Chemoclinal

Chemoclinal is a term used in oceanography and limnology to describe a zone of rapid change in chemical properties within a body of water. This is typically a vertical transition, similar to a thermocline (temperature) or halocline (salinity), but instead refers to a significant gradient in the concentration of one or more chemical constituents. These gradients can occur in lakes, fjords, or ocean basins.

The most common chemical properties exhibiting chemoclinal behavior include dissolved oxygen, hydrogen sulfide, and nutrients such as phosphate or nitrate. A chemocline can form when there is a stratification of the water column, preventing thorough mixing. For example, in some meromictic lakes, a chemocline separates the oxygenated surface waters from the anoxic, sulfide-rich deep waters.

The presence of a chemocline can have significant ecological implications. Organisms adapted to oxygen-rich environments may be unable to survive below the chemocline, while anaerobic microbes can thrive in the reduced conditions. Chemoclines play a role in nutrient cycling and can influence the overall productivity of aquatic ecosystems. The development and persistence of a chemocline are influenced by factors such as water depth, inflow and outflow rates, temperature, and salinity.