Tuesday, June 10, 2008

Mariculture Biofuels--Seaweed to the Rescue!

The oceans of Earth are considered the birthplace of life. Oceans receive most of the sunlight and absorb and convert most of the CO2 produced by nature--including humans. Now mariculturists are experimenting with seaweed a partial solution to the world's energy price crisis. Understand? Sunlight plus CO2, a priceless combination for plant life.
The oceans are the largest active carbon sink on the planet, covering more than 70 per cent of its surface area, and are predicted to grow as sea levels rise. Our seas also receive a larger proportion of the world's sunshine than land does, particularly in the tropical and subtropical belt where land is scarcer.

To agriculturalists, the oceans are vast and grossly underused fields well provided with sunlight and water.

...In Costa Rica and Japan, seaweed farming has been re-established to produce energy. It can quickly yield large amounts of carbon-neutral biomass, which can be burnt to generate electricity. High-value compounds — including some for other biofuels — can be extracted beforehand.

We have calculated that less than three per cent of the world's oceans — that's about 20 per cent of the land area currently used in agriculture — would be needed to fully substitute for fossil fuels. A small fraction of that sea area would be enough to fully substitute for biofuel production on land.
_CheckbiotechBioenergy
Three percent of the world's oceans to fully substitute for fossil fuels? What about using seasteads as centers of mariculture, in addition to all the other renewable energies they will utilise?

How difficult would it be to create an oasis of sea life on the normally life-depleted "desert" of the high seas? Most sea life lives along island and continental shores, and continental shelves and seamounts. What could a serious movement into seasteads do toward expanding life in the oceans?

3 comments:

  1. I have heard of something similar happening at (I believe) old oil rigs where the coral and seaweed attaches, small fish are attracted and eventually an ecosystem can emerge.

    I also think there was a Wired News article some time back that suggested floating fish farm cages with robotic food dispensers. The fish waste would not fowl coastlines as some open aquaculture systems can. If instead of floating across the ocean, they were established in connection with sea steading they could grow the seaweed and fish, combining resources like staff and energy in the same processing facility.

    Now, even less than 3% sounds like it might be a bit much if you want to avoid making ships dodge and weave around them. Maybe it all depends on how they are spread out. but even a smaller fraction means a lot of capacity if combined with land biomass.

    Maybe they could use the fish and seaweed to make dried fish food pellets which could be shipped at a higher density to inland fish farms that are closer to markets.

    Another product might be biochar. The seaweed could be pressed, dried and charred at low oxygen to yeild the biochar, enriched with fish processing byproducts for nitrogen and phosphorus and sold to inland agriculture. Since it would not spoil you could use slow but efficient boats to get it to port. Biochar reduces the need for fertilizer and keeps water far longer which could mean currently unproductive land could be used for agriculture and biomass production.

    Some of the more shallow regions might see these facilities mining organic muck from the sea-floor to provide fertilizer for the seaweed. maybe they would extend some of those long sewage outlet pipes out to the seasteads. Those pathogens that were not killed by the salt water or the sun light at the seaweed farms would simply be washed off by sea water before using the seaweed to feed the fish .

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  2. Interesting ideas, Baron.

    Where do you think seasteaders will come from? Who would go to sea permanently?

    Designers of these communities need to think about what women will tolerate. Long term colonies without women will not work. Historically, it has been men who spend years and lives afloat.

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  3. The importance of community would likely to be key to seasteading success. If smaller installations (more agricultural based habitats) were clustered around larger constructions which could sustain more industrial processing and packaging as well as shopping/entertainment options it might resemble settlement patterns where farms and ranches are served by a "main street" town center.

    Movement between the installations would need to be quick and easy, not like getting in and out of dingies and rowing. A developer might build the central installation and lease habitat/horticulture units at low prices in order to create a supply for the processing plants and build a market so that they could lease shop space at the central installation. A helicopter landing pad or two could connect tourists the community if distance to shore were reasonable and there were some significant attraction such as a tower large enough to support an observation deck restaurant. Dinning miles from land and meters above the waves while being able to see for vast distances and watching the lights of the nearby habitats wink on in the evening might be a draw.

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