Meduxnekeag River Salmonid Fisheries Management

FISHERY PROGRESS REPORT SERIES NO. 2T

By Frank O. Frost

Maine Department of Inland Fisheries and Wildlife
Fisheries and Hatcheries Division
Augusta, Maine

July 2002

Jobs F-103 and F-104

Progress Report No. 1

SUMMARY

The Meduxnekeag River in Southeastern Aroostook County, Maine, supports popular sport fisheries for wild brook and brown trout. Resident and nonresident anglers frequent the river during April to September, depending on river conditions (flow and temperature), and experience trout fishing in a relatively remote setting near the population center of Houlton. The lower mainstem River is surrounded by agricultural lands whereas the drainage upstream from Houlton is mostly forested. Pollution during the 1950s severely limited trout habitat in the mainstem, but environmental regulation has since improved water quality.

During the late 1980s, anglers petitioned the Department of Inland Fisheries and Wildlife to change regulations on the River to conservatively manage the trout fishery. Anglers wanted to protect the populations from over-harvest, increase population size, and increase size of trout caught. In 1990, the bag limit was reduced from 10 fish to an aggregate of two brown and brook trout, the minimum length on brown trout was increased from 6 to 12 inches, and terminal gear was restricted to artificial-lures-only (ALO). In 1992, the special regulation section was expanded an additional 5 miles, including all tributaries downstream of the first road crossing, from the Route 1 bridge in Houlton to the Maine/Canada boundary in Littleton. At this time the brook trout minimum length was increased to 10 inches. The biological basis for the new regulations was to increase survival of trout by reducing harvest in the fishery and reducing hooking mortality of legal and sublegal trout caught. Increased survival of trout to older ages might result in increased spawning escapement and ultimately increased populations.

The sport fishery and fish populations were monitored through intensive creel and electrofishing surveys. Creel surveys were conducted during 1988-1994 and focused on the lower mainstem River. Electrofishing surveys were conducted at Big Brook, a tributary to the lower mainstem River, 8 years during the 1990s, and surveys were also made in 1973, 1977, and 1987 while the study area was under general law fishing regulations.

The reduced bag and length limits met the objective of reducing trout harvest in the lower mainstem River, but did not definitively increase catch rates during this study. In 1988 when general law regulations were still in effect, brook trout harvest was 18 times higher than the level observed during 1992-1994. However, catch rates (number of trout caught per hour), increased during 1991-1992 but then decreased to levels lower than those observed during general law regulation. Voluntary release of legal trout increased after 1990, but it was relatively high even under general law during the late 1980s, indicating a strong conservation ethic among most anglers participating in the fishery.

Average size of harvested brook trout was 10.3 in and 0.47 lb during this study based on 45 trout sampled during 1988-1994. Average size of brown trout was 14.1 in and 1.2 lb based on 21 trout sampled. The new regulations probably did result in higher trout survival: older-age brook trout (age 3-4) and brown trout (age 4-5) were present in the harvest late in the study whereas age 2 brook trout and age 2-3 brown trout supported the fishery during 1988-1990.

The increased number of older trout likely resulted in higher spawning populations and increased recruitment of young trout within the Big Brook study section after special regulations went into effect. At Big Brook, the densities of trout, particularly brook trout, increased dramatically during the mid-1990s. Brook trout young-of-year (generally 2-3.5 inches) increased 11-fold during the 1990s, and the numbers of brook trout → 6 inches increased 2-3 fold, whereas during some years prior to 1991 trout of this size were non-existent. The brown trout population was higher than brook trout for all years sampled except 1993 and 1996. Population estimates at Big Brook, particularly of brook trout, were generally much higher after 1991 than estimates in 1973, 1977, and 1987.

Trout populations in the lower Meduxnekeag River were likely being over-fished prior to 1990. Trout survival, spawning, and recruitment likely increased after 1990 when special regulations were first implemented. Most importantly, however, definitive positive results were not seen in the sport fishery during this study. Depressed catch rates were likely due to high harvest during the late 1980s, producing weak year classes of trout (documented in Big Brook in 1990-1991) that subsequently would have supported the fishery in 1993-1994. Weather and river conditions can influence success of anglers in catching trout, and certain environmental extremes (e.g., drought and mid-winter flooding) can affect trout populations and fishing many years later. Special, conservative regulations provide many benefits to maintaining healthy trout populations. However, trout angling may be no less variable under special regulation than under general law. The conservative fishery regulations on the Meduxnekeag River should be maintained and fully evaluated with an additional 3 years of creel survey.

For more information or a complete report, please contact:

Frank Frost
Maine Department of Inland Fisheries and Wildlife
Fisheries Division
PO Box 447
Ashland, Maine 04732-0447
Tel 207-435-3231
Frank.frost@maine.gov