Intactness in Oceanic and Island Systems

Humans have influenced island species and coastal ecosystems from the earliest colonization events, as abundantly illustrated by archeological records of faunal and floral transformations.  Islands depend on isolation, from continents and each other, for development of unique assemblages over time.  Intactness of islands, or even of portions of islands, is closely connected to maintenance of isolation.  Therefore a large proportion of conservation management on islands is devoted to preventing or reversing invasion of island systems by alien species or human activities.  In contrast, oceanic systems are fluid and borderless, appearing to be intact almost by definition.  However, human influences on ocean processes are now pervasive, and these impacts have transformed some marine systems and threaten processes and ecosystem elements that are global in scope.  Can active management in both island and oceanic systems retain critical aspects of intactness into the future?