Salmon spawning numbers are dropping in Canterbury's rivers this year and Fish & Game can't figure out why.
For the past 23 years Fish & Game has been monitoring the fish stocks by surveying the headwaters of both the Rakaia and Waimakariri rivers, but say so far this year the salmon numbers are well down.
March and April are peak spawning season for salmon, which leave the Pacific Ocean and travel up rivers to hatch their eggs.
Fish & Game officers view the rivers from air (Newshub.)
An aerial sweep in a helicopter revealed just 587 fish spawning on both rivers. Normally at this time of year there's three times that number, Fish & Game officer Steve Terry says.
Mr Terry and his team will carry out two more aerial sweeps of the area in the next month to ensure the peak spawning season is fully monitored.
Spotting salmon in the river (Newshub.)
Newshub.
