Live Rock vs. Seeded Dead Rock

[smithcreek]

No it isn't. An increase in the number of a species you already have isn't an increase in diversity, it is simply a population increase for that particular organism. In other words, "more of the same."

So you want to get into a game of symantics? You think you know the definition of biodiversity or just diversity in general?

 

Here, the fastest I could find, from Wikipedia:

 

Biodiversity describes the structure of ecological communities. This not only involves the number of species, but also the number of individuals of each species.

 

Sorry, but that wasn't the point I was making anyway so why don't you address what I said rather than just trying unsuccesfully to find a problem with the specific wording. If you're having trouble understanding the basic premise then read it again.

 

Having a number of organisms that have been outcompeted to the point that their populations are for all intents and puroposes non-existent, is hardly diversity. Technically they are present, but their numbers are so small they aren't contributing to the environment at all. The dry rock may give many small populations an opportunity to thrive, at least for a while.

[MrAnderson]

Another possibility is that dry rock is like a barren field waiting to be populated. Many organisms that have been outcompeted in large numbers still exist on/in live rock that you seed with, but in small numbers. The dry rock gives these "pioneer" species which may be very benficial a place to thrive for a long time until they are eventually outcompeted.

 

This is the basis for seeding dead rock to begin with, and why people do it in the first place... Nobody's disagreeing with you about that so I'm not sure why you're stating the obvious..

 

So you want to get into a game of symantics? You think you know the definition of biodiversity or just diversity in general?

 

I think you're misinterpreting the meaning as well. The term "biodiversity" in reference to a population of a single species refers to genetic polymorphisms. A dog show, for example, is considered extremely "biodiverse" because of the array polymorphs of the species Canis lupus familiaris, even though entirely comprised of a single species.

 

It's an irrelevant distinction in this conversation in my opinion, because ecologically-equilibrated wild microorganisms are typically clonal, meaning genetically identical.

 

And don't get snippy in my thread. It's been very civil so far and I'd like to keep it that way.

[kismetsh]

So you want to get into a game of symantics? You think you know the definition of biodiversity or just diversity in general?

 

Here, the fastest I could find, from Wikipedia:

Sorry, but that wasn't the point I was making anyway so why don't you address what I said rather than just trying unsuccesfully to find a problem with the specific wording. If you're having trouble understanding the basic premise then read it again.

 

Having a number of organisms that have been outcompeted to the point that their populations are for all intents and puroposes non-existent, is hardly diversity. Technically they are present, but their numbers are so small they aren't contributing to the environment at all. The dry rock may give many small populations an opportunity to thrive, at least for a while.

 

I honestly wasn't trying to be rude, though it appears you took it that way.

 

I wouldn't rely on wiki for definitions of scientific terms. In this case, and in most discussions of a technical or even semi-technical nature semantics are important. AFAIK when one speaks of intraspecific diversity, the term customarily refers to genetic (allelic) diversity. Now it has been a number of years since my last ecology/population biology course and I'm too lazy to dig out my old texts.

 

At any rate...do I think adding dry rock to a tank will cause a shift (temporary or otherwise) in the population dynamics? Quite possibly! I just don't know whether this population shift would be as good/better than a greater "starting diversity."

 

Bottom line, there are obviously a number of different ways to have a successful reef tank, and the fact that some of them started with dead rock seeded with live rock speaks for itself.

 

Again, I apologize if my other post came off rude...I am told I can be quite abrupt at times.

 

KC

[smithcreek]

This is the basis for seeding dead rock to begin with, and why people do it in the first place... Nobody's disagreeing with you about that so I'm not sure why you're stating the obvious..

Ok, snippyness off, apologies accepted and extended. My original intent was not to argue but to look at a different possible outcome of seeding dry rock, where diversity is actually increased.

 

I've not seen anywhere in the discussion that the basis for seeding dry rock would be to do anything but transfer the existing organisms from the live rock to the dry rock. And your postulate was this would result in less diversity. I am merely stating that it's "possible" that the diversity would increase as smaller dormant populations increased as the dry rock was colonized compared to larger dominant species found on the seeded live rock.

