montée d'acide

CONT: The autumn acidic pulses have apparently been amplified by drought conditions, for the acidic pulse of this autumn (1983) coincided with widespread yellowing (chlorosis) of the spruce foliage at Solling, the Harz Mountains, and elsewhere.
CONT: When the snowpack melts in the spring, the accumulated acids from both sulphates and nitrates flow into rivers and lakes. This surge of acidity is known as ""spring shock"" and, because it occurs at the most critical stage in the life cycle of many aquatic species, can kill fish eggs and fry (newly-hatched fish).
OBS: Following snowmelt and storm runoff.