UK National Parks go it right with the Sandford Principle:
“Where irreconcilable conflicts exist between conservation and public enjoyment, then conservation interest should take priority”
(Source: http://www.nationalparks.gov.uk/learningabout/whatisanationalpark/ aimsandpurposesofnationalparks/sandfordprinciple)
UK Parks cite an example:
"A fisherman would like to fish at a lake shore. He has access to the lake and so he can enjoy his day fishing, which fulfills the National Park purpose of understanding and enjoyment.
There are also Ospreys nesting in a tree nearby, which catch fish in the lake. Ospreys are a protected bird species and are easily disturbed by noises and movements during their breeding season. Looking after the breeding Osprey fulfills the National Park purpose of conservation.
In this example the two main purposes of National Parks, conservation and understanding and enjoyment are in conflict. By applying the Sandford Principle the conflict is resolved and conservation, in this case the nesting Ospreys, take priority. The fisherman is encouraged to find another fishing spot during the osprey breeding season. When they Ospreys have migrated away in winter, the fisherman can fish in the lake."
Good Stuff.