Whitebaiters warned to watch out for ‘mini piranha’

Wairarapa whitebaiters who are two weeks into a new season are being asked to keep a watchful eye out for a pest fish described by DOC rangers are being a "mini piranha".
Gambusia, sometimes called mosquito fish, have nothing to recommend them and although their presence has not been confirmed in Wairarapa there has been one report from Lake Onoke investigated.
DOC biodiversity officer Tony Silbery said as a result of the report he set nets in the lake trying to determine whether the dreaded little fish that congregates in schools and "leaps out from cover to attack other fish" is actually in the district.
"We are hoping that the report was a case of mistaken identity and that the fish found was a more friendly type."
Although it is known colloquially as mosquito fish, the truth is gambusia does not help the environment by feeding on mosquito larvae and is simply a pest.
Mr Silbery said it is found in many other places throughout New Zealand and can be recognised because it is thick-bodied with reddish-coloured fins.
"It shouldn't be too hard to recognise if it exists in Wairarapa because it schools with others of its kind."
Mr Silbery said he would be concentrating on the area known as Onoke flatgate in future attempts to determine whether gambusia is in South Wairarapa.
He said gambusia was probably introduced into New Zealand waterways through being brought into the country as an aquarium fish.
Meanwhile, the whitebait season has got away to a slow start mostly due to rough weather arriving just as the season opened.
Mr Silbery said the eastern rivers were only just cleaning up from a southerly that went through on August 16 causing them to "dirty up".
"That kept a lot of guys away from fishing but I noticed a few were out and about during my travels yesterday."
Apart from keeping a lookout for gambusia, whitebaiters are being asked to take care not to introduce didymo - or rock snot - to Wairarapa waterways.
North Island rivers are free of it, as far as is known, but South Island waterways are infected.
Mr Silbery said whitebaiters and other fishermen who move freely from one district to another are more at risk of bringing didymo - a pest algae - to Wairarapa, especially if they have been fishing in the South Island.
The best means of avoiding contamination is to check gear, clean it after each use and make sure it is completely dry before fishing again.