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Oxygen is an important parameter in water quality assessments since sufficient oxygen is essential to aquatic life and is necessary to support healthy biological communities . ( 3 ) For example , oxygen concentration is a supporting element to the biological quality elements in the European Water Framework Directive , ( 21 ) is one of the ecological objectives in the Helsinki Commission ' s ( HELCOM ) eutrophication assessment of the Baltic Sea , and is included in the European Marine Strategy Framework Directive as an effect parameter of eutrophication .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Anatomy 
Text: {0} 
Answer:
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