Urban ecological restoration - Do effective design guidelines exist for restoring instream habitat for the longfin eel within New Zealand urban coastal rivers?

Abstract

The longfin eel is New Zealand’s largest freshwater fish, and the largest freshwater eel in the world. They are endemic to New Zealand, and are a key species within freshwater ecosystems, and have significant value to many facets of New Zealand, including culturally, ecologically, economically and recreationally. Substantial habitat loss, urbanisation of lowland habitat and the degradation of remaining instream habitat has left this species in a constant state of decline. Currently, there are broad guidelines for fish species in general to restore degraded instream habitat conditions, however there is very little known of guidelines and the effectiveness on the longfin eel species. This thesis will answer the principal research question of: Do effective design guidelines exist for restoring instream habitat for the longfin eel within New Zealand urban coastal rivers? It was found that there are no guidelines for restoring instream urban habitat for the longfin eel in New Zealand. The implication of this is the longfin eel will face probable extinction if action is not taken to stabilise and restore their populations to healthy numbers.