How Are Crushed Corals Harvested? Is It Sustainable?

[Natereef]

This just popped in my mind a few minutes ago. As reefers we are generally responsible when it comes to sustainability of our hobby. One example is the explosion in popularity of aqua cultured corals and captive bred fish. But one thing thats been bothering me is how are crushed corals really harvested? Is it sustainable? We use crushed corals for all kinds of applications. Should we be shying away from using this media? Anyone have any insight on this topic?😓

[seabass]

I haven't really thought about it.  However, they definitely aren't crushing live corals to make it.  I believe it's just very course sand taken from the ocean floor.  Although, I suspect it can also be mined from deposits on land.

 

I suppose that it could be actually crushed (rock and/or shells) as part of its processing.  However, I would think that a lot of it is just sand/gravel (that was crushed by the ocean currents, or passed through the digestive tracts of coral eating fish), which is then graded into particular sizes.  I wouldn't suspect a problem with sustainability.

[Ratvan]

I've assumed that it was gathered as dry rock and then processed 

[seabass]

3 hours ago, Ratvan said:

I've assumed that it was gathered as dry rock and then processed 

Yeah, if you were mining dry rock, there would be lots of little bits which could be graded and/or further processed into crushed coral.

 

However, a number of them come from the ocean, like:

• Nature's Ocean Pacific Coral Gravel
• Nature's Ocean No.8 Premium Atlantic Crushed Coral

 

[Natereef]

Or better yet how are coral skeletons used in calcium reactors harvested? 😓 ive looked around and havent really seen how companies process these things. 

[seabass]

I assume it's pretty much the same thing, only it's more coarse (and likely, more uniform in size) than typical crushed coral.  CaribSea talks about grading them (with screens).  They process so much substrate that they can market just about every bit of what is collected (for some purpose or another).  I don't believe anybody is destroying a reef (live or dead) just to collect substrate or reactor media.

[A.m.P]

I imagine most is harvested from old seabed-limestone deposits in Florida or similar areas and then crushed to whatever size they're looking to package, some of the old live-rock producers from the Gulf coast actually re-seeded such rock by tossing it back into the ocean lol...

[mndfreeze]

Its all mined on dry land.  Not much of anything rock wise comes from the ocean anymore with few exceptions like tampa bay saltwater and gulf live rock.  Too much damage to the environment, expensive to do, etc.  

[mcarroll]

From Nature's Ocean's website:

Quote

6-Question. Where does Live Sand come from?

Answer: Live sand comes from the bottom of the ocean floor. It varies in its composition depending on where it was collected, but it usually consists of coral sand that is pulverized and eroded pieces of coral. Some of the sand around coral reefs is the result of the feeding activity of parrot fish. These fish scrape the coral surfaces with their hard beaks to get at algae and then crush the calcareous material into fine particles. The parrot fish excrete this indigestible debris in big clouds and the resulting material ends up on the sea floor. Live Sand is harvested responsibly and is not dangerous to the long term health of any reef worldwide.

 

CaribSea doesn't seem to post anything about the origin on their site.....but I've heard it's all mined from the surface, and there seems to be some circumstantial evidence to support that.  For example, if you drag a powerful magnet though a bag of their sand, it's highly likely that you'll pull out bits of teeth from their grinding apparatus.  (I highly recommend doing this so the particles don't wind up stuck to the wrong side of your cleaning magnet after the tank is set up.  Sc-r-a-a-a-t-ch!!)