Portions of the Savannah River far downstream from Augusta have fish with the highest levels of toxic mercury, according to newly revised consumption advisories.

In its annual update, the South Carolina Department of Health and Environmental Control said the most severe restrictions on eating fish are recommended along the portion of the river from the South Carolina Highway 119 bridge into Georgia's Effingham County downstream to U.S. Highway 17.

Anglers in that area should not eat any largemouth bass, the advisory said.

Closer to Augusta, mercury levels in fish tissue are substantially less, and so are the consumption advisories, said James Glover, the manager of DHEC's Aquatic Biology Section.

"One thing to remember is that these are based on the amount of mercury we find in fish tissue that we test," he said. "They are broad recommendations, but some people see them as absolutes."

The advisories, which typically don't change from year to year, are made with data from three years of testing. Such tests typically include 15 fish of various sizes from one location, Dr. Glover said.

There are no advisories from the base of Thurmond Dam to its confluence with Stevens Creek, and minimal advisories from Stevens Creek downstream to Jasper County.

Dr. Glover said there were no significant changes this year to advisories involving the Savannah River.

A similar list of advisories from Georgia's Environmental Protection Division is almost identical to South Carolina's.

Subtle differences include Georgia's Thurmond Lake advisory for largemouths, which stipulates fish 16 inches or larger.

Georgia also maintains an advisory list for public lakes and most major streams. The list is online at: georgiawildlife.dnr. state.ga.us/content/displaycontent.asp?txtDocument=32.

Reach Rob Pavey at 868-1222, ext. 119, or rob.pavey@augustachronicle.com.