The arrival of fall signals one of the most fascinating of natural phenomena, that of migration.

For most, the term calls up images of huge flocks of birds making their annual trip to warmer climates, but birds are not the only animals migrating.

In Western New York, the season brings on the annual migration of salmon from Lake Ontario into the many tributaries along the lake. The salmon aren't looking for warmer conditions, however these fish are heading from the lake to the streams and rivers to spawn. And they aren't heading to any random stream, they have the amazing ability to locate the exact stream they were born in!

Mike Wilkinson is an Aquatic Biologist for the New York Department of Environmental Conservation. "As young fish, they go through this stage called smolting, where they're actually in the freshwater streams, they're actually imprinting to the water quality or water chemistry or odor of that water you might call it, as a young fish, so they can maintain that in their memories, however they maintain that, and then they return to those streams as adults."

Once in the streams, the adults complete the spawning cycle, laying and fertilizing their eggs. The genesis of one life signals the exodus of another, however, and the adult Salmon die shortly after. This isn't the end of their contribution to the environment, though.

The decaying bodies of the deceased adults now add nutrients to the water, enriching the food chain and eventually helping feed the young Salmon at an important point in their lives.

"The adults in essence sacrifice themselves for the benefit of the youngsters," says Wilkinson. "Not only do they have this fairly complex system for finding the streams, but also ultimately deliver these nutrients in the form of their bodies to the streams to benefit the youngsters."

The Salmon were originally imported from the Pacific Northwest in an effort to curtail the population of another invasive species, the Alewife, which was growing out of control. It's an interesting yet rare example of a non-native species actually benefiting to it's adopted environment.

"The story isn't always one sided when it comes to invasives, there are definitely benefits to some of these invasives," Wilkinson explains. "It's a hard thing to say as a biologist because in some cases we're supposed to sort of tow the company line that invasives are all bad, but there's definitely good sides to them, and we've seen it here in the Great Lakes."

Although there is some natural reproduction going on among the stocked fish, the region's waterways are not conducive to Salmon reproduction. In an effort to improve the mortality rates of young fish, there are several pen rearing projects being undertaken on sites along the lake. Instead of being released directly into the streams, these young salmon are held in pens for a few more weeks. The Niagara River Anglers Association has been pen rearing salmon since 1999, releasing hundreds of thousands of young into the Niagara River.

Paul Jackson is President of the Niagara River Anglers Association, "The fish actually get to stay in that river system for a month more than the other ones, the other ones they just turn loose and they go right out to the lake. So they get more of a chance to imprint, become a smolt, as they say."

Wilkinson continues, "You hold them in the pens for about three weeks, they're fed, the fish are fed and well cared for, they're protected from predators, from fish predators and bird predators, and so forth. The idea there is fish suffer lower mortality because they're protected from predators but also they're right in the location you want them to program through this smolting process to that water quality, so they'll return there."

So why all this effort for a few fish? The answer is easy... following the salmon is a migration of another species... Anglers from all across the country find their way to Niagara County, and that means a lot of tourist dollars coming with them.

Wilkinson tells 2 The Outdoors, "You can see if you visit the parking lot there at Burt Dam, the number of cars there is pretty phenomenal, and the license plates come from many different states throughout the Northeast, so people are coming long distances here and spending money on bait and tackle and accommodations and so forth."

Jackson agrees, "There's millions of dollars spent here along the shore of Lake Ontario and the Niagara River by the sportsmen. Not only locally, but people come up from Pennsylvania, Ohio, West Virginia. Ask any businessman along all of Lake Ontario shoreline,and he'll tell you what this means to his business."