[Coral-List] RE: NH4 Levels In Aquaria

Charles Delbeek delbeek at waquarium.org
Mon Jan 2 17:32:17 EST 2006

We conducted a study of growth rates in three species of Acropora in our 
open systems that receive water from a saltwater well system. This system 
is described in Atkinson et al. 1995 (Coral Reefs 14:215-223). Our well has 
elevated inorganic nitrogen and phosphate levels but corals still grow 
fine. Unfortunately, we never worked up the data beyond a few graphs, and 
never completed the paper. Maybe its time to take a look at those numbers 
again and compare it to in situ growth rates! We measured buoyant weight 
and counted the number of branches over a 10 month period. Bruce Carlson 
published some work on comparing the density of Calaustrea furcata grown in 
our systems to C. furcata from the same colony in the wild and found they 
were about 50% lower.

I know that ammonium nitrate has been used to enhance the growth of 
tridacnid clams e.g. Hastie et al. 1992 (Aquaculture 106) and Fitt et al. 
1993 Aquaculture 104) so why not corals too? However, it was found that 
while the clams grew faster, often the shells were thinner and more brittle 
compared to clams from unenriched water. This was most likely a case of the 
shell growth not being able to keep up with tissue growth and the same may 
apply to corals??


J. Charles Delbeek

At 08:05 AM 1/2/2006, you wrote:
>With reference to NH4 Levels in Aquaria (Steve Lowes)
>Dear Coral List:
>Julian makes a good point to the "potential" benefit of dosing ammonia to
>stimulate strong coral growth. I can add that I am currently experimenting
>with this in the aquaculture of Pacific scleractinian species. Following a
>guideline offered by Jorg Kokott (Coral, Vol 2 No 1, p68 2005) I am dosing a
>250 mM stock solution of ammonium chloride to a fully matured, closed, coral
>propagation system. I am only doing so to the extent that I raise the
>nitrate levels in the system from undetectable (< 0.25 ppm) to approximately
>1 ppm. Ammonia and nitrite levels remain undetectable using colorimetric
>aquarist test kits. I am also employing several mechanisms of nitrification
>including sand beds so without daily dosing the nitrate level is quickly
>reduced to undetectable. Together with herbivores I am able to control
>nuisance algae growth.
>I do not pretend that the above is a rigorous scientific approach but I am
>looking to try and quantify the coral growth rates across species. Since we
>are dealing with a multi-variable dynamic system it is always going to be
>difficult to get a categorical handle on quantifying the effects of a dosing
>protocol of this type. Assuming that increased growth rates could be
>demonstrated, it would be interesting to determine if this is from the
>corals use of ammonia or the oxidized products (nitrite and or nitrate).
>Only other info that I can offer to this interesting thread is reference to
>the paper - Titlyanov et. al. Effects of dissolved ammonium addition and
>host feeding with Artemia salina on photoacclimation of the hermatypic coral
>Stylophora pistillata Mar. Biol. 137: 463-472 (2000).
>Coral-List mailing list
>Coral-List at coral.aoml.noaa.gov

J. Charles Delbeek M.Sc.
Aquarium Biologist III
Waikiki Aquarium
2777 Kalakaua Ave.
Honolulu, HI, USA 96815

808-923-1771 FAX

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