Cobden wetlands īnanga habitat assessment and recommendations for future management

Abstract

This short report describes an assessment of the Cobden Island floodplain area and Aromahana Lagoon shoreline. A large scale ecological restoration project has been underway since 2013 on Cobden Island. The project has made considerable progress towards its objectives. The level of weed control being maintained has been very successful and the lack of gorse, broom, and blackberry is notable considering the size of site and high light levels. In most places a dense grass sward has developed grading into rushes and herbs in many wetter areas creating a mosaic of riparian vegetation types. Within the artificial channel network, a variety of in-stream habitats were also noted as a result of different channel widths, incision depths, shading, exposure to flood tide flows, and sedimentation rates. With regards to īnanga spawning habitat, the project has hugely increased the length of river/channel bank available for spawning by 7 km, with few comparable sites in New Zealand.