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Auckland / Waikato Reel Life Jan 2017

Published on Wednesday, January 18, 2017 - 13:00

Anglers, it’s dry fly time

Fish & Game staff were recently on the Whakapapa and Whanganui Rivers monitoring water quality and witnessed some amazing hatches in the late evening, and heard cicada sounding off all day. 

Multiple trout were gulping flies off the surface in almost every pool just before dark, well after most anglers had given up for the day.

So if you’re lucky enough to get out there this month plan to stay late if you can. 

Whakapapa mayfly that is a good match with the Kakahi Queen fly pattern.

Oraka freshwater crayfish kill

By now you’ve probably watched the shocking footage of hundreds or possibly thousands, of dead crayfish rolling along the bottom of the Oraka Stream, near Putaruru that was filmed just before Christmas.

Despite a timely response, the council has yet to determine the cause of the mass kill.

It is very difficult to determine what causes die offs in rivers due to the dilution and constant flow washing away the evidence.

Fish & Game staff are also investigating the incident and would like to hear from anyone who may have information about the cause of the die-off.

If you do happen to come across something that looks suspicious in the Waikato please call the WRC incident response team as soon as possible on 0800-800 401.

What we do know is that the Oraka die off is unlikely to be an isolated incident because freshwater crayfish have virtually disappeared from the Waikato River and the Riverine lakes. 

Freshwater crayfish are only holding on in clear streams in wooded gullies and bush parks.

The good news is that the trout in the stream were not immediately impacted and the river is open for fishing. 

Right: A now rare koura.

Study links loss of trout & native fish to dairy farms

A recent University of Otago study has yet again linked dairy farming with the loss of invertebrates, native fish and brown trout. 

The researchers compared water quality, fish and invertebrate samples from catchments with varying degrees of dairy farming, to look at the impact based on the percent of the catchment that was intensively farmed. 

As you’d expect, declines in trout and native fish numbers were associated with increased dairy farming in the catchment. 

The most frightening finding was that catchments with more than 50% of the land in dairy were completely devoid of trout. 

The researchers also looked at water quality at the sampling sites and found that more dairy farming in a catchment was linked with declines in water quality. 

Most of the key contaminants that have been identified in the Healthy Rivers Plan Change (Plan Change 1; nitrogen, phosphorus and suspended solids) increased with increasing dairy farming within a catchment.

This is quite an important reminder considering that the proposed Plan Change 1 has a heavy focus on dry stock farmers and only seeks to reduce the impact of the worst (25%) dairy farms in terms of nutrient loss. 

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