New research on copper toxicity to coral

Differential effects of copper on three species of scleractinian corals and their algal symbionts (Symbiodinium spp.)
http://www.sciencedirect.com/scienc...serid=10&md5=99388eddcb039e088c51a085d5217955

From it:

c Department of Biosciences, Faculty of Science, University of Mauritius, Reduit, Mauritius

Received 19 August 2009; revised 17 December 2009; accepted 22 December 2009. Available online 4 January 2010.

Abstract
Land-based sources of pollution have been identified as significant stressors linked to the widespread declines of coral cover in coastal reef ecosystems over the last 30 years. Metal contaminants, although noted as a concern, have not been closely monitored in these sensitive ecosystems, nor have their potential impacts on coral-algal symbioses been characterized. In this study, three species of laboratory-reared scleractinian corals, Acropora cervicornis, Pocillopora damicornis, and Montastraea faveolata each containing different algal symbionts (Symbiodinium A3, C1 and D1a, respectively) were exposed to copper (ranging from 2 to 20 μg/L) for 5 weeks. At the end of the exposure period, copper had accumulated in the endosymbiotic dinoflagellate ("œzooxanthellae") and animal tissue of A. cervicornis and the animal tissue of M. faveolata; however, no copper accumulation was detected in the zooxanthellae or animal tissue of P. damicornis. The three coral species exhibited significantly different sensitivities to copper, with effects occurring in A. cervicornis and P. damicornis at copper concentrations as low as 4 μg/L. Copper exposure affected zooxanthellae photosynthesis in A. cervicornis and P. damicornis, and carbonic anhydrase was significantly decreased in A. cervicornis and M. faveolata. Likewise, significant decreases in skeletal growth were observed in A. cervicornis and P. damicornis after copper exposure. Based on preliminary results, no changes in Symbiodinium communities were apparent in response to increasing copper concentration. These results indicate that the relationships between physiological/toxicological endpoints and copper accumulation between coral species differ, suggesting different mechanisms of toxicity and/or susceptibility. This may be driven, in part, by differences in the algal symbiont communities of the coral species in question.
 
Randy, if I remember correctly, these copper levels (ranging from 2 to 20 μg/L) are below what you found in your tank and are below what one salt mix published their copper levels at?
 
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so what your saying is copper in a reef tank is bad...didnt we already know this....it is very nice to see them taking a deeper look into the health effects of metals on the reefs at large..mind you your second post is very alarming...that is something i wasnt aware of at all...no idea our salt mixes contained trace amounts of copper..
 
I have found few research papers regarding copper toxicity to coral. There is some research regarding copper toxicity to algae. Very few coral species have been studied as have algae species. This paper adds insight for three more species of coral and has identified the symbiotic algae strains. Other research I have found dates back to the 90s.

Scientists have no real understanding as to how copper toxicity occurs inside of the algae of coral (the mechanisms envolved).

If I remember correctly Randy tested his tank years ago and found copper levels around 30 - 40 μg/L, although my memory has failed me before. :lol:

These are the only other research papers I have been able to find regarding copper toxicity in coral or marine algae:

(Effects of copper on coral/algae)
Zooxanthellae loss as a bioassay for assessing
stress in corals
http://www.int-res.com/articles/meps/149/m149p163.pdf

Uptake and internalisation of copper by three marine microalgae: Comparison of copper-sensitive and copper-tolerant species
http://www.sciencedirect.com/scienc...serid=10&md5=81effe596506618bb00873cea5410320
 
Feature Article: Inland Reef Aquaria Salt Study, Part I (this is an old article)
http://www.advancedaquarist.com/2005/11/aafeature1

From it:

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It would be interesting to know (not gonna buy the article) if those copper doses were in addition to whatever levels were in their synthetic lab water already, or if they have some mix with no measurable copper in it to start with.
 
Thanks for the info Cliff! Do you or Randy know of any salt that does not contain copper? Also, I read a RC post that said RC/IO contains organic compound(s). Is this so and if yes, what is it?
 
Thanks for the info Cliff! Do you or Randy know of any salt that does not contain copper? Also, I read a RC post that said RC/IO contains organic compound(s). Is this so and if yes, what is it?

Terri,

As far as I know all salt mixes contain copper & other heavy metals. Copper is needed at very low levels for tank inhabitants.

I know that RC adds vitamins, but the levels and type are unknown by me. Instant Ocean does not add vitamins as far as I am aware.
 
Other than the copper levels Randy found in his reef tank, AWT reports levels similar to this posted results:

"(GOOD) Your copper level is within the recommended range. We recommend continuing with your current water change schedule, being careful to use only RO/DI water for makeup/top-off water. Use of activated carbon can also help keep this level in check. Copper is fatal to marine invertebrates at levels as low as 0.05 mg/L for many species.
Alkalinity (meq/L)
Natural Seawater Value: 2.5 meq/L
Acceptable Range: 2.5 to 5.0 meq/L"

This is where I get confused as the copper levels are being reported in meq/L, ppb & mg/L.
 
Ok, I little work on my part and hopefully it sinks into my brain this time:

mg/L = ppm

μg/L = ppb

I have not been able to find the conversion factor for converting meq/L copper to say ppb. :D
 
AWT is the only source I have seen publish copper recommendations in meq/L. They use mg/L for results, then swith to meq/L for recommendations. :lol:

From the above post:

Natural Seawater Value: 2.5 meq/L
Acceptable Range: 2.5 to 5.0 meq/L"
 
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How do you test for copper? Are there copper test kits? I've seen "Water hardness" test kits. Can't say I've seen copper off hand.
 
How do you test for copper? Are there copper test kits? I've seen "Water hardness" test kits. Can't say I've seen copper off hand.


There are no ordinary home copper tests that read low enough for operating reef tanks. I used an $80,000 machine. :)
 
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