Placing an economic value on these services is challenging, but that doesn't keep resource economists from trying. Recently, resource economist Edward Barbier and colleagues reviewed U.S. studies that estimated the dollar value of these services. Their results:

• Coastal protection from storm surges and flooding. Value = $3,334/acre/year
• Water purification through the uptake of pollution and excess nutrients such as nitrogen. Value = $785 - $15,000/acre/year
• Carbon sequestration, whereby salt marsh plants take up carbon and deposit it in sediments. Value = $12/acre/year
• Recreational fishing, which depends on salt marshes to provide nurseries, shelter and food for both shellfish and finfish. Value = $981 -$6,471/acre/year

Nevertheless, the total value of this incomplete list is impressive: $5,112 - $24,817/acre/year. Assuming that these values are applicable here, our 1,100 acres of salt marsh have a minimum estimated value of $5.6 million to $27.3 million per year.

Another approach to estimating how much our salt marshes are worth is to look at how much someone, say a developer, who wants to destroy a wetland has to pay to compensate for its loss. For this we can turn to state wetland mitigation programs that require compensatory payments by developers who destroy wetlands. Several states along the East Coast have established payment levels for such programs, including Massachusetts where earlier this year the Department of Fish & Game and U.S. Army Corps of Engineers established a fee of $621,165/acre for coastal wetlands. At this price, Westport's 1,100 acres of salt marsh are worth $683 million.

One-half of the world's salt marshes and an estimated 37% New England's salt marshes have been filled, dredged or in other ways lost to human development. Although state and federal laws now offer strong protection for coastal wetlands in Massachusetts, indirect and unintentional factors such as toxins, excess nutrient loads and alteration of tidal flows continue to threaten their health.

For example, a 2002 report by the Buzzards Bay National Estuaries Program identified 20 places in Westport where bridges, paths, culverts, and other structures were impeding tidal flows of importance to the health of our salt marshes. Restricted tidal flushing general results in more fresh water in the marsh which, in turn, generally results in dense stands of phragmites replacing native vegetation, with serious consequences for fish and wildlife. These tidal flow restrictions range from relatively small ones, such as the inadequate culvert that, at the time of the study, connected Cockeast Pond with the west branch of the river, to very large ones such as the Route 88 bridge over the river and the rubble under Hix Bridge. WRWA worked with the Town of Westport Highway Department, the Westport Fishermen's Association and many other individuals and groups to restore the tidal flow into Cockeast Pond by inserting a larger culvert in 2010, and we are now collaborating with the Town of Westport, Mass DOT and U.S. Army Corps of Engineers to remove the rubble and restore natural flows-and oyster beds-at Hix Bridge. Much more obviously remains to be done.

As the economic values of salt marshes indicate, the costs of such restoration projects are often well justified. While assigning a dollar value to the multiple benefits provided by the Westport River and its salt marshes is useful for shaping policies and securing funding for conserving them, we also recognize that the dollar is not the only measure of value. Many of us, if asked the value of the Westport River and its salt marshes, would reply "priceless." We believe that conserving these rich ecosystems and the diversity of life they harbor and that we enjoy is, regardless of their economic value, simply the right thing to do.