16503
The influence of natural dissolved organic matter ( DOM ) on acute waterborne Cu toxicity was evaluated in the euryhaline copepod Acartia tonsa at 3 different water salinities .
 Chemical: Cu
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: Cu