What does the cryptic crossword clue "Coot up in the air suspect product of pollution in pond (14)" mean?

The wordplay uses an anagram. anagram of COOT + UP + IN + THE + AIR = EUTROPHICATION The answer is EUTROPHICATION.

Coot up in the air suspect product of pollution in pond (14)

Daily Mail Cryptic #16743 | 6 Across | 2022-01-04 flower