r o m sound to sea 



Currituck Struggles with Saltwater Intrusion 



The health of Currituck Sound is 

 failing. 



The vast beds of wild celery, 

 widgeongrass, pondweed and Eurasian 

 watermilfoil that flourished in its fresh 

 waters are now withered by the sting of 

 salt water. In turn, the loss of critical 

 habitat has taken a toll on the fish, crabs, 

 ducks and geese that seek refuge and 

 food in the sound. 



Currituck is losing its draw as a 

 paradise for sportsmen and naturalists. 



"The causes are difficult to pinpoint 

 and correct," says Barbara Doll, N.C. 

 Sea Grant's coastal water quality spe- 

 cialist. "There are major gaps in our 

 field of knowledge — unanswered ques- 

 tions and lack of information — that 

 make management of the sound a chal- 

 lenge." 



Among the challenges is whether to 

 manage Currituck Sound as a freshwater 

 or saltwater system. Before 1830, it was 

 a saltwater ecosystem. That began to 

 change, however, when the Old 

 Currituck Inlet at the North Carolina- 

 Virginia border closed and the sound 

 began to freshen. Today, Currituck and 

 Back Bay are managed as freshwater 

 systems, although recent increases in 

 salinity have posed the possibility that 

 the area might be returned to a marine 

 ecosystem. 



The sound's future is also clouded 

 by the lack of a management plan for its 

 entire drainage system. A shallow finger 

 of water, Currituck extends to the north- 

 ernmost boundary of the Albemarle- 

 Pamlico estuarine system, where it's fed 

 by the North Landing and Northwest 

 rivers. It drains large portions of Vir- 

 ginia with expanses of heavy develop- 

 ment. Canals dredged for the Intra- 

 coastal Waterway, flood control and 

 agriculture link the sound to the Chesa- 

 peake Bay and the North River. As a 

 result, many different agencies regulate 

 activities within portions of the sound, 

 but no single agency or group of agen- 

 cies cooperates to manage the drainage 

 basin as a whole. 



Yates Barber, a biologist and 

 resource conservationist, says the 

 importance of the sound to Currituck 

 County, North Carolina and the entire 

 mid- Atlantic has been neglected for too 

 long. His opinions are grounded in 50 

 years of personal and professional 

 experience on these waters. 



At one time, Barber says, Currituck's 

 100,000 surface acres of fresh water, 

 combined with Back Bay's 26,000 acres, 

 were the most productive black bass rec- 

 reational fishing grounds on the East 

 Coast. But by 1988, virtually all of the 

 vegetation was gone and, with it, the 

 famous black bass fishery. 



Salinity was identified as the culprit. 

 The blame was cast on multiple causes: a 

 severe local drought, the hourly pumping 

 of 1 million gallons of salt water from the 

 ocean into Back Bay, the reduced flow of 

 10 million gallons daily from Northwest 

 River, and saltwater intrusion from 

 Chesapeake Bay by way of Virginia 

 Beach Canal Number 2. 



The practice of pumping salt water 

 into Back Bay had ended by September 

 1987, and in 1989, the drought broke 

 with rainfall some 40 to 50 percent 

 above the normal 45 inches per year. 

 These changes offered hope that 

 Currituck Sound and Back Bay would 

 again freshen, aquatic vegetation would 

 recover and black bass and other fish 

 would return. 



Unfortunately, Barber says, there 

 has been only limited progress toward 

 recovery. In 1992, volunteer monitoring 

 through the Albemarle-Pamlico Estuarine 

 Study recorded salinities high enough to 

 kill black bass eggs and wild celery, an 

 important food for waterfowl. Monitoring 

 by the N.C. Wildlife Resources Commis- 

 sion has turned out similar findings. 



But it's still too early to rule out the 

 possibility that normal rainfall will return 

 salinities and the bass population to suit- 

 able levels, Doll says. 



Sampling by the Wildlife Resources 

 Commission has shown excellent recruit- 

 ment for newly hatched bass during the 



last three years. Catches haven't im- 

 proved yet, probably because bass grow 

 slowly in saline environments. But fish- 

 ing should improve in the next year or 

 two if salinities remain relatively low. 



Barber, however, theorizes that the 

 plants critical to fish and other wildlife 

 will be slow to recover. 



First, he says, salt water continues 

 to invade Currituck Sound through 

 Coinjock Canal. The canal is a dredged 

 portion of the Intracoastal Waterway 

 that connects the sound to the North 

 River, a tributary of Albemarle Sound. 

 Since the canal was built in 1 859 and 

 enlarged in 1920, water has exchanged 

 between the North River and Currituck 

 Sound, but both waters have been 

 mostly fresh in the past. 



So why is Coinjock Canal now so 

 salty? The explanation may lie in low 

 freshwater flows, perhaps another rea- 

 son for a slow recovery. 



Barber suspects fresh water is being 

 diverted from the upper basin of the 

 North River to the Pasquotank River. 

 Historically, thousands of acres of the 

 southern Great Dismal Swamp had been 

 drained by the North River. But recent 

 aerial photos show vast drainage and 

 land-clearing operations that may have 

 redirected large quantities of water from 

 the Dismal Swamp to the Pasquotank 

 River. As a result, reductions in fresh 

 water have allowed salt water to creep 

 into the mouth of the North River, 

 through Coinjock Canal and eventually 

 into the upper Currituck Sound. 



But how this inflow of salt com- 

 pares to other sources such as the 

 Chesapeake Bay remains unknown. The 

 tributaries of the bay are linked to 

 Currituck Sound through the 

 Intracoastal Waterway and other canals. 



Whatever the causes, the problem 

 is complicated by a scarcity of records 

 on water quality and quantity for North 

 River, Currituck Sound, Back Bay and 

 their tributaries. Likewise, there are 

 essentially no baseline records of circu- 

 lation and tidal movement in the sound. 



22 NOVEMBER/DECEMBER 1994 



