Track River's Health 



These questions have scientists 

 looking to the latest technology for 

 answers. 



Paerl, Pinckney and a host of 

 graduate students are "fingerprinting" 

 different species of algae. Using 

 sophisticated diagnostic equipment 

 and the latest in computer technology, 

 the team is deciphering pigment 

 "signatures" for a host of marine algae, 

 including harmful dinoflagellates and 

 blue-green algae. 



Just as people have distinctive 

 fingerprints, each algal group has 

 distinctive photopigments. 



Pigments are like antennae, Paerl 

 says. They collect light energy and 

 transfer it to chlorophyll for growth in 

 a process called photosynthesis. But 

 because there is so much competition 

 among marine algae for the light 

 available in water, each species harvests 

 light from different regions of the 

 spectrum and develops distinctive 

 photopigments to compete and coexist 

 with other species. 



Using an array of methods and 

 equipment — high performance liquid 

 chromatography, spectrophotometry 

 and computer graphing tools — Paerl 

 and Pinckney can identify algal groups 

 according to their characteristic pig- 

 ment signatures. Ultimately, it comes 

 down to a computer-generated pigment 

 analysis marked by multicolored 

 vertical lines. Each line corresponds 

 to different photopigments, which 

 indicate the abundance of major 

 algal groups. 



After a few comparisons to their 

 "library" of pigment fingerprints, Paerl 

 and Pinckney can determine exactly 

 which algal groups are present in a 

 water sample and how abundant they 

 are — all in a matter of hours. Before 

 development of this technology, this 

 analysis would have taken weeks in the 

 lab and hours of tedious, demanding 

 work at the microscope. 



This technology may also soon 

 enable scientists to analyze coastal 

 waters for the presence and abundance 

 of suspended algae, called phytoplank- 

 ton, from imagery collected by aircraft 

 or satellites. The researchers are 

 supplying photopigment data to 

 scientists developing the technology 

 needed to make such analysis feasible 

 and practical. 



Paerl and James Pinckney take water 

 samples with a graduate student at 

 the hydrocorrals. 



Paerl says aerial sensory informa- 

 tion, called remote sensing, may allow 

 scientists to predict algal blooms, 

 specifically blue-green algae and 

 dinoflagellates, before they occur. 

 And scientists may be able to track 

 the responses of the phytoplankton 

 communities to the slug of nutrients 

 that drains from watersheds into 

 adjacent waters after heavy rainfalls. 



In another laboratory advancement, 

 Paerl and Pinckney are inoculating 

 phytoplankton photopigments with 

 radioactive carbon 14. The rate at 

 which the carbon 14 is used for 

 photopigment synthesis indicates how 



Continued 



COASTWATCH 1 1 



