For instance, in the early morning and late evenings, the light compensation point Ic may be reached as photosynthetic activity decreases and respiration increases.

It may be measured by whole-leaf isotopic gas exchange, or be estimated in the Laisk method using an intermediate "apparent" value of C* with correction.

[2] Respiration occurs by both plants and animals throughout the water column, resulting in the destruction, or usage, of organic matter, but photosynthesis can only take place via photosynthetic algae in the presence of light, nutrients and CO2.

[6] In well-mixed water columns plankton are evenly distributed, but a net production only occurs above the compensation depth.

[6][7] The compensation depth between photosynthesis and respiration of phytoplankton in the ocean must be dependent on some factors: the illumination at the surface, the transparency of the water, the biological character of the plankton present, and the temperature.

[7] It is also lower in the winter seasons in the Baltic Sea according to a study that examined the compensation point of multiple photosynthetic species.

A concern regarding the concept of the compensation point is it assumes that phytoplankton remain at a fixed depth throughout a 24-hour period (time frame in which compensation depth is measured), but phytoplankton experience displacement due to isopycnals moving them tens of meters.