Barriers threat to life cycle of freshwater fish
The Department of Conservation is calling on citizen scientists to celebrate World Fish Migration Day by downloading an app and checking out a new video to help assess fish passage barriers.
DoC freshwater manager Elizabeth Heeg says freshwater fish need free-flowing rivers without barriers to complete their life cycles.
“New Zealand has 51 native freshwater fish; 76 percent of these are threatened or at risk of extinction.
“Many of our freshwater fish species, like whitebait and eels, move between freshwater and the sea to complete their lifecycles.
“Some species move upstream and downstream between different habitats in rivers and streams.”
Elizabeth Heeg says in-stream structures such as culverts, weirs and dams can prevent migratory fish like whitebait and eels from moving within waterways and up and downstream to the sea if they’re not designed, installed and maintained properly.
“So far, we’ve identified more than 100,000 in-stream structures in New Zealand, and we want the public to help us assess them for their risk to fish passage and find any additional structures.
“One way we can help our threatened fish species is to improve their access up and down waterways.
“By identifying and recording barriers using the fish passage assessment tool app developed by NIWA last year, you’re adding to a database that will help us see the scale of the problem, visualise instream structures that need to be removed or improved and track progress on work intended to restore fish passage.”
Elizabeth Heeg says a new video on the fish passage assessment tool, developed by DoC and the New Zealand Fish Passage Advisory Group (representing businesses, organisations, councils and government agencies involved in fish passage management) illustrates the importance of freshwater fish, the problem with some instream barriers and how to use the fish passage assessment tool.
Information collected by the app is automatically uploaded overnight to the national database and can be viewed and downloaded from NIWA’s fish passage assessment tool webpage.
World Fish Migration Day was celebrated globally on October 24, with New Zealand opening the celebrations in Whangarei and events throughout the country providing people with a great opportunity to find out more about fish, their lifecycle, and how to protect them.
Go to niwa.co.nz/freshwater/management-tools/fish-passage-assessment-tool to download the app.