Prescription 

 for the 

 Pamlico 



By Kathy Hart 



The Tar-Pamlico is a river in trouble. 



Fewer and fewer schools of spot and 

 croaker fill fishermen's nets. 



Slicks of dead fish and algal blooms 

 occasionally foul the waters. 



And ugly sores afflict crabs and fish with 

 sickening frequency. 



Etles Henries Jr. put it like this at a 

 public hearing in June: "I think maybe 

 people would understand a little better if 

 they could ride down and see fish swim- 

 ming around with holes in them, crabs eat 

 up, just general terrible bad water— water 

 bad enough that you don't want to get in 

 it." 



"The river is yelling and screaming for 

 help," says Doug Rader, a senior scientist 

 with the N.C. Environmental Defense Fund. 

 "There is nothing else the river can do." 



Like other rivers nationwide and in 

 coastal North Carolina, the Tar-Pamlico is 

 showing the symptoms of human abuse. 



The ailment is a condition called eutro- 



phication, a scientific term that means the 

 river has too many nutrients, namely 

 nitrogen and phosphorus. 



What causes the ailment? You and me. 



It's the output from our waste treatment 

 plants and industries; the runoff from our 

 farms, forests, backyards and city streets; 

 and the acid-laden rain from the sky. 



As a result of this ailment, the N.C. Envi- 

 ronmental Management Commission re- 

 cently classified the Tar-Pamlico "nutrient- 

 sensitive" from the headwaters of the Tar 

 River to a line in the Pamlico River connect- 

 ing Roos Point and Persimmon Tree Point. 



The Tar-Pamlico joins the Chowan, 

 Neuse and upper Cape Fear rivers in 

 sharing this nutrient-sensitive designa- 

 tion. Like the Tar-Pamlico, these rivers are 

 rich in nutrients and plagued by algal 

 blooms. 



By designating a river nutrient-sensitive, 

 the EMC places restrictions on nutrient 

 input. 



Now, nutrients are flowing into the Tar- 

 Pamlico like water from a faucet. Scientists 

 at the N.C. Division of Environmental Man- 

 agement calculate phosphorus levels at 

 Tarboro average 0.15 milligrams per liter; 

 nitrogen levels, 0.85 milligrams per liter. 



These figures compare similarly to the 

 Chowan River in the late 1970s and early 

 1980s when thick, malodorous blue-green 

 algal blooms were as much a part of the 



Photo by Kathy Hart 



Albemarle summer as watermelon and 

 mosquitoes. Then, phosphorus levels in 

 the Chowan measured 0.12 milligrams per 

 liter; nitrogen, 0.96 milligrams per liter. 



A 1988 study indicates that most of the 

 nitrogen in the Tar-Pamlico comes from in- 

 direct sources management officials call 

 nonpoint sources. These include 30 per- 

 cent from farm runoff, 21 percent from 

 forest runoff and 19 from acid rain. 

 Another 15 percent of the total nitrogen 

 comes from the pipes of waste treatment 

 plants that discharge into the river. 



In contrast, phosphorus flows mainly 

 from point sources. About 50 percent 

 comes directly from the pipes of Texasgulf 

 Inc. in Aurora and 14 percent from waste 

 treatment plants. Another 12 percent 

 washes off farmland. 



Two recent events will change phos- 

 phorus inputs. A phosphate detergent ban, 

 enacted in 1987, has already reduced 

 phosphorus by 8 percent. And a new dis- 

 charge permit issued to Texasgulf Inc. will 

 reduce the phosphate company's input by 

 90 percent by July 1, 1992. Then Texas- 

 gulf's overall phosphorus contribution to 

 the Tar-Pamlico will drop from 50 percent 

 to 9 percent. 



An abundance of nutrients can trigger a 

 chain of events that begins with an in- 

 crease in the growth of single-celled 

 organisms, such as algae and dinoflagel- 

 lates, and culminates in low dissolved oxy- 

 gen levels and fish kills. 



It works like this. 



Nitrogen and phosphorus spur nuisance 

 algae and dinoflagellates to grow and 

 multiply. In some rivers, such as the Neuse 

 and Chowan, blue-green algae form "sur- 

 face scum so thick you can almost walk 

 on it," says Hans Paerl, a Sea Grant scien- 

 tist who has studied algal blooms. 



In other incidences, the algae and dino- 

 flagellates spread densely through the first 

 foot or two of surface water. There, they 

 photosynthesize, adding lots of oxygen to 

 surface waters. 



But the algae block the penetration of 

 sunlight and slow photosynthesis by plants 

 deeper in the water column. If these plants 

 can't photosynthesize, they don't produce 

 oxygen. The water can become anoxic, or 

 oxygenless. 



That's when you find fish floating belly up. 



But there are other causes for anoxia. 



