The microfauna and microflora are food for the oysters, shrimp and larger organisms, as we all know, and if they are decimated, than the shore and larger marine faunas will also be decimated.
Moreover, will intake of these dispersants by food species cause illness to humans?

And certainly those around the Bay of Campeche and elsewhere in the Gulf know what damage the Pemex blowout there did to the offshore ecosystem and their income. Some onshore bird species and turtles are still recovering.