Red Tide

i want to write about red tides:
what is red tide?
is it bad or good? how?

red tide is occurred when there is a high concentration of algae called "Karenia brevis". this is caused when there is warm ocean surface temperatures, low salinity, high nutrient content, calm seas and other factors.

this is not good for the fish because the algea use up most of the oxygen in the water, making it hard for the fish to breathe. it is also bad for humans that eat shell fish, because the shell fish eat the kerenia brevis and when people eat the shell fish, they get "neurotoxic shellfish poisoning".

http://www.youtube.com/watch?v=PvDHzQKaqqI

http://www.tpwd.state.tx.us/landwater/water/environconcerns/hab/redtide/faq.phtml

http://www.whoi.edu/redtide/

http://www.cdc.gov/hab/redtide/pdfs/activities.pdf