The state Department of Environmental Conservation reclaimed Lower Sargent Pond in Hamilton County in late October.
During the week of Oct. 21-25, DEC staff used rotenone, a pesticide, to kill off the non-native fish in the pond. The DEC now plans to stock the water body with fingerling brook trout next September, with the hopes the water will once again be a naturally reproducing brook trout pond.
DEC Fisheries biologist Rob Fiorentino, who works out of the Warrensburg office, said DEC became aware of largemouth bass in the pond in 2004. After that, DEC started to monitor it. As the years went on, DEC biologists noticed more largemouth bass and fewer brook trout. Those that were remained were older fish.
DEC staff treat Lower Sargent Pond in October as they work to reclaim the pond for native brook trout.
(Photo courtesy of DEC)
Non-native fish, such as bass, yellow perch and golden shiner, negatively impact the native fish communities and ecosystems of Adirondack waters. Non-native fish prey on the eggs and young of native fish. They outcompete brook trout and other native fish by consuming large quantities of zooplankton (very small aquatic animals) and other prey food that the native fish feed upon.
"As the largemouth got larger and more numerous, we started to see no young of the year, or younger ones, and 2-year-old brook trout present in our surveys," Fiorentino said. "Our 2012 survey found no younger trout, only larger individuals."
Adirondack heritage strain Little Tupper brook trout will be stocked in the pond next year. It is projected that in the next three to five years, Lower Sargent Pond will once again be a high quality wilderness brook trout fishing destination.
"We're hoping we'll only have to stock it once or twice, like before, with the increased water qualities that we've been seeing over the last decade or so in the Adirondacks," Fiorentino said. "And the fact that it was self-sustaining beforehand, we're pretty confident that it should only take one or two stockings to get it up and going again."
For decades Lower Sargent Pond was considered a high quality fishery, which sustained naturally reproducing brook trout population. It was one of the most popular fly-in fishing destinations in the Adirondacks, and many anglers would walk the two miles into the pond to fish for brook trout.
Fiorentino said that there are a number of reasons why brook trout have done well in the past.
"It's got a max depth of 30 to 31 feet, so that allows a lot of space for the trout," he said. "It's got probably a handful of springs in it. It's got a good mixture of gravel types on the bottom, so with the springs and the appropriate-sized gravel. There's lots of different spawning areas. And it's a pretty good sized 131 acres. There's lots of water, lots of room."
The reclamation of Lower Sargent Pond is the largest reclamation in New York State in several decades.
A considerable amount of resources and an extensive coordination were needed to complete the reclamation over the five-day period. The effort included the participation of dozens of DEC staff from various regions and programs, and assistance from the State Police Aviation Unit for helicopter transport of personnel, equipment and supplies. There were 37 trips by helicopter during the project, but many workers still had to walk two miles to and from the nearest road carrying equipment and supplies.
Brook trout survive on a diet of insects and other invertebrates, and grow to large size in ponds that do not have minnows as forage. The current state record brook trout is a 6-pound fish caught in an Adirondack wilderness pond that contains no other fish species. Minnows can become abundant in a pond or lake and compete with brook trout for food, thus decreasing the brook trout population.
It is illegal to move fish from one water body to another without a permit from DEC. The possession or use of fish as bait is prohibited in Lower Sargent Pond and many other trout ponds in the Adirondacks to prevent the introductions of non-native fish.
The eradication of non-native fish, followed by restocking with native brook trout is a key component of DEC's Brook Trout Restoration Program. DEC is a partner in the Eastern Brook Trout Joint Venture, which is working to protect, restore and enhance brook trout populations and habitats across their native range.
More information on protection of native brook trout, impacts of non-native fish, rotenone and other topics can be found on the DEC Protecting Adirondack Fish web page.