Height (above substratum)
Height (above substratum): Height above the surface of the substratum of an individual or single modular colony. e.g a blade of seagrass, a seaweed thallus, projecting tube worm, upright sea pen etc.
- [[HeightAboveSubstratum|Height (above substratum)]]
The definition does not include the height reached by a reef or other biogenic structure e.g. horse mussel sits only a few cm above the substratum, while a horse mussel reef can be several metres high and extend for several kilometres. However, an individual colony of the coral water coral Lophelia can be several metres high and across, and the reef can be several metres high and extend for many kilometres. Descriptor expressed as either the minimum, maximum or average value in millimeter, centimeter, meter.