There are concerns by catfish control co-ordinator volunteer after his nets were stolen and ripped.
William Anaru, aka Te Arawa Catfish Killer, has been leading the charge for volunteers of Te Arawa to control the growth of the fish in Lake Rotorua and Lake Rotoiti for the past three years but his efforts are being hindered.
Catfish are plaguing damaging Rotorua's lakes, they eat everything. Bullies, smelt, trout eggs, they even eat each other - they eat all the native species.
"Mainly because of the competition for other species. Particularly the native species, they're known to predate on koura," says Anaru.
Catfish were first discovered in Lake Rotoiti in 2016. Anaru is responsible for mobilising volunteers to help eradicate the pests.
"Us as Māori, we need to be more acting in that realm of kaitiakitanga. And that's what I'm trying to push," he says.
The exact number of Catfish in Rotorua and Rotoiti is unknown. In three years of the Te Arawa Lakes Trust eradication programme though, they've destroyed almost 70,000 catfish.
Anaru says their efforts are being hampered by local vandalism, "I've had two nets stollen since the programme started and one, we still haven't retrieved.
"We've had another one in Okareka, which has been slashed."
He says, "There's two theories: either the acclimatisation society introduced them into the Waikato River and from there they've just spread. The other theory is that when the Americans came down they had a barrel full of catfish."
Geoff Mewit has been eradicating catfish in Taupō and Rotorua for more than 10 years now. He says the vandalism does not help with eradication efforts.
Breeding fish can lay up to 6000 eggs so there's a huge task ahead.