harmful interference
(5) the term “harmful interference” means— (A) flying or landing helicopters or other aircraft in a manner that disturbs concentrations of birds or seals; (B) using vehicles or vessels, including hovercraft and small boats, in a manner that disturbs concentrations of birds or seals; (C) using explosives or firearms in a manner that disturbs concentrations of birds or seals; (D) willfully disturbing breeding or molting birds or concentrations of birds or seals by persons on foot; (E) significantly damaging concentrations of native terrestrial plants by landing aircraft, driving vehicles, or walking on them, or by other means; and (F) any activity that results in the significant adverse modification of habitats of any species or population of native mammal, native bird, native plant, or native invertebrate;