Athletes jump into the water to compete in the swimming race in the Seine River during the mixed relay triathlon at the 2024 Olympic Games, in Paris, France, on Aug. 5. Martin Bureau / Pool Photo via AP

During this week’s intermittent rain, I found myself watching more of the Paris Summer Olympics than originally planned. The vast variety of sports is impressive across the board, but I’m always particularly compelled to watch the water sports.

This year, there are officially 46 different aquatic events that span five sports — swimming, artistic swimming, open water swimming, diving and water polo. But if you add in sailing, surfing and canoeing, there are many more. All of these sports are a testament to how much people enjoy the water in so many different ways.

At this time of year in Maine, many people are out enjoying the water. In August, the waters have finally warmed and it is more comfortable to go for a swim in the otherwise chilly Atlantic. There’s something freeing about swimming in a natural body of water rather than in a pool. That was the original plan for the open water swimmers at the Paris Olympics — a swim in the Seine, which goes right through the city and meanders past many of the other Olympic venues. Early on in the planning stages for these Olympics, it was clear that it was going to be a major challenge to accomplish this goal, however. Because the Seine flows right through the city, the water quality is less than healthy for humans. Nevertheless, it was an opportunity to try to clean up the river in time for this summer’s games.

After billions of dollars and an immense amount of work, Paris Mayor Anne Hidalgo swam in the Seine just this past July, in a display of confidence that the water was safe for the incoming Olympic athletes. Then, just this past Monday, the first swimmers tested the water. Mixed triathlon relay athletes were able to swim a course of 6.2 miles consisting of six laps back and forth to and from Pont Alexandre III. The Olympic Committee had tested fecal bacteria levels including E. coli and enterococci and determined that the levels were low enough to be safe for the swimmers. The next day, however, the planned test swim for the marathon swimmers was canceled due to higher-than-acceptable levels of bacteria in the lower part of the river, which is part of their course. The hope is that these marathon swimmers will be able to compete on Thursday and Friday of this week — something readers will probably know by the time of this column’s publication but is still unclear at the time of writing.

These events are a historic moment for the Seine, which has been closed to swimming since 1923. The city spent somewhere in the order of 1.4 billion euros to clean it up. They repaired the city’s sewage system, updated water treatment plants and built a retaining pool to catch rainwater and excess wastewater from entering the river before it could be treated — all things that will leave a lasting positive impact on the city and the Seine well beyond this summer’s Olympics.

As is true of water quality worldwide, it depends so much on what happens on the land around it. This week, our intertidal areas were closed to shellfish harvest due to bacteria levels that would make that shellfish unsafe for human consumption. This is a common occurrence after there is plenty of rain and typically doesn’t last long, with nature doing its job of flushing and filtering out the toxins with the tides and returning the waters to healthy levels. We are fortunate in Maine to generally have clean coastal waters, but the impacts of rain are a good reminder of how tenuous this is and how directly what we do on land impacts water quality. Things like improperly functioning sewage systems, the use of fertilizers and pesticides, and the cutting of coastal vegetation all contribute to poor water quality and closures after the rainfall.

Hopefully, as this week comes to an end, it will be safe for both Olympic swimmers to swim in the Seine and for Brunswick shellfish harvesters to dig in our intertidal. Regardless, both examples are important reminders of how taking good care of our natural bodies of water allows us to fully enjoy them and everything they have to offer.

Susan Olcott is director of strategic initiatives for Maine Coast Fishermen’s Association.