High-tech hatchery supplies fish to local rivers and lakes
By Denise Coffey - Staff Writer
Central Village - posted Mon., Apr. 18, 2011
At 7:30 a.m., on April 15, two men took turns carrying nets full of trout from a 50-foot diameter pool to a truck sitting a few strides away. The nets were heavy, and the men had to lift the handles to a worker standing on top of the tanker truck. The fish were then dumped carefully into the tanks for their trip to the Salmon River in Colchester.
Five trucks left the Quinebaug Valley Trout Hatchery that day, loaded with about 6,000 trout. The delivery was just in time for the opening day of trout season in Connecticut.
“The Salmon is a nice river,” hatchery supervisor David Sumner said. “They get a lot of fish. So does the Natchaug River and the trout parks. They even get them past opening day.”
Sumner oversees an operation that produces more than 530,000 trout each spring. It is one of the biggest hatcheries east of the Mississippi. Sumner is charged with keeping it going 24 hours a day, seven days a week. He does it with the help of a well water system with more than 13 wells, an oxygen generator system, a monitor with more than 2,000 alarms and a 600kw backup generator, in case they lose power. Power is crucial.
“If we lose power, we start to lose fish in 20 minutes,” he said.
The year-round operation consists of incubator tanks and three progressively bigger tanks, in which the fish are sorted and kept as they grow. A million and a half eggs are hatched every year.
“Rainbows are quickest. They hatch out at about 28 days,” said Sumner. “Brooks and browns hatch in about 40 days.”
When they come out of the incubators, between 30,000 and 50,000 are put into 6-foot diameter tanks. The hatchery has 48 of them. The fish will remain in these tanks until they reach about 3 inches long.
From those tanks, the crew will sort them to size and move them to another building, where 30 20-foot diameter tanks will hold them until they reach 6 to 7 inches.
They sort them a final time and put the bigger fish in 50-foot diameter tanks that are outside under a canopy of nets. By the time they are stocked out, fish range from 1.2 to 1.5 pounds.
“It takes about 16 to 18 months to grow a 10- to 15-inch fish,” Sumner said. Older surface hatcheries require from 26 to 28 months to grow an adult fish.
The reason Quinebaug Valley can do it quicker is that they use well water.
“There are two big advantages to well water,” Sumner said. “It’s a constant temperature, around 52 degrees, so it gives a good rate of growth through the winter. And it’s a closed system, so you don’t get parasites.” Older hatcheries use some type of surface water like a spring or a brook, and the temperature can get so cold in the winter that the fish don’t grow. Fish growth is related to water temperature.
There can be problems with brook or spring water.
Quinebaug Valley used to have problems with parasites, but that all changed when the outdoor ponds were covered with nets in 1996. Osprey and blue heron used to fish in the ponds, and they brought parasites with them. Though it was fairly easy to treat, they still lost about 100,000 fish a year.
Because well water is low in dissolved oxygen, the hatchery has an oxygen generator system.
“We actually generate our own oxygen,” Sumner said.
Three compressors push air through an air dryer to remove moisture. Then it’s passed into oxygen generators that pump it to different areas of the hatchery. It puts oxygen into the water and drives the nitrogen out.
“Most hatcheries shoot for seven parts per million to keep the fish in healthy condition,” he said. “With our oxygen system, we keep it at nine to 10 parts per million, so it’s close to saturation. It all makes for a healthy environment for fish - so healthy that Quinebaug Valley trucks 250,000 fish over to the Burlington hatchery every June.”
With all the wells and ponds, oxygen generators and automatic feeding systems, the hatchery is loaded with monitors and alarms. Feeders are staggered so they aren’t all going off at the same time. The water and oxygen levels must be monitored. And Sumner can reuse the water that courses through the different pools. He estimated that he was using about 1,000 gallons a minute to help feed the hatchery.
It all adds up to costing about $5 a pound, Sumner said.
The fish end up in 308 rivers and streams and 82 lakes and ponds. All areas must be open to the public. His crews will get their trucks as close to the water as possible. If they are releasing into a lake, they might be able to quick release them with hoses. At streams, someone actually has to run them from the truck to the water.
On the last day before opening season, some of the brood fish were being loaded into the trucks heading to the Salmon River. The hatchery will keep brood fish for up to four years before they release them. In four years, trout can grow to 10 and 12 pounds. They were so big that the men carried one fish at a time in their nets. They were the stuff of legend, the sort that anglers everywhere on opening day were dreaming about.