PLANKTON AS RELATED TO NUISANCE 

 CONDITIONS IN SURFACE WATER 



By JAMES B. LACKEY 



THE BLAKISTON COMPANY, PHILADELPHIA, PA. 



Man has never been able to do without water very long. Preferably 

 clear, cool, virtually tasteless and odorless; not like the "arf-a-pint o'water 

 — green" that crawled and stunk, which Gunga Din gave the British 

 Tommy. But, like the Tommy, we are grateful for even that kind if no 

 other is available. Gunga Din's water must have been taken from a pool 

 in full bloom, well exemplifying those nuisances which blooms can cause. 

 For they all too frequently turn surface waters into nauseous soups of 

 some green, brown or red shades that truly stink. Hence the reason for 

 an article on "Plankton as Related to Nuisance Conditions in Surface 

 Water." 



Plankton may be defined loosely as suspended aquatic small plants 

 and animals. A bloom is an unusually large number of plankters, usually 

 one or a few species, per unit of the first few centimeters of surface water. 

 An arbitrary definition (Sawyer, Lackey and Lenz 1944) has set 500 indi- 

 viduals per ml as constituting a bloom. Extremely small algae, such as 

 Chlorella or Gleocapsa, are not crowded at such an aggregation, but 

 Pandorina would be. There are, of course, plankters of which a single indi- 

 vidual exceeds 1 mm in diameter, or 1 ml in volume. 



Nuisances due to peak occurrences of these organisms are many. A 

 partial list includes: Nauseous tastes and odors in drinking water; 

 lakeshore decay with odor and debris; interference with bathing, boating 

 and fishing ; killing of fish ; prevention of stock watering ; shortening of filter 

 runs in water purification plants; effects on industrial water use, such 

 as growths in cooling systems; poisoning of waterfowl, stock, and possibly 

 man; poisoning of mussels; secondary fish depletion because copper sulfate 

 has been used to control blooms ; secondary increases in mosquito nuisances 

 by increasing larval food. 



This list could be extended by specific instances. For example, during 

 the war a sewage plant efiiuent was turned into an otherwise dry stream 

 bed near a small Texas town. The effluent, highly purified, produced heavy 

 growth of filamentous algae which, in turn, produced pooling. In the stag- 

 nant waters, mosquitoes — some of them anophelines — bred abundantly. 

 This is a highly specialized case and it might be questioned, academically, 

 that either surface waters or plankton were concerned. The complaints 

 of fishermen concerning the vast mats of filamentous algae in some Wis- 

 consin lakes are similar, but there is no doubt that these algae can be 



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