Echoes - Stromatolite Reef - Hypersaline

[rhizotron]

Echoes - Stromatolite Reef - Hypersaline

This is a journal discussion for a new setup I'm building to recreate a stromatolite reef environment. Stromatolites are pillow, pillar or mushroom-shaped underwater stone structures built by photosynthesizing microbial mats through complex processes. They were dominant features of the oceans through much of the Earth's history and fossil stromatolites are among the oldest evidence of life. But they began to decline in extent more than a billion years ago, probably as a consequence of competition and predation from eukaryotic organisms occupying the same habitats. Today, stromatolites only occur in special extreme environments, such as hypersaline lagoons, that exclude most competing life forms.

I have not found much evidence of stromatolite culture in aquariums, so this project is all experimental. I hope I can get results growing the microbial mats and the stromatolites by maintaining the right water chemistry and other parameters. Hardware is basic. The tank is a shallow square (24" X 24" X 10" [61cm X 61cm X 23cm]) illuminated with a Kessil A160 Tuna Sun and with an economy wavemaker powerhead for water movement.

The floor of this tank is expanded PVC sheet, which is substantially less costly and lighter in weight in comparison with thick plate glass. And practically unbreakable. Silicone sealant does not stick to PVC very well, but the seams are sealed around three sides and sandwiched in that plastic base, so I doubt I will get any leaks.

Here's the layout with grey aragonite sand and stone bases that are intended grow the stromatolite microbial mats. I flattened the top surfaces of this "dry live rock" by grinding against our concrete sidewalk, which is easy to do with such soft material.

Thanks for reading. I'll post more details and updates as I put this project together.

 

[blaxsun]

Sounds interesting.

 

[rhizotron]

The stromatolites of Hamelin Pool in Shark Bay, Australia are probably the best known living example. Extreme saline conditions have persisted there for thousands of years because of restricted water exchange with the ocean combined with sunny skies and high temperatures, which increase water evaporation...

https://www.sharkbay.org/publications/fact-sheets-guides/stromatolites/

While they are less famous, stromatolites also occur in Great Salt Lake, Utah, USA. As in Shark Bay, the Great Salt Like stromatolites have grown in conditions much too salty for most creatures that could compete with or eat the cyanobacteria and other microorganims that form the stromatolite microbial mats.

A friend of mine helped me with this project by collecting loose stones from the vicinity of the Great Salt Lake stromatolites--he did not remove material from the stromatolites themselves as these are such fragile and rare natural features. He also got some great habitat photos...

The tops of many of the stromatolites are exposed due to historically low water levels as a consequence of the Western drought and water diversion.

This shot shows a submerged stromatolite...

The microbial mats on these stromatolites are a very dark green to black color. This small stone sample mailed to me by friend shows the living microbial mat pretty well...

The water sample that came with this stone and other substrate samples was off my refractometer's scale. Great Salt Lake is usually not quite this salty in most places, but salinity must be elevated due to the very low water levels...

I set up the stones, sand and mud in a 10-gallon tank and over the course of a couple weeks added small amounts of freshwater to bring the salinity down to 85ppt for a value that I could both measure and maintain...

 

[rhizotron]

Here's a couple more recent update pics with the tank a couple weeks after set up...

There is some algae growth on the stone top surfaces, although it is all of an amber color and with a dusty texture, so I think it's all dinoflagellates. I hope this will cycle through as part of the ecological succession and be replaced over time with the dark green cyanobacteria. I have nestled a few pieces of the live stromatolite rock into crevices in the new stone as inoculum.

 

[Chrisv.]

Well this is completely nuts and I love it. Can anything that isn't a microbe live in 85ppt water? Triops perhaps?

 

[rhizotron]

Well this is completely nuts and I love it. Can anything that isn't a microbe live in 85ppt water? Triops perhaps?

Thanks. I hope I can get the biofolim to establish and start to form new rock. It will probably take a while.

The samples I got from the lake were a good deal saltier than that and there were live brine shrimp and brine fly larvae in there when I opened the box. The brine flies died out, although the brine shrimp are still going in the 10G culture tank where I still have most of the original pieces of substrate.

 

[Chrisv.]

Thanks. I hope I can get the biofolim to establish and start to form new rock. It will probably take a while.

The samples I got from the lake were a good deal saltier than that and there were live brine shrimp and brine fly larvae in there when I opened the box. The brine flies died out, although the brine shrimp are still going in the 10G culture tank where I still have most of the original pieces of substrate.

I wonder what else lives in the lake!! Have you ever visited the stromatolite reef in Utah? There must be other creatures in there!

Any idea what stromatolite growth rate is? Is this like "it may take a while"= 5000 years per cm growth?

 

[Chrisv.]

