Mangrove meandering, and the part where Scott kicks his own butt for not doing something already! Yeah, fun!

As the "Estuary" line from Tannin starts to find it's legs, we're seeing some interesting applications of mangrove roots/branches and interpretations of various mangrove habitats. As I talk with our customers, I am awash with new ideas! 

Like, too many ideas. Driven to the point of distraction...and INACTION! "Analysis paralysis" at its finest.

Time for another public "self-flogging"- my preferred technique for getting myself off my ass to do something! :)

And I'm kind of angry about it. I've been keeping my latest mangrove root project "dry" for way too long. WAY too long...LIke, WAAAAAY too long! 

I've been doing a stupid amount of research into different themes for my office mangrove root habitat, which has been delayed more times than the NASA Space Launch System" over the past year, and I'm more than ready to go now...And of course, at the last minute- I'm contemplating a particularly radical departure from my original plan..possibly a full-strength saltwater estuary replication... 

"...Just when I thought I was OUT, you pull me back IN....!!!!"  Protein skimmers, calcium reactors, trendy overpriced coral frags with stupid names...arghhh!

Well, it's not really that bad...I mean, it COULD be- but I don't think it is. I think this could be pretty matter which direction I go with it!

I say that now...

("Yeah, keep mocking me, you mother-----!")

One of the things that I found/find interesting is that there are plenty of things going on in mangrove habitats that can be potentially modeled in the aquarium, with so many possible approaches!  We've done some of this already in our blackwater, botanical-style systems, and there is more potential in brackish/marine tanks than we'd imagine for this type of setup!

It all starts with the decomposition of "stuff." Like, typically, leaves.

Fungi and bacteria in brackish and saltwater mangrove ecosystems help facilitate the decomposition of mangrove material, just like in their pure freshwater counterparts. Interestingly, in scientific surveys, it's been determined that bacterial counts are generally higher on attached mangrove leaves than they are on freshly-fallen leaf litter, and this is kind of interesting, because ecologists feel that attached, undamaged mangroves leaves don't release much tannin, which, as we know might have some ate-bacterial properties. However, it's also been found that materials like humic acid, which are abundant in the mangroves, stimulate phytoplankton growth there. 


The leaves of mangroves, as they break down, become subject to both leaching of the compounds in their tissues, as well as microbial breakdown. Compounds like potassium and carbohydrates are commonly leached quickly, followed by tannins. Fungi are the "first responders" to leaf drop in mangrove communities, followed by bacteria, which serve to break don't the leaves further.

It's long been known that mangroves are extremely productive communities, and that numerous organisms thrive in the areas associated with them. That's part of the reason why mangrove habitats are a sort of "nursery" for many species of fishes and invertebrates. One interesting example is that of the Jellyfishes. Planula larvae of Cassiopea species have been found by scientists to show a strong preference for mangrove "substrata", specifically settling and undergoing metamorphosis on submerged, deteriorating mangrove leaves. 

This is a unique, but not uncommon utilization of the mangrove environment by many life forms.

Plankton, fungi, and larval crustaceans abound. Copepods are the most abundant group in the mangrove mesoplankton (organisms between 200 μm and 2 mm). And of course, some of these types organisms are now available as "live" cultures from hobby-level purveyors, like Reef Nutrition, etc., so the potential to "stock your mangrove system with an appropriate compliment of living supplemental food sources is better than ever before! 

And with all of those mangrove roots and a rich substrate to play in, can you imagine the potential for "pre-stocking" the tank with a supplemental food source in these animals? 

Yeah, I can! 

Because they are typically found in environments with muddy and/or sandy sediments, submerged mangroves roots, trunks, and branches are sort of "oasis" which attract rich "epifaunal" communities (Defined by Wikipedia as "Aquatic animals, such as starfish, flounder, or barnacles, that live on the surface of a sea or lake bottom or on the surface of a submerged substrate, such as rocks or aquatic plants and animals, but that do not burrow into or beneath the surface.") The epifauna represents a really diverse assemblage of invertebrates, like  sponges, anemones, polychaetes, hydroids, barnacles and ascidians (like the Jellyfishes), just to name a few. Organisms like sponges colonize the roots, and may become food sources for higher organisms like fishes. 

It's a really interesting food web! 

