I'm sorry, but this is simply not true. The solubility of methane in both fresh and salt waters is far from negligible.
"At atmospheric pressures, the methane solubility in water ranges from 26 to 32 mg/L."
The above is for fresh water. The higher salinity of seawater probably dictates a somewhat lower value at atmosphteric pressure, but that is offset by the higher pressures sub-sea, which should mean the solubility is significantly higher, but the above number is sufficient to make my point. I haven't located a value for seawater yet.
When my wife wakes up, I'll ask her. She is a retired petroleum engineer, and methane solubility is brines is a BIG part of reservoir characterization.
I mean to get back to you earlier, as this is an enjoyable discussion.
I my solubility table, the solubility of methane in round numbers, in generic sea water at 10 degrees C, and 1 atmosphere of pressure is 3 MILLIONTHS of a mole per liter. That happens to be two orders of magnitude LESS than oxygen under the same conditions, and as far as common atmospheric gases go, only helium is a ‘worse’ solute than methane. If our tables differ, then we can blame the publishers. Arguably, subjectively, methane is a lousy solute in water IN COMPARISON to other common gases.
Now in fact you may end up coming out ahead on this point (solubility), or you may not — it;s just irrelevant to the real issue of environmental damage. But to YOUR point, indeed methane IS measurably soluble in sea water. Where we both lose is when we use words like “completely” or “essentially.”
Just (both of us) to try to stay on point here, the real ‘argument’ I was on is to dispute the suggestion that methane escaping into the Gulf of Mexico is a problem. Logically and scientifically I cannot support the idea / hypothesis that a methane release, even one of this magnitude, is or was a threat to the marine ecosystem.
Why?
Gas concentrations in any solvent exposed to air (1 atmosphere) will ALWAYS reach a steady state on their own, based on the nature of the solvent/solute and temperature. Vapor pressure and solubility ‘laws’ did not disappear in the Gulf. What’s my point? Absent ANY action by man or bacteria, methane gas concentrations (dissolved methane), over time, would return to a ‘normal’ steady state.
Secondly methane is NON TOXIC. So what’s the risk to the environment?
AFAIK “we” are aware of methane-oxidizing Bacteria as well as methanogenic and anaerobic methane-oxidizing Archaea that live around the “vents” on the ocean floor. These organisms do indeed utilize methane as food, and ‘oxidize’ them with either sulfur or oxygen to make energy. But I am unaware of any reported blooms of these Classes of bacteria in the Gulf. My point? A reporter can write about blooms of bacteria metabolizing dissolved methane that reduce dissolved O2 levels, but I have yet to read a fact-based report of ANYTHING like that. MANY areas of the Guld have dead/hypoxic regions — the result of fertilizer (nitrogen- phosphorous- and organic iron-based chemicals) run off. but I digress.
The root cause of my very first ranting post on this thread was that I perceive it to be complete and utter poppy cock that a methane release is a biological/ ecological disaster. I am unaware of ANY science supporting the hypothesis that methane, dissolved or gaseous, is harmful to the marine environment.
We can have a sidebar argument over the correct adjective to apply to methane solubility, but the real issue (to me) is that NO ONE should cry havoc over a marine methane release.
Your turn ;-)
Note that the concentration for dissolved oxygen necessary for fish is only 5-10 mg/L. So a methane concentration of 26 to 32 mg/L is quite high enough to be “significantly biologically effective”.