Old News Archive

The Eastern Brook Trout Joint Venture

July 17, 2006 - TRC

The Eastern Brook Trout Joint Venture (EBTJV) is a range-wide conservation effort to protect, enhance, and restore aquatic habitats for wild brook trout (Salvelinus fontinalis). This broad scale conservation effort seeks to maximize existing partnerships and expertise throughout the US’s native brook trout range through a collaborative, non-regulatory framework. The multi-state, multi-jurisdictional partnership has completed a range-wide assessment of wild brook trout status from Maine to Georgia, determined and ranked threats to brook trout range-wide, and developed a predictive model of brook trout status where current information is lacking or unknown.

These efforts have highlighted the plight of wild brook trout across their native range. Currently, thriving and intact wild trout populations occupy only about 9% of their historical range in the United States and little is known regarding the status of brook trout within large river systems or the status of anadromous, or sea-run, brook trout in coastal streams.

In addition, the range-wide assessment identified top threats to sustaining brook trout throughout their range. These include increasing water temperatures, land use changes associated with agriculture and development, degraded riparian habitats, and the effects associated with exotic species introductions into brook trout waters.

The partners of this broad effort include all the state agencies that manage wild brook trout from Maine to Georgia, federal agencies responsible for land and water management, academic institutions, national organizations such as Trout Unlimited and the Izaak Walton League, local groups, municipalities and concerned citizens.

The overall goal of this monumental conservation effort is to sustain healthy, fishable populations of wild brook trout throughout their native range. Each state is currently drafting conservation strategies that address each state’s needs and threats that were identified in the range wide assessment. For additional information regarding this effort and the partnership, please check out this link: http://www.brookie.org/

What does this mean for Maine?
The assessment confirms Maine’s importance as a remaining reserve of intact brook trout populations where close to 20% of the nation’s resources occur. In addition, this work highlights the position of Maine as the primary steward of 97% of the thriving wild trout inhabiting large lakes in the US.

However, this effort also identifies Maine’s need for basic information where about 55% of our trout habitats are either unsurveyed or existing data does not meet the standard for analysis. Therefore, the analysis was unable to determine the amount of lost brook trout habitat in Maine. We have a lot of work to do in the near future to address these knowledge gaps, as well as continue existing efforts, and possibly develop new strategies for wild brook trout conservation statewide.

Another component of the assessment identified and ranked the threats most likely affecting brook trout management. In Maine, the top threats in streams are factors that contribute to habitat fragmentation, such as passage constraints and dams, and some land use practices that contribute to stream bank degradation and increased sedimentation rates. The factors identified as the greatest threats to lake populations of brook trout include the effects associated with exotic species introductions and degrading water quality.

What is Maine’s basic need?
First and foremost, we need to make significant progress toward filling in the gaps of our knowledge. Of Maine’s 1053 subwatersheds, we lack current and adequate data in 716 of them. This translates to be roughly two-thirds of the state’s total area. Hence, we are actively collaborating with and seeking assistance from the Venture’s partners in order to enhance our survey programs. The next few years may well prove to be very exciting times for brook trout in Maine.

As an overall greater survey effort increases statewide, this also provides us with an incredible opportunity to garner additional information regarding a variety of issues and concerns currently facing fisheries management in general. For example, crews will inventory habitat quality while conducting fishery surveys, which assists with identifying opportunities for habitat improvement or for addressing fish passage concerns. This statewide effort will also provide valuable information regarding the distributions of other native fish species, as well as documenting new occurrences of unwelcome invaders. Primarily, we will compile an incredible storehouse of knowledge regarding the status and condition of one of Maine’s most valuable resources, our wild brook trout!

Merry Gallagher, Research Fishery Biologist, Maine Department of Inland Fisheries and Wildlife.

Eastern Brook Trout – A Closer Look
Scientific Name: Salvelinus fontinalis
Origin: Native
Range and Habitat: Brook trout are native to the coldwater lakes and streams of Maine, and occur in 1,100 lakes and ponds and 30,000 miles of streams. They are more abundant in the interior highlands of the state where they prefer water that seldom exceeds 70 degrees Fahrenheit and where competition form warmwater fish species is minimal. Along the coastal lowlands, where temperatures are marginal and competing fish species are abundant, brook trout populations are typically supported by stocking. Some coastal streams support sea-run populations of brook trout.

Spawning: Brook trout spawn in the fall in gravelly areas of streams or, less frequently, in springs. Eggs are deposited in a depression in the gravel dug by the females with their tail. Eggs are fertilized by the male as they are laid, then quickly covered with gravel by the female. They hatch in early spring, but the young sac-fry remain below the surface of the gravel until the yolk sac is absorbed, they then venture out and establish territories. As brook trout reach a larger size, they may migrate within the stream or to lakes within the system.

Food: Brook trout may subsist on insects throughout their life, but will forage on fish, including smelt, if they are available.

Adult Size: Size varies greatly, depending on water temperature, productivity, and food sources. The statewide average length of 3 year-old brook trout in Maine lakes is 13.3 inches. However, same age trout from different lakes range from 7.5 to 17.5 inches in length. Stream populations are typically slower growing than lake populations. Some high elevation trout populations mature and reproduce at lengths smaller than 6 inches.

Identification: Color is variable, depending on habitat. Brook trout can be distinguished from other members of the trout family by the dark, wavy, worm-like line on their back and the white leading edges of their fins, including the tail.

Submitted by Mark Latti, IFW

NOTE - This article reflects the views of the author and not necessarily those of the TRC Alliance Team.