 

I'm not sure I understand your dog analogy. I haven't been speaking about within a species, but across. Here's what I would consider an example of what I'm talking about:

-The live rock you buy has very little hair algae on it since it has been largely kept in check in the wild

-Hair algae goes wild on your new dry rock since there is nothing that can compete with it

-Amphipods find shelter in hair algea and population increases dramatically

 

Pretty simple and sometimes unavoidable occurence. I would think this same scenario would happen for a multitude of organisms from bacteria to corals. If the rock was all live a lot of this could not take place. The dominant species would be too established.

[MrAnderson]

Ok, snippyness off, apologies accepted and extended. My original intent was not to argue but to look at a different possible outcome of seeding dry rock, where diversity is actually increased.

 

Your usage of relative terms is different than mine. When I say "biodiversity decreases" I mean relative to the origin, a specimen from a natural, wild reef. You're saying a seeded rock has "increased diversity" in terms of it's own origin, lifelessness. Or are you saying that seeded dead rock has "increased diversity" above that of a natural reef??

 

I've not seen anywhere in the discussion that the basis for seeding dry rock would be to do anything but transfer the existing organisms from the live rock to the dry rock.

 

I honestly tried envisoning how "far back" to go regarding background for what I wrote. I thought the point of seeding dead rock was a given and something that didn't need to be stated.

 

And your postulate was this would result in less diversity. I am merely stating that it's "possible" that the diversity would increase as smaller dormant populations increased as the dry rock was colonized compared to larger dominant species found on the seeded live rock.

 

More than 100 years ago, Louis Pasteur's claim to fame was the "swan-necked flask experiment", where he demonstrated that new life cannot spontaneously arise from lifelessness. In the context of this conversation where I am referring to "biodiversity" as inter-specific differences, biodiversity cannot increase spontaneously in a closed system.

 

You say you don't mean intra-specific diversity (what I call population growth), but in this statement and your examples, that's exactly what you are asserting!!

[kismetsh]

In the context of this conversation where I am referring to "biodiversity" as inter-specific differences, biodiversity cannot increase spontaneously in a closed system.

 

That was my point, but you said it more succinctly.

 

KC

[smithcreek]

Or are you saying that seeded dead rock has "increased diversity" above that of a natural reef??

Compare it to people. If the US was all white/european except one african american, one asian, one native american and one hispanic would that be as diverse as 70% white/european, 15% african american etc.?

 

Since I'm not a biologist I won't use scientific terms, or I'll be sure to get thing wrong, so I'll oversimplify the true situation to see if I can clearly state what I'm trying to get across.

 

Lets say that the live rock you buy has 10 species of organisms living on it. 95% of the organisms are from the first species, 4% are from from the second, .5% are from the third and so on. By the time you reach the last species the numbers are very small. They have been outcompeted by the others and they are there, but not contributing to the ecological system in any meaningful manner. There may be 10 species but it's not very diverse.

 

You introduce that piece of live rock to the dry rock in your system. It's possible that species #8, #9 or #10, whose numbers are very small has some biological advantage. Like weeds after a forest fire, they are able to propagate very fast on the new dry rock. So after a month in your tank the percentages of each organism has changed. Now species one accounts for - 50%, species two - 25%, species 3 - 12.5%. With a definition of diversity that includes not just number of species, but their distribution within the population, this would be an increase.

 

If there's another term for this type of diversity then I don't know it which may well be the case, but I haven't seen any that preclude some sort of distribution as a component.

[MrAnderson]

Lets say that the live rock you buy has 10 species of organisms living on it. 95% of the organisms are from the first species, 4% are from from the second, .5% are from the third and so on. By the time you reach the last species the numbers are very small. They have been outcompeted by the others and they are there, but not contributing to the ecological system in any meaningful manner. There may be 10 species but it's not very diverse.

 

You introduce that piece of live rock to the dry rock in your system. It's possible that species #8, #9 or #10, whose numbers are very small has some biological advantage. Like weeds after a forest fire, they are able to propagate very fast on the new dry rock. So after a month in your tank the percentages of each organism has changed. Now species one accounts for - 50%, species two - 25%, species 3 - 12.5%. With a definition of diversity that includes not just number of species, but their distribution within the population, this would be an increase.

