In water as the depth increases so does the pressure, whilst at the same time the temperature, light, food supply and fish abundance decreases. These changes have effect on which types of organisms can live and grow at different depths. As the depth increases the environmental conditions change gradually. The different zones can be identified by both physical and biological factors.
However on Divers Who Want To Learn More the different zones are categories whereby the topic of the blog decides which zone the blog lives in…
Sunlit Zone 0-200m
Includes blogs about anything and everything that is living, breathing and swimming beneath the surface.
Twilight Zone 200-1000m
Includes blogs about ocean geology, water, buoyancy and tides & waves.
Dark Zone 1000-4000m
Includes blogs on the waters of our oceans, includes geograpical zones, endemic species and depth zones.
Abyssal Zone 4000-6000m
Includes blogs on just about anything diving related on the surface.
Hadal Zone 6000m and deeper
Includes blogs about underwater technique involving Sidemount, Twinset and Rebreather.