BIOL150 Lecture : Life in Water.docx
Document Summary
3. 1 the hydrologic cycle exchanges water among reservoirs. Reservoirs": lakes, rivers, oceans, plus atmosphere, ice, organisms. Water enters each reservoirs as precipitation or as surface/subsurface flow. Oceans: 3,100 years lake: days to centuries depending on depth, area, rate of drainage. 3. 2 life in water and the natural history of aquatic environments. The biology of aquatic environments corresponds broadly to variations in physical factors such as light, temperature, and water movements and to chemical factors such as salinity and oxygen. Organisms need a lot of oxygen to undergo oxidative respiration. Oxygen not gaseous but is dissolved in water. Arctic (smallest and in north hem only), atlantic, indian, pacific(largest), southern. Oceanic circulation driven by prevailing winds and moderates earth"s climate (cold and warm covers over 360 million km^2 of earth"s surface (70%) water currents and streams) Oceanic: epipelagic, mesopelagic, bathypelagic, abyssal zone, hadal zone.