|
Saturday, May 28, 2005
Salmon stocking an art and science
Copyright © 2005 Blethen Maine Newspapers Inc. | ||||||||
 |
||||||||
"There's a big rock out here somewhere, I know it," said central Maine fisheries biologist Scott Davis as he -- and a load of nearly 850 salmon -- tore down Great Moose Lake in Hartland. "This is great, huh?!" he yelled over the roar of his vintage model Evinrude outboard, while he shielded his face from the driving rain that pelted his exposed skin. When he reached the target drop point, he opened the hatch and salmon ejected from an escape tube mounted on the transom, beside the motor. The dime-bright, silvery fish hit the dark lake water, kicked their tails and disappeared into the depths. BOAT STOCKING 101 Lake St. George was the first of five lakes stocked with salmon on Thursday. Also stocked were Great Moose in Hartland, Wasookeag in Dexter, Parker Pond in Mt. Vernon and Upper Narrows in Winthrop. Numbers ranged from 200 in Upper Narrows to 1,000 in Lake St. George. Each year, the Department stocks hundreds of Maine's lakes, ponds and rivers. Many Maine waters require periodic stocking because spawning habitat is limited -- particularly in central and southern Maine, where tributaries tend to be slower, and warmer. Salmon can be especially finicky about where they spawn -- so stocking can be critical to a successful fishery, said Davis. On Thursday, Davis, together with Steve Trembley and Mike Andrews from the Casco Fish Hatchery, met at the Lake St. George parking lot around 9:30 a.m. The process seemed simple enough: Fish are transferred from holding tanks in the stocking truck to a smaller, aerated tank in the boat. The boat is launched, the fish are taken to the middle of the lake, then dropped off at high speed. Salmon are scattered over deeper, open water, rather than just placed in a single location near shore, where they are most vulnerable to shallow-water predators like bass, pickerel and, most importantly, fishermen. Stocking fish by boat is time and labor intensive. On days of lousy weather, like last Thursday, it can be dangerous, and difficult. But it's the best way, said Davis. "Boat-stocking these fish offers them their best chance of survival," Davis said. "We want them to grow up and become big salmon." When "fish food," or forage is in good supply and the body of water can support them, the Department stocks yearling salmon -- usually just 8 to 10 inches in length, and well below the legal limit on most lakes. "Why not let the lake do the work of growing big fish?" said Davis. GROWING BIG FISH Growing big fish is the goal, but it's rarely an easy task. "People often look at a stocking report and think, more fish means better fishing, but that's just not the case," Davis said. Stocking rates average just had a fish per acre, and only in exceptional cases will the department stock more than one salmon per acre on a lake or pond. Doesn't sound like much, does it? Establishing a successful salmon fishery is more than just adding lots of fish, Davis said. Just as a trout fishermen can identify a fishy looking riffle, or nice trout pool, biologists have learned to recognize the best salmon waters. Dave Boucher is the Department's expert on salmon. He knows good salmon water when he sees it. "The ideal picture of good salmon habitat, is a large, deep cold lake that has good oxygen in the bottom water," he said. But habitat, and water quality, are only part of the equation. "The lake has to have an abundant supply of smelt, which is the principle forage for landlocked salmon. And that smelt population has to be stable over time," Boucher said. Davis agrees. "Without a good, stable population of smelt, we grow a bunch of wet socks," he said, referring to the skinny salmon that are often the result of a depleted forage base. Peter Bourque, Fisheries Division manager at the Department, has seen the salmon program evolve and change over the years, and understands the difficulties as well as anyone. "Salmon is probably the most finicky fish we deal with," he said. "It's not easy to get the predator/prey balance right." Unlike brown trout, which feed on a wide variety of fish and insects, salmon are more picky about what they eat. "A lot of people think that if we put a 20-inch length limit on salmon, you'll immediately start catching 20-inch salmon. That's just not the case," Davis said. Every pond has a different potential to grow salmon -- and receives more, or less salmon accordingly. Lake St. George, in Liberty, for example, has one of the most stable smelt populations in central Maine, Davis said. Because of that, the Department stocks 1,000 salmon in the lake. Wasookeag, in Dexter, also has a good run of smelt, but is smaller, so it receives slightly less fish -- just 800. Other lakes aren't doing as well. Echo Lake, in Mt. Vernon, is only stocked every third year, to avoid overwhelming the finicky smelt population. Parker Pond, also in Mt. Vernon, has exceptional habitat, and water quality, but the smelt run has dwindled in recent years. To help it rebound, the Department is careful to stock only 400 salmon a year there. UNEXPECTED PROBLEMS Fishing is 90 percent luck, 10 percent skill. The same goes for stocking. "We walk a fine line with salmon," Bourque said. The potential for unexpected problems is endless: A smelt run crashes. Pollutants enter a lake. A new species is illegally introduced. Fishing pressure increases unexpectedly. The list goes on and on. By the end of the day on Thursday, Davis' luck had run out. More than two feet of standing water from the past month's heavy rains had inundated the boat access site on Upper Narrows Pond. It was impossible to launch his boat. It was getting late. Everyone was cold, and wet. It would have been easy to dump the fish near the culvert off the Narrows Pond Road -- particularly since it was only a small batch of just 200. But Davis wouldn't do it. He was concerned that the salmon might get flushed down into Lower Narrows Pond, which doesn't have a strong enough smelt run to support any more salmon. Instead, he and the crew headed off, up the shore of the pond and away from the culvert. About a half mile distant, he was satisfied. "We don't stock salmon from shore, but sometimes, there's nothing you can do," he said. Bucket by bucket, Davis and his crew dropped the fish off in the pond. The little salmon didn't linger. Davis watched as they quickly skittered away. "Every fish counts," he said. Dave Sherwood 621-5648 dsherwood@centralmaine.com |
||||||||
enlarge