Eutrophication

noun (uncountable)

/juːˌtrɒf.ɪ.kɪˈkeɪ.ʃən/

The process by which a body of water becomes excessively enriched with minerals and nutrients (principally nitrogen and phosphorus), causing dense algal blooms that reduce oxygen levels and block sunlight, ultimately leading to hypoxic 'dead zones' and mass fish mortality. Cultural (anthropogenic) eutrophication, driven by agricultural runoff, sewage discharge, and industrial effluents, is far faster than natural eutrophication. India's Dal Lake (J&K), Vembanad Lake (Kerala), and Hussain Sagar (Telangana) are frequently cited UPSC examples of eutrophication from nutrient loading.

✍️ Usage in a UPSC answer

The unchecked discharge of phosphate-rich agricultural runoff into Chilika Lake has progressively triggered eutrophication, threatening its Ramsar wetland status and the migratory bird populations that depend on its open-water zone.

Synonyms

nutrient enrichmentalgal bloom inductionhypertrophicationover-fertilisation (of water)

Antonyms

oligotrophicationwater claritynutrient depletion

🌱 Word Family

eutrophicate (verb), eutrophic (adjective), oligotrophic (adjective), eutrophy (noun), hypereutrophic (adjective)

🔡 Root

Greek eu- = well, good, abundantly; Greek trophē = nourishment, food; -ation = process

📜 Etymology

From Greek eutrophos (well-nourished), first applied to lake classification by German scientist C.A. Weber in 1907 and formalised by Einar Naumann in the 1910s–1920s. The irony captured in the etymology is deliberate: 'too well nourished' leads to ecological collapse rather than health.

🧠 Memory Hook

EU (good/abundant) + TROPHIC (food). Think: the lake ate too good — so much fertiliser ran into it that algae went wild, choked the oxygen, and the fish died. 'Too much of a good thing' is the eutrophication story.

🌿 Environment & Ecology 📖 Seen in: Ecology Fundamentals — Ecosystems, Foo... 📋 Also in Key Terms

Tip: press Alt+S to hear pronunciation