A SCIENTIFIC ASSAULT 



ON HARMFUL ALGAL BLOOMS 



The discovery of Pfiesteria piscicida by 

 North Carolina Sea Grant researchers 

 JoAnn Burkholder and Ed Noga of North 

 Carolina State University in 1991 caused a 

 media stir. 



Since then, scientists have been trying 

 to unravel the secret of this mysterious 

 organism that has 24 different life stages. 

 It can transform itself from a harmless cyst 

 into a sometimes toxic dinoflagellate 

 capable of killing fish. 



But for many environmental scien- 

 tists, P. piscicida is one more harmful algal 

 bloom (HAB) to add to the list of indicators 

 that something is wrong with the water 

 quality of the state's rivers and estuaries. 



In previous decades, Sea Grant 

 scientists focused on the effects of red 

 tides, brown tides and blue-green algae. In 

 1987, red tide closed shellfish beds and 

 beaches along more than 250 miles of 

 North Carolina shoreline — a $25 million 

 loss to seafood and tourism industries. 



Today, Sea Grant researchers 

 continue to search for environmental 

 common denominators that trigger HAB 

 events. Factors include excess nutrient 

 runoff from upstream, depletion of oxygen 

 and salinity levels, temperature and 

 sunlight. Atmospheric deposition and 

 climatic change also could figure in the 

 equation. 



Water quality experts know the key to 

 solving the HAB problem is providing the 

 right scientific information to create policy 

 and management plans. 



Here's an update on the scientific 

 assault on HABs: 



• DNA Markers: In a project that 

 started with funding from North Carolina 

 Sea Grant, Parke Rublee of the University 



of North Carolina at Greensboro teamed 

 with Burkholder to develop DNA probes 

 that can detect Pfiesteria species in water 

 samples. DNA amplification or fluores- 

 cent dye markers then make the presence 

 of Pfiesteria obvious. 



With help from Rublee's work on the 

 Pfiesteria probe, Burkholder identified and 

 named Pfiesteria shumwayae, a second 

 Pfiesteria species that shares many of P. 

 piscicida's qualities — including a strong 

 attraction to fish, the ability to manufac- 

 ture toxins, a complex life cycle with an 

 amoebic stage, and an animal-like pattern 

 of behavior. P. shumwayae appears to 

 thrive best in coastal waters with high 

 nitrogen levels, while P. piscicida prefers 

 higher phosphorus levels, although both 

 can stimulate its growth. 



The probes have been used to 

 determine the geographic distribution of 

 Pfiesteria and its presence or absence at 

 sites offish kill or lesion events. 



Colleagues at University of 

 Maryland's Human Virology Institute 

 developed probes to detect P. shumwayae 

 and a cryptoperidiniopsis species that is a 

 " Pfiesteria-Wke organism." 



• FerryMon: In 2000, Sea Grant 

 researchers Hans Paerl, of UNC-Chapel 

 Hill, and Joe Ramus and Larry Crowder, of 

 Duke University Marine Lab, collaborated 

 with the N.C. Department of Environment 

 and Natural Resources and the N.C. 

 Department of Transportation (DOT) to 

 launch FerryMon, an innovative way to 

 study water quality of the Pamlico Sound 

 and Neuse River. Automated devices are 

 attached to several DOT ferries that make 

 multiple daily crossings on three different 

 routes of the river and the sound. These 



devices can detect and relay real-time 

 data on surface water nutrient levels, 

 salinity, turbidity, chlorophyll, oxygen 

 and other dissolved materials that may 

 trigger HABs. 



• Studying Nutrient Runoff: 

 Nitrogen continues to be the nutrient 

 controlling algal production in the Neuse 

 River estuary, and Paerl, Crowder and 

 Ramus track seasonal pulses of nitrogen 

 loading that can support algal blooms. 

 Meanwhile, Sea Grant researchers Martin 

 Posey and Larry Cahoon, both at the 

 University of North Carolina at 

 Wilmington, continue to study the 

 estuarine and coastal waters of the Cape 

 Fear River region on the southern coast 

 of the state. The high rate of develop- 

 ment, along with the large number of hog 

 farms in the region, increases the risk for 

 nutrient loading — and HAB outbreaks. 



• Atmospheric Increases: 

 Coastal algal blooms appear to be 

 increasing in regions downwind of 

 growing atmospheric nitrogen deposition 

 associated with agricultural and urban 

 expansion in upwind airsheds, Paerl 

 reports. 



Paerl continues to examine the 

 connection between ammonium 

 enrichment and the potential for blue- 

 green algal blooms (cyanobacteria). 

 Given that animal waste is rich in 

 ammonium, and that atmospheric 

 deposition of ammonium in coastal 

 regions has increased in the past few 

 decades, there may be a link between this 

 growing nutrient source and increasing 

 cyanobacterial dominance in the Neuse- 

 Pamlico estuary. — P.S. 



COASTWATCH 31 



