Providing fish passage
Have you ever thought about what could be swimming in your local stream? New Zealand is home to more than 50 native freshwater fish species. Of these, around 70% are at risk of, or threatened or at risk of extinction.
Photo by Shyam Morar
The Wellington region is home to at least 20 species of native fish, which makes our region one of the most diverse for freshwater fish in New Zealand. Many of these fish need to migrate between freshwater rivers and streams and the sea to complete their life-cycle. Tuna (eels) and whitebait are well-known examples of native fish that need unimpeded ‘fish passage’ to survive and reproduce.
There are a number of things that can act as a barrier to the movement, up or down stream, of freshwater species. Some of these barriers are natural, like waterfalls and large rapids. However poorly installed and maintained man-made structures such as culverts, flood gates, ford, weirs, and dams can also be barriers to fish passage.
One of the key steps we need to take before we can begin to improve passage for our native fish is to identify where instream structures are and assess whether they pose a barrier to fish passage. In order to do this, we walk the length of a waterway and use the NZ Fish Passage Assessment Tool App to record information on any structures and assess whether they are a fish passage barrier.
We are currently approaching landowners on the Kāpiti Coast who have waterways on their properties to request permission to access their properties and assess any instream structures found. The information gathered will be used to develop an Action Plan for prioritising and remediating fish passage barriers in our region, including how we will work with and assist landowners with any remediation work. The information gathered through this project will be fundamental in helping us develop this plan.
The information gathered from these assessments will be made publicly available on the NIWA website, but will not include any personal or private landowner information.
How a fish passage barrier is fixed will depend on the species present, and what ability they have to move through the waterway. It will also need to be site-specific to ensure the solution will work in that location.
Ideally, structures that are fish passage barriers should be removed if the structure is no longer required. Where this isn’t possible there are a number of potential options for remediating existing structures.
The New Zealand Fish Passage Guidelines for structures up to 4 metres is an excellent resource which sets out recommended practise for the design of instream infrastructure to provide fish passage.
We all have a responsibility to protect the passage of our native freshwater fish when we own and/or manage instream structures. Greater Wellington’s Proposed Natural Resources Plan (PNRP), the National Policy Statement Freshwater Management and the National Environmental Standards for Freshwater all contain requirements for Greater Wellington to improve fish passage management in our region’s waterways.
The Department of Conservation (DOC) also has responsibility for enforcing the Freshwater Fisheries Regulations, so any culverts, fords, dams or diversion structures may need approval from DOC. For more information on fish passage authorisations under the Freshwater Fisheries Regulations please visit the DOC website.
Keeping informed is one of the best things you can do to help – to find out more please head to the DOC Fish Passage Management information hub.
You can also ensure that any new structures built on your property allow for fish passage. You may need a resource consent for this type of work.
If you have an existing structure that may require fish passage remediation or are seeking to install a new instream structure to allow for fish passage a resource consent may be required.
You can also contact us for fish passage advice or if you would like to notify us of instreams structures on your property.