Cutting the Grass

January 7, 2007
By Damond Benningfield

Beds of grass are great natural habitats -- on land or in the sea.

Healthy seagrass bed. Photo: National Oceanic & Atmospheric Administration

They provide food, hiding places, and hunting grounds. They stabilize the soil, and filter out pollutants.

Seagrass beds, in fact, are some of the most productive habitats on Earth. Small fish and shellfish hide among the blades. Larger fish gobble up these small fry. Birds eat the fish, as well as some of the grass. And other land animals eat the birds and their eggs.

These busy, robust ecosystems are found in shallow waters along the coast, where they get plenty of sunlight along with nutrients from the land. But that prime location is also placing many seagrass beds in danger.
A global monitoring program, known as SeagrassNet, has found that seagrass beds around the world are being thinned out. The most likely culprit is human activity.

Global climate change may contribute to the loss. But SeagrassNet founder Frederick Short, a researcher at the University of New Hampshire, says most seagrass losses are caused by local events, not global ones.

Development along the seashore has damaged some of the seagrass beds. It’s also added pollutants and nutrients to the beds, and altered the balance of fresh and salt water. And it’s stirred up sediments, blocking sunlight -- the source of energy for grasses on land and sea.

Losing seagrass beds can decimate fish populations, chase away birds, and lower the quality of the water. And that lowers the natural beauty and quality of life along our delicate coastlines.

This program was made possible by the Texas Sea Grant Program, the Coastal Bend Bays and Estuaries Program, and the National Park Service.

copyright 2006, The University of Texas Marine Science Institute