Parrotfish and coral

[novadiver]

Split from long hose thread as completely off topic - simbrooks

Not to take this off topic, but just to inform the world of the dreaded parrot fish. it seems this fish chews coral, yup that fish is responcible for damaging millions of trillions of pounds of coral. where do you think beach sand comes from?

so it would appear that coral can and does take mother natures wrath all the time and has made it up till now. my concern is divers damaging artificial reefs

 

[detroit diver]

Great idea. Let's all stand on the reef, bring some sledge hammers, and create some beach sand.

Brilliant.

 

[novadiver]

Great idea. Let's all stand on the reef, bring some sledge hammers, and create some beach sand.

Brilliant.

most home improvement stores sell it by the bag, and if your home has any mortar, concreate or any other portland product then you've got coral sand in it

 

[jonnythan]

most home improvement stores sell it by the bag, and if your home has any mortar, concreate or any other portland product then you've got coral sand in it

The stuff you get at building supply stores isn't beach sand, it's made from quarry rock. It's mostly inert chemically, unlike beach sand.. so it's safe to use in a freshwater aquarium, for instance.

You make a valid point about the fish, but the difference is that the fish 'destroy' coral on a natural and sustainable scale, unlike humans.

 

[simbrooks]

Not to take this off topic, but just to inform the world of the dreaded parrot fish. it seems this fish chews coral, yup that fish is responcible for damaging millions of trillions of pounds of coral. where do you think beach sand comes from?

so it would appear that coral can and does take mother natures wrath all the time and has made it up till now. my concern is divers damaging artificial reefs

Yes Nova you are right on there, judging by how much coral there is in the world and the fact it can only grow in certain climatic regions and depths of ocean i would certainly expect that all the sand of the world in fact comes from the crumbs of coral falling out of the mouths of parrotfish - its a conspiracy....

Ever heard of attrition? Where larger particles of material are ground into smaller particles by wave action and the like. Ever heard of sediment transport? Where particles are transported by water and drop out/sediment when the energy of that flow is too small to keep them suspended in the water. Of course depending on the chemical composition of the material will depend on how it reacts to these two functions. I think between these two functions you will find that is how most of the sand we have is created. The inland sand was formed in similar ways, just a long time before our current coastlines.... But maybe the aliens had a big problem with sand, it was toxic to them, so they dredged it up and dumped it on our planet?

Back on topic - I like how my long hose can hug my body and not get snagged on stuff like the traditional octo hanging low from some holder that most likely wont do it job and you generally end up either stuffing it in a pocket and having the hose hanging out in all sorts of directions or worse still dragging it along the bottom, hanging it up on coral and who knows what else.

 

[simbrooks]

Now as to the parrot fish... they taste jut like chicken.

A bit crunchy at the mouth end and kind of gritty nearer the other end, must be something they ate.

 

[Dan Gibson]

When I was in Roatan last December, they claimed the Parrot fish pooped 3 tons each year. I can't verify that number (doesn't seem unreasonable if you do the math), but with all the Parrot fish out there, it no longer seems like a sustainable scale.

You make a valid point about the fish, but the difference is that the fish 'destroy' coral on a natural and sustainable scale, unlike humans.

 

[divad]

Eat the Parrot Fish.

 

[simbrooks]

When I was in Roatan last December, they claimed the Parrot fish pooped 3 tons each year. I can't verify that number (doesn't seem unreasonable if you do the math), but with all the Parrot fish out there, it no longer seems like a sustainable scale.

To put some kind of science to this - but with some assumptions (specific gravity (G)~1, moisture content (w) ~30%, saturation (S) =100%) - hopefully not too far off with these:
Vs (solid volume) = Wt/(G*Unit Wt water) = 6000#/(1x64pcf) = 93.75 CF
Vt (total volume) = Vs*(1+w*G/S) = 93.75*(1+0.3*1/1) ~ 122 CF
122CF/365 days = 1/3 CF/day

Now lets consider the fish itself - that is might be only about 24" long (i read adult size ranges between 18" and 4-ft long - that is one huge parrotfish) as an example, maybe being 12" in height (seemed to be ~ 1/2 length) and about 4" wide (guesstimate from proportions i have observed UW) = 2/3 CF total volume (assume its a box of that size), it has to devour, digest and expel almost half its body volume every day!

 

[knotical]

Only some parrotfish munching is done on living coral. A lot of their feeding is scraping algae off dead coral and rock.