Xref: utzoo sci.bio:4031 sci.aquaria:972 sci.environment:8800
Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!think.com!linus!agate!shelby!rosentha@sierra.Stanford.EDU
From: rosentha@sierra.Stanford.EDU (Peter A. Rosenthal)
Newsgroups: sci.bio,sci.aquaria,sci.environment
Subject: coral reefs, C02, food, and farming.
Message-ID: <720@sierra.stanford.edu>
Date: 30 Nov 90 19:27:21 GMT
Lines: 63




rosentha@sierra.Stanford.EDU (Peter A. Rosenthal) writes:
>>
>>	It is well known that healthy coral reefs are quite
>>effective at fixing carbon dioxide into calcium carbonate skelatons.
>>They are also remarkably productive ecosystems that support enormous 
>>diversity in an astoundingly nutrient poor environment.  I would
>>like to start some discussion on the possible importance 
>>of coral in fixing C02 from the atmosphere.

Ben Chase says:

>As for Peter's question, IMO I don't think reef-building corals can be
>effectively used to abate atmospheric CO2.  I think their ability to
>fix CO2 will be limited by calcium and other nutrients.  Also,
>reef-building corals are restricted to warm waters.  

>the simplest solution to reducing atmospheric CO2 is of course to stop
>putting CO2 into the atmosphere.  One quarter of all the CO2 generated
>by humans is generated within the USA.  Note that this is far larger
>than the percentage of humans that live in the USA.

I would like to follow up on this.
	I agree with Ben that reducing sources of C02 into the atmosphere
is the most important and simplest way to reduce any greenhouse effect related
climate changes.  I think there are some other imaginative things to
consider too.  I don't think Calcium limits reef growth in nature, though
it may deplete quickly in a closed aquarim.

	Coral reefs get most of their calcium  directly from disolved
calcium bicarbonate in the sea water.  There is a virtually inexhuastible
supply of calcium in the ocean in this context.  The whole reason I
started this thread was that I was struck by how little actually goes
into a coral reef other than solar energy, and calcium carbonate.  Sure
there must be some nitrogen and minor elements for building biomass,
but mainly the coral reefs get everything they need from the seawater, the
sun and the atmosphere.  Aquarists bend over backwards trying to remove
nutrients from their aquaria to help their corals grow.  The wet dry
filters, ozonizers, protein skimmers that occupy so much attention among
mini-reef keepers attests to this point.

	Coral reefs, including all the concomittant lifeforms such as 
fish, molluscs, worms, sponges, etc. could probably grow in any clean,
well illuminated tropical sea if they had a suitable substrate at the
right depth and were seeded with a wide enough diversity of life.

	Open deep tropical ocean is a relatively unproductive place.
There are not enough nutrients to grow much algae or zooplankton, so the
main inhabitants are relatively large pelagic creatures that feed off of
each other and ultimately from more productive areas such as coral reefs
or nutrient rich upwellings such as are found in the northern seas.

	If one could float large substrates out in the open ocean several
meters below the surface, and properly seed them, I would bet that
reefs would grow very well on them provided they were located in a
stable, well lit, clean place.  Coral occupies only a small area on
the planet presently;  I wonder how many square miles?  How difficult
would it be to double the area artificially? 

	Coral reef farms of this sort would also be a great sustainable
food source for humanity as well as the rest of the world.


Brought to you by Super Global Mega Corp .com