Kill the sea? really?
One would have to ignore the fact that there are many microorganisms that EAT oil living in the sea.
That is one of the methods used to clean the oil. Dispersant chemicals create small oil attractive particles and the microorganisms eat the result.
Funny...don't buy into the company line so much. Those very dispersant chemicals are recently being show to kill phytoplankton and zooplankton (meroplankton). It's also been show to inhibit
Psuedomonas life cycle, the primary group of microorganism you are referring to.
And, there are not "many" microorganisms that eat oil. There are a few, and those are incredibly specialized with the proper enzymes to break the carbon chains into usable sizes. Crude oil isn't, after all, an abundant food source normally. Though, one could make an argument that we are creating a selective pressure for the adaptation of just that ability, over the past 100 years or so.
The main impact will be to the marshes and estuarine fisheries of the gulf. Unless, that is, a large amount of oil hits the loop current and gets pushed into the Florida Keys. Given the stressors already present on the reefs there (water is already hot, and bleaching has started early- also a lot of disease vectors present currently on
Acroporid corals), a large influx of heavy oil into that system could very well collapse the coral communities past any foreseeable recovery.
And, given that some genus',
Acroporids in particular, are already at about 5% of historical abundance in many locations, it won't take much.
The IXTOC spill never had a chance to reach the reef system in any major concentration, due to the currents of the Gulf that took it the long way around, and actually concentrated it around Texas. This spill (Deepwater Horizon) has a pretty direct line to the Keys.
Old TOPEX showing gulf current structure
