The document discusses the different divisions of the marine environment including pelagic, benthic, and land environments. It notes there are over 250,000 known marine species ranging from bacteria to the largest animal, the blue whale. The pelagic environment contains more biomass than the benthic environment due to greater sunlight. Organisms are classified into taxa using the Linnaeus system of five kingdoms. Marine life also exhibits adaptations to conditions like temperature, salinity, dissolved gases, and water transparency.