When seen from below by a predator, the animal's light helps to match its brightness and colour to the sea surface above. Counter-illumination is a method of active camouflage seen in marine animals such as firefly squid and midshipman fish, and in military prototypes, producing light to match their backgrounds. Marine animals of the mesopelagic (mid-water) zone tend to appear dark against the bright water surface when seen from below.
A landscape is usually made up of a hardscape and a softscape which means the trees, plants and grass. The use of boulders, tiles, sculptures, walkways or bird baths can be used to create a beautiful sitting area, a place for entertaining guests, or an outdoor cooking space.
This is unfortunate, because the word, zero leads the mind to think of nothing -- in this case, a landscape with nothing in it (or nothing pretty, at least). But xeriscape landscaping techniques need not result in a big zero for landscape design aesthetics.