RE: What happens to jet fuel when it is dumped in mid-air?

I hate to give you an answer like this, but ... MAYBE.

Certainly, jet fuel, which is primarily kerosene (hydrocarbons with 11-12 
carbons, just longer than gasoline), will have an effect on the wildlife.  
However, what that effect is depends upon how concentrated the fuel was.
As a jet throttles back for a landing, fuel is being dumped in small amounts.
Despite what the engineers may tell us, this becomes a significant amount 
when you have plane after plane coming in over the same area.  If you've ever 
parked for a trip under the landing approach to an airport, you know that 
kerosene accumulates under the approach area.

There is actually good news in this... because that small amount of kerosene
is continuously being dumped near the airport, the wildlife are most likely 
well-adapetd to deal with small levels.  However, if the dump was in an area
not adapted to this sort of contamination, the effects could be devastating.
Again, this depends upon the concentrations.  At high concentrations,
the oils that make animals waterproof are dissolved, and ducks, beavers, etc.
freeze to death in scores.  A new plant ecology takes over, killing the plants 
which are sensitive to petroleum products, and leaving the more hearty plants
to thrive, sometimes choking the entire ecosystem without their natural 
competition for nutrients.  If the concentrations are this high, it will 
probably be easier to clean things up.  The best way to do this is with
"bioremediation" (which has been used successfully for jet fuel spills 
in several cases already) if the spill is fairly spread out or with 
incineration if it is in one small area.  If the contamination is in 
wetlands of the river, it becomes a much more insideous problem, with no easy 
answer on how to clean it up.  

If the contamination is low level on a new wetlands area, scientists may 
claim that little ecological damage is expected.  Current research is 
showing that this is not necessarily true.  Many invertebrates actually 
use hydrocarbon compounds to cue spawning or settling.  No effect may be
noticed for the current populations, but steady dwindling of the 
population follows over the next few years with no acute reason to cite.
If the spill is small enough or the area is cleaned up in a reasonably
short period, the populations generally recover pretty well.

There is a lot of information about jet fuel spills available on the 
internet.  For environmental research topics in general, check out a search 
on "rachel" or "hazardous waste."  Also, there are experts in the field of 
bioremediation at University of Minnesota and at several universities in 
Michegan.

I hope I've given you some useful information.  Good luck.
jt