said of a body of water: rich in dissolved nutrients, e.g. phosphates, but often shallow and seasonally deficient in oxygen: compare mesotrophic, oligotrophic
eutrophication /-ʹkaysh(ə)n/ noun
eutrophy /ʹyoohtrəfi, yoohʹtrohfi/ noun
[prob via German from Greek eutrophos well nourished, nourishing, from eu- + trephein to nourish]