Thursday, December 12, 2013
By KEN ALLEN
Recently, an article in the summer/fall issue of "Eddies" from the U.S. Fish and Wildlife Service caught my eye because the message could easily apply to Maine.
In 1994, folks at the California Department of Fish and Game first noticed an illegal northern-pike introduction in Lake Davis, a 4,000-acre water with 32 miles of shoreline. This prompted them to apply rotenone to the lake to rid it of pike, killing 65,000 of the toothy predators.
Such success elated the fish and game officials, but the invasive fish re-established themselves.
The use of rotenone, a piscicide derived from four types of plants in the Leguminosae family, drew complaints from other California officials. So, in 2007, the fish and game department resorted to CFT Legumine to eradicate the pike, and that application has worked -- for the time being anyway. In September 2009, Lake Davis was declared free of northern pike. Time will tell.
One point in the story intrigued me, though. Rotenone is the main ingredient in the compound CFT Legumine, and the additional chemicals in it aid in dissolving rotenone in water. Go figure.
After allegedly extirpating the pike, California later stocked 31,000 rainbow trout, and then in subsequent years, the output of hatchery fish in Lake Davis hit 1 million. In 2010, this water has a fine trout fishery.
The success of the Lake Davis pike program gave me pause for thought. If California can achieve this goal on a 4,000-acre lake and tributaries, why can't Maine do the same -- at least in some places where people have illegally introduced pike?
For example, Long Pond in the Belgrade Lakes chain, a two-basin water, measures 2,714 acres, Messalonskee in this chain covers 3,510 acres and Great Pond 8,239 acres. The Belgrade chain has other waters, too, and pike have worked their way into most of them. A dam on East Pond blocks pike, but that could change any year -- particularly if a bucket biologist transports pike from nearby North Pond and into East.
Through the years, Maine's Inland Fish & Wildlife officials have told me they cannot eradicate invasive species from individual waters or even reduce the population enough to give our salmonids a chance to thrive, but their reasons have struck me as specious at best.
IF&W biologists have often told me that inadequate manpower and lack of funds keep the department from tackling invasive fish species with a piscicide or electro-fishing.
From late spring to early fall, though, IF&W fisheries biologists spend a great deal of time electro-fishing tiny brooks that support brook trout. Many of the brooks do not run into larger rivers or into or from ponds and lakes with self-sustaining brookie populations.
Why do we need to study brooks over and over if manpower and money are tight? I could understand this management program if the brooks were nurseries and spawning habitat for recreational fisheries. Many of these brooks -- particularly tiny or infertile ones -- do not grow 6-inch brookies, the legal minimum length for anglers to keep.
Wouldn't it be a better investment to attack pike in suitable waters? I do not know the definitive answer to that question, but think the topic needs public discussion beyond bureaucrats telling us it can't be done. After all, other states, such as California, have been successful.
Invasive species control does have built-in problems:
First, if a lake or pond has a marshy area, it's difficult to kill fish; however, IF&W does reclaim ponds, such as Egypt in Vienna and Chesterville. The outlet runs through a large marsh, and IF&W has reclaimed this pond multiple times through the decades -- at least once to eradicate sunfish and another time hornpout. It helps the salmonids there.
Second, IF&W officials have told me that lots of Mainers and tourists in this state like northern pike. These fans would squawk if IF&W tried killing them -- say in Belgrade's Long Pond or other pike waters such as Sabattus Pond in Sabattus, Greene and Wales.
Another point is important. Maine has much more sterile waters than many states in the nation, so we couldn't dump 1 million salmonids into a 4,000-acre pond or lake as other states do. However, California can eradicate or control invasive species to help salmonids. That's the message.
Not to belabor the point bass may be fine in appropriate waters, but they raise havoc in brook-trout waters. When thoughtless people dumped black bass into a blue-ribbon brookie pond in New York's Adirondacks, biologists started an electro-fishing program to keep bass populations in check. New York's intense management plan worked on this pond.
Other states are beginning to throw money at unwanted invasive species in their waters, too. It can be done.
Ken Allen of Belgrade Lakes is a writer, editor and photographer. He can be contacted at: