18491
Although the amplitudes of copepods increased only 7 % at 150 micro g / L atrazine , the maximum and minimum copepod densities at that concentration were reduced 61 and 63 % , respectively .
 Chemical: atrazine
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: atrazine