Montshire Minute: Atlantic Salmon II

Originally aired during the week of July 30, 2001

Monday

In autumn, Atlantic salmon females lay their eggs on the bottom of the river. Baby salmon, called fry, hatch in early spring. About two years later, the fish are seven to thirteen inches long. Undergoing a process called smoltification, the salmon turn silver, and their bodies prepare to live in salt water. The smolt swim downstream, and arrive at the Atlantic Ocean. Suddently they are a small fish in a big pond. If they are able to avoid predators, they may swim hundreds of miles north to the waters off Greenland. The salmon reach maturity after two or three years. Then they face the long swim back to their birthplace. Dam building hundreds of years ago blocked the migratory route of the Atlantic salmon. As a result, few of these fish live in the Connecticut River today. Restoring efforts help keep Atlantic salmon from becoming extinct.

Tuesday

The first dam on the Connecticut River was built in 1796. That was good news for consumers of water power, but bad news for migratory fish! An anadromous species, Atlantic salmon are born in fresh water, migrate to the ocean, and return to their native rivers to reproduce. Located at Turner's Falls in Massachusetts, this early dam project blocked the migratory route of the Atlantic salmon. Within a few years, hardly any of these fish remained north of the dam! Since the 1960s, the US Fish and Wildlife Department has been working to restore the Atlantic salmon population in our rivers. Dams now have fish ladders, which provide an avenue for fish moving upstream. Hatcheries harvest millions of salmon eggs each year. Some of the baby salmon, called fry, are released directly into the Connecticut River. Even though only a small number return, stocking salmon plays a vital role in boosting the Atlantic salmon population.

Wednesday

One fish, two fish, red fish, blue fish...well, almost! Visiting a fish ladder, you would see lots of fish make their way upstream. In the Connecticut River, dams block the migratory route of the Atlantic salmon. But the salmon need a way to get back to their spawning grounds. Fish ladders are man made pools built at graduated levels, which simulate the natural rises of a river. Atlantic salmon can jump an incredible twelve feet in the air! So, getting up the fish ladders is not a problem for them. Some dams are high tech--they have fish elevators. Hey, going up? The elevators, like one at the Holyoke Dam, lift the fish over the dam, and back into the Connecticut River. As many as two thousand fish, including an occasional Atlantic salmon, are given a lift each hour. Fish ladders and elevators help Atlantic salmon reach their birthplace to spawn in the spring.

Thursday

The Atlantic salmon restoration process begins anew each October. The US Fish and Wildlife Department has a hatchery in Bethel, Vermont, where 10 million eggs are harvested each year. The eggs are closely monitored as they incubate throughout the winter. The unsuccessful ones are removed, and in spring, 6.5 million salmon fry hatch! Over a period of a few weeks, local river temperatures are ideal for the fry. Released in the rivers, the fish mature over a period of two years. During the journey to and through the Atlantic Ocean, a large majority will fall prey, or be killed by other natural causes. A small number of salmon will make it back a few years later, instinctively returning to mate in their native rivers. Although only 41 Atlantic salmon have returned to the Connecticut so far this year, restoration efforts insure that the salmon population isn't entirely wiped out.

Friday

After the Turner's Falls Dam was built in 1796, the Atlantic salmon population of the upper Connecticut River largely died out. For their annual spring migration, adult Atlantic salmon must swim upstream through a watery obstacle course that includes dams and falls. Recent efforts by the US Fish and Wildlife Service and other groups have been launched to reintroduce the fish into the Connecticut River. Among other things, state and federal agencies have created fish elevators or ladders and stock juvenile Atlantic salmon in the Connecticut River watershed. You can see Atlantic salmon at Montshire's freshwater fish tanks. The Museum is an education center for the Silvio O. Conte National Wildlife Refuge, operated by the U.S. Fish and Wildlife Service.