Monique Coombs is the director of community programs for the Maine Coast Fishermen’s Association. She is also a member of the Coastal Access Strategy Exchange (CASE).

Most water quality issues don’t begin in the ocean. They start on land. The everyday choices we make in our yards, farms/gardens, parks and neighborhoods can have a serious impact on the health of Maine’s coastal waters, especially for the people and businesses who depend on them.

Whether you’re a local resident or a seasonal visitor, here’s something you may not know: just 2 inches of rain in 24 hours triggers an automatic closure of all mudflats for shellfish harvesting. Even 1 inch in 24 hours can lead to emergency closures in specific coves and streams, sometimes lasting for days or even weeks.

These closures are more than just temporary inconveniences. They affect local jobs, seafood supply chains and the broader economy tied to Maine’s working waterfronts. Shellfish harvesters, aquaculture farmers, seafood processors and restaurants all feel the ripple effect when polluted runoff makes shellfish unsafe to eat.

What causes these closures? In short: pollution. Runoff from roads, lawns and parking lots carries pet waste, fertilizers, pesticides, bird/animal droppings and other contaminants into nearby rivers, coves and the ocean. These pollutants raise bacteria levels in the water and can even feed harmful algal blooms that further threaten marine ecosystems.

But the good news is we can do something about it.

One simple and powerful step is to rethink how we care for our lawns and gardens. Fertilizers may help your grass look green, but when it rains, those nutrients often wash into storm drains, or if you are near the coast, directly into the ocean. Once there, they feed excessive algae growth, which can cloud the water, deplete oxygen and harm marine life. Over time, this can lead to harmful algal blooms that pose serious risks to both human and animal health.

By reducing or eliminating lawn fertilizers and pesticides, planting native vegetation and leaving buffer zones along shorelines and streams, homeowners can help reduce runoff and improve the resiliency of our coastal ecosystems. It’s a small shift that can make a big difference.

Properly maintaining septic systems or overboard discharge systems is also a must. If you have a septic system, have it inspected and pumped at least every three to five years, and never flush anything but human waste and toilet paper. Remember, oil, grease and chemicals can damage your septic system, and when that happens, it can lead to groundwater contamination and bacteria entering local waterways.

Another simple step that makes a huge difference is cleaning up after pets. Always dispose of pet waste when walking your dog on the road or trail visiting the dog park. When we don’t remove pet waste, rain washes it into rivers, streams and estuaries, triggering mudflat closures (due to bacteria) that can be economically detrimental to shellfish harvesters.

And boaters should be mindful of how they dispose of waste, too! What goes overboard can also affect the same waters we all depend on, so learn more about proper waste disposal, pump-out stations and how to reduce your impact while on the water.

Ultimately, healthy coastal waters are not just about harvesting clams or growing oysters. They are about our identity as Mainers, our economy, our food system and the quality of life we all value. Whether you harvest, eat seafood, swim in or simply admire the ocean, we all have a role to play in keeping it clean.

Let’s protect the coast and people who rely on the ocean for their livelihoods, starting from our own backyards.