If we restore it will they come?

What happens if riparian vegetation, in-stream habitat complexity and stability have been restored to the best of our knowledge but the plants and animals which lived there prior to the disturbance fail to re-establish themselves as expected?

Natural recolonisation of a restored habitat can be hindered if the connection is lost with sources of colonists such as natural or artificial barriers or the organism has low dispersal ability (e.g. due to a short life history, non-winged life stage or they are poor fliers). Natural recovery of streams is a long-term process: recovery of aquatic invertebrate populations may lag behind physical recovery of the habitat. As a consequence, the community structure in restored streams may differ from more natural streams, often because the rates of arrival and the sequence of species arrival can strongly influence the resulting community.

One possible way to speed up the recovery of our target organisms is via artificial introductions, which include the re-introduction of a species into an area that was previous considered in its historical range or translocation; the movement of a species within its current range from one location to another with the intention of establishing viable self-sustaining populations.

Below: Jackson Creek, Christchurch, four years after stream enhancement project.