The first environments that come to mind are the marine environments, since many oil spills happen at sea. The sparsity of life in the cold, open and salty ocean causes the mistaken idea that the oil mass, or its components will not reach land.
The volatile compounds in oil that dissipate early on contain many toxins that will not affect life when the oil reaches the shallower and more populated parts of the marine biome. But oil retains many qualities and many substances that can move, poison and smother.
Not only does the oil present grave threat to biomes and life, the toxins that are introduced by humans in order to dissipate or break up the oil will add to the devastation.
When oil spills are broken down by chemical means, the chemical introduces two problems: the chemicals themselves as poisonous or toxic substances, and the dissipated oil, which can now travel farther and in different forms to poison, suffocate or chemically alter air, water and soil.
As the tides bring the oil/chemical masses closer to land, temperatures get warmer. The denser components of the oil mass still manage to form into tar balls and sink to the ocean benthic zone creating hazards to the masses of larvae, eggs, microscopic life, emerging and established plant, bacterial and even more advanced life forms. The effects of the warmer temperatures on the chemicals is an unknown hazard, but the chemicals, themselves will arrive with the oil.
Chemical dissipation breaks up the buoyancy of the oil mass and separates the heavier from the lighter components of the oil. The heavier components have to go somewhere, accelerating the tar ball process if the oil is not effectively removed. And massive quantities of oil and tar balls are never recovered during major spills.
As the food chain is either poisoned or smothered, the rest of the food chain must suffocate, be sickened and unable to escape predators, starve or move on to more overpopulated grounds.
As the oil /chemical mass approaches land, it not only affects the brackish and freshwater biomes, it incorporates into the soil, threatening riparian, or land based plant, animal, microscopic and underground dwelling life forms. Land based water tables are poisoned.
In the 2010 gulf oil disaster, the land/ocean interface is unique in the world. The land of the Northern Gulf Coastis an extensive region of low lying brackish, estuary, marsh, bog and tidal zones, that have already virtually turned into “lace” from sea incursions and rising waters. This unique environment along with other low lying gulf zones can easily end up with miles of inland incursion by the oil mass.
The weather will play a part in the ongoing disaster that the oil spill presents. The combination of low lying land and volatile atmospheric conditions will lead to miles of inland oil incursion along with violent mixing of soil, oil, man made chemicals and water that will occur during the hurricane season.
Finally, the current and future choices and decisions that will be made might favor the corporation over humans and life forms; might favor humans over animals; or might favor human recovery and economic development over natural habitat, and will lead to decisions that may delay or prevent riparian and other restoration efforts.
The effects of existing oil spills, such as the Exxon Valdez and the Exxon Houston are still devastating to the marine, economic and riparian environments and lifeforms, so the environmental damage from the British Petroleum spill and any chemicals that are used to break up the oil is just beginning and should be expected to continue for many generations.