Brook trout hatchery study results promising for anglers

Saturday, December 10, 2005

Myriad ponds and lakes, particularly in the bottom third of Maine, have wonderful water quality for salmonids but little to no spawning habitat. In short, these waters would not support a sustainable recreational fishery without stocking. It's that simple.

Because of that fact, we need quality hatchery fish, and in the past nine years, the Maine Department of Inland Fisheries and Wildlife has quietly conducted an exciting, two-phase research project to evaluate four strains of hatchery brook trout, based on growth rate, survival and return to anglers.

With little fanfare, fisheries biologists and hatchery personnel have collected solid data to see which strains worked best -- Nesowadnehunk, Kennebago, Maine Hatchery and Kennebago crossed with Maine Hatchery.

Statistics from the study surely promise better fishing for central and southern Maine and for brook trout anglers in the immediate future because until the somewhat recent past, most of our hatchery brookies did not survive the year after being released into the wild.

DIF&W now stocks fish with more longevity than ever before, and part of the reason begins with this research, showing which strain has the best survival and growth rate.

In the study, DIF&W fisheries biologists routinely trap-net 3- to 5-year-old brookies, particularly in places where stricter regulations insure anglers kill less fish, giving the trout a chance to grow.

With the right water quality, modern hatchery brookies can pop an angler's eyes wide open.

DIF&W eliminated the Nesowadnehunk strain in the late 1990s, according to William Woodward, a fisheries biologist involved in the study.

Then, the department concentrated on the Kennebago, Maine hatchery and cross-strain.

Data from these three strains look promising.

In one water, Kimball Pond in Vienna and New Sharon, growth and survival rates over a one-year period showed the Kennebago strain grew 5.3 inches and had a 13 percent survival, MHS 1.9 inches and 2 percent, respectively, and Kennebago-MHS cross 3.8 inches and 20 percent.

Woodward said the study is winding down now, and as the statistics illustrate in Kimball, the decision of which strain to use has no cut-and-dry answer.

For instance, the Kennebago strain grew the fastest in this pond but the Kennebago-Hatchery cross had the highest survival, creating a conundrum.

Do you want higher survival or faster growth?

Dennis McNeish, a biologist supervisor at the Department, said that different strains would be suitable for varying habitats.

In short, choices depend on the management program's aim of put and take or put-grow-take, competition from predators such as bass, pickerel, etc., and other factors that restrict or promote longevity and growth.

One of the offshoots of this research caught my eye more than anything else.

Ponds with strict regulations such as Kimball and Little in Damariscotta produce 3- to 5-year-old brookies in numbers, leading to an irrefutable conclusion.

Suitable ponds stocked with brook trout need more quality-fishing regulations because under general law, anglers are fishing them out in a year, according to Woodward.

Right now, fishing activists in Maine have put great energy into saving indigenous brook trout that have never had their genes polluted by hatchery fish, and this writer applauds the effort.

However, we must remember that stocked waters also need protection, and in an indirect way, growing 2- to 5-pound fish in the bottom third of Maine will remove pressure from north-country ponds.

If anglers can catch big brookies in heavily populated southern and central Maine, then they will be less apt to traipse north and fish for indigenous trout.

Purists would rather go to northern Maine ponds and catch these jeweled beauties where stocking trucks have never roamed, but the majority of department's customer base would prefer tangling with a 3- to 5-pound brute from a place like Little Pond rather than tangle with an 8-inch "flippety-flop" from a pristine jewel far from roads.

(A brookie that can survive years in the wild is no stink fish, either!)

Circa the late 1980s, the department raised the minimum salmon length limit from 14 to 16 inches on Long Pond in the Belgrade Lakes, and the following year, biologists noted a disastrous result.

The 2-inch increase saved so many landlocks from being killed that these fish overpopulated the pond, causing the smelt population to crash.

This resulted in scrawny fish the next year.

So, they lowered the stocking number the following season, and presto, smelts came back and the fish fattened into the shape of footballs.

They were incredible, and the good times rolled for a few years before northern pike and over-fishing killed Long Pond's salmon fishery.

The above parable has two lessons: 1) Raising the length limit can save fish in the right circumstances, and 2) stocked fisheries are much easier to manage than wild ones.

Long Pond had too many salmon, so the decrease in stocked fish saved the department money and remedied the situation.

In contrast, a wild salmonid fishery with an overcrowding problem needs liberal limits to attract anglers; however, what's the next option if fishing crowds don't respond?

There is none.

The moral of the story?

In waters with no spawning habitat, fisheries biologists can fine-tune fish populations with stricter regs and hatchery fish, putting the license-buying public into a win-win situation on a water that nature neglected to grace with trout.

Ken Allen, of Belgrade Lakes, is a writer, editor and photographer.