Lecture 8

L1 /

CH3041

NUTRIENTS

• Plants carrying out photosynthesis in the
surface layers of water and require CO2, H2O and sufficient light + nutrients

• Euphotic zone - the upper waters of a lake or sea into which sufficient sunlight penetrates for photosynthesis and abundant plant growth to occur.

• Nutrients like Mg2+ are abundant in natural waters but others (eg. N, P) are present in low concentrations & limit plant production.

• Phytoplankton growth in lakes is generally P limited, long term biotic mechanisms can generally restore N and C deficiencies.

• Si is a limiting nutrient for diatom formatn
in marine waters.


	Euphotic zone in a lake is approximately the same as the epilimnion – can extend below it though.
	Euphotic zone in ocean (around 200m) is part of the mixed layer (0 – 300m)