Frederick Sparber wrote:
Pollution, Bloom, or not, Jed, all of the water from watershed runoff
contains algae.
Yes. Way too much. We should be trying to reduce that.
Figure out how much algae is available per unit volume after you've
allowed for feeding aquatic life and available natural plant
nutrients. Cost effective
harvesting using stream (gravity) flow since maximum production is near the
surface, doesn't seem intractable.
This sounds like a large scale project that may hurt the ecosystem,
especially if we curb the pollution that causes algae blooms, and
reduce the amounts to natural levels. The amount you should leave to
feed aquatic life is easily computed: it is exactly the amount that
nature has been providing for millions of years before we got into
the picture. Species are evolved to eat that much. As soon as we get
back of the picture and stop polluting the water, we should also stop
harvesting the stuff.
We should also stop harvesting wild fish, by the way. We should only
eat domesticated ones grown by us.
In other words, it is not a good idea to remove millions of tons of
food from the ecosystem food chain for any reason, whether the food
will be eaten by fish (algae) or by people in Mexico (corn). I think
it would be far better to tap solar energy with less invasive
devices, such as wind turbines and solar-thermal collectors.
Again, the reason boils down to the fact that natural photosynthesis
is inefficient; it takes a lot of sunlight to produce a little
chemical fuel. The latest solar cells are 400 times more efficient
per square meter than the best naturally occurring photosynthetic
conversion. Therefore, they will have a smaller impact on the ecosystem.
Unnatural photosynthesis in a heated pond charged with CO2 from a
fossil fuel plant is an entirely different story. It is far better to
start with, and you might improve it with domesticated species of
algae. I have read there are some that might be far more efficient.
U.C. Berkeley has engineered a stain that might be 100,000 times
better at producing hydrogen than natural algae. See:
http://www.wired.com/science/discoveries/news/2006/02/70273
Domesticated species are often more efficient, but as I said
previously there is an inevitable trade-off: they cannot survive in
the wild. They are weak. For example, in food crops, we redirect most
of their metabolism to producing grain, which weakens their natural
defenses and other adoptions. If you plant human bred corn (maize) in
the middle of a meadow in the woods, it attracts too many herbivores,
and the seeds fall so thickly around the plant the next generation
does not survive. Natural corn -- the type that was first
domesticated by native Americans -- had smaller cobs with fewer grains.
- Jed
