Coral Harvesting--CO2 release comparison

Yoshi Mizuno y at
Thu Feb 4 18:48:47 EST 1999

Dear Coral-Listers,

At 08:36 99/01/19 +0100, Miriam Huitric wrote:

>Ultimately, private aquaria coral is a luxury item (after the 2,000 dollar
>estimate for the equipment needed - if you can afford that, you can afford
>to travel to the reef). In times of healthy reef abundance this market is
>  It has been argued on the list that to have corals in your home brings you
> nearer to the reef and its nature - in that case private owners should be
> more than sympathetic to a ruling in the favour of coral reefs. Those yet to
> live through the experience of privately owning coral could make do with
> visiting the aquaria or seeing an actual coral reef  in the mean time - or?

As a reef keeper and a scuba diver, I have been thinking about the above 
for a while.  Dr. Carlson and others have pointed out the eventual positive 
effect of coral farming/collecting to the health of the coral reef.  Assumin
g that 
the global warming has contributed to this bleaching event, I have come up 
with the following estimation.  I would love to hear any comments or critici
on the issue.

Comparison of Reef Keeping vs. Reef Visiting in terms of CO2 production
--Compare one trip to Maldives (family of three)  vs. reef tank run for a year
--Average power consumption of a reef tank: 500W
--Estimated fuel consumption per passenger on 747 traveling
  long distance: 20 km/liter  (From Japan Airline Webpage)
--Distance from Tokyo to Male, Maldives via Singapore: 8750km
--Specific gravity of Jet fuel : 0.8 
--Carbon content of Jet Fuel : 0.68kg/liter (My guess)
	Since Jet Fuel is hydrocarbon,  assuming it is normal alkane
	cabon/hydrogen ratio is Cn vs. Hn x2 + 2.  If n=7,  H:C(wt) =16:84
	So one liter of Jet fuel has  1liter x 0.8 kg/liter x 0.85 = 0.68 kg of car
--Ignore CO2 production for the aquarium equipment manufacturing; 
	Ignore CO2 production other than jet fuel for the trip.
Jet Fuel of a reef trip (a family of three).  
  8750km x 2  / 20km/liter = 880 liter.  (Round trip)
  880 liter x 3 = 2.6k liter ;-O
As Electricity in Tokyo is generate by 
  43% Nuclear 34% LNG, LPG 12% Oil 7% Hydroelectric. 4% Coal.
CO2 (grams of carbon)  producing potential per 1kWh generated
  Coal 270  Oil  200 LNG 178 Nuclear 6 Hydroelectric 5
270 x 0.04 + 200 x 0.12 + 178 x 0.34 + 6 x 0.43 + 5 x 0.07 = 98.25 g/kWh
However, Tokyo Denryoku (Electric Power) officially claims that they achieve
81g/kWh of Carbon. So let's use that number.
Reef tank power consumption in a year 
	500W x 24h x 356 days = 4380kWh

Reef Trip for Three:        2.6kl x 0.68kg/l carbon = 1770kg of carbon
Reef Tank in Tokyo:        4.4MWh x 81 kg/MWh = 356kg of carbon

The bottom line:  "Running reef tank one year" produces about five times less 
CO2 compared to a  "reef trip for three."

PS.  I think my reef tank is sucking CO2 out of atomosphere ;-) 
 -- I notice pH drop when I have a lots (over 20) people in my living room. 
. .

Yoshi Mizuno
y at

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