This series of videos records the removal of the adipose fin from a pen of about 90,000 Chinook salmon smelt on 21st February 2015. The clipping was carried out under the control of the North Canterbury Branch of New Zealand Fish and Game at the Upper Rakaia “Montrose” hatchery by a group of about 30 volunteers and family from NZ Fish and Game in conjunction with the NZ Salmon Anglers Association .

The process involves capture of the smelt then transferring into a tub of water containing about 10 ml of an anaesthetic fluid which results in anaesthesia for a maximum of about 4 minutes.

Once the salmon have their adipose fin removed with the use of curved scissors the smelt are returned to the pen where they sink to the bottom to slowly recover.The survival rate is extremely high if they handled quickly and returned to the pen.
The salmon recover from the ordeal very well as seen at the end of the video when the automatic feeder spreads tiny pellets into the pen. Video made by and courtesy of Kevin Belcher.