Algal bloom

As algal blooms ( occasionally water bloom ) refers to a sudden, massive proliferation of algae or cyanobacteria ( blue-green algae ) in a body of water. Due to the algae bloom the water surface is colored green, in special cases, blue or red ( Red Dawn or Red Tide ), the water is turbid and " cloudy". Cause is usually an over-fertilization of the water with phosphate.

In a narrower sense we speak of algal blooms in the mass development of each a single algal species or Cyanobakterienart, which is characterized by their ability to accumulate directly on or below the water surface. This, as with various cyanobacterial species ( Microcystis sp., Oscillatoria sp., Anabaena sp. Etc. ) done by buoyancy, or, as in a number of flagellated algae ( Karenia brevis, Euglena sp., Oocystis sp. Etc. ) through active prospecting the surface. The Euglena sanguinea may stain the surface of fiery red, a Oscillatoria - type (O. rubescens ) blood - to raspberry, a Microcystis - kind sky blue. The term " bloom " is then close.

When algal blooms, the light is already much reduced at the surface, so that only up to shallow depths sufficient light for photosynthesis is present. Including consumed by both the sinking algae and by increasingly growing consumer oxygen. For details, see lake ecosystem. Furthermore, the algae and cyanobacteria often produce toxic substances that can be dangerous for living things in the lake and also bathers (eg microcystins ).

Large-scale algal blooms in oceans are due to nutrient-rich ocean currents and upwelling effects.

Off the coast of Dubai and Abu Dhabi, with periodic local algal blooms ( red tide ), although rarely assumes greater proportions, but then the barrier beaches of leads ( most recently in 2003 and in April 2009). In Fujairah, the occurrence of the red tide in June 2009 led to a large number of fish killed.

There are plans to use the algae for energy in the form of biogas and biofuels. A pilot project launched this in 2013 in the Fiji Islands, the coasts of which are often affected by algal blooms.