Aquatic Biomes

Aquatic Biomes   Water provinces cover more than 72 per cent of the earth’s surface. They include standing fresh water (such as lakes), running fresh water  (such as streams), as well as the ocean and seas around the world. 

All aquatic ecosystems show gradients in light penetration, water temperature, salinity and dissolved gases. These factors vary daily and seasonally. Thus the primary productivity also varies in the aquatic ecosystems. Estuaries , internal zones,  rocky and sandy shores, tropical reefs and regions of the open ocean are major marine ecosystems. 

Estuaries are the areas where freshwater streams or rivers merge with the ocean. The mixing of water  creates a unique ecosystem . Microflora like algae, and macroflora such as seaweeds, marsh grasses and mangrove trees ( only in the tropics) can be found here. 

Coral Reefs are widely distributed in warm shallow waters. They can be found as barriers along continents. Besides  corals several species of micro- organisms, invertebrates, fishes, sea urchins, octopuses and sea stars also  reside in the coral reefs,. Photosynthetic activity is greatest in shallow waters and in regions of upwelling. Upwelling is an upward movement of deep, cool ocean water that often carries nutrients to the surface.