Importance of trace elements

[East1]

OK, we have different opinions on the utility of strontium. My opinion is not based on lack of depletion in some systems, but simple nonutility.

IMO, and in the scientific literature, it looks and acts like calcium, and gets incorporated into calcium carbonate skeletons for that reason alone (and gets into abiotic precipitated calcium carbonate to the same extent), without causing any benefit or "need" by most organisms.

IMO, the only need by organisms are a very few unusual creatures (not corals) that are known to have a specific need for it. These include gastropods, radiolaria, and acantharia.

FWIW, the scientific literature has never identified strontium as something corals need.

This has more:

Aquarium Chemistry: Strontium and the Reef Aquarium

This article on strontium is the second of several that delve into a variety of issues involving magnesium and strontium.

reefs.com

Agreed, I was about to link you to this

https://link.springer.com/article/10.1007/s00338-004-0369-y which I found here:

and then I realised you're actually referenced in the quote, lol.


I think that if strojntium depletion in my aquarium, anecdotally, and at least one others: https://www.reef2reef.com/threads/strontium-and-the-reef-tank.172464/ indicates it must have some biological purpose, even if it's not a critical function. the fact that coral colouration and the robustness of the tissue is visibly altered in 24 hours with no changes to the tank otherwise sould be validity enough to confirm it has utility within the coral tissue?

I'm genuinely curious because it seems my conclusions may be biased and I'm interested in removing those by getting to the bottom of this - given the parameters of the aquarium I currently run I believe the only way to avoid a tank crash is to identify and supplement missing elements however I've been dosing and identifying changes by watching the coral, and then undertaking testing to verify my dosages, rather than the inverse of chasing levels.

I'm disappointed I didn't take photos of the acropora looking 'dry' only to compare to less than 20 minutes later when their entire tissue mass appeared to increase, to explain what I mean

 

[Randy Holmes-Farley]

I think that if strojntium depletion in my aquarium, anecdotally, and at least one others: https://www.reef2reef.com/threads/strontium-and-the-reef-tank.172464/ indicates it must have some biological purpose, even if it's not a critical function.

There are lots of reports by aquarists that see a benefit to strontium, and a lot that do not.

But the depletion itself says nothing about utility, since simple abiotic precipitation of calcium carbonate will deplete strontium. The fact that it slips into calcium carbonate, in coral skeletons or simple precipitates, in place of calcium means it gets used, but not that it has any benefit when doing so.

 

[East1]

There are lots of reports by aquarists that see a benefit to strontium, and a lot that do not.

But the depletion itself says nothing about utility, since simple abiotic precipitation of calcium carbonate will deplete strontium. The fact that it slips into calcium carbonate, in coral skeletons or simple precipitates, in place of calcium means it gets used, but not that it has any benefit when doing so.

Understood,

I think it was Fauna Marin that talks of this precpitation abiotically, not necessarily of Strontium but rather some trace elements generally that precipitate into calcium carbonate. That principle seems to imply that coral skeletons have an abiotic reservoir of these elements that is a function of ambient water column levels and from this precipitate, the corals themselves are able to make use of the elements - which is why I theorised that there is a breakdown in depletion in the water column and a lag from the decline in coral vitality

 

[Randy Holmes-Farley]

Understood,

I think it was Fauna Marin that talks of this precpitation abiotically, not necessarily of Strontium but rather some trace elements generally that precipitate into calcium carbonate. That principle seems to imply that coral skeletons have an abiotic reservoir of these elements that is a function of ambient water column levels and from this precipitate, the corals themselves are able to make use of the elements - which is why I theorised that there is a breakdown in depletion in the water column and a lag from the decline in coral vitality

The first part of that is certainly true. Lots of elements are trapped in coral skeletons, including uranium and plutonium, and the amount is directly releted to the amount in the water.

The second part seems highly far fetched to me. Such ions will not be released unless the organism dissolves the surrounding matrix of calcium carbonate.

That is quite different than ions simply and reversibly adsorbing into a very thin surface layer on calcium carbonate, such as phosphate and magnesium are known to do. Those come on and off in proportion to the amount in the water. But as soon as they are buried under more calcium carbonate deposition, they are lost from the biological system.

 

[Ardeus]

I think it's important to acknowledge the limited studies on what roles each element in NSW play in the metabolism of the different animals we keep in our tanks.

Based on this limitation, a safe route to reef keeping is to try our best to mimc NSW levels of as many elements as we can.

Once again searching for safer routes, the elements we should pay more attention are those present at higher concentration and easier to test.

Strontium falls right into this category.