This is a list of the longest-living organisms that includes oldest individual bioforms. This is usually defined as: ( 1 a) Having a longer life-span than any other known individual species (such as the Methuselah tree) OR. The Jurupa Oak colony is estimated to be at least 13,000 years old, with other estimates ranging from 5,000 to 30,000 years old. 2  A huge colony of the sea grass Posidonia oceanica in the Mediterranean Sea is estimated to be between 12,000 and 200,000 years old.
Greater abundances of solid particles in the water will decrease the depth of light penetration. Therefore, water near the seashore that is more turbid (cloudy) due to particles will show a decrease in light transmission, even in shallow water.
By the way how do you know the true depth of frost penetration? Take the city of Rhinelander Wisconsin with clean granular soil of low moisture content. Water mains at 8 feet depth freeze, while generally building codes seem to list the frost depth as 4 feet.