The first comprehensive inventory of Suffolk’s shorelines in about 40 years has been released to the public.

In the 1970s, the Virginia Institute of Marine Science developed “shoreline situation reports” that became “the foundation for shoreline management planning in Tidewater Virginia,” the institute says.

The institute is in the process of updating the reports, as required by its charter set by the General Assembly, and Suffolk’s is complete.

According to Karen Duhring, marine scientist supervisor with the institute’s Center for Coastal Resources Management, researchers traveled 124 miles of waterways by boat during three days in July, and studied a further 136 miles of shoreline using maps.

Duhring presented the findings during a Nansemond River Preservation Alliance meeting Tuesday, describing them as “hot off the press” after analyzing the data with technical staff last week.

“One of the main reasons we are doing this is to give the information to groups like you … to hopefully apply this information in useful ways,” she told the group’s members.

The 2013 Tidal Marsh and Shoreline Inventory for the City of Suffolk will also help local policymakers — including, in their own small way, private landholders with a slice of shoreline in their backyard — render better decisions for the health of waterways like the Nansemond River, and also in dealing with sea level rise, she said.

Vegetation, bank erosion, tidal beaches and access structures are among elements inventoried in the report.

Researchers identified 766 different tidal marsh areas covering just more than 5,000 acres, “some of them very big, some of them very small,” Duhring said.

More than two-thirds of that is “extensive marsh” — defined as a large marsh with similar length and width. Fringe marsh, or narrow strips of marsh vegetation along shorelines, makes up almost one-fifth, while embayed marsh, which surrounds headwater areas, accounts for almost 15 percent.

Brackish mix, with no dominant species, and salt marsh, which floods during high tide, both cover almost 1,700 acres, while about 821 acres were not surveyed for plant communities, Duhring reported.

“We can’t really look at a photograph of a marsh and tell what the plants are,” she said.

The report also tallies docks, boathouses, boat ramps, private and public docks and marinas.

Suffolk’s dominant land use type is forest, it concludes, which Duhring described as “a highly beneficial situation to have for water quality.”

Bank heights also came under scrutiny, with researchers eyeballing them and concluding 86 percent are between zero and five feet high, Duhring said.

Duhring said banks in Suffolk are low, putting a lot of shoreline at risk of flooding. But in terms of erosion, 99 percent of banks are stable.

Duhring said she and her colleagues at the College of William and Mary-based institute have found “you can’t legislate” for shoreline health — it takes action on the part of communities.

The report is online at www.ccrm.vims.edu.