In the world of scuba divers of the St. Lawrence River, Ron MacDonald is a legend. He was born and bred in Cornwall, owned and operated Ron’s Scuba Shop for 46 years until 2015, and has been diving in the river for more than 60 years. Put another way, he is de facto an expert on all things related to diving in the St. Lawrence and can easily tie his observations to timeframes and anecdotes.

In our first conversation in 2018, Ron pointed out that different sections of the river have unique qualities when it comes to water clarity. He also had important generalizations to offer, backed up by his log books.

In the 1960s and 1970s, he told me, visibility while diving was only about two to three feet. Ron remembered his diving group using four-foot-long ropes to keep track of one another. By the mid-1990s though, he said the water clarity improved significantly. In some sections, like near the Thousand Islands and Brockville area, divers could sometimes see in excess of 100 feet! The 82-year-old also reported a recent decline of visibility—something he’d noticed happening since 2015.

For the purposes of the Great River Rapport, Ron’s decades of observations add depth to the project as we link his knowledge with scientific findings to tell the complete story of the river’s health. For example, we can look at Ron’s observations of water clarity and tie that to the period when invasive mussels were introduced into the St. Lawrence. These animals filtered the water which increased clarity but also changed the flow of nutrients through the food web reducing the amount food available to other organisms. Thanks to this filtering of the water, predators reliant on clear waters for feeding benefited from this change in the river, including osprey.

In a follow-up call to Ron a year after our initial conversation, I was amazed to find him still an active diver, about to set out on his 99th dive of the season. I had the pleasure of accompanying him on a dive the next day. We went in at the Cornwall Harbour, just next to the Cotton Mills. Greeted almost immediately by smallmouth bass as we ventured along the harbour wall, we saw walleye as we made our way out into deeper water. Much further down, freshwater drum cruised past us and as we neared the end of the dive, approaching the shallows again, a school of perch welcomed us. That was a real highlight. This hour-long dive marked the first time I was able to see the fish of the St. Lawrence first hand underwater. But it was also my introduction to the garbage that lay beneath the surface of the water: the many beer cans, a shopping trolley, sections of discarded fishing line that Ron bundled up as we went along, and a set of about a dozen navigational batteries. We also came across one sad fish with a long piece of plastic stuck in its mouth that we could not retrieve. It was a reminder that we still have plenty of work to do to bring the river back to good health.

Luckily, we have allies— scientists, community groups, and river observers like Ron—to help us get there.

“Never underestimate the power of water and the stupidity of man”

-Ron MacDonald