Aquaculture in the Classroom Newsletter
Volume 3, No.2, February 2015
Good February to You All (that's Yankee for Y'all):
In the last newsletter we talked about biosecurity and keeping things clean. Here are two extra notes
about this. 1) When is clean too clean? Do not scrub your tanks and biofilters too much. Do not use
detergents and soaps when cleaning them. Water and a brush is usually enough and the bacteria you are
trying to cultivate come back quicker with the next round. As my mother likes to say, "You've got to get
your daily dose of dirt." If a system contracts a disease then all bets are off and sterilize as well as you
can. Again, not with soap or detergent, but with bleach or Virkon. 2) Although it is rare that pathogens
are in your system soup, all students and teachers should wash hands each time after working with an
RAS and if they get a cut or puncture, have it treated promptly and properly.
STEM and AQUACULTURE
You may have noticed there is a bit of science and math involved with aquaculture. It is good to
understand the biology of the fish and the bacteria and the recycling of waste. It helps to use numbers to
define starting and ending points, calculate production, yields, costs and so on. But what about the T and
the E in the middle? How does technology and engineering come into play with our systems?
Technology turns water heaters on an off. It can automatically feed the fish. It can turn on emergency
life support systems when needed. It can automatically backwash the biofilters on your system. Nifty,
time-saving devices that allow you to spend more time watching the fish are brought to you by engineers.
Remember your one or two tank system can be tended to rather quickly, but 20 - 100 tank systems
require more time and, therefore, more technology.
Aquaculture is moving to more and more technologically advanced systems. Farms can be established
in warehouses next to the cities consuming the product. Engineers need to figure out how to squeeze all
the necessary stuff into a smaller space. One of the great things about a rural farm is there always seems
to be room to expand. This is not to say rural farms will become things of the past. The technology will
be applied here as well. Engineering has resulted in technology on rural catfish farms in California that
allow raising 140,000 lbs/acre. That's a lot of catfish. Currently in Arkansas and Mississippi the highest
production is 25,000 lbs/acre. Many years ago when laboratories using zebrafish to conduct research
started out, they fed all the aquaria by hand. Now, there are so many aquaria they have robots to feed the
fish. Did I mention engineering and technology?
Recently, there was an article in TechRepublic discussing the use of engineers in aquaculture
(http://www.techrepublic.com/article/why-engineers-are-critical-to-the-future-of-sustainable-farming/).
This is a good article to read to help us understand that aquaculture and other food production requires
STEM and the science, technology, engineering, and math, teachers need to be working with the
aquaculture and agriculture teachers so students understand the linkage between all these disciplines.
They are not distinct. They are not stand-alone concepts. They do connect to one another. One cannot
exist without the others. Oh dear, the vein on my red forehead is popping out. The point here is one
student may find a great deal more enjoyment engaging STEM in a computer environment and another
student may get more out of STEM with fish or goats or peas, but we must get both students to
understand they are still doing STEM and they are needed for our successful future.
TEST KIT CHEMICALS
Last year I had students perform a boatload of water quality testing and the other day I was perusing
my two kits to see what needed replacement. It also occurred to me some of the chemicals might be out
of date. How can you tell? Well, funny you should ask. At the time I was checking out LaMotte kits, so
I went to their website and they have quite a good explanation how to tell when something was
manufactured and then a list of all their chemicals and how long they last. So
visit http://www.lamotte.com/en/support/resources/reagent-list#backup for this useful information. For
those of you using Hach test kits, they have the expiration dates listed on the labels, so you don't have to
think so much. Not that thinking is a bad thing, mind...
Do you have the big kit (LaMotte AQ2 or Hach FF-1A) with six to nine tests in it that costs $240-300?
Do you use all the tests? No? Do you feel like you were ripped off? Okay, deep breaths, take it easy.
The LaMotte AQ2 and Hach FF-1A are good kits. They provide everything you need, especially when
you start. But, the dissolved oxygen tests are cumbersome and take quite awhile to run and there's only
50 tests before you run out of chemicals. If you have two tanks and you check DO every day, you are
done in less than a month. The pH tests are good for ponds because pond pH shifts greatly over the
course of the day, but they are not quite as accurate as we'd like for an RAS. So, what should you have?
To show the various things you are trying to teach with an RAS, you need to be able to run these tests:
Alkalinity
Ammonia (Total ammonia as nitrogen, TAN)
Chlorides (not chlorine, I'm just sure)
Dissolve oxygen
Hardness
Nitrite
pH
The LaMotte AQ2 costs $240. To buy each kit individually (excluding DO and pH) is about $300 at
Pentair Aquatic Eco-Systems. They have a pH pen available for $85 that floats, is waterproof and
measures pH to the tenth. This is far more useful than the color wheel for these systems. Then you can
buy the DO meter. There are several types. You do not need the bounce-proof version made by YSI to
withstand being run over by a tractor on a farm. I have a YSI DO200 that is about 6 years old and is still
working. It is a modest meter in the dissolved oxygen world, but has performed nicely and cost about 1/3
other models sold. You need to assume you will buy a new probe every 2-3 years.
You remember I said earlier I was looking at my reagents. Well, I figured out I can take out some tests
in my LaMotte AQ2 and have room for my DO200 meter and my pH pen meter. I have the nice carrying
case and everything is there in one spot. So, if budget is a problem, buy the AQ2 or the FF-1A in year 1
along with a pH pen. Then buy the DO meter in year 2. I'll discuss this in greater detail in the March
newsletter. Of course, none of this matters if your students don't do the testing. Collect the data. Interpret
the data. See if your interpretations seem to fit what is happening in the tanks.
GET YOUR FISH HERE...
Three more schools received fish this past week which goes to show it is never too late. Also,
remember you can keep those fish over the summer and let them spawn and blammo, you have a new set
of fish for your tanks in the Fall.
WORKSHOPS
For those of you pining to attend a workshop on aquaculture, I will be devising a method to make this
happen. Full details will be out in the next newsletter but here is the concept. I will hold workshops
around the state this summer. I'm not yet sure how many, but the idea is to have them so you do not have
to travel more than an hour to get to the workshop. I think I will have the morning set up for folks who
are new to it all. Then in the afternoon, the workshop will be geared to teachers who feel comfortable
with the basics but want to move on with something new.
As I work on this, two things would be most helpful for organization and logistics. 1) Let me hear
from you if you would like to attend such a workshop. Based upon your responses, I will better be able to
figure out where to hold them to make logistics easier for you. 2) If you are a teacher that would like to
be the host site (I do all the work, you just provide the meeting place and a functioning aquaculture
system), let me know and I'll see what I can do. If I am to give you full details in the next newsletter, you
need to respond right now.
Together, I think we can make a productive regional event that will get you the information you want
to move your aquaculture classes in the direction you think best for your students.
Best Fishes,
Bauer Duke
Extension Aquaculture Specialist
Desk: 870.575.8143
Cell: 870.718.7998
FAX: 870.543.8985