Fish kills, decaying matter sources of foul odor from waterways

That unpleasant odor coming from the Pamlico-Tar River, or other area waterways, is more the result of a decaying matter and less the result of sewage spills that occurred during Hurricane Irene, according to the N.C. Department of Environment and Natural Resources.

That odor should be a signal that perhaps residents and visitors should not swim in area waterways until those waterways are determined to be safe for swimming and/or wading, said Heather Jacobs Deck, the Pamlico-Tar River Foundation’s riverkeeper for the Pamlico-Tar River.

“They sampled the beaches first, last week,” Deck said Tuesday. “This week, they are working on the inland rivers. They’re sampling the Neuse, I think, (today). They’re hoping to get to the Pamlico either Thursday or Friday, but they’re thinking by Thursday. If we don’t see anything come Friday as far as elevated (bacteria) levels or notices of swim advisories, that means the Pamlico is probably OK at this point.”

The sampling of local waters could or could not take place later this week.

“It just depends on our schedule. We’ve got some crazy weather coming in,” said Jill Paxson, with the Pamlico Rapid Response Team stationed at the DENR regional office in Washington, on Tuesday.

The team routinely monitors water-quality conditions in the Pamlico basin and investigates fish kills.

The odor is coming from an increase in decaying matter entering area waterways as a result of Hurricane Irene. Other than some scattered sewage spills reported during Irene, Deck said, she is unaware of any subsequent sewage spills in the area. Sewage spills caused by Irene did occur in New Hanover County, Greenville, Carolina Beach and other areas in eastern North Carolina, according to the Department of Environment and Natural Resources. Greenville Utilities reported a spill of 6,500 gallons during Irene.

Deck said a lot of organic matter washed into the waterways, where it degrades because of bacteria. That degradation process uses oxygen in the water, the main cause of recent fish kills in area waters.

The combination of the dead fish and the organic matter breaking down is causing the foul odors, Deck said.

“Some people have asked why they don’t really recollect this from (Hurricane) Floyd, and it may be, and this is just an educated guess, it may have been with Floyd that there was just so much water, which was a lot more rainfall than we had with this system, that it flushed it out a lot more,” Deck said.

“It’s just a process of decomposition. … It’s so stinky that people think it’s a sewage spill,” said Paxson.

Paxson said fish kills are occurring in waters throughout a “wide geographic area” in eastern North Carolina. Individual fish-kill reports since Irene have placed the number of dead fish in the hundreds, Paxson said. The number of dead fish won’t be counted, she said.

“It’s pointless. We’d be working day and night,” Paxson said.

“People should not be alarmed if they see fish kills in eastern North Carolina,” said Coleen Sullins, director of the N.C. Division of Water Quality, in a news release. “We saw this same phenomenon right after hurricanes Bonnie, Floyd and Isabel. Based on what we’ve seen in the past, we’ll probably see more fish kills in the next few days, but then conditions are likely to improve rapidly in just a few weeks.”

Prior to Irene, fish in many eastern rivers were already stressed because extremely warm weather, too, creates lower-than-normal levels of dissolved oxygen, according to DWQ. Irene dumped much rain, debris and other pollution such as wastewater and fertilizer in rivers and streams. As the decomposing leaf litter, woody debris and other waste broke down, the process used up oxygen in the water and left little for fish and other aquatic life.

Scientists with the Division of Water Quality and state Wildlife Resources Commission estimate that hundreds of fish have turned up dead in the Tar-Pamlico, Roanoke and Pasquotank rivers since Hurricane Irene made landfall in North Carolina on Aug. 27.

State scientists began seeing dead fish in the same rivers where in the past few days they have documented extremely low levels of the dissolved oxygen fish need to survive. Fish kills are not uncommon after a hurricane because powerful storms can set in motion a complex process that robs fish of dissolved oxygen.

Staff members from both agencies report that oxygen levels in the rivers have steadily decreased each day since the hurricane passed. As the oxygen levels decreased, staff have seen stressed fish gasping for air and others dying.

“They’re still finding very little to no dissolved oxygen out there this week … so it’s hard to tell how many dead fish are out there,” Deck said.

People who see a fish kill are asked to report it to the N.C. Division of Water Quality at the agency’s fish kill hotline, 1-877-337-2383, or the agency’s regional offices in Washington, 252-946-6481, or Wilmington, 910-796-7215.