A quick Google says it depends on what kind and where: 0.4 mm/year from one locale, 1-5 cm/yr from another.

 

[rhizotron]

I wonder what else lives in the lake!! Have you ever visited the stromatolite reef in Utah? There must be other creatures in there!

Any idea what stromatolite growth rate is? Is this like "it may take a while"= 5000 years per cm growth?

I understand that the the brine flies and brine shrimp are basically all there is for fully aquatic animals in most parts of the lake. There are other aquatic invertebrates and fish around springs and in less saline bays, but not in the main lake. Lots of birds do use the whole lake as foraging habitat.

Stromatolites usually grow very slowly. I have read the ones in Shark Bay only put on .5mm/year. If the biofolim develops on these, I hope I can get faster measurable growth by adding sand to the tops. Stromatolites can develop both through precipitation of CaCO3 and by trapping of sediments by the microbial mat.

 

[Chrisv.]

Super cool project. Looks like you're doing it right. Any idea if it's ever been done before?

 

[rhizotron]

Super cool project. Looks like you're doing it right. Any idea if it's ever been done before?

Stromatolite biofilms have been cultured in laboratories for microbial studies, but I've found only a couple examples of them in display aquariums. They have some in a tank at Shark Bay in Australia and there is also this scientific institute in the Netherlands....

http://teusinkbruggemanlab.nl/wp-content/uploads/2015/04/171123-MSc_2017_MSR_Rob_3.pdf

When and if I start to see establishment of the cyanobacteria, I'll start measuring and dosing with 2-part for calcium and alkalinity.

 

[Chrisv.]

Stromatolite biofilms have been cultured in laboratories for microbial studies, but I've found only a couple examples of them in display aquariums. They have some in a tank at Shark Bay in Australia and there is also this scientific institute in the Netherlands....

http://teusinkbruggemanlab.nl/wp-content/uploads/2015/04/171123-MSc_2017_MSR_Rob_3.pdf

When and if I start to see establishment of the cyanobacteria, I'll start measuring and dosing with 2-part for calcium and alkalinity.

I wonder if it would be worth it to have your friend send a sample off for ICP. Super concentrated synthetic salt may not be the same as super saline natural great salt lake salt plus other (no doubt concentrated) trace elements.

 

[rhizotron]

I wonder if it would be worth it to have your friend send a sample off for ICP. Super concentrated synthetic salt may not be the same as super saline natural great salt lake salt plus other (no doubt concentrated) trace elements.

It's already been described many times...

Google: great salt lake water chemistry analysis

I could probably figure out a comparison with seawater by sifting through some of that.

I've just mixed this water up with Instant Ocean, mainly for the sake of convenience. I imagine it's not so critical to match water chemistry exactly because microbial communities tend to be resilient and adaptable as long as conditions are maintained within a certain favorable range.

 

[rhizotron]

There's simplified answer right here with a chart that shows a comparison between Great Salt Lake water and seawater for major ions...

https://geology.utah.gov/popular/ge...great-salt-lake-lake-bonneville/#toggle-id-13

It's comparable for most, although the calcium value for the lake is quite a bit lower.

 

[Chrisv.]

There's simplified answer right here with a chart that shows a comparison between Great Salt Lake water and seawater for major ions...

https://geology.utah.gov/popular/ge...great-salt-lake-lake-bonneville/#toggle-id-13

It's comparable for most, although the calcium value for the lake is quite a bit lower.

The row that describes the dead sea is super neat. Never knew it was as magnesium rich as it is saline.

 

[rhizotron]

The row that describes the dead sea is super neat. Never knew it was as magnesium rich as it is saline.

Looks like there's lots of igneous rock in its drainage and that could be a source of extra magnesium...

https://www.researchgate.net/figure...s-including-Khirbet-edh-Dharih_fig1_229889746

 

[Chrisv.]

How's your project going?

 

[rhizotron]

How's your project going?

It's coming along.

Some time ago the setup went through a pretty wild diatom bloom, followed by a cyanobacteria bloom. The cyanobacteria appeared to be the same one growing on the live piece of stromatolite rock from the lake. I did a few water changes with sand rinses because quite a lot of it was growing on the sand as well as the stone surfaces.

The stone is now mostly colonized with a thinner growth of the cyanobacteria along with other microbes. They have had a more difficult time establishing on the smooth top surfaces, but they are slowly spreading to cover there as well.

 

[Chrisv.]

Looking cool! I wonder how well the sample you added inoculated the tank with the wild microbes. Maybe an aquabiomics sequencing would be interesting.

 

[rhizotron]

Yeah I really would like to get a sample sequenced. Do you have any tips for that?

I also still have some of the original rock sample along with some of the sand from the lake in a 10-gallon tank with hypersaline water mix and a little light.