GO TO ANY PORT town along New England’s coast and you’ll find a local seafood market filled with the day’s freshest catch of local fish and shellfish. These iconic small businesses that define our coastal communities rely on healthy estuaries to survive economically. The locally caught seafood these vendors sell needs the environmental habitats found in our bays and estuaries to thrive. It is a delicate balance.

Estuaries such as Narragansett Bay are like “breadbaskets” to fish. These environments that are a mix of fresh and saltwater provide food, shelter and breeding areas essential to fish survival. Clean, non-polluted water and diverse aquatic habitats improve estuarine conditions, thereby supporting healthy fish stocks for local commercial and recreational fishermen.

About 68 percent of the value derived from commercial fish landings in the United States comes from fish and shellfish that use estuaries for food, shelter, reproduction or as nursery habitat. According to a recent report released by the National Oceanic and Atmospheric Administration, this percentage is even higher for recreational fishing. About 80 percent of fish harvested recreationally in marine and coastal environments use the natural resources of estuaries during their life cycles.

Commercial and recreational fisheries generate billions of dollars of revenue each year for the U.S. economy, with $4.1 billion brought to shore in 2007 by the commercial sector alone. In the North Atlantic, 83 percent of the total fish landed commercially use estuaries, including cod, haddock, scallop, crab and lobster. Similarly, 98 percent of the North Atlantic’s recreational harvest is composed of species that depend upon estuaries — fish such as striped bass, bluefish, cod, scup and flounder.

Estuarine areas provide vital functions and services, but their health is declining due to human activities such as coastal development and pollution. In Narragansett Bay, prime fish habitat has been degraded by filling coastal land and by restricting tidal flow into coastal marshes.

From 1930-1990, over 1,700 acres (or 48 percent) of the coastal marshes in Narragansett Bay were physically altered by reducing tidal flow and/or by cutting ditches to drain the marsh surface. Between the 1950s and 1990s, nearly 306 acres of salt and brackish marshes in the Bay were lost.

In addition to coastal marsh degradation, low oxygen (called “hypoxia”) that has been linked to excess nutrients from fertilizers and septic systems contribute to fish kills, as was seen in Greenwich Bay in 2003 and, to a lesser extent, during the past summer in Upper Narragansett Bay. Combined sewer overflows, especially those that occur after large storms, close shellfish beds in the Upper Bay and beyond because of human health concerns. These factors, when combined, have troubling implications for our local economy, environment, and food stocks.

Providence is now hosting the 4th National Conference on Coastal and Estuarine Habitat Restoration, which continues until Wednesday at the Rhode Island Convention Center. The conference is sponsored by Restore America’s Estuaries, a nonprofit organization whose mission is to preserve America’s estuaries by protecting and restoring the lands and waters essential to the richness and diversity of coastal ecosystems. The sessions, workshops and restoration activities provide a great opportunity for scientists, policy-makers, practitioners, businessmen and interested citizens to advance the state of knowledge and take action to protect and restore estuarine habitat. The conference is also a significant opportunity to engage with coastal managers and learn how public policy currently protects these ecosystems, and how to support pending federal legislation that may help estuaries in the future when global climate change will further stress these natural systems.

With the change in federal administration in January 2009, the country’s new leaders must understand the importance of healthy estuaries to the nation’s economy. Politicians and voters need to ensure that funds are invested into local, state, and federal programs that restore degraded habitats and protect unaltered habitats.

Investments in research that will enhance understanding of how estuarine habitats may change in response to such things as climate change and the introduction of non-native species are increasingly vital. Fishery managers in Rhode Island can use this information to make management decisions based on the best scientific information available, thereby improving the management — and hopefully the rehabilitation — of local fish stocks.

Estuaries and coasts are an integral and important part of Rhode Island’s history, culture, and economy. We all stand to lose if our estuarine waters continue to be destroyed — our local fishing industry, coastal communities, visitors to Rhode Island and all Ocean State residents who value a clean and productive Narragansett Bay and coast.

Kimberly Lellis-Dibble is a Coastal Fellow at the University of Rhode Island Coastal Institute. To learn more about Restore America’s Estuaries 4th National Conference on Coastal and Estuarine Habitat Restoration, visit the conference Web site at: http://www.estuaries.org/.