Mariculture in Austin

[Subsea]

No, I am not talking about the cliche, “Keep Austin Weird” culture. I am talking about the specialized field of aquaculture that deals with marine organisms. Specifically seaweed and pods. Early in the process, it became obvious that air was the best use of energy to move water, plus no electricity in salt water, which is a big deal. I have had resistive heater and pumps short out into the water. Without a proper grounding circuit, the potential for electric shock is high. In outside mariculture, as much as possible, I remove electricity from the salt water. One perfect example is geothermal heating. I use Trinity Aquifer water from 1000’ deep at 78 degrees to heat my pilot system of 900 gallons consisting of six 150G tanks. Three Rubbermade tanks are buried in the ground with two more on south patio. The sixth 150G tank is glass and is 4’ by 2’ by 32” deep.

Cooling is by far the #1 concern and cost in the Texas Hill Country. I evaporate 50 GPD to maintain water temperatures between 85-75 degrees. When I operated my 10KG system in a greenhouse, my monthly electric bill hit $1000 and I pulled the plug on the system.

The last picture is looking south from south patio. Looking across 900 gallon pilot system then Jacuzzi, then 6’ fence around garden, then 20’ by 40’ arched dome greenhouse.

 

[Subsea]

Several factors to consider with balancing chemistry in intensive mariculture. From previous discussion with algae doctors, I have found that phytoplankton combines carbon, nitrogen and phosphorus in the
Redfield Ratio of 106:16:1

Macro algae is much more variable but in general it combines C:N in the ratio of 560:30:1 with some N ratio as high as 80:1 and some as low as 10:1.

Consider the high carbon content of seaweed as the largest contributor of seaweed biomass by a factor of 18:1. Where does this carbon come from is an obvious question, particularly if it cost a lot. My friend, Professor Tzachi Samocha wrote a book on intensive shrimp cultivation with a zero discharge system. When interviewed, he was quoted as saying that the #1 reason for failure at mariculture was throwing excessive carbon at the shrimp. At the time I first heard that, I did not understand what that meant. More recently in a conversation with Professor Jerry Brand, Director of Culture Collectio of Algae at UT. I enjoyed a tour of the facility at Austin. At the time, it boosted the largest algae collection in the world. I was honored by a visit from both Director and curator PHD to my facility. In one conversation with Doctor Brand he cautioned me about my use of organic carbon dosing. His words were, “organic carbon grows bacteria, not algae. Dana Riddle said it differently about growing coral. His words, “carbon dioxide grows coral”. Carbon dioxide gas readily combines with water adding to carbonate and bicarbonate alkalinity, which combines during photosynthesis to form glucose which is carbon for the reef.

For me, it is a no brainer. I use air to move water to enhance evaporative cooling. At the same water air interface as evaporative cooling is a more important gas exchange process. As controlled by Dynamic Equilibrium of gas partial pressure law: carbon dioxide, oxygen and nitrogen go back and forth. So, if carbon dioxide grows coral then put system on steroids. I will shortly be installing a calcium reactor at several locations.

 

[Subsea]

The 150 glass tank was used to tumble culture Halymenia dilatata. In March when I started, I soon found that I lost control of algae monoculture. I bleached tank. All water added to tank went thru a 40W UV sterilizer. Initially, salt was added and tank allowed to circulate as I waited on starter culture of Dragons Tongue which is the Pacific version of Dragons Breath from Gulf of Mexico. Algae grew on glass during seven day wait. Seaweed mariculture manuals all stated that cross contamination was the number one reason for failure. So I used swimming pool shock treatment of chlorine to sterilize tank for three days. When I started over, I added Dragons Tongue to 120G glass tank in Austin, Texas with PAR values
> 5000. Even though I could control the temperature with evaporative cooling, the intense sun grew algae on surfaces of desirable algae. Not all of the Halymenia dilatata was overtaken by nuisance algae. Not being a red algae scientist, I read what the scientist say about Rhodophyla seaweed.

http://nsgl.gso.uri.edu/nhu/nhuh14001.pdf

http://www.vcbio.science.ru.nl/en/virtuallessons/redalgae/

“Red algae are haplo-diplonts with a complicated life cycle that often involves three phases.”

As I weeded out undesirable Dragons Tongue, I noted that new growth did not have nuisance algae on surfaces but old growth did. So the tedious job to salvage desirables and bring back inside under controlled conditions with 55G monoculture tumble tanks set up inside. My inside mariculture is in dissary due to two seperate 55G tanks leaking at seam half of their water on wood floor. Unknown to me, the first leak got into electrical wall plug taking out all electricity in living dining area for one week while I dismantled stacked 55G tanks to get to electrical wires inside the wall behind the established tank. I just did stack the second 55G stand and will move Dragons Tongue into this tank once I get UV hooked up.

 

[Subsea]

With many differrent macro algae competing for dominance, I have decided to go with encouraging a monoculture of Ulva. To that end Ulva likes nitrogen and cooler temperature. So evaporative cooling and ammonia dosing is emphasized for this 900G system.

I already have large amphipods and cultivated copepods in this system. I am working on pod collection systems to reduce collection labor?

I will take pictures outside when it cools down.

 

[Subsea]

While adding ammonia separately to each tank, I noted the tumble culture of Red Gracilaria in 150G glass tank. At first, I thought growth was heavy biofilm. While it was somewhat leathery, I realized it was part of the cylindrical stems. I had seen this a few years before when I pushed a tumble culture of
Gracilaria HayI with iron dosing. The color change to a robust fire engine red happened overnight. It took a week for me to notice the bladders attached to stems. Then I recalled an article that @Randy Holmes-Farley wrote concerning dosing iron in a reef tank. From this article and what micro biologist have said, “everything organic in our reef tanks needs iron” to prosper. Randy completed his article mentioning “iron storage ability” of macro. I saw those bladders today on Gracilaria Parvispora. I also saw big pods.

 

[Subsea]

To further increase diversity of live food, I seeded three species of cultured copepods from AlgaeBarn. Coupled with this is effort on my part to adjust some environmental conditions: increased nitrogen, decreased temperature < 80 degrees.

 

[Subsea]

@lapin
To further enhance evaporative cooling on outside mariculture, here s a first design swamp cooler that focuses on chilling salt water on my back porch.

 

[Subsea]

Swamp cooler created too much salt water loss due to mist drift. I went back to 20” box fan blowing perpendicular to water surface.