High levels of environmental contaminants are most likely the primary factor contributing to the decline of alligators on Lake Apopka.
(High levels of environmental contaminants; are most likely; the primary factor contributing to the decline of alligators on Lake Apopka) (the primary factor; contributing; to the decline of alligators on Lake Apopka)
High levels of environmental contaminants the primary factor
are most likely contributing
the primary factor contributing to the decline of alligators on Lake Apopka
to the decline of alligators on Lake Apopka