How does marine life cope with its saline environment?
Most marine vertebrates are able to regulate the salt and water content in their bodies through a chemical process called “osmoregulation.” They pass water through osmosis, where water diffuses from high salt concentration to low salt concentration between permeable membranes, and excrete excess salt through their skin and gills. They take in water through drinking to maintain the water balance. Gases Gases are also dissolved by seawater. Carbon dioxide (CO2) is dissolved in ocean water and used by phytoplankton to produce plant matter. Oxygen and nitrogen dissolved at the surface from the atmosphere are also present in seawater. Conversely, the ocean also releases these gases into the atmosphere. Like solids, temperature also regulates the dissolution of gases; however, the rate of dissolution is reversed for gases: cold water holds gases better than warm water. This is an important distinction because marine life depends on oxygen and carbon dioxide for metabolic processes such as re