Why We Need Intact Watersheds

Most watersheds throughout Europe and North America have histories of long term and intense anthropogenic exploitation and few watersheds are intact from their headwaters to the ocean.  In contrast, watersheds with habitats that are intact are present in Southeast Alaska.  These watersheds offer a rare opportunity to understand how natural processes from the headwaters to the ocean interact to create a salmon rich environment.  Furthermore, they provide an example of how salmon stocks can recover from severe overexploitation when provided with habitats that retain natural processes and connectivity. Multi-dimensional connectivity is one feature of these watersheds. Related to this are natural flow regimes with seasonal floods. The influence of large riparian trees on streams and salmon habitat is reasonably well known.  However, their effects depend on natural disturbance events such as wind throw, landslides, and beaver activity. Intact watersheds are not static environments. Some examples of these processes can be observed the Kadashan River, in southeast Alaska.  Understanding and measuring processes in intact watersheds can provide an opportunity to test major river paradigms and may provide reference points for watershed restoration projects elsewhere.  In the meantime these watersheds provide the resilience needed to sustain harvestable salmon stocks throughout southeast Alaska.