Tagging and clipping units. - Photo Credit: n/a

Monitors show technicians what is occuring in each unit. - Photo Credit: n/a

Fish await their destiny in a reservoir attached to clipping unit. - Photo Credit: n/a

The first automatic clipping and tagging trailer purchased by the USFWS arrived at Iron River National Fish Hatchery (NFH) on September 15, 2009 to begin marking lake trout destined for Lake Huron in 2010.  A crew from Northwest Marine Technology (NMT) arrived at the hatchery to thoroughly disinfect the trailer inside and out.  They then began the meticulous procedure of calibrating the units to process the size structure of the fish correctly.  Test fish are run through the machine until the sorting and tagging units are honed.

Once the marking units are calibrated, the tagging can begin in earnest.  Fish are netted from the raceway into a holding tank in the trailer in small batches.  From the holding tank, the fish are then netted into a small chamber that sends them past an electronic eye that measures and sorts the fish by size.  The sorted fish are sent down small pipes to another holding reservoir attached to the clipping/tagging machine.  As the fish passes through the machine, small foam grippers hold the fish firmly so that the adipose fin can be cut off and a tag inserted into its head. 

All six marking units are equipped with an electronic sensor, tag reader and camera that ensure the fish is being marked correctly.  Six small monitors show technicians exactly what is taking place in each unit.  Data is generated and displayed on another monitor that includes length frequency, fish per pound and total number tagged.

Some fish do not “conform” to the size standards and are sent to another holding reservoir where veteran fin-clippers from Iron River NFH take over and manually clip and tag the fish.  Any rejects that a unit’s sensor finds is also sent to a reservoir for the fin-clippers to check/tag/clip.  After a fish is properly marked, fish are then sent out of the trailer and into an awaiting raceway.  In less than six days of operation, 126,226 fish were marked, 15% (18,923) of which were rejects and tagged by hand.  Upon completion, the NMT crew disinfected the contents of the trailer and packed up all the gear for travel.  Next stop, Jordan River National Fish Hatchery.