It takes a lot of work to raise 900,000 fish.
It can be even harder to keep track of them.
That's why staff at the Allegheny National Fish Hatchery is marking each and every fish.
Article Photos
Times Observer photo by Josh Cotton
High-tech operation
The inside of the AutoFish trailer looks more like NASA Mission Control than a series of devices designed to clip and tag fish. The lake trout enter the far end of the trailer and are then sorted into one of six machines based on their size. The blue boxes, five of which are pictured, are the devices that place a coded wire strip with a unique identification number into the nose of each fish. At left are fingerling lake trout to be tagged.
Tagging operations have been underway this week and will continue for several days as small wire tags with a unique identification number is placed in the nose of each fish and the adipose fin on each lake trout is removed.
Larry Miller, project leader with the U.S. Fish and Wildlife Service, said the tagging operations started on Saturday and will run through the end of the week, before starting up again on Sept.5 for another four or five days.
Tagging is taking place in a mobile trailer set up with six different machines. Each machine is calibrated to process a different size of fish.
The fish are sorted into the machine that fits their size, there is enough current in the small holding area to require the fish to swim upstream and enter the machine head first, ensuring that the fin is removed correctly and the wire is properly placed.
Once inside, a cutting device lops off the adipose fin of each fish. The fin, located on the top of the back, "doesn't serve any purpose," according to Miller. "It's like clipping their fingernail. There's not much of a blood supply to it."
Removing the fin allows the fish to be more easily recognized as a hatchery-raised fish when it is caught in the future.
The next step is implanting a small coded wire into the nose of each fish.
"Every fish we stock out has a coded wire tag. It's really small (about one millimeter) and has a code number on it," Miller said. The number is so small it has to be viewed under a microscope.
"When the fish is later captured, we can see where it moved from compared to where it was stocked, what its growth rate was, what stock it was (and) in particular what strain it was because we use three different strains." Not only does the tagging allow officials to determine what hatchery the fish was raised at, the code also allows for the specific part of the raceway that that fish was raised in to be accurately determined.
The system is automated. Jim Webster, from the Green Bay office of the Fish and Wildlife Service, said the device measures each fish down to one-tenth of a millimeter. "The clipper finds the fish, locates the clipper and looks again" to verify the clip was cut correctly.
Before the fish are returned to the raceway, Webster said that the wire implant is also double-checked by a device that emits a slight magnetic force to ensure the coded wire is properly located.
The device successfully processes approximately 90 percent of the fish that are introduced, with the remaining ten percent being expelled into catch bins and then processed by hand. The fish are processed in lots of 41,000 with 5,000 to 7,000 clipped and tagged each hour.
Miller said, before the automation, the hatchery would hire six to eight temporary employees to tag and clip the fish. "They could probably do, at best, 25,000 fish a day," Miller said. "We've already had this machine and trailer up to 70,000 fish a day and we only need like four people to operate it. It has really speeded things up."
The trailer is actually owned by the New York Department of Environmental Protection and is on loan to the hatchery. Cooperation has been a key component of their work. "We've all been working on cleaning up the pollution, improving the habitat, controlling the invasive species and trying to reinstall the heritage fish species that were here before so that they can provide angling and be available to the public," Miller said.
He added that the device was originally designed for salmon in places such as the Columbia River in the western U.S. but, "We found it works well for lake trout, too."
The fish tagged and clipped this week will remain at the hatchery until next April or May when they will be sent to their final home, either Lake Ontario or Lake Erie.
They originally came to the hatchery in December in the form of one million lake trout eggs from Vermont's Salisbury Fish Hatchery and the Sullivan Creek Fish Hatchery in Michigan.
Before they leave, a new "fish pump" will be installed to make their journey into trucks headed to the lakes a little easier. Asked if it is essentially a vacuum cleaner for fish, Miller responded, "That's exactly what it is."
Additionally, 2,200 five-year-old lake trout that were brought in last November also reside in the raceways and will mature later this year, allowing the hatchery to collect the eggs and begin the process all over again.
"We're growing really good fish," Miller said. "We're having the best growth rates that they've ever had here and we think that has to do with the improvements that we've made."
Miller invited anyone who might be interested to come out to the hatchery and see what is going on. "They can come out anytime between 8 a.m. and 2 p.m. and tour the hatchery," Miller said. While he asked for people to be careful around the piping that is currently transporting fish from the trailer to raceways, and to wash their feet in the available footbaths so as to not reintroduce the disease that shut down the hatchery for five years, he noted that the hatchery is a "public facility. The public is invited to come out and take a look."