To determine how the Neuse River 

 and blue-green algae respond to 

 changes in nutrient levels, Don 

 Stanley and Bob Christian will be 

 studying the role of "new" nitrogen 

 and recycled nitrogen in the blue-green 

 algal blooms. New nitrogen originates 

 from sources such as wastewater ef- 

 fluent and urban or agricultural 

 runoff. Recycled nitrogen has been 

 used by animals and organisms in the 

 estuary and excreted as ammonia. 



With information generated by this 

 project, managers can determine what 

 effects reduced nutrient inputs will 

 have on the Neuse River and algal 

 blooms. And they can incorporate this 

 knowledge into the management plans 

 proposed for the basin. 



While Stanley and Christian focus 

 on what causes blue-green algal 

 blooms, Hans Paerl and Rolland 

 Fulton will examine how the blooms 

 affect the estuarine food chain. 

 Evidence already gathered by Paerl in- 

 dicated blue-green algae may be toxic 

 or inedible to lower levels of the food 

 chain — zooplankton. And lower level 

 changes may affect organisms higher 

 on the food chain — namely important 

 commercial and recreational species of 

 fish. 



Paerl and Fulton believe the algae 

 may decrease the efficiency of the es- 

 tuarine food chain and alter the kinds 

 of fish living at bloom sites. They will 

 test these hypotheses in laboratory 

 and field experiments. 



In a laboratory at UNC- 

 Wilmington, Ron Sizemore will em- 

 ploy biotechnology techniques to ex- 

 amine marine vibrio, a bacteria com- 

 mon to North Carolina's coastal 

 waters. He will study bacteria taken 

 from polluted and nonpolluted sites 

 along the state's coastal waters. 

 Sizemore may be able to use his techni- 

 ques to "construct" a bacteria that 

 will break down complex pollutant 

 mixtures. 



The researchers: 



Don Stanley, Institute for Coastal and 



Marine Resources, East Carolina 



University 

 Bob Christian, Department of 



Biology, East Carolina University 

 Hans Paerl, Institute of Marine 



Sciences, University of North 



Carolina at Chapel Hill 

 Rolland Fulton, Institute of Marine 



Sciences, University of North 



Carolina at Chapel Hill 



Ron Sizemore, Department of 

 Biological Sciences, University of 

 North Carolina at Wilmington 



Shelling out results 



During the mid-1970s. North 

 Carolina fishermen discovered a lode 

 in the state's estuaries — hard clams. 

 With northern clams frozen in their 

 beds, southern mollusks brought prices 

 that sent fishermen raking, tonging 

 and dredging for the valuable nuggets. 

 In Core Sound, fishermen forsook 

 traditional harvest methods, turning 

 instead to efficient mechanical har- 

 vesting methods. By 1981 hard clam 

 catches had increased fivefold. 



Photo by Neil Caudle 



Mark Sobsey 



Fishery managers worry the intense 

 harvest is depleting hard clam stocks. 

 The N. C. Division of Marine Fisheries 

 already imposed some restrictions. But 

 they may consider more. 



Charles Peterson will supply 

 managers with more facts about hard 

 clams as he continues to research the 

 mollusks. He will focus on the survival 

 and growth of clam larvae in different 

 habitats and test the hypothesis that 

 removal of adult clams enhances larval 

 survival. Similar tests will be conduc- 

 ted for bay scallop larvae. 



To help clam gardeners (fishermen 

 who raise clams on leased bottomland) 

 with predation problems, Peterson will 

 study two of the the clam's greatest 



enemies — blue crabs and snapping 1^ 

 shrimp. Using field tests, Peterson will ! 

 estimate the predators' abundance and 

 appetite in areas suitable for clam gar- 

 dening. And he will test methods for 

 excluding the predators from gardens. 



Overfishing isn't the only problem 

 facing the clam fishery. Pollution also 

 poses a hazard. Clams and their 

 relatives, oysters, become con- 

 taminated when their habitat is 

 polluted. Sewage treatment plants, 

 faulty septic systems, land runoff and 

 boats discharge waste that can carry 

 enteric viruses and bacteria. 



In his Chapel Hill laboratory, Mark 

 Sobsey will continue to study one of 

 the most serious viral contaminants — 

 hepatitis A. Using sophisticated detec- 

 tion methods, Sobsey will study the oc- 

 currence of hepatitis A in field samples 

 of shellfish, the relationship between 

 bacteria levels and virus levels, the up- 

 take and elimination of the virus, and 

 its inactivation by heat. 



Under controlled conditions, Sobsey 

 will examine the elimination of 

 hepatitis A and other viruses in 

 depuration systems. In depuration 

 plants, polluted shellfish are placed in 

 tanks of clean water where they purge 

 their contaminants. Sobsey will study 

 the length of time and optimal condi- 

 tions (water temperature, flow rate, 

 density) for viral elimination in 

 depuration systems. 



The researchers: 



Charles Peterson, Institute of Marine 

 Sciences, University of North 

 Carolina at Chapel Hill 



Mark Sobsey, Department of Environ- 

 mental Sciences and Engineering, 

 University of North Carolina at 

 Chapel Hill 



On the job 



When it comes to supplying resource 

 managers with answers, most research 

 is aimed at understanding complex 

 ecological and biological factors. But 

 there's a people side of management. 

 And understanding fishermen is just as 

 important as understanding fish. 



That's why Mike Orbach and Jeff 

 Johnson are learning more about 

 North Carolina fishermen who ply this 

 state's waters and other states' too. 

 North Carolinians are among the most 

 mobile, aggressive fishermen on the 

 East Coast, fisheries managers report. 



