Reef balls event and reef balls at shoreline
Approximately 200 volunteers participated in the April 2017 Earth Day event (left) to plant 15,000 salt-tolerant (Spartina) plugs of grass. The after-shot in July 2017 (right).

In Stratford, Connecticut, where the Housatonic River feeds Long Island Sound, coastal marshland once helped absorb flood water and protect the coastline. But over time, the marsh was destroyed and the shoreline severely eroded.

A few years ago, Jennifer Mattei of Sacred Heart University thought of a way to tackle the problem.

Mattei: “Reef balls are sort of hollow concrete structures. They look like a giant gumdrop with holes in them.”

They were originally invented to help rebuild coral reefs. But Mattei had a hunch that they could slow erosion by reducing the impact of waves.

As a test, rows of the heavy domes, each about three feet wide, were installed just offshore. They’re fully visible at low tide, and partly submerged at high tide.

Mattei: “It was enough to slow the water so that sediments were deposited rather than being washed away.”

The area protected by the reef balls became a place where marsh grasses could grow again.

Now, the experiment has expanded, and reef balls span a thousand feet of beach. Mattei hopes they’ll help protect the shoreline from heavy waves and storms.

Reporting credit: Sarah Kennedy/ChavoBart Digital Media.
Photos: Courtesy of Jennifer Mattei.

Jan Ellen Spiegel is a long-time Connecticut-based journalist whose career has included radio, television, print, and digital reporting. She has won awards for her reporting on energy, environment, climate...