Water stratification is a phenomenon in which regions of water with different properties, such as salinity, oxygen content, density and temperature, form barriers to mixing of the water.
These barriers also create channels, referred to as sound fixing and ranging (SOFAR) channels. In these channels, the sound has a specified path. It travels slower than normal, but due to reduced dissipation to the surroundings, the sound travels for larger distances.
<span>In order for individuals best suited for growth and reproduction in a particular environment to contribute disproportionately to the next generation natural selection must take place. Natural selection is one of the basic mechanism of evolution. This mechanism leads</span> to adaptations and adaptations contribute to survival and reproduction.