ingesting pathogenic bacteria and viruses. 

 Shellfish, which filter their food from the 

 water, retain bacteria and viruses in their 

 bodies. Eating contaminated shellfish can 

 result in hepatitis, polio and typhoid. 



Along North Carolina's coast, more 

 than 56,000 acres of shellfish beds are 

 permanently closed to harvesting as a result 

 of high bacterial levels. This area nearly 

 doubles after it rains, when temporary 

 closures give shellfish time to flush the 

 additional bacteria 



The White Oak River Basin, which 



waters of Bogue Sound." 



In addition, the watershed was not 

 heavily developed and did not contain an 

 obvious point source of bacterial loading. 

 "It's a small watershed. Most of the 

 potential sources are in a relatively small 

 area — that will help us," Line says. 



Problems at Jumping Run are likely to 

 be mirrored at other coastal sites, so 

 pinpointing the sources of bacterial 

 contamination, and determining how each 

 source contributes to the overall problem, is 

 essential. Then, engineers like Doll can 



includes Jumping Run and portions of 

 Bogue Sound, has a significant acreage of 

 both permanently and temporarily closed 

 waters. Jumping Run is a perfect site to 

 demonstrate ways of limiting the amounts 

 of bacteria reaching shellfish beds. 



"We felt we could isolate the 

 problems," says Dan Line, extension 

 specialist with NC State's Department of 

 Biological and Agricultural Engineering, 

 who works closely with White. "Jumping 

 Run was one of the first areas closed by 

 Shellfish Sanitation, indicating that it's a 

 major source of bacteria to the adjacent 



choose water-control strategies to remedy 

 the flow of bacteria-rich water at specific 

 locations. 



"The bottom line is, if you can't fix the 

 bacterial problem in Jumping Run Creek, 

 then you can't fix it anywhere," Doll says. 



Searching for Clues 



The Jumping Run Creek Shellfish 

 Restoration Project takes advantage of long- 

 term water-quality monitoring in the White 

 Oak River basin, which has been collecting 

 data on bacterial levels since the 1960s. 

 "We're trying to piece together the 30-year 



history of the watershed," says Line. 

 Together, he and White work to produce an 

 understanding of how and why bacterial 

 levels have changed over time. 



Since 1997, when the restoration 

 project began, researchers have inventoried 

 land uses along the creek, including 

 residential neighborhoods, mobile home and 

 recreational vehicle (RV) housing, an 

 industrial facility and open space — fields, 

 forest and swampland. Aerial photographs 

 from the last three decades show how the 

 land uses have changed over time, allowing 

 speculation on how those changes might 

 contribute to increases in bacterial loading. 



In other fact-finding efforts, surveyors 

 visually assessed septic systems for leaks, 

 and found only two out of more than 50 that 

 appeared to be suspect. Researchers also 

 counted the numbers of outdoor pets and 

 estimated the numbers of wildlife, since 

 animal waste can contribute significantly to 

 bacterial problems. 



"Waste is like a time-release system for 

 bacteria" says Doll. "Bacteria can live for a 

 long time in that environment, and every 

 time it rains, more get flushed into the creek 

 through runoff." 



Scientists also tested the creek itself for 

 valuable data. By injecting dye into the creek 

 at specific locations, researchers can 

 determine how fast the water moves from 

 tributaries to the main stem of the creek. 

 Regular "grab" samples, or water dipped 

 directly from the creek, allows routine 

 monitoring for bacteria and other pollutants. 



Additional storm samplers automati- 

 cally collect water samples over the course 

 of rain storms. When the samples are 

 combined, they provide a snapshot view of 

 any additional bacteria or pollutants washed 

 into the creek by increased runoff. 



The results from these monitoring 

 efforts suggest that most of the bacteria 

 come from residential areas and open 

 spaces. After rainfall, bacterial counts were 

 elevated in the creek's two residential 

 tributaries. The culprits are most likely pet 

 and wildlife waste and home septic systems, 

 though researchers are not sure about the 

 role septic systems play. 



Continued 



COASTWATCH 21 



