The park is largely made up of native New Zealand beech forest. Throughout the Park, the bush is regenerating at an accelerated rate due to the eradication of wilding pines and other unwelcome plant pests.
There are seal colonies scattered throughout the Park. Pods of dolphins are regular visitors to the waters along the Abel Tasman, and small pods of Orca sometimes make a welcome appearance. The Tonga Marine Reserve, which stretches northward from Bark Bay to Awaroa, is helping marine creatures flourish both within and outside of the Reserve.