3252
Specifically , for both the community structure and abundance of Daphnia spp . the lowest - observed - effect concentrations ( LOEC ) were 0 . 03 and 0 . 3 mu g / L for the series with fluctuating and constant water levels , respectively .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
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