BB Dick

A volunteer places a temperature sensor in a Williamstown stream.

If you go to MassWildlife’s “Coldwater Fisheries Resources,” a map of the commonwealth appears with coldwater lakes and streams in blue. The short definition for “cold water” is capable of sustaining trout, at least for a while. The climate crisis threatens these waters.

It is good news that the Division of Fish and Wildlife and the Department of Environmental Protection, which handles permitting, agree on the definition, as they haven’t always. The state has 1,300 coldwater fishery resources, totaling 4,000 miles. Although Berkshire County is laced with blue lines, they become less dense as you move east. By the time you cross I-495, virtually nonexistent. Is that the future for our part of the state?

The Hoosic, Housatonic and Farmington watershed associations, together with Berkshire Environmental Action Team and the Regional Planning Commission, are taking water temperature readings this summer as part of a DEP grant that also involves Berkshire Community College. What are the waters most capable of retaining coldwater characteristics and what can be done to prolong their lives?

Loss of the trout, the prime sports fish of the Appalachians, would be bad enough, but trout represent an entire ecosystem: what trout eat, what eat trout, other cold water fish and their habitat. Trout fishing produces income in Berkshire. In other ways, including local pride, the presence of trout improves the quality of human lives.


Coldwater fish resources — streams, rivers or tributaries in which reproducing coldwater fish are found — are shown in blue in this Division of Fisheries and Wildlife map of Massachusetts.

Water temperature does not track air temperature exactly, yet warmer weather indirectly warms the water — especially in open ponds, say behind a dam. CFR classification is forgiving. The test for a waterway is that it “meet one or more of [fish] life history requirements.” So the map, for example, shows many Berkshire waters where “the maximum daily temperature in the summer over a seven-day period” exceeds 68 degrees F, a temperature unfriendly to trout. They still might find a deep hole or a shaded spot or temporarily refuge in a colder tributary.

Other life requirements include “high water quality, natural flow regimes, intact riparian areas, highly oxygenated water, complex and diverse physical habitat, longitudinal and lateral connectivity.” These suggest the kinds of steps that can be taken to prolong CFRs.

The first step, and the reason for the temperature measuring, is to determine which water bodies are most likely to stay cool. Around here, nature tends to bless the brooks tumbling down from high elevations, and the streams and ponds into which they flow. Fortunately for us, and the fish, much of the high elevation land is protected by steep slopes, state forests or Scenic Mountain Act and other zoning.

Humans can take actions to assist what elevation and forests provide. Banks are key: They should be tree-lined or at least vegetated, in order to shade the water — and hold the stream bed and filter pollution. Riparian land can be protected by owner’s actions, conservation easement or outright conservation ownership in order to maintain the banks.

Trees should be left in or over the water unless they constitute a flood threat. They provide cover for fish, which have avian predators, and they provide shade. Trees can be dropped into the stream and secured in place. The common pattern of a stream, pools and riffles, can be augmented, if necessary, by excavating deeper pools.

Dams no longer in use can be removed. Although breaching larger ones can be complicated and expensive, many homeowners have created small dams in the stream the runs by their backyards. Permission from the Conservation Commission granted, their removal might be fairly simple.

To date, the state’s Wetlands Protection Act does not include heat. Towns can write their own regulations that consider the potential warming of streamside development.

So if you see volunteers in wading this month, they may be doing more than cooling their toes. They may also be collecting temperature data along with other water quality information. At least, that’s how it looks from the White Oaks.

Writer and environmentalist Lauren R. Stevens is a regular Eagle contributor.