Many years ago, an old friend of my husband’s who I didn’t know very well was visiting. He is fairly understated and I was not sure how or if we would have much to talk about. However, somehow the unlikely subject of environmental history served as a bridge — and the start of a conversation that continued over many future visits. It started with a shared book that we both had read in college: Bill Cronon’s “Changes in the Land.” The book is a detailed account of the impacts of European colonization on the natural ecology of New England. I have to admit, if I weren’t reading it for school, I might not have made it through the sometimes dense material. But I’m glad that I did — not just for the friendship that it initiated but also for the appreciation I gained from it of the importance of environmental history as a whole.

Fast forward many years and another friend, this one a nature writer, asked me about some of the specific changes I’d observed along the coast in recent years. As I started to piece together what I had and not seen at different times, I found myself tying those observations to events in my life as reference points — whether I’d been back in Maine for long, my girls were walking yet or I was with certain friends that I met at a particular time. Soon, I realized that what I’d pieced together was a timeline — a kind of environmental history of my own. Without one consistent record of these observations, it required some further sleuthing into old photos, past Intertidal columns and journals. The result helped me to look at changes that might have seemed incremental at the time but now were significant.

This was a good lesson in the value of everyday, casual but careful observations that, when encapsulated in a photo or written record, can help to reveal important environmental shifts. They can even help to identify some of the causes of those shifts. I have written about more structured community science projects many times over the years in this column, some of which I’ve participated in and others that I’ve simply heard about and have shared with readers. But it didn’t occur to me how much “scientific” data I’ve collected as an individual over the years and how much so many other people also have that is outside of these organized projects. There is tremendous value in anecdotal information that doesn’t necessarily fit neatly in a community science project and almost has to be gathered in the manner of forensics — rooting clues out of old stories and recordings.

Going forward, I aim to do a better job at keeping a record of these observations and would encourage others to, as well. Tracking small changes over time can help to better understand our impacts on the environment, be it more land-focused as in Cronon’s book or more coastal in my case. It might also foster unexpected conversations and even friendships.

Susan Olcott is the director of strategic partnerships at Maine Coast Fishermen’s Association.