Seagrasses are the “coastal canaries” of oceans and bays. When these underwater flowering plants are sick or dying, it means the ecosystem is in big trouble — typically due to pollution that reduces water quality. But when they are thriving and expanding, it is a sign that the ecosystem is becoming healthier.

We have collaborated on seagrass research for three decades in the Chesapeake Bay and beyond. One of us (Bob “JJ” Orth) has mapped and studied the bay’s submerged aquatic vegetation since the 1980s. And the other (Bill Dennison) studies seagrass ecophysiology and has led efforts to make this science understandable and useful.

Seagrasses are critical to a healthy Chesapeake Bay. They provide habitat for fish and shellfish, stabilize sediments and help clarify the water. The bay’s grasses declined sharply in the 1970s, as pollution and development degraded its water quality. States around the bay have been working together since 2010 on a sweeping plan to clean it up and restore its ecosystems.

In a new study, we provide conclusive evidence that reducing discharges of nitrogen, phosphorus and other pollutants into the bay has produced the largest resurgence of underwater grasses ever recorded anywhere. This success shows that coastal ecosystems are resilient and that concerted efforts to reduce nutrient pollution can result in substantial improvements.

Read the full article about cutting pollution in the Chesapeake Bay at The Conversation.