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2074814 
Journal Article 
Long-term water quality and biological effects of alum treatment of Lake Morey, Vermont 
Smeltzer, E; Kirn, RA; Fiske, S 
1999 
Lake and Reservoir Management
ISSN: 1040-2381
EISSN: 2151-5530 
BIOSIS/00/05126 
15 
173-184 
English 
BIOSIS COPYRIGHT: BIOL ABS. Lake Morey received one hypolimnetic treatment with alum and sodium aluminate in 1986 to reduce the occurrence of algae blooms caused by internal P loading. Thirteen years of post-treatment monitoring have documented a sustained improvement in water quality in the lake. Comparison of pre-treatment (1977-1985) and post-treatment (1986-1998) data indicated that significant improvements occurred in all water quality variables measured, including spring TP (reduced 66%), summer photic zone TP (reduced 68%), summer photic zone Chl a (reduced 61%), summer Secchi disk transparency (increased 79%), late summer hypolimnetic TP (reduced 83%), and late summer hypolimnetic DO (increased 193%). The one-time alum/aluminate treatment of Lake Morey has thus far succeeded in breaking a cycle of sediment P release and re-precipitation that was initiated during an earlier period in the lake's history. Rela tive weight loss was observed in samples of large yellow perch during the 3 years immediately following the treatment. Yellow perch condition returned to pre-treatment levels by 1991. Toxicity from elevated dissolved aluminum concentrations in the water column during the summer of treatment may have caused the observed weight loss in fish. The benthic macroinvertebrate community in the upper hypolimnion experienced a 90% decline in density during the year immediately following the alum treatment. The benthic community recovered during subsequent years with density and taxa richness generally exceeding pre-treatment values, possibly in response to improved hypolimnetic DO conditions. 
; Algal blooms; Environmental impact; Phosphorus; Phytoplankton; Freshwater fish; Restoration; Water quality control; Lakes; Plant control; Long-term changes; Water pollution treatment; Ecosystem management; Nutrients (mineral); Zoobenthos; Environment management; Pisces; Historical account; Water quality measurements; Macrofauna; Chemical treatment; Dissolved oxygen; Algae (see also Individual groups); Fish (see also Individual groups); Aluminium sulphate; Toxicity (see also Lethal limits); Oxygen (Dissolved); Hypolimnion; Fish; Toxicity; Algae; Alum; USA; Vermont; Morey L.; sodium aluminate/