Red tide

1. 

   Red algal bloom at Leigh near Cape Rdney

   PHOTO BY MIRIAM GODFREY

   
   Red tide, also known as harmful algal blooms (HAB), is caused by algal blooms which discolour coastal water (Bruckner, 2014). Algal blooms usually arise due to excess nutrients released into water, encouraging rapid growth of algae. At the coast, favorable winds and waves push surface water offshore so deep water moves to the coast, bringing excess nutrients from the ocean to the surface (EPA, 2014). As a results, these excess nutrients promote abundant algae growth in such coastal areas. Red tide can spread to other area by wind, waves, storms and ships, which transport the algae related to the bloom elsewhere (Bruckner, 2014).
2. 
   A small percentage of algae produce toxins that can kill fish, shellfish, birds, mammals, and even humans (when consume poisoned shellfish or fish). Non-toxic algae can cause harm to marine wildlife. When large masses of algae die, decomposers take in oxygen to break down the dead matter, causing waters to become oxygen depleted and this leading to fish kills.
3. References
Bruckner, M. 2014. Red Tide - A Harmful Algal Bloom. [ONLINE] Available at:http://serc.carleton.edu/microbelife/topics/redtide/index.html. [Accessed 29 October 14].

EPA. 2014. Climate Change and Harmful Algal Blooms. [ONLINE] Available at:http://www2.epa.gov/nutrientpollution/climate-change-and-harmful-algal-blooms. [Accessed 29 October 14].

NOAA. 2014. Why do harmful algal blooms occur?. [ONLINE] Available at:http://oceanservice.noaa.gov/facts/why_habs.html. [Accessed 29 October 14].
1.  
2.