Floodplain rehabilitation as a way to preserve migratory connectivity

For species that rely on river networks to migrate, changes in storm frequency, duration, intensity or temperature might have a major impact on whether enough water is available to migrate at all.  Groups of individuals such as salmon, which mature in the ocean but spawn in river networks, need a long enough window of connectivity to be able to migrate through the entire river system to preferred spawning grounds.  But if climate change alters storm patterns, what strategies help ensure that these migrations can continue?  By combining models predicting climate shifts, storm shifts, water flow, and bioenergetic requirements of migrating steelhead, Boughton and Pike, in their recent Conservation Biology paper, asked: could rehabilitation of floodplains enhance transient storage of storm water enough to mitigate the varied effects of climate change on water availability or flow, and thus preserve network connectivity?  Using steelhead that migrate through the Pajaro River in California as their study system, the authors are able to show that migration is most sensitive to shifts in storm frequency, and less affected by shifts in temperatures and storm intensity or duration.  A proposed rehabilitation scheme for the Pajaro River would be successful in extending the window of connectivity for migration, with a focus on slowing flow and increasing water depth through changes in substrate and channel width.  This success could be counted on regardless of the uncertainty inherent in many climate change predictions.  Management of the ecosystem to maintain network connectivity in this way could ensure that a migration corridor would be preserved regardless of what the future might hold.