Airplane buzzing the bay - update

They sprayed thousands of gallons of oil on the swamps and jungle of Panama when they were building the canal to try and combat malaria.

In Florida I recall that Lee County did something similar, using a type of light non-toxic vegetable oil that when properly applied prevented the mosquito larvae from hatching before dissipating without any undesired effects, if I recall correctly. This was used on the barrier islands including Sanibel-Captiva that would've otherwise been practically uninhabitable by fair-skinned yankees and other snowbirds.