28,000 catfish caught in Rotorua Lakes during summer period

Catfish. Photo / File

More than 28,000 catfish were caught in Rotorua lakes during the summer netting season, according to new figures from the regional council.

Bay of Plenty Regional Council said in a written statement that 28,060 catfish were caught during this year's summer netting season.

This represents a drop of 18 per cent compared to last year's figures, despite almost double the amount of nets being set, the statement said.

The total number of catfish caught since the first one was discovered in Lake Rotoiti in 2016 is now nearly 63,000.

Bay of Plenty Regional Council biosecurity officer Lucas MacDonald said there is still a long way to go and the fight would continue as long as catfish were discovered in the lake.

"It's definitely a step in the right direction but given that a single catfish can lay up to 6000 eggs at once and the discovery of the species near Mokoia Island in Lake Rotorua during December 2018 means that the battle is far from over," MacDonald said.

The regional council and Te Arawa Lakes Trust have been working closely with locals in the last nine months to raise awareness and started a community netting programme in the Rotorua Lakes.

The Te Arawa Catfish Killers have netted 3125 catfish to date, while volunteers are also on the lookout in the wider Rotorua Lakes by netting in lakes Ōkāreka, Rotoehu, Rotomā and Tarawera.

Council-funded research currently being undertaken by Niwa and the University of Waikato to find new surveillance methods and tools to stop the spread of the pest is showing promise.

In the last year the council has increased its focus on educating the public on how to stop the further spread of catfish and other aquatic pests to surrounding lakes. Catfish-specific efforts included the placement of educational signs at popular boat ramps in the region.

What catfish look like
The Brown bullhead catfish can grow up to 40cm long and are typically a dark brown/green colour with thick and leathery skin. They are easily identifiable by a sharp toxic spine on their fins and have four pairs of barbels around the mouth

Why they are a problem
They feed on small native fish, trout and their eggs. Catfish also compete for food with other native species, including koura (freshwater crayfish). They lower water quality by stirring up mud to feed.

How to prevent the spread of all aquatic pests
Before leaving a lake, waterway or river:
1. Remove all weeds from your boat trailer and gear. Not only does this prevent any aquatic weeds hitching a ride from being spread but also any small catfish or eggs that could be hiding in the weed.

2. Empty any lake water or ballast you may be carrying. This is especially relevant to those water-skiing and wakeboarding.

3. Don't leave your trailer in the water.

If you see a catfish in any Bay of Plenty waterway, report it by calling 0800 STOP PESTS (0800 786 773).