Many of New Zealand’s iconic freshwater fish species are diadromous, which means they need to migrate between fresh water and the ocean to complete their life cycles. Some man-made structures such as culverts, weirs, stormwater pump stations, tide gates, and dams can obstruct diadromous fish migrations and prevent fish from reaching critical habitats.
This can result in the gradual decline and loss of fish species from some rivers, and streams and lakes. Protecting the connection between upstream and downstream habitats of our indigenous fish is as important as protecting their habitats themselves.
We do not yet have enough data to provide a national picture on fish barriers, so we report on known barriers to freshwater fish passage in the Hawke’s Bay region from culverts, weirs, and stormwater pump stations.