In full-strength marine environments, mangroves and their associated leaf litter and roots are home to some interesting aquarium-friendly fishes, like gobies, Damselfishes, and Cardinalfishes. Most are small, relatively peaceful (well, not ALL Damslefishes are) fishes which make great aquarium subjects. And of course, there are other fishes, such as livebearers, gobies, Mudskippers, Pipefishes, etc. associated with mangroves in fresh/brackish habitats.

If you're thinking what I'm thinking, you may want to "evolve"- or even start out your "tinted"/botanical-style mangrove aquarium experience with a full-strength marine population. Almost no one I know has tried this. Talk about a wide-open field to unlock some interesting things! 

(The über-cool Banggai Cardinalfish...a fave during my days at Unique Corals, is a perfect candidate for this kind of system!)

Mangrove ecosystems are dynamic, highly complex, not well-understood habitats. Our representation of them in the aquarium, while certainly limited in terms of function, can provide a very interesting habitat for a variety of fishes which have not previously benefitted from more suitable accommodations in aquariums! 

Those of you working with wild livebearers, for example, could have a real "field day" with a mangrove-themed, brackish water aquarium! And don't think I"m not eying THAT idea as well!

SO, the key takeaways from this little journey:

1) Mangrove root communities are very rich habitats.

2) You can attempt to "recreate" at least part of a mangrove "food web"- albeit on a very, very basic and superficial level in the aquarium, by encouraging fungal and bacterial growth in mangrove leaf litter. Lots to do here!

3) You'll be operating a very nutrient-rich system, which will require a lot of observation and regular maintenance to keep it from turning into a potentially very messy tank! Much like i the freshwater botanical -style tank, a brackish/marine botanical-style aquarium will require much experimentation and "tweaking" to create truly compelling results- but the potential is huge!

4) The potential to keep fishes like, Pipefishes, gobies, and some full-on marine fishes in an aquarium representation of their natural habitat is a "geek magnet!"

5) Scott is all over the ^*&^(* -ing place with his ideas today!

Yeah, it's many ideas, not enough time, tanks, or space to pull all of them off. Oh wait, that's pretty much "normal" for our hobby, huh? 


Stay active. Stay creative. Stay resourceful...


Oh, and...

Stay Wet.


Scott Fellman

Tannin Aquatics 



Scott Fellman
Scott Fellman


2 Responses

Scott Fellman
Scott Fellman

January 06, 2018

As usual- excellent info! I agree about the maintenance required. Like BWBS tanks, Brackish tank set up like this are no “set and forget”, and I’d imagine an aquarist being in for a rude awakening if he/she assumes that! Good thoughts o the fish selections, too- I think this is where many wild livebearers will really shine and come to prominence in the hobby!


January 05, 2018

While my estuarine aquarium is on hold indefinitely (we need space for baby stuff more than fish stuff!) I can sympathize with you on many levels of the research! There seem to be alternately too many options – and yet so many options don’t work! The additional level of misinformation or downright ignorance further confuses the issue. I’d like to share my favourite picks for brackish setups, since I did the research but can’t use it at the moment!

Tank size is the biggest issue, while nutrient export is a challenge for many fish options – too saline for java fern, but not saline enough for seagrasses or macroalgae. Creating a whole ecosystem is a real challenge, as “community” fish are a no-go in this intense waterscape, falling hard on either side of the “prey” (livebearers and inverts) or “predator” (Jack Dempseys, crazy fish, puffers). Fish that are messy eaters like puffers will not only pollute your attempts at leaf litter, but also destroy any cleanup crew that might be used. Others, like archerfish, mudskippers, or four-eyed fish require unusual setups that will need lots of attention.

Aquarists looking for a low-maintenance brackish setup (if that even exists) should look to keeping small fish in a large tank – less variance in salinity and greater room for error is even more of a benefit than with freshwater. The best option for plants is honestly algae, which will adapt to almost any salinity and will serve as cover or a food source. The best options that I found for fish were livebearers (mollies and guppies specifically, although some species of swordtails can live in low salinity) and many species of killifish, which were a nice and often colourful surprise! Those looking to save on their energy bill should look at temperate coastal fish like the Florida flagfish and other pupfish such as the sheepshead minnow. Interesting inverts are many types of crabs, lobsters and crayfish.

I hope that this is helpful for someone! As always, do research beyond what I have given here, especially from scientific sources, as many of these fish will prefer vastly different setups in terms of wood, rock, substrate type and colour, supplemental organisms and algae.

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