DOC’s latest fresh water fish survey.

Electric stun fishing does not kill the fish. 

The Department of Conservation’s new threat classification report for fresh water fish 2017 was released in August this year. There are three species that are found in the Mangaiti Stream system that have the “At risk – declining” status; giant kokopu, longfin eel and inanga, .

The giant kokopu (Galaxias argenteus) inhabits the ponding area in the gully below Sexton Road and has been found in the main stream. These tend to be active at night so are rarely seen. It was when Waikato Regional Council’s scientists were doing a fish survey using the electrical stunning method that they were located. Only one giant kokopu was recorded in the stream.

The Longfin eel (Anguilla dieffenbachia) has been mentioned several times on this website. The report noted that the decline in water quality in many areas has resulted in the shortfin eel (which has a “not threatened” status) occupying habitat that formerly held the longfin eel which suggests that the two species may be competing within a habitat or it could be that the longfin eel prefers better water quality. Either way it is clearly evident that the shortfin eel is the dominant species in the Mangaiti waterways. In the 2012 survey there were 2 longfin eel and 21 shortfin eel counted in a fifty metre length of stream. The longfin eel has a very long life and the ones we are seeing appear to be mature adults. The worry is that the population is not being maintained with juveniles moving upstream in their normal life cycle. 

In the 2012 survey, 29 inanga (Galaxias maculatus) were recorded. 

Planting the stream edge becomes all the more important when you are aware of the status of some of the occupants.