Unearthing the secrets 

 of N. C.'s geologic past 



Over the years. Xorth Carolinians who spent 

 most of their days living next door to the Atlantic 

 learned to respect their neighbor. Those that got 

 to know her built their homes and shops in places 

 protected from her gusting winds and tides. 



But those who spent only a few weeks of each 

 year in her company often put cottages right on 

 her doorstep. The Atlantic didn't seem to care 

 whose property she blew and washed away in her 

 daily cleaning. In many cases, it didn't take her 

 long to over run her neighbors' lands. 



Many newcomers and summer people didn't un- 

 derstand their great neighbor. No one explained 

 to them that shorelines are retreating about five 

 to 10 feet per year, while sea level continues to rise. 



Nobody told them because nobody really knew 

 the changes time had witnessed in the state's shore- 

 lines. Even today, a picture of the geologic forces 

 that shaped — and are still shaping — North Caro- 

 lina's beaches is not complete. But a study in the 

 Roanoke Island area by East Carolina University 

 geologists. Drs. S. R. Riggs, and M. P. O'Connor, 

 should add key pieces to the geologic puzzle of 

 coastal North Carolina. Their studv is supported 

 by UNC Sea Grant. 



The research aims at learning what minerals 

 and soils make up coastal lands both above and 

 below the water's surface, where they are located 

 and in what amounts. 



Tied closely to their study of soils is research 

 to unravel the geologic processes that chiseled 

 Xorth Carolina's present coastline. 



Relying on old maps of the area as well as 

 sophisticated tests and analyses of the soils and 

 fossils found at various levels beneath the soil sur- 



Studies of geologic forces acting on the state's 

 coast can help pinpoint areas where development 

 might be unwise. 



face, Riggs and O'Connor have traced many of the 

 changes shaping the state's coast for the past 

 40,000 years. Such forces as a rising sea level, 

 constant shifting of the barrier islands and the 

 periodic opening and closing of inlets and channels 

 shaped today's shoreline, the researchers say. 



From their evidence of the past, the geologists 

 hope to better predict shoreline changes. 



Riggs and O'Connor believe their findings will 

 provide sound bases for decisions on how coastal 

 lands should be used in the future. They will make 

 their findings available in a geologic atlas to be 

 published later this year. 



Wise coastal land-management hinges on an 

 understanding of the processes that have and will 

 continue to act on coastal lands, Riggs and O'Con- 

 nor contend. Their atlas will be aimed at informing 

 land-policy decision-makers of these processes and 

 at providing guidelines for wise coastal develop- 

 ment. 



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Changing dredge spoil 

 to valuable marshland 



To a lot of folks, the swampy marsh that sepa- 

 rates hard, dry land from the Atlantic looks pretty 

 worthless. 



But scientists know that marsh offers more than 

 meets the eye. The grasses that grow there and the 

 tidal waters that flood the marshes offer nursery 

 and nutrients for young, growing shrimp and fish. 



Marsh, vital to the growth of many fish and 

 shellfish, has shrunk alarmingly in recent decades, 

 the victim of man's hunger for land. 



Meanwhile, not far from the marsh, in the shal- 

 low sounds and estuaries between North Carolina's 

 mainland and its Outer Banks, machines with long 

 arm-like claws suck sand and mud from the bottom 

 of channels and pump it onto beaches or into open 

 waters. Dredging channels, keeping them deep 

 enough for boats, is a never-ending chore. All too 

 quickly, dredge spoil, having no grass or vegetation 

 to hold it, makes its way back into the channel. 



Years of costly dredging with its wear and tear 

 on the environment, coupled with a mounting con- 

 cern over the loss of marsh, has prompted a stern 

 look at both problems. And for once, scientists 

 figure they can "kill two birds with one stone." 



The answer, they believe, is to turn dredge spoil 

 into marsh by covering it with grasses that grow 

 in the natural marsh, the most dominant of which 

 is smooth cordgrass. 



Supported by the UNC Sea Grant Program, the 

 Center for Marine and Coastal Studies and the U.S. 

 Army Corps of Engineers, Dr. W. W. Woodhouse, 

 North Carolina State University soil scientist, 

 began testing smooth cordgrass on dredge spoil in 

 late 1971. Dr. E. D. Seneca, NCSU botanist, and 

 S. W. Broome, research associate, have assisted in 

 learning how smooth cordgrass (Spartina alterni- 

 flora) is established, grown and reproduced on 

 spoil. 



In the short time they have worked with the 

 grass, the scientists have shown it can be a success- 

 ful stabilizer. 



According to the scientists, complete cover can 

 be achieved with smooth cordgrass in two growing 

 seasons. Seeding or transplanting can be used to 

 establish a cover, and both have advantages. Seed- 

 ing is fast and cheap, but transplanting is adapt- 

 able to a wider variety of conditions, the research- 

 ers say. 



Woodhouse, who for more than a dozen years has 

 worked to stabilize N. C.'s sand dunes with beach- 

 grasses and sea oats, has also turned his attention 

 to halting eroding shorelines with marsh grasses. 

 His work, aimed at building new marsh while 

 stabilizing shorelines, holds promise for property 

 owners whose beach-front lots are being gobbled 

 up by winds and tides. 



Smooth cordgrass is a successful stabilizer of 

 dredge spoil and eroding shorelines. 



Fighting marsh insects 



Dunes, shorelines and spoil have enemies that 

 are more secretive — and less direct — in their 

 attack than winds and tides. Those enemies are the 

 insects feeding on grasses that hold coastal lands 

 in place. 



Hoping to slow the guerilla-style warfare waged 

 by certain insects, Dr. William V. Campbell, North 

 Carolina State University entomologist and Sea 

 Grant researcher, is studying their strategies. 



His research focuses on a new species of scale 

 insect (Eriococcus carolinae) found devastating 

 American beachgrass south of North Carolina's 

 Oregon Inlet. 



Recently, Campbell has broadened his study to 

 beetles that feed on smooth cordgrass, the domi- 

 nant marsh grass in North Carolina, which is now 

 being used to stabilize eroding shorelines and spoil. 

 Early stages of this research are aimed at learning 

 what effects, if any, the beetles have on marsh 

 grass. 



In his study of the scale insect, Campbell has 

 found that in its larval, or immature, stage, the 

 scale sucks the sap of beachgrass plants. Eventu- 

 ally the plants die, leaving the sand unprotected 

 from winds. 



Luckily, beachgrass is not alone in its battle 

 against the scale's attack. Just one pound of active 

 ingredient of the chemical dimethoate applied per 

 acre wipes out the scale infestation, says Campbell. 

 Once the pest is eradicated from an area, its return 

 is slow since the female scale does not fly. 



Campbell is also testing other control methods, 

 including mixed plantings of a variety of grasses, 

 controlled burning and application of a high grade 

 oil. 



