Auckland Council is undertaking a major effort to remove pest fish from Te Wai Ōrea / Western Springs Lake, utilizing an electric fishing boat to stun and collect unwanted species. The operation, which began this week, aims to improve water quality and protect native freshwater life.
Pest Fish Removal Underway
The council team is targeting koi carp, brown bullhead catfish and even unwanted pet goldfish and turtles. The largest carp caught so far weighed 14.5kg and measured 81cm long. The electric fishing boat works by emitting a pulsed current that temporarily stuns the fish, allowing them to be safely collected with nets.
Collected fish are being euthanized and processed, with the resulting biomass converted into bio-ethanol. Council officials emphasize the harm caused by releasing unwanted pets into waterways, stating that these animals are often ill-equipped to survive and can disrupt the natural ecosystem.
Impact on the Ecosystem
Pest fish negatively impact the lake by disturbing sediment, releasing nutrients, and fueling algal blooms, which cloud the water. They also compete with and prey on native species, including tuna (eel), for which the lake is a significant habitat. A proposal is under consideration to declare Western Springs an eel sanctuary.
The council advises pet owners who can no longer care for their fish to find a new owner, return the animal to the pet store, or contact a rehoming organization such as Auckland Fish Rescue or North Shore Turtle Rescue.
Frequently Asked Questions
What types of fish are being removed from Western Springs?
Koi carp, brown bullhead catfish, goldfish, and turtles are being removed from the lake.
How does the electric fishing boat work?
The boat applies an electric current to the water, temporarily stunning the fish so they can be collected with nets.
What happens to the fish after they are caught?
The exotic fish are euthanised and then sent to a plant where they are turned into bio-ethanol.
As the council continues its efforts to restore the health of Te Wai Ōrea / Western Springs Lake, will this approach prove sustainable in the long term, and what further steps might be necessary to protect this key ecosystem?
