramp-up period. They do nothing for first few weeks, then slowly start to "come around."

 

[wasp]

Yep - Mangroves are another one of those phases that came and went.
Don't do any harm, and can look good and interesting, just do not compete with other methods of nutrient export.
Pity, because I live next to a mangrove swamp. If I could sell them I'd be a millionaire

 

[PRC]

My mangroves are growing in my refugium which is a 50G Rubbermaid ag tub. The tub has ~4.5" of sugar fine aragonite which leaves about 5" for water. The fuge is fed direct from a tee off my overflow at about 90gph. I recently added a 110gph powerhead because the flow was looking too slow. My salinity runs between 1.024 and 1.025. I'm not sure where the idea that mangroves are sensitive to salinity changes or that they don't do well in high/low salinity. I've seen many comments to this effect, but they don't really make sense to me and IME are not true. THe research that I've seen states that mangroves grow best in brackish water but that they will grow in almost any salinity. Mangroves in the wild often live in estuarine conditions which have highly variable salinity due to incoming tides and outflowing rivers. I have several growing outside in pots that regularly get fresh water from rain (almost every day here) and whenever I get a chance (every few days or so) I give them water from my tank. The oldest of these trees is about 9 mos now and at last count had 26 leaves, I guess I'd call that thriving?
My fuge currently has two four foot T8 daylight deluxe fluorescents over it. The bulbs are almost touching the taller mangroves. I have a 150W HPS light that I plan to install over the fuge when I get a chance. IMO HPS is definitely the best bang for the buck when it comes to plant lights. I think most people don't provide enough light for their mangroves.
I'm planning on trying some seagrass as soon as i get a chance.
Here's the closest thing I could find to a scientific study on mangroves ability to remove nutrients: http://www.athiel.com/lib10/mangrove7.rtf
seems pretty straightforward to me. Either way, I just like the way they look.

 

[phdezra]

Here's the closest thing I could find to a scientific study on mangroves ability to remove nutrients: http://www.athiel.com/lib10/mangrove7.rtf
seems pretty straightforward to me. Either way, I just like the way they look.

Seems scientific enough for me.

 

[prop-frags]

my mangroves rotted.
My fault, I'm sure, I couldn't figure an easy way to get them to only be partially submerged. I think I'll try again later though.

 

[stevemc]

PRC, I have the same feelings about the salinity thing. I live over in Sarasota, and have several mangroves that I moved outside that never get salt and are doing fine. I have even planted them in the yard, but dont let them dry out or they will die. A few years ago there was a 15 year old (galleon) who was a moderator here, and would say stuff like a slight change in salinity would cause leaves to fall off, and stuff like that, and maybe some people thought that was true. As soon as he said that I poured saltwater from my tank into the pot with mangroves that had been living on fresh only, nothing happened. Like you say, they live in a constantly changing environment. High salinity to pure fresh. I also feel that what you said about lots off light is definitly true, the more the better. They like it outside, and it is hard to give them that much light in a sump or refugium, without heating the room or water. They look good in a big refugium, but dont have a huge export, except maybe at the bottom of the sand. Also the roots that use nutrients are at the bottom of the stem, and are fine, the angled roots are prop roots and dont use anything. Steve.

 

[PRC]

Mike, try using styrofoam and cut a slit or small notch to hold the mangrove. Only about the bottom third has to be in the water. You can check out the picture in my gallery for some visual help.

Steve, thanks for the confirmation. I was beginning to wonder if I was the only one seeing this. Actually, the thing about mangoves not being able to handle salinity changes is mentioned in Bob Fenner and Anthony Calfo's new Reef Invertabrates book.

 

[Fzech]

Here is a link to a Web Site that I have found very informative on mangroves. You will have to download the info.

http://twolittlefishies.com/tlf_prod_plants.html

Thanks: Fzech

 

[RicksReefs]

here's another.

http://www.advancedaquarist.com/issues/apr2002/feature.htm