Threats to native fish
- Half of our fish species spend time at sea. These migratory species are affected by dams and badly made or maintained culverts, which can prevent them from migrating from the sea to freshwater habitats.
- Native fish habitat is shrinking as wetlands are drained, and streamside vegetation removed.
- Some fish compete with native fish for food and space, prey on their eggs and young, or can change the quality of water.
- Contaminates such as sediment and chlorine discharged into the water can affect fish.
- Water abstraction – take too much and there might not be enough for fish to live in!
How you can help native fish
There are a number of ways you can be involved with freshwater fish conservation efforts, including protecting their habitat and ensuring migration routes are passable.
- Protect streamside vegetation, fence off stream edges from stock and plant alongside streams to create a shady cool habitat.
- Make sure that culverts and weirs in your stream are fish-friendly – native fish can’t jump and need wet surfaces to wriggle their way upstream.
- Think twice before killing an eel – after 25 years of growing, that big one could be just about ready to start its 1,500 km journey to breed.
- Protect wetlands, particularly in lowland areas – they are often valuable native fish breeding grounds. Even fencing off whitebait spawning areas for a few months each year might be enough to help them.
- Avoid introducing other fish and plants. It is illegal to move aquatic plants and animals between waterways, but it often happens by accident. Before you move to a new spot, make sure you clean fishing gear, trailers, boots etc. It is important to remove even the tiniest of seeds, eggs, and weed fragments.
- Avoid drag-lining streams.
- Maintain water quality and quantity.
School children looking at Whitebait, Orowaiti Estuary, near Karamea