 

In this context, I wouldn't call it an increase because the numeric value of the finite array of distinct species has not changed; I would call it a change in ratio.

 

But to each his/her own. If you're going to converse using an entirely different set of definitions for terms whose contextual meanings are already established and evident through previous use in this conversation then I'll let someone else pick up from here... You have reduced this to a frustrating semantic quibble by introducing and insisting upon using a peculiar and irrelevant form of the term "biodiversity".

 

Also, I already made your above point about changes in relative populations in my first post ("some may go extinct, some may grow, and others wait for better conditions" - and any permutation implied), but thought it was long enough where I couldn't illustrate, clarify and qualify everything.

[smithcreek]

You have reduced this to a frustrating semantic quibble by introducing and insisting upon using a peculiar and irrelevant form of the term "biodiversity".

Feel free to question my assumptions, this has really been an more of a theoretical exercise rather than a conclusive dissertation.

I set out a pretty simple hypothesis, that even I don't think is right or wrong. If you don't want to discuss the possibilty that there may be a different definition of diversity, one that takes into accout more than a simple number of species present regardless of ratio, or that there may be some variables you haven't taken into consideration in your conclusion that "live rock invariably" has more diversity then don't invite discussion.

 

Personally most of my live rock came from a large reef tank that has had additions and subractions of live rock over the course of several years.

[MrAnderson]

I set out a pretty simple hypothesis, that even I don't think is right or wrong. If you don't want to discuss the possibilty that there may be a different definition of diversity, one that takes into accout more than a simple number of species present regardless of ratio, or that there may be some variables you haven't taken into consideration in your conclusion that "live rock invariably" has more diversity then don't invite discussion.

 

What you're calling a "different definition of diversity" has it's own term, "population kinetics", because that and "diversity" (in this context) are two distinct ideas. As a matter of fact, your wiki quote gives two definitions - I intentionally separate those two concepts in my post!

 

The topic at hand goes way past the point where the two phenomena can be combined into one term, although in other contexts they may safely be (as your wiki quote indicates). As a matter of fact, a main point of my post was to discuss the difference between the two concepts and the impact of each, separately, upon our little ecosystems. You've indicated that you realize this, yet insist on using a single semantic oversimplification of these terms and improper contexts thus giving them your own customized meanings. By insisting on calling two distinct concepts by the same name (and erroneously, in my opinion) I feel like you are deliberately confounding the discussion.

 

It's as if we are having a discussion about rectangles AND squares and their different contributions to the world of visual shapes, and you're belaboring the point that squares are actually a form of rectangle.

 

Furthermore, I haven't seen any "variables" mentioned by you that haven't already been discussed.

[smithcreek]

If you want to use two different definitions for the two concepts then that's fine by me, but you're basing your conclusion that "diversity", which you define as the number of different species, makes using all live rock better when it would be better to use both "diversity" and population kinetics".

 

I see that you did mention earlier something about some organisms waiting for a better environment, but I didn't see anything discussing how dry rock might provide that environment better than live rock for some organisms.

 

I'd be more than happy to discuss this further, but it all just really a mental exercise as you pointed out so there isn't really a right or wrong, and for some reason you seem to have a strong urge to belittle the point I made when it clearly was not made earlier.

[MrAnderson]

ok great, thanx for stopping by!

[MJD]

I think smithcreek raises some valuable points. With his "version" of diversity what he said could in fact occur.

 

MJD

[MrAnderson]

What he says does indeed occur. As a matter of fact, what he describes almost invariably occurs everytime a dead rock is seeded.

 

He just insists on calling it the same name as something completely different, for some unfathomable reason.

[MJD]

I dont see anything wrong with that.

 

BTW good thread.

 

MJD

[MrAnderson]

I find it really confusing and it just doesn't make sense to me. I think anyone with a biology background would feel the same way.

 

lol yer all a bunch of trolls!

[kismetsh]

Sorry folks, proper terminology *is* important.

 

If I invite you over for "pumpkin pie" and I put a cooked rat on your plate you would probably agree that words matter.

 

KC

[reefman225gal]

im not touching this topic with a ten foot pole...lol anderson you sure are a great debater i guess it's easy when your in your element it started off as a good topic but i think your point was was lost along the way but over all i get the jist of what your saying