High-Tech Took 



By Kathy Hart 



Sea Grant researchers Hans Paerl 

 and James Pinckney are doctors of 

 sorts. 



Their patient is an ailing coastal 

 ecosytem with a litany of symptoms — 

 algal blooms, fish kills and oxygen 

 depletion. The diagnosis is simple and 

 obvious, even to the untrained eye. It's 

 eutrophication — too many nutrients — 



Hans Paerl explains pigment analysis. 



spurring massive algal blooms that 

 harm waters where they multiply. 



To determine a treatment, Paerl and 

 Pinckney are using tools that range 

 from microscopes to computers, from 

 hydrocorrals to satellites. 



During recent decades, our state's 

 rivers, estuaries and ocean have been 

 inundated with nutrients. Nitrogen and 

 phosphorus pour from waste treatment 

 plants and industries; drain from 

 farmlands, forests and city streets; 

 trickle through groundwater from hog 

 lots and poultry houses; and rain from 

 clouds seeded by factory, agricultural 

 and fossil fuel emissions. 



This deluge of nutrients into 

 ecosystems already rich in their own 



natural supply causes eutrophication, 

 which is responsible for a variety of ills 

 now plaguing salt marshes, brackish 

 coastal rivers and nearshore waters. 



Large doses of nitrogen can spur 

 planktonic algal species into rapid 

 growth patterns called blooms. Some 

 species are advantageous, offering a 

 ready supply of meals for creatures 

 higher up the food chain. Other algae 

 aren't so desirable. 



Surface blooms of blue-green algae, 

 for instance, are inedible for some 

 marine animals because they release 

 toxins and are too big for tiny zooplank- 

 ton to eat. A bloom can also alter light 

 penetration to the bottom and rob the 

 water of oxygen when it dies. As a 

 result, desirable species of plants, fish 

 and shellfish are often driven away or 

 killed. 



Dinoflagellates, a form of algae, 

 can be toxic to fish and shellfish or 

 contaminate them with toxins that 

 make them undesirable meals for 

 others, including humans. The red tide 

 dinoflagellate, Gymnodinium breve, 

 blew ashore from the Gulf Stream in 

 1987, contaminating shellfish and 

 causing minor respiratory problems 

 for beachcombers and fishermen. 



As increasing amounts of nutrients 

 flow into coastal ecosystems, the 

 incidence of nuisance algal and dino- 

 flagellate blooms has increased. 

 Scientists such as Paerl and Pinckney 

 know there is a relationship between 

 marine algal species and nutrients, but 

 they are not sure of the specifics. 



What forms of nitrogen cause the 

 species to grow? 



How fast do nuisance algal species 

 grow in nutrient-rich coastal waters? 



Which combination of conditions, 

 natural and man-made, spur nuisance 

 algae and dinoflagellates to bloom? 



Can scientists predict when massive 

 algal or dinoflagellate blooms are likely 

 to occur? 



10 JULY/AUGUST 1995 



