If anglers are sharing information, there's got to be a reason.

In recent years, Trout Unlimited members and other like-minded fishermen have organized get-togethers on the Kennebec River -- roughly once a summer, in late May or early June, to swap stories, gather information from one another and, most importantly, fish for American shad.

The reason for such a group effort is simple. Shad are not easy to catch; thus, here in central Maine, there aren't a lot of solid tips out there for how to get the job done.

"On a scale of one to 10, with a permit being a 10 and a sunfish being a one, I'd say shad are about a seven," said Nate Gray, a biologist with the state's Department of Marine Resources.

Anglers in the Kennebec Valley region, however, just found out there's soon to be a larger sample size when it comes to finding shad, fishing for the elusive species and learning exactly how to go about landing more of the sought-after fish.

With the removal of the Fort Halifax Dam in Winslow last year, American shad are joining other herring species in returning in numbers to our river systems.

"We are blessed here in this state with three anadromous herring species -- American shad, blueback herring and alewives," said Gray, who has been working almost exclusively at the Benton Falls Dam since the first of May to try to study the shad which are being spotted there for the first time this spring.

"That's really, really important. It's good for our inland river systems, as well as for the greater good of the Gulf of Maine."

American shad are roughly 3- to 5-pounds in size as average adults, though they can grow up to twice that size if ample forage exists. They look similar to alewives -- "except multiplied," according to Gray -- and like their herring cousin, they, too, spend most of their lives in salt water before returning each spring to spawn in the same rivers in which they were born.

"We're seeing something here that hasn't been seen in 200 years," Gray said. "It's pretty damn humbling."

That the shad are here, truly isn't all that surprising. When the Edwards Dam was removed from the Kennebec in Augusta nearly a decade ago, anadromous fish returned to the more northern reaches of the river.

Likewise, the shad are joining others now that the Fort Halifax Dam has been taken out in moving into a place where they otherwise could not access before.

One thing remains unclear, however. Though there is plenty of anecdotal evidence of the arrival of the shad to Benton, no one is certain how many have shown up. Anglers are seeing them, and the DMR biologists are seeing them, too. But they're not being seen at the same time -- and they are not using the fishway.

Yet.

"We've seen them," said Gray, adding that the fishway itself is being reconstructed to better support the habits of shad. "We're reconfiguring it to specifically try to target them at the tail end of the river herring run. It's a steep learning curve, though, because they're so difficult to catch -- and we're not dealing with great numbers, so the opportunities are few.

"We're trying to increase the attraction flow, reset the position of the (fishway) to allow the fish to come in but make it more difficult for them to get out. That's the big trick."

Why are shad so difficult to catch?

For biologists, it's because they are constantly on the run.

"Shad don't hang out like bluebacks and alewives do. They never stop," Gray said. "They are constantly, constantly seeking out a way to go. They never stand still, not for one split second. They're constantly hunting -- that's what makes them so tricky do deal with."

For anglers, it's because they're not only moving, but -- despite having a voracious appetite that keeps them on the move -- because they are finicky.

"You've really got to match the color just right (that's attracting them), and then you've got to wait for them to get there," Gray said.

When you do hook into a shad, you'd better not set that hook too emphatically, either.

"They have real (paper-thin) mouths," Gray said. "You can't really yank on them, or you'll lose them."

Shad spawn at night, out of sight of predators -- with males and females swirling together to fertilize eggs in the rivers. Their eggs are almost buoyant -- floating in the current in their larval stage, and when they are finally hatched, the shad represent, as Gray described it, "threads with eyes." They spend most of the first stretch of their life without the strength to even swim against the current.

And now that they are back in the Sebasticook River, there will likely be plenty more time for everyone -- scientists and recreational fishermen -- to study shad. To learn about them. To figure out what makes them tick.

Pretty soon, we won't have to all get together and share information at every turn. Heck, they'll turn into virtually every other species, and anglers will be keeping their best secrets from one another with knowing grins.

"They're an overall health indicator of the river system, as well as a grand fishing opportunity," Gray said. "They're a real sprightly fish, kind of vigorous fighters. They can utilize that stretch of river as spawning grounds, because it's a prime-time river system.

"We've come a long, long way from where we were 20 years ago. It's an outstanding success story."

Travis Barrett -- 621-5648

tbarrett@centralmaine.com