Seagrass Provides Lifeline for Fish and Coastal Economies

© NOAA

A flounder swims through a bed of seagrass in Narragansett Bay, Rhode Island. An acre of seagrass can contain up to 40,000 finfish and 50 million small invertebrates. The habitat needs better protection under the Magnuson-Stevens Act.

Boaters motoring along many areas of shoreline on the United States’ Eastern Seaboard will eventually encounter blades of seagrass rustling propellers just below the surface. For boaters, this can be a problem. For marine life, seagrass is a major benefit.

Seagrasses are a type of submerged flowering grass, with leaves, roots, and veins that distribute nutrients and water throughout the plant. Seagrass, which is different from seaweed, provides food and shelter for thousands of species. For example, the small organisms that live on or around the seagrasses are food for many species targeted by commercial and recreational fishermen, including flounder, striped bass, bluefish, weakfish, tautog, spot, croaker, and red drum.

The Smithsonian Institution’s National Museum of Natural History reports that 1 acre of seagrass can support as many as 40,000 finfish and 50 million small invertebrates. Seagrasses also help to stabilize the seafloor, clean the surrounding water, and remove carbon dioxide from the atmosphere.

But these flora are dying in vast tracts across the globe. Industrial pollution and runoff, warming waters, and the introduction of invasive species are among the factors contributing to the loss of 1.5 percent of the world’s seagrass beds every year—or the loss every hour of enough seagrass to cover about two football fields. That threatens not only the marine life that depends on the seagrass but also the economies of coastal communities that rely on commercial and recreational fishing.

Congress can help

Congress has an opportunity to improve protections for all marine habitats when it reauthorizes the primary law that governs U.S. ocean fishing, the Magnuson-Stevens Act.

In the U.S., seagrasses thrive in shallow areas that are usually close to shore, in state-managed waters. But scientists say the health of the plants affects the broader marine ecosystem, including fish populations in federally managed fisheries farther offshore. That’s one reason the National Oceanic and Atmospheric Administration’s Fisheries Service (NOAA Fisheries) recommends minimizing damage to important habitats like seagrass.

Congress could help achieve that goal by strengthening Magnuson-Stevens to require projects funded or authorized by federal agencies, such as dredging, to follow NOAA Fisheries’ recommendations.

Local organizations work to reverse the decline

Fortunately, some local organizations and agencies are taking steps to save these critical flora. In the Chesapeake Bay and coastal Florida, seagrass restoration programs are slowing and, in some cases, even reversing some of the losses. Jurisdictions are doing this by curtailing nutrient runoff, which can lead to algae blooms that block essential sunlight, and by upgrading wastewater treatment plants to minimize pollution runoff. They’re also replanting areas where seagrasses have dwindled.

As Congress works to renew the nation’s federal fisheries law, it’s a prime opportunity to step up protection for the places fish need to grow, eat, and reproduce. The act is turning 40 years old in April and could use an update. It’s time for a new focus in fisheries management. For more information, please visit pewtrusts.org/healthyoceans.

Peter Baker directs ocean conservation efforts in New England for The Pew Charitable Trusts.