algal bloom; water bloom
Refers to the phenomenon of rapid algae growth in water, often seen as a greenish layer on the surface.
See also: アオコ
In summer, algal blooms appear in the pond.
lotus flower
Literally 'water flower'; used poetically for lotus flowers blooming on water.
The lotus flowers blooming on the pond are beautiful.
Japanese sea bass
Archaic female term for Japanese sea bass (スズキ). Rarely used in modern Japanese.
See also: スズキ
In the past, women called the Japanese sea bass 'water flower'.
スズキ is the standard modern term for Japanese sea bass; 水の花 is an archaic female term for the same fish.
Standard kanji spelling for the expression.
Variant spelling using 花 instead of 華; both are used.
Compound of 水 (water) + の (possessive particle) + 華/花 (flower). The meaning 'algal bloom' is a metaphorical extension of 'water flower', while the archaic fish name likely derives from a poetic association.