WILLIAMSTOWN — Climate change is such a huge challenge, at times it seems as though we can do nothing meaningful. But here is a local matter on which we can have a significant impact.

According to a Manomet Center/National Wildlife Federation study (2012), climate change may severely limit the viability of trout in Massachusetts by mid-century. Seventy degree water temperatures kill eggs, fry and adults. On a warm summer day, with low water, many of our rivers are hotter than that. That's why trout are holed up in colder tributaries and deeper pools at this time of year — and why fisher folk should lay off the stressed fish.

And that's why five summer interns from Williams College are spending Fridays this July walking tributaries to the Hoosic River, to try to determine which are most likely to retain their cold water characteristics in the face of climate change. The Massachusetts portion of the Hoosic is a cold water fishery.

It is rich in fish, including the angler's prime quarry. Trout — native brook, brown and rainbow — reproduce in the Hoosic and its tributaries, unusual in southern New England. That people are advised not to eat fish caught below North Adams, due to polychlorinated biphenyl (PCB) and biological pollution, only increases the trout population. Fisher folk use barbless hooks and return their catch to the river.

Nor is this a matter for sportsmen only. Trout, what the trout eat and what eat the trout provide a cold water fishery ecosystem that is a measure of the health of a river. Our communities are deeply related to our rivers.

Data collection comes first. Guided by volunteer Dick Schlesinger, several Williams faculty and the Hoosic River Watershed Association, students have placed data loggers in nine locations. These are recording water temperatures during the hottest part of the summer. In addition, the students are dragging temperature data loggers behind them as they move upstream. They are also recording information about the conditions in the water and along the banks.

After the students have walked four or five tributaries comparing the temperature of the water to stream conditions, they will rate which brooks are likely to remain coolest. Then they will pass their findings on to Massachusetts College of Liberal Arts students who will create a climate adaptation plan for the Hoosic River this fall.

The next step will be for the watershed association to see what it can do to improve conditions for the fish in the brooks and along side them. This could include a range of strategies from planting trees to shade the water to urging land trusts to negotiate with land owners to protect corridors to creating in-stream cover or deep holes. Maybe we can prolong the lives of trout in the tribs, at least.

Trout thrive in cold, well-oxygenated, clean water. If there's a gravel or sandy bottom to create nests for spawning, so much the better. Can we keep our fish cool, even as the world heats?

Of course the first step of all is to alter our lives in ways that reduce carbon emissions,. thereby mitigating climate change. Hey, if it's good for the fish, it's good for us, too.

At least, that's how it looks from the White Oaks.

A writer and environmentalist, Lauren R. Stevens is a regular Eagle